Internet Draft C. Adams, Nortel draft-ietf-cat-idup-gss-05.txt June 11, 1996 Independent Data Unit Protection Generic Security Service Application Program Interface (IDUP-GSS-API) STATUS OF THIS MEMO This document is an Internet-Draft. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet- Drafts as reference material or to cite them other than as "work in progress." To learn the current status of any Internet Draft, please check the "1id-abstracts.txt" listing contained in the Internet-Drafts Shadow Directories on ds.internic.net (US East Coast), nic.nordu.net (Europe), ftp.isi.edu (US West Coast) or munnari.oz.au (Pacific Rim). Comments on this document should be sent to "cat-ietf@mit.edu", the IETF Common Authentication Technology WG discussion list. ABSTRACT The IDUP-GSS-API extends the GSS-API [RFC-1508] for applications requiring protection of a generic data unit (such as a file or message) in a way which is independent of the protection of any other data unit and independent of any concurrent contact with designated "receivers" of the data unit. Thus, it is suitable for applications such as secure electronic mail where data needs to be protected without any on-line connection with the intended recipient(s) of that data. The protection offered by IDUP includes services such as data origin authentication with data integrity, data confidentiality with data integrity, and support for non-repudiation services. Subsequent to being protected, the data unit can be transferred to the recipient(s) - or to an archive - perhaps to be processed ("unprotected") only days or years later. Throughout the remainder of this document, the "unit" of data described in the above paragraph will be referred to as an IDU (Independent Data Unit). The IDU can be of any size (the application may, if it wishes, split the IDU into pieces and have the protection computed a piece at a time, but the resulting protection token applies to the entire IDU). However, the primary characteristic of an IDU is that it represents a stand-alone unit of data whose protection is entirely independent of any other unit of data. If an application protects several IDUs and sends them all to a single receiver, the IDUs may be unprotected by that receiver in any order over any time span; no logical connection of any kind is implied by the protection process itself. Adams Document Expiration: 11 Dec. 1996 1 As with RFC-1508, this IDUP-GSS-API definition provides security services to callers in a generic fashion, supportable with a range of underlying mechanisms and technologies and hence allowing source- level portability of applications to different environments. This specification defines IDUP-GSS-API services and primitives at a level independent of underlying mechanism and programming language environ- ment, and is to be complemented by other, related specifications: - documents defining specific parameter bindings for particular language environments; - documents defining token formats, protocols, and procedures to be implemented in order to realize IDUP-GSS-API services atop particular security mechanisms. TABLE OF CONTENTS 1. IDUP-GSS-API Characteristics and Concepts .................. 3 1.1. IDUP-GSS-API Constructs .................................. 5 1.1.1. Credentials ............................................ 5 1.1.2. Tokens ................................................. 5 1.1.3. Security Environment ................................... 5 1.1.4. Mechanism Types ........................................ 5 1.1.5. Naming ................................................. 5 1.1.6. Channel Bindings ....................................... 6 1.2. IDUP-GSS-API Features and Issues ......................... 6 1.2.1. Status Reporting ....................................... 6 1.2.2. Per-IDU Security Service Availability .................. 7 1.2.3. Per-IDU Replay Detection and Sequencing ................ 7 1.2.4. Quality of Protection .................................. 7 1.2.5. The Provision of Time .................................. 10 2. Interface Descriptions ..................................... 10 2.1. Credential management calls .............................. 11 2.1.1. Relationship to GSS-API ................................ 11 2.2. Environment-level calls .................................. 12 2.2.1. Relationship to GSS-API ................................ 12 2.2.2. IDUP_Establish_Env call ................................ 13 2.2.3. IDUP_Abolish_Env call .................................. 15 2.2.4. IDUP_Inquire_Env call .................................. 16 2.3. Per-IDU calls ............................................ 17 2.3.1. Relationship to GSS-API ................................ 17 2.3.2. Parameter Bundles ...................................... 17 2.3.3. IDUP_Start_Protect ..................................... 21 2.3.4. IDUP_Protect ........................................... 24 2.3.5. IDUP_End_Protect ....................................... 25 2.3.6. IDUP_File_Protect ...................................... 26 2.3.7. IDUP_Start_Unprotect ................................... 27 2.3.8. IDUP_Unprotect ......................................... 30 2.3.9. IDUP_End_Unprotect ..................................... 31 2.3.10. IDUP_File_Unprotect .................................... 32 2.4. Special-Purpose calls .................................... 35 2.4.1. Relationship to GSS-API ................................ 35 2.4.5. IDUP_Form_Complete_PIDU ................................ 35 2.5. Support calls ............................................ 37 2.5.1. Relationship to GSS-API ................................ 37 2.5.2. IDUP_Parse_token call .................................. 37 2.5.3. IDUP_Get_Policy_Info ................................... 38 Adams Document Expiration: 11 Dec. 1996 2 3. Related Activities ......................................... 40 4. Acknowledgments ............................................ 40 5. Security Considerations .................................... 40 6. References ........................................... 41 7. Author's Address ........................................... 41 Appendix A, B ................................................. 42 Appendix C .................................................... 43 1. IDUP-GSS-API Characteristics and Concepts The paradigm within which IDUP-GSS-API operates is as follows. An IDUP-GSS-API caller is any application which works with IDUs, calling on IDUP-GSS-API in order to protect its IDUs with services such as data origin authentication with integrity (DOA), confidentiality with integrity (CONF), and/or support for non-repudiation (e.g., evidence generation, where "evidence" is information that either by itself or when used in conjunction with other information is used to establish proof about an event or action (note: the evidence itself does not necessarily prove truth or existence of something, but contributes to establish proof) -- see [ISO/IEC] for fuller discussion regarding evidence and its role in various types of non-repudiation). An IDUP-GSS-API caller passes an IDU to, and accepts a token from, its local IDUP-GSS-API implementation, transferring the resulting protected IDU (P-IDU) to a peer or to any storage medium. When a P-IDU is to be "unprotected", it must be passed to an IDUP-GSS-API implementation for processing. The security services available through IDUP-GSS-API in this fashion are implementable over a range of underlying mechanisms based on secret-key and/or public-key cryptographic technologies. During the protection operation, the input IDU buffers may be modified (for example, the data may be encrypted or encoded in some way) or may remain unchanged. In any case, the result is termed a "M-IDU" (Modified IDU) in order to distinguish it from the original IDU. Depending on the desire of the calling application and the capabilities of the underlying IDUP mechanism, the token produced by the protection processing may or may not encapsulate the M-IDU. Thus, the P-IDU may be the token alone (if encapsulation is done) or may be the logical concatenation of the token and the M-IDU (if encapsulation is not done). In the latter case, the protecting application may choose whatever method it wishes to concatenate or combine the token and the M-IDU into a P-IDU, provided the unprotecting application knows how to de-couple the P-IDU back into its component parts prior to calling the IDUP unprotection set of functions. The IDUP-GSS-API separates the operation of initializing a security environment (the IDUP_Establish_Env() call) from the operations of providing per-IDU protection, for IDUs subsequently protected in conjunction with that environment. Per-IDU protection and unprotection calls provide DOA, CONF, evidence, and other services, as requested by the calling application and as supported by the underlying mechanism. Adams Document Expiration: 11 Dec. 1996 3 The following paragraphs provide an example illustrating the dataflows involved in the use of the IDUP-GSS-API by the sender and receiver of a P-IDU in a mechanism-independent fashion. The example assumes that credential acquisition has already been completed by both sides. Furthermore, the example does not cover all possible options available in the protection/unprotection calls. The sender first calls IDUP_Establish_Env() to establish a security environment. Then, for the IDU to be protected the sender calls IDUP_Start_Protect(), IDUP_Protect() for each buffer of data, and IDUP_End_Protect() to complete the IDU protection. The resulting P-IDU, which may (depending on whether or not encapsulation was chosen/available) be either the token itself or the logical concatenation of the token and the M-IDU, is now ready to be sent to the target. The sender then calls IDUP_Abolish_Env() to flush all environment-specific information. The receiver first calls IDUP_Establish_Env() to establish a security environment in order to unprotect the P-IDU. Then, for the received P-IDU the receiver calls IDUP_Start_Unprotect(), IDUP_Unprotect() for each buffer of data, and IDUP_End_Unprotect() to complete the P-IDU unprotection. The receiver then calls IDUP_Abolish_Env() to flush all environment-specific information. It is important to note that absolutely no synchronization is implied or expected between the data buffer size used by the sender as input to the protection calls, the data buffer size used by the receiver as input to the unprotection calls, and the block sizes required by the underlying protection algorithms (integrity and confidentiality). All these sizes are meant to be independent; furthermore, the data buffer sizes used for the protection and unprotection calls are purely a function of the local environment where the calls are made. The IDUP-GSS-API design assumes and addresses several basic goals, including the following. Mechanism independence: The IDUP-GSS-API defines an interface to cryptographically implemented security services at a generic level which is independent of particular underlying mechanisms. For example, IDUP-GSS-API-provided services can be implemented by secret-key technologies or public-key approaches. Protocol environment independence: The IDUP-GSS-API is independent of the communications protocol suites which may be used to transfer P-IDUs, permitting use in a broad range of protocol environments. Protocol association independence: The IDUP-GSS-API's security environment construct has nothing whatever to do with communications protocol association constructs, so that IDUP-GSS-API services can be invoked by applications, wholly independent of protocol associations. Adams Document Expiration: 11 Dec. 1996 4 Suitability for a range of implementation placements: IDUP-GSS-API clients are not constrained to reside within any Trusted Computing Base (TCB) perimeter defined on a system where the IDUP-GSS-API is implemented; security services are specified in a manner suitable for both intra-TCB and extra-TCB callers. 1.1. IDUP-GSS-API Constructs This section describes the basic elements comprising the IDUP-GSS-API. 1.1.1. Credentials Credentials in IDUP-GSS-API are to be understood and used as described in GSS-API [RFC-1508]. 1.1.2. Tokens Tokens in IDUP-GSS-API are to be understood and used as described in GSS-API [RFC-1508] with the exception that there are no context-level tokens generated by IDUP-GSS-API. The IDUP-GSS-API token may (depending on the underlying mechanism) encapsulate the M-IDU or may be logically concatenated with M-IDU prior to transfer to a target; furthermore, for some evidence services the token may be sent independently of any other data transfer. 1.1.3. Security Environment The "security environment" in IDUP-GSS-API is entirely different from the concept of security contexts used in GSS-API [RFC-1508]. Here, a security environment exists within a calling application (that is, it is purely local to the caller) for the purpose of protecting or unprotecting one or more IDUs using a particular caller credential or set of credentials. In GSS-API, on the other hand, a security context exists between peers (the initiator and the target) for the purpose of protecting, in real time, the data that is exchanged between them. Although they are different concepts, the env_handle in IDUP-GSS-API is similar to the context_handle in GSS-API in that it is a convenient way of tying together the entire process of protecting or unprotecting one or more IDUs using a particular underlying mechanism. As with the GSS-API security contexts, a caller can initiate and maintain multiple environments using the same or different credentials. 1.1.4. Mechanism Types Mechanism types in IDUP-GSS-API are to be understood and used as described in GSS-API [RFC-1508]. 1.1.5. Naming Naming in IDUP-GSS-API is to be understood and used as described in GSS-API [RFC-1508]. Adams Document Expiration: 11 Dec. 1996 5 1.1.6. Channel Bindings The concept of channel bindings discussed in GSS-API [RFC-1508] is not relevant to the IDUP-GSS-API. 1.2. IDUP-GSS-API Features and Issues This section describes aspects of IDUP-GSS-API operations and of the security services which the IDUP-GSS-API provides. It also provides commentary on design issues. 1.2.1. Status Reporting Status reporting in IDUP-GSS-API is to be understood and used as described in GSS-API [RFC-1508], with the addition of the following IDUP-GSS-API major status codes. As with GSS-API, minor_status codes, which provide more detailed status information than major_status codes, and which may include status codes specific to the underlying security mechanism, are not specified in this document. Table 1: IDUP-GSS-API Major Status Codes Fatal Error Codes IDUP_S_BAD_TARG_INFO all target information is invalid or unsuitable for IDU protection IDUP_S_BAD_DOA_KEY DOA key has expired or been revoked IDUP_S_BAD_KE_KEY key used for key establishment between orig. and targ. has exp. or been revoked IDUP_S_BAD_ENC_IDU encrypted IDU is defective/invalid IDUP_S_INCOMPLETE there is not enough info. in token for P-IDU verification IDUP_S_SERV_VERIF_INFO_NEEDED the Service_Verification_Info parameter bundle is required IDUP_S_SERVICE_UNAVAIL mech. does not support requested service IDUP_S_REQ_TIME_SERVICE_UNAVAIL the time service requested is not avail. in this environment IDUP_S_INAPPROPRIATE_CRED the credentials supplied cannot be used to unprotect P-IDU Adams Document Expiration: 11 Dec. 1996 6 IDUP_S_NO_ENV no environment recognized for env_handle IDUP_S_NO_MATCH Service_Verification_Info and input token do not match IDUP_S_UNKNOWN_OPER_ID requested operation id. is unsupported Informatory Status Codes IDUP_S_ENCAPSULATION_UNAVAIL encapsulation of M-IDU into pidu_buffer is not supported IDUP_S_MORE_PIDU_NEEDED more p-idu data is needed for IDUP_Start_Unprotect() IDUP_S_MORE_DATA_NEEDED more data is needed for protection or unprotection 1.2.2. Per-IDU Security Service Availability Per-IDU security service availability in IDUP-GSS-API is to be understood and used as described in GSS-API [RFC-1508], with the exception that any combination of services requested by the calling application and supported by the underlying mechanism can be applied simultaneously to any IDU. GSS-API callers desiring per-message security services should check the relevant service OBJECT IDs at environment establishment time to ensure that what is available in the established environment is suitable for their security needs. 1.2.3. Per-IDU Replay Detection and Sequencing The concept of per-IDU replay detection and sequencing discussed in GSS-API [RFC-1508] is not relevant to the IDUP-GSS-API. 1.2.4. Quality of Protection The concept of QOP control in IDUP-GSS-API is to be understood essentially as described in GSS-API [RFC-1508]. However, the actual description and use of the QOP parameter is given as follows. Adams Document Expiration: 11 Dec. 1996 7 The qop_algs parameter for IDUP is defined to be a 32-bit unsigned integer with the following bit-field assignments: 31 (MSB) (LSB) 0 ---------------------------------------------- | U(19) | TS(5) | IA(4) | MA(4) | ---------------------------------------------- where U is a 19-bit Unspecified field (available for future use/expansion) -- must be set to zero; TS is a 5-bit Type Specifier (a semantic qualifier whose value specifies the type of algorithm which may be used to protect the corresponding IDU -- see below for details); IA is a 4-bit field enumerating Implementation-specific Algorithms; and MA is a 4-bit field enumerating Mechanism-defined Algorithms. The interpretation of the qop_algs parameter is as follows. The MA field is examined first. If it is non-zero then the algorithm used to protect the IDU is the mechanism-specified algorithm corresponding to that integer value. If MA is zero then IA is examined. If this field value is non-zero then the algorithm used to protect the IDU is the implementation- specified algorithm corresponding to that integer value. Note that use of this field may hinder portability since a particular value may specify one algorithm in one implementation of the mechanism and may not be supported or may specify a completely different algorithm in another implementation of the mechanism. Finally, if both MA and IA are zero then TS is examined. A value of zero for TS specifies the default algorithm for the established mechanism. A non-zero value for TS corresponds to a particular algorithm qualifier and selects any algorithm from the mechanism specification which satisfies that qualifier (which actual algorithm is selected is an implementation choice; the calling application need not be aware of the choice made). The following TS values (i.e., algorithm qualifiers) are specified; other values may be added in the future. When qop_algs is used to select a confidentiality algorithm: 00000 (0) = default confidentiality algorithm 00001 (1) = IDUP_SYM_ALG_STRENGTH_STRONG 00010 (2) = IDUP_SYM_ALG_STRENGTH_MEDIUM 00011 (3) = IDUP_SYM_ALG_STRENGTH_WEAK 11111 (31) = IDUP_NO_CONFIDENTIALITY Adams Document Expiration: 11 Dec. 1996 8 When qop_algs is used to select a DOA/integrity algorithm: 00000 (0) = default integrity algorithm 00001 (1) = IDUP_INT_ALG_DIG_SIGNATURE (integrity provided through a digital signature) 00010 (2) = IDUP_INT_ALG_NON_DIG_SIGNATURE (integrity without a dig. sig. (e.g., with a MAC)) 11111 (31) = IDUP_NO_INTEGRITY Clearly, qualifiers such as strong, medium, and weak are debatable and likely to change with time, but for the purposes of this version of the specification we define these terms as follows. A confiden- tiality algorithm is "weak" if the effective key length of the cipher is 40 bits or less; it is "medium-strength" if the effective key length is strictly between 40 and 80 bits; and it is "strong" if the effective key length is 80 bits or greater. ("Effective key length" describes the computational effort required to break a cipher using the best-known cryptanalytic attack against that cipher.) A five-bit TS field allows up to 30 qualifiers for each of confiden- tiality and integrity (since "0" is reserved for "default" and "31" is reserved for "none", as shown above). This document specifies three for confidentiality and two for integrity, leaving a lot of room for future specification. Suggestions of qualifiers such as "fast", "medium-speed", and "slow" have been made, but such terms are difficult to quantify (and in any case are platform- and processor- dependent), and so have been left out of this initial specification. The intention is that the TS terms be quantitative, environment- independent qualifiers of algorithms, as much as this is possible. Use of the qop_algs parameter as defined above is ultimately meant to be as follows. - TS values are specified at the IDUP-GSS-API level and are therefore portable across mechanisms. Applications which know nothing about algorithms are still able to choose "quality" of protection for their message tokens. - MA values are specified at the mechanism level and are therefore portable across implementations of a mechanism. - IA values are specified at the implementation level (in user documentation, for example) and are therefore typically non- portable. An application which is aware of its own mechanism implementation and the mechanism implementation of its intended P-IDU recipient, however, is free to use these values since they will be perfectly valid and meaningful for protecting IDUs between those entities. The receiver of a P-IDU must pass back to its calling application (in IDUP_Start_Unprotect()) a qop_algs parameter with all relevant fields set. For example, if triple-DES has been specified by a mechanism as algorithm 8, then a receiver of a triple-DES-protected P-IDU must pass to its application (TS=1, IA=0, MA=8). In this way, the application is free to read whatever part of the qop_algs parameter it understands (TS or IA/MA). Adams Document Expiration: 11 Dec. 1996 9 1.2.5. The Provision of Time IDUP mechanisms should make provision in their protocols for the carrying of time information from originator to target(s). That is, a target (a legitimate recipient) should get some indication during unprotection regarding the time at which the protection operation took place. This is particularly important if the mechanism offers non-repudiation services because in some cases evidence verification may only be achievable if the time at which the evidence was generated is known. Depending upon the platform and resources available to the implementation, an IDUP environment may have access to a source of trusted (secure) time, untrusted (local) time, both kinds of time, or no time. OBJECT IDs indicating such availability are returned by the IDUP_Establish_Env() call. When starting a protection operation, an application may specify which time services it wishes to have applied to the IDU. Similarly, for unprotection, an application may specify which kind of time (if any) to consult when the validity of the P-IDU is to be established. Specifying both kinds of time is interpreted to mean that the calling application does not care which kind of time is used. 2. Interface Descriptions This section describes the IDUP-GSS-API's operational interface, dividing the set of calls offered into five groups. Credential management calls are related to the acquisition and release of credentials by API callers. Environment-level calls are related to the management of the security environment by an API caller. Per-IDU calls are related to the protection or unprotection of individual IDUs in established security environments. Special-purpose calls deal with unusual or auxiliary evidence generation/verification requirements. Support calls provide extra functions useful to IDUP-GSS-API callers. Table 2 groups and summarizes the calls in tabular fashion (an asterisk marks the calls which are identical to the GSS-API specification). Table 2: IDUP-GSS-API Calls CREDENTIAL MANAGEMENT * GSS_Acquire_cred acquire credentials for use * GSS_Release_cred release credentials after use * GSS_Inquire_cred display information about credentials * GSS_Add_cred add credential info. (see [GSSv2]) ENVIRONMENT-LEVEL CALLS IDUP_Establish_Env establish IDUP environment (to protect and unprotect IDUs) IDUP_Abolish_Env abolish env. when no longer needed IDUP_Inquire_Env indicate characteristics of env. Adams Document Expiration: 11 Dec. 1996 10 PER-IDU CALLS IDUP_Start_Protect begin the protection process IDUP_Protect protect the IDU (perhaps 1 buffer at a time) IDUP_End_Protect end the protection process; create a token which contains info. necessary for the legitimate receiver(s) of the P-IDU to unprotect it IDUP_File_Protect protect an IDU (input as a file) IDUP_Start_Unprotect begin the unprotect process IDUP_Unprotect use the token to unprotect the P-IDU (possibly one buffer at a time) IDUP_End_Unprotect end the unprotect process IDUP_File_Unprotect unprotect a P-IDU (input as a file) SPECIAL-PURPOSE CALLS (might not be supported by all mechanisms) IDUP_Form_Complete_PIDU insert in P-IDU any data not provided by the protection call(s) SUPPORT CALLS * GSS_Display_status translate status codes to printable form * GSS_Indicate_mechs indicate mech_types supported on local system * GSS_Compare_name compare two names for equality * GSS_Display_name translate name to printable form * GSS_Import_name convert printable name to normalize form * GSS_Release_name free storage of normalized-form name * GSS_Release_buffer free storage of printable name * GSS_Release_oid_set free storage of OID set IDUP_Parse_Token examine an input token to determine mech_type IDUP_Get_Policy_Info return policy info. for a given policy_id 2.1. Credential management calls 2.1.1. Relationship to GSS-API Credential management in IDUP-GSS-API is to be understood and used as described in GSS-API [RFC-1508]. The calls GSS_Acquire_cred(), GSS_Release_cred(), and GSS_Inquire_cred() are unchanged (the call GSS_Add_cred() from GSS-API v2 [GSSv2] is also included). However, the interpretation (and possible modification) of the cred_usage parameter for IDUP purposes is for further study. Adams Document Expiration: 11 Dec. 1996 11 2.2. Environment-level calls This group of calls is devoted to the establishment and management of an environment for the purpose of IDU protection and unprotection. Before protecting or unprotecting any IDU, an application must call IDUP_Establish_Env() to initialize environment information and select the underlying IDUP-GSS mechanism to be used. A series of protection or unprotection calls is made to process each IDU, the protection calls resulting in a P-IDU for each. Finally, IDUP_Abolish_Env() is called to flush all environment information. Semantically, acquiring credentials and establishing an environment is (in many cases) analogous to logging in to a system -- it authenticates a local user to the system and gives that user access to a set of operations which can be performed. 2.2.1. Relationship to GSS-API The set of calls described in this section are used in place of the calls GSS_Init_sec_context(), GSS_Accept_sec_context(), GSS_Delete_sec_context(), GSS_Process_context_token(), and GSS_Context_time() which are described in [RFC-1508], since those calls are specific to a session-oriented environment. Adams Document Expiration: 11 Dec. 1996 12 2.2.2. IDUP_Establish_Env call Inputs: o claimant_cred_handle CREDENTIAL HANDLE, -- NULL parameter specifies "use default" o req_mech_type OBJECT IDENTIFIER, -- NULL parameter specifies "use default" o req_policy OBJECT IDENTIFIER, -- NULL parameter specifies "use default". -- This environment-level policy identifier is separate from -- the policy provisions connected with credentials, if they exist o policy_time INTEGER, -- the security policy rules available at the specified time -- NULL parameter specifies "use default" o req_services SET OF OBJECT IDENTIFIER, Outputs: o major_status INTEGER, o minor_status INTEGER, o env_handle ENVIRONMENT HANDLE, o actual_mech_type OBJECT IDENTIFIER, -- actual mechanism always indicated, never NULL o actual_policy OBJECT IDENTIFIER, -- actual policy always indicated, never NULL o actual_policy_time, -- actual time at which the above policy rules came into effect o ret_services SET OF OBJECT IDENTIFIER, Return major_status codes: o GSS_S_COMPLETE indicates that environment-level information was successfully initialized, and that IDU / P-IDU processing can begin on the newly-established environment. o GSS_S_DEFECTIVE_CREDENTIAL indicates that consistency checks performed on the credential structure referenced by claimant_cred_handle failed, preventing further processing from being performed using that credential structure. o GSS_S_NO_CRED indicates that no environment was established, either because the input cred_handle was invalid or because the caller lacks authorization to access the referenced credentials. Adams Document Expiration: 11 Dec. 1996 13 o GSS_S_CREDENTIALS_EXPIRED indicates that the credentials provided through the input claimant_cred_handle argument are no longer valid, so environment establishment cannot be completed. o GSS_S_BAD_MECH indicates that a mech_type unsupported by the IDUP_GSS-API implementation was requested, causing the environment establishment operation to fail. o GSS_S_FAILURE indicates that environment setup could not be accomplished for reasons unspecified at the IDUP-GSS-API level, and that no interface-defined recovery action is available. This routine is used by an application which protects or unprotects IDUs. Using information in the credentials structure referenced by claimant_cred_handle, IDUP_Establish_Env() initializes the data structures required to protect or unprotect IDUs. The claimant_cred_handle, if non-NULL, must correspond to a valid credentials structure. This routine returns an env_handle for all future references to this environment; when protection, unprotection, or IDUP_Abolish_Env() calls are made, this handle value will be used as the input env_handle argument. It is the caller's responsibility to establish a communications path to the intended recipients of the P-IDU, and to transmit the P-IDU to those recipients over that path. This may occur subsequent to the IDUP_Abolish_Env() call. The req_services parameter may be used by the calling application to request that data origin authentication with integrity, confidentiality with integrity, evidence generation, and/or evidence verification services be available in the established environment. Requests can also be made for "trusted" or "untrusted" time services. Requesting evidence generation or verification indicates that the calling application may wish to generate or verify evidence information for non-repudiation purposes (note: an IDU protector may request that a flag be inserted into a P-IDU asking a recipient to provide an evidence of the type "non-repudiation of delivery"; however, the IDUP-GSS-API cannot by itself guarantee that the evidence will be sent because there is no way to force a target to send an evidence_token back to the IDU protector). Not all features will be available in all underlying mech_types; the returned value of ret_services indicates, as a function of mech_type processing capabilities and the initiator-provided input OBJECT IDs, the set of features which will be available in the environment. The value of this parameter is undefined unless the routine's major_status indicates COMPLETE. Failure to provide the precise set of services desired by the caller does not cause environment establishment to fail; it is the caller's prerogative to abolish the environment if the service set provided is unsuitable for the caller's use. The returned mech_type value indicates the specific mechanism employed in the environment, and will never indicate the value for "default". Adams Document Expiration: 11 Dec. 1996 14 The following OBJECT IDs are defined for protection and unprotection services. It is recognized that this list may grow over time. PER_CONF = { xx } -- perform data confidentiality (i.e., encrypt data) PER_DOA = { xx } -- perform data origin authentication with data integrity PER_POO = { xx } -- perform (i.e., create) non-repudiable "proof of origin" PER_POD = { xx } -- perform (i.e., create) non-repudiable "proof of delivery" REC_CONF = { xx } -- receive data confidentiality (i.e., decrypt data) REC_DOA = { xx } -- receive / verify DOA with data integrity REC_POO = { xx } -- receive / verify "proof of origin" REC_POD = { xx } -- receive / verify "proof of delivery" TTIME = { xx } -- trusted time availability UTIME = { xx } -- untrusted time availability The PER_CONF return value (in the ret_services paramater) indicates whether the environment supports confidentiality services, and so informs the caller whether or not a request for encryption through a confidentiality service input to IDUP_Start_Protect() can be honored. In similar fashion, the PER_DOA return value indicates whether DOA services are available in the established environment, and the PER_POO and PER_POD return values indicate whether evidence generation services are available. The TTIME and UTIME values indicate whether trusted time and untrusted time are available for protection / unprotection services. Note that, unlike a GSS "context", an IDUP environment does not have an explicit lifetime associated with it. Instead, it relies on the lifetime of the calling entity's credential (set by the caller in the GSS_Acquire_cred() call). When the credential expires (or is explicitly deleted using the gss_release_cred() call), no new operations are allowed in the IDUP environment (although operations which have begun, such as the Protection set of calls, can be taken to completion). 2.2.3. IDUP_Abolish_Env call Input: o env_handle ENVIRONMENT HANDLE Outputs: o major_status INTEGER, o minor_status INTEGER, Adams Document Expiration: 11 Dec. 1996 15 Return major_status codes: o GSS_S_COMPLETE indicates that the environment was recognized and that relevant environment-specific information was flushed. o IDUP_S_NO_ENV indicates that no valid environment was recognized for the env_handle provided, so no deletion was performed. o GSS_S_FAILURE indicates that the environment is recognized, but that the requested operation could not be performed for reasons unspecified at the IDUP-GSS-API level. This call is made to flush environment-specific information. (Once an environment is established, cached credential and environment-related info. is expected to be retained until an IDUP_Abolish_Env() call is made or until the cred. lifetime expires.) Attempts to perform IDU processing on a deleted environment will result in error returns. 2.2.4: IDUP_Inquire_Env call Input: o env_handle ENVIRONMENT HANDLE, Outputs: o major_status INTEGER, o minor_status INTEGER, o mech_type OBJECT IDENTIFIER, -- the mechanism supporting this env. o policy OBJECT IDENTIFIER, -- the policy used in this env. o policy_time, -- time at which the policy rules came into effect o ret_services SET OF OBJECT IDENTIFIER, Return major_status codes: o GSS_S_COMPLETE indicates that the referenced environment is valid and that mech_type and other return values describe the corresponding characteristics of the environment. o GSS_S_CREDENTIALS_EXPIRED indicates that the environment is recognized, but that its associated credentials have expired, so that the requested operation cannot be performed. o IDUP_S_NO_ENV indicates that no valid environment was recognized for the env_handle provided, so no return values can be provided. o GSS_S_FAILURE indicates that the environment is recognized, but that the requested operation could not be performed for reasons unspecified at the IDUP-GSS-API level. This routine provides environment-related information to the caller. Adams Document Expiration: 11 Dec. 1996 16 2.3. Per-IDU calls This group of calls is used to perform IDU protection and unprotection processing on an established IDUP environment. Some of these calls may block pending network interactions (depending on the underlying mechanism in use). These calls may be invoked by an IDU's protector or by the P-IDU's recipient. The two sets of members of this group form a pair; the output from the protection set is typically meant to be input to the unprotection set. The per-IDU calls can support caller-requested data origin authentication with data integrity, confidentiality with data integrity, evidence, and evidence-requested-from-target services. The protection operations output a token which encapsulates all the information required to unprotect the IDU. The token is passed to the target (possibly separate from the M-IDU) and is processed by the unprotection calls at that system. Unprotection performs decipherment, DOA verification, evidence verification, or notification of evidence requested, as required. Each of the two main operations (protection and unprotection) may be separated into three parts: "Start_Operation"; "Operation" (which may be called once for each buffer of input data); and "End_Operation". This separation is available for the case where the IDU or P-IDU is to be processed one buffer at a time. "Start_Operation" allows the caller to specify or retrieve the appropriate "Quality" used during the processing. "Operation" is concerned with the processing itself, receiving a buffer of input data and potentially returning a buffer of output data. "End_Operation" performs any required clean-up and creates the appropriate token or states whether the input token was verified. If the IDU or P-IDU is wholly contained in a single buffer, the three-part protection/unprotection processing need not be done. Instead, protection and unprotection can be accomplished using only the "Start_Operation" call, simplifying application code. 2.3.1. Relationship to GSS-API The set of calls described in this section are used in place of the calls GSS_Sign(), GSS_Verify(), GSS_Seal(), and GSS_Unseal() -- now named GSS_GetMIC(), GSS_VerifyMIC, GSS_Wrap(), and GSS_Unwrap() -- which are specified in [RFC-1508], since those calls are specific to a session-oriented environment. 2.3.2. Parameter Bundles The concept of "parameter bundles" is used in the calls presented in the following subsections in order to simplify their presentation and (hopefully) clarify their intended purpose and use. A parameter bundle is simply a set of closely-related parameters of a call which are either all used by / available to the calling application or all not used by / unavailable to the calling application. These parameters may be all input parameters, all output parameters, or any combination of the two. Adams Document Expiration: 11 Dec. 1996 17 A typical use envisioned for parameter bundles in a language such as C would be as a structure, where individual parameters in the bundle are structure members. The calling application wishing to use a particular bundle would then allocate the appropriate structure variable, assign the desired input values to the appropriate members, and pass the address of the structure as the bundle "parameter". On output, the values of the appropriate output members may be read. An application not wishing to use a particular bundle (or one which is satisfied with default values for all input parameters of the bundle and which doesn't care about output values), can pass NULL as the bundle "parameter". From the mechanism implementor's perspective, if a parameter bundle is not supported (for example, if it represents a security service which is not supported by the implementation), then any non-NULL value passed as the bundle parameter will generate an error status return code. The following parameter bundles are used in the subsequent protection and unprotection sets of calls. A parameter preceded by "(I)" is an input parameter; one preceded by "(O)" is an output parameter; one preceded by neither is an input if the bundle itself is an input and is an output if the bundle itself is an output. o Mech_Specific_Info PARAMETER BUNDLE -- actual parameters included in this bundle are defined by (and -- specific to) the underlying mechanism o Idu_Sensitivity PARAMETER BUNDLE, -- actual parameters included in this bundle are defined by (and -- specific to) the underlying mechanism, but may include -- codified values for "Unclassified", "Secret", "Top Secret", -- and so on o Service_Creation_Info PARAMETER BUNDLE -- actual parameters included in this bundle are defined by (and -- specific to) the underlying mechanism, but it is mandatory -- that they include at least service_id and Quality. o Service_Verification_Info PARAMETER BUNDLE -- actual parameters included in this bundle are defined by (and -- specific to) the underlying mechanism, but it is mandatory -- that they include at least service_id and Quality. o Quality PARAMETER BUNDLE o qop_algs UNSIGNED INTEGER, o validity UNSIGNED INTEGER, -- protection guaranteed to be valid until time specified o policy_id OBJECT IDENTIFIER, -- security policy under which protection is/was carried out o allow_policy_mapping BOOLEAN, -- determines whether or not mapping between policy -- identifiers is allowed Adams Document Expiration: 11 Dec. 1996 18 o Idu_Information PARAMETER BUNDLE, o idu_type_oid OBJECT IDENTIFIER, o idu_type_string OCTET STRING, o idu_title OCTET STRING, o Idu_Sensitivity PARAMETER BUNDLE, o Prot_Information PARAMETER BUNDLE, o originator_name INTERNAL NAME, o Idu_Information PARAMETER BUNDLE, o protection_time INTEGER, o Special_Conditions PARAMETER BUNDLE, o prot_oper_id INTEGER, o use_trusted_time BOOLEAN, o use_untrusted_time BOOLEAN, o Bad_Target_Name PARAMETER BUNDLE, o (O) bad_targ_name INTERNAL NAME, o (O) bad_targ_status INTEGER, -- a (mechanism-defined) status flag giving the reason -- for rejection of the name in bad_targ_name o Target_Info PARAMETER BUNDLE, o targ_names SET OF INTERNAL NAME, o (O) bad_targ_count INTEGER, o (O) Bad_Target_Name PARAMETER BUNDLE, o General_Service_Data PARAMETER BUNDLE, o Target_Info PARAMETER BUNDLE, o (O) unencapsulated_token OCTET STRING, -- zero length if encapsulation_request is TRUE; -- unused in the unprotection set of calls o (O) minor_status INTEGER, Adams Document Expiration: 11 Dec. 1996 19 Three types of protection services are defined in IDUP. These are 1. perform unsolicited service (i.e., act on a locally-generated service request), 2. perform solicited service (i.e., act on a remotely-generated service request), and 3. perform service solicitation (i.e., send a service request to the remote end). As an originator, applying data confidentiality with data integrity, or data origin authentication with data integrity, or proof of origin evidence is an example of service type 1. As a target, creating a proof of delivery (i.e., receipt) evidence token as the result of a request received from the originator is an example of service type 2. Finally, as an originator, submitting a request that one or more targets return a receipt for the data sent is an example of service type 3. The first four parameters in the Prot_Service parameter bundle pertain to all service types; the fifth parameter is used if and only if service type 2 is desired; parameters 6-8 are used if and only if service type 3 is desired. o Prot_Service PARAMETER BUNDLE o (I) prot_service_type INTEGER, o (I) service_id OBJECT IDENTIFIER, o (I) Quality PARAMETER BUNDLE, -- NULL specifies default Quality o (I) General_Service_Data PARAMETER BUNDLE, o (I) Service_Creation_Info PARAMETER BUNDLE, o (I) service_to SET OF INTERNAL NAME, o (O) Service_Verification_Info PARAMETER BUNDLE, o (O) service_verification_info_id INTEGER, Also, three types of unprotection services are defined. These are 1. receive unsolicited service (i.e., process unrequested remotely-generated service), 2. receive solicited service (i.e., process remotely-generated response to locally-generated request), and 3. receive service solicitation (i.e., process req. from rem. end) As a target, unprotecting an encrypted message, or verifying the originator's proof of origin is an example of service type 1. As an originator, verifying a proof of delivery which you requested from a target is an example of service type 2. Finally, as a target, receiving a request from an originator for a proof of delivery is an example of service type 3. Adams Document Expiration: 11 Dec. 1996 20 The first four parameters in the Unprot_Service parameter bundle pertain to all service types; parameters 5-6 are used if and only if service type 2 is required; parameters 7-8 are used only if service type 3 is required. o Unprot_Service PARAMETER BUNDLE o (O) unprot_service_type INTEGER, o (O) service_id OBJECT IDENTIFIER, o (O) Quality PARAMETER BUNDLE, -- actual Quality specified (never NULL) o (O) General_Service_Data PARAMETER BUNDLE, o (O) service_verification_info_id INTEGER, o (I) Service_Verification_Info PARAMETER BUNDLE, o (O) service_to SET OF INTERNAL NAME, o (O) Service_Creation_Info PARAMETER BUNDLE, 2.3.3. IDUP_Start_Protect call Inputs: o env_handle ENVIRONMENT HANDLE, o Mech_Specific_Info PARAMETER BUNDLE, -- NULL selects the mechanism-defined default values o Idu_Information PARAMETER BUNDLE, o Special_Conditions PARAMETER BUNDLE, o encapsulation_request BOOLEAN, o single_idu_buffer OCTET STRING, -- non-zero length for this buffer means that Protect/End_Protect -- won't be called (i.e., entire IDU is contained in this buffer) o Target_Info PARAMETER BUNDLE, o Services_to_Perform SET OF Prot_Service, Outputs: o major_status INTEGER, o minor_status INTEGER, o midu_buffer OCTET STRING, -- zero length if encapsulation_request is TRUE or if -- single_idu_buffer has zero length Adams Document Expiration: 11 Dec. 1996 21 o pidu_buffer OCTET STRING, -- zero length if encapsulation_request is FALSE or if -- single_idu_buffer has zero length Return major_status codes: o GSS_S_COMPLETE indicates that the protection process can begin (or has completed, if single_idu_buffer has non-zero length). o GSS_S_CONTINUE_NEEDED indicates that at least one of the buffers supplied is too small to hold the generated data. The application should continue calling this routine (until GSS_S_COMPLETE is returned) in order to get all remaining data. o GSS_S_CREDENTIALS_EXPIRED indicates that the environment is recognized, but that its associated credentials have expired, so that the requested operation cannot be performed. o IDUP_S_NO_ENV indicates that no valid environment was recognized for the env_handle provided. o IDUP_S_ENCAPSULATION_UNAVAIL indicates that the underlying mechanism does not support encapsulation of the M-IDU into the token. o IDUP_S_MORE_DATA_NEEDED indicates whether protection is completed by this call or by IDUP_End_Protect() (e.g., whether more data buffers are required for evidence generation) o IDUP_S_SERVICE_UNAVAIL indicates that the underlying mechanism does not support the service requested. o IDUP_S_REQ_TIME_SERVICE_UNAVAIL indicates that the time service requested (TTIME or UTIME) is not available in the environment. o IDUP_S_UNKNOWN_OPER_ID indicates that the input prot_oper_id value is not recognized or supported in the underlying mechanism. o GSS_S_BAD_QOP indicates that the provided qop_algs value is not recognized or supported for the environment. o IDUP_S_BAD_TARG_INFO indicates that all the information regarding the target(s) is invalid or is insufficient for the protection of an IDU, so P-IDU cannot be created. o GSS_S_FAILURE indicates that the environment is recognized, but that the requested operation could not be performed for reasons unspecified at the IDUP-GSS-API level. Adams Document Expiration: 11 Dec. 1996 22 Using the security environment referenced by env_handle, initialize the data structures required to begin the process of protecting the IDU buffers. The caller requests specific protection services by supplying the appropriate Prot_Service parameter bundles in Services_to_Perform. Each service is able to return a minor status code to the calling application, if necessary. The calling application, knowing the size of the IDU it wishes to protect and the buffer size which it has available to it, can choose to input the entire IDU in a single buffer and omit the subsequent IDUP_Protect() and IDUP_End_Protect() calls. Furthermore, the application can request that the resulting M-IDU be encapsulated in the token -- so that the token contains the entire P-IDU -- rather than having it be returned separately in midu_buffer. Encapsulation, however, may not be supported by all underlying mechanisms or implementations; if this is the case, the IDUP_S_ENCAPSULATION_UNAVAIL major status code will be returned and M-IDU will be returned in midu_buffer. For those mechanisms which allow or require multiple stages of processing, each producing a different aspect of protection for the IDU, the operation identifier prot_oper_id is used to specify which stage is currently being requested by the application. An example where this would be useful is a mechanism which implements the signed Message Security Protocol [MSP]. As another example, a mechanism may choose to do a digital signature in two stages: one for the hashing of the message and another for the signature on the hash. The calling application would therefore use the protection set of calls on the IDU in stage 1 and then use the protection set of calls on the token (from stage 1) in stage 2. Note that prot_oper_id is simply an integer (1, 2, 3, ..., n, where "n" is the number of stages as defined by the mechanism (typically 1 or 2)). The calling application uses this parameter to indicate to the underlying mechanism whether it wishes to do stage 1 of protection / unprotection processing, or stage 2, and so on. If one or more of the targets in targ_names cannot be used as a valid recipient of the P-IDU, these names will be returned in bad_targ_names (with associated status codes in bad_targ_status). As long as at least one of the targets can be used, this does not cause this call to fail; it is the caller's prerogative to discontinue IDU protection if the target set which can be used is unsuitable for the caller's purposes. Note that each Prot_Service parameter bundle can also input a list of targ_names; this is used if a separate list is to be used for that service only (the general list of targets is to be used for all services unless overridden in this way). Adams Document Expiration: 11 Dec. 1996 23 2.3.4. IDUP_Protect call Inputs: o env_handle ENVIRONMENT HANDLE, o input_buffer OCTET STRING, Outputs: o major_status INTEGER, o minor_status INTEGER, o output_buffer OCTET STRING -- may be zero length if encapsulation_request was set to TRUE in -- IDUP_Start_Protect() (depends on underlying mechanism) Return major_status codes: o GSS_S_COMPLETE indicates that the input_buffer has successfully been included in the protection computation. o IDUP_S_NO_ENV indicates that no valid environment was recognized for the env_handle provided. o GSS_S_FAILURE indicates that the environment is recognized, but that the required operation could not be performed for reasons unspecified at the IDUP-GSS-API level. Using the security environment referenced by env_handle, continue the protection processing on the data in input_buffer and, if the underlying mechanism defines this, put any resulting P-IDU/M-IDU data in output_buffer. The application calls this routine over and over again with new buffers of data until it has protected all the data buffers of the IDU. It then calls IDUP_End_Protect() to complete the protection processing. Adams Document Expiration: 11 Dec. 1996 24 2.3.5. IDUP_End_Protect call Inputs: o env_handle ENVIRONMENT HANDLE, Outputs: o major_status INTEGER, o minor_status INTEGER, o Services_to_Perform SET OF Prot_Service, o final_midu_buffer OCTET STRING, -- zero length if encapsulation_request was set to TRUE in -- IDUP_Start_Protect(), in which case pidu is used o final_pidu_buffer OCTET STRING, -- zero length if encapsulation_request was set to FALSE in -- IDUP_Start_Protect(), in which case token and midu are used Return major_status codes: o GSS_S_COMPLETE indicates that the protection computation has been successfully completed and the resulting P-IDU is ready for transfer. If defined by the underlying mechanism, final_midu_buffer will contain any residual M-IDU data. o GSS_S_CONTINUE_NEEDED indicates that at least one of the buffers supplied is too small to hold the generated data. The application should continue calling this routine (until GSS_S_COMPLETE is returned) in order to get all remaining data. o IDUP_S_NO_ENV indicates that no valid environment was recognized for the env_handle provided. o GSS_S_FAILURE indicates that the environment is recognized, but that the requested operation could not be performed for reasons unspecified at the IDUP-GSS-API level. Using the security environment referenced by env_handle, complete the protection processing on the data and place the computed output in final_pidu_buffer (or final_midu_buffer and the unencapsulated_token parameter for each Prot_Service). If a service was requested from one or more targets in Start_Protect() - and if this is supported by the underlying mechanism - Service_Verification_Info will hold whatever data is necessary for the mechanism to verify a service returned by a target (unprotector) of the P-IDU. Successful application of IDUP_End_Protect() does not guarantee that the corresponding unprotection set of calls can necessarily be performed successfully when the P-IDU arrives at the target (for example, it may be damaged in transit). Adams Document Expiration: 11 Dec. 1996 25 2.3.6. IDUP_File_Protect call Inputs: o env_handle ENVIRONMENT HANDLE, o Mech_Specific_Info PARAMETER BUNDLE, -- NULL selects the mechanism-defined default values o Idu_Information PARAMETER BUNDLE, o Special_Conditions PARAMETER BUNDLE, o input_filename INTERNAL FILE NAME, o Target_Info PARAMETER BUNDLE, o Services_to_Perform SET OF Prot_Service, Outputs: o major_status INTEGER, o minor_status INTEGER, o output_filename INTERNAL FILE NAME, Return major_status codes: o GSS_S_COMPLETE indicates that file protection is complete. o GSS_S_CREDENTIALS_EXPIRED indicates that the environment is recognized, but that its associated credentials have expired, so that the requested operation cannot be performed. o IDUP_S_NO_ENV indicates that no valid environment was recognized for the env_handle provided. o IDUP_S_SERVICE_UNAVAIL indicates that the underlying mechanism does not support the service requested. o IDUP_S_REQ_TIME_SERVICE_UNAVAIL indicates that the time service requested (TTIME or UTIME) is not available in the environment. o IDUP_S_UNKNOWN_OPER_ID indicates that the input prot_oper_id value is not recognized or supported in the underlying mechanism. o GSS_S_BAD_QOP indicates that the provided qop_algs value is not recognized or supported for the environment. o IDUP_S_BAD_TARG_INFO indicates that all the information regarding the target(s) is invalid or is insufficient for the protection of an IDU, so P-IDU cannot be created. Adams Document Expiration: 11 Dec. 1996 26 o GSS_S_FAILURE indicates that the environment is recognized, but that the requested operation could not be performed for reasons unspecified at the IDUP-GSS-API level. This call is almost identical to the IDUP_Start_Protect call except that instead of single_idu_buffer the input is a filename and instead of midu_buffer or pidu_buffer the output is again a filename. This can greatly simplify and improve the performance of applications which work primarily with files instead of buffers of data. It is important, however, to note two caveats. Firstly, for reasons of simplicity, unencapsulation is not available to callers of this function (as it is to callers of IDUP_Start_Protect); encapsulation is the only option available. Secondly, and more importantly, because of the INTERNAL FILE NAME parameters (input_filename and output_filename), callers of this function are very likely to be non-portable across different computing platforms (since handles to files may differ from platform to platform). Because of the above caveats, this call is specified to be optional, and may not be supported by all underlying mechanisms or implementations. 2.3.7. IDUP_Start_Unprotect call Inputs: o env_handle ENVIRONMENT HANDLE, o Mech_Specific_Info PARAMETER BUNDLE, -- NULL selects the mechanism-defined default values o single_pidu_buffer OCTET STRING, -- non-zero length for this buffer means that IDUP_Unprotect() and -- IDUP_End_Unprotect() will not be called (i.e., the entire P-IDU -- is contained in this buffer) o partial_pidu_buffer OCTET STRING, -- may be an arbitrary-sized piece of the full pidu (if the -- applications buffer isnt large enough to hold entire pidu), -- or may be a service token (if encapsulation was not used). -- Used if pidu_buffer will be input a buffer at a time (except -- that the final buffer must be passed in final_pidu_buffer -- rather than partial_pidu_buffer). Only one of -- single_pidu_buffer and partial(final)_pidu_buffer can have -- nonzero length. o final_pidu_buffer OCTET STRING, o Special_Conditions PARAMETER BUNDLE, Adams Document Expiration: 11 Dec. 1996 27 Outputs: o major_status INTEGER, o minor_status INTEGER, o Services_to_Receive SET OF Unprot_Service, o Prot_Information PARAMETER BUNDLE, o single_idu_buffer OCTET STRING, -- if this buffer has non-zero length, then service processing has -- been completed on the data in single_pidu_buffer o initial_idu_buffer OCTET STRING, -- holds any data from partial(final)_pidu_buffer which has been -- unprotected; remaining data will be returned by Unprotect and -- End_Unprotect as they are called with successive buffers of -- pidu o Service_Verification_Info PARAMETER BUNDLE, -- used only if target is on "service_to" list in Unprot_Service o service_verification_info_id INTEGER, -- used only if target is on "service_to" list in Unprot_Service Return major_status codes: o GSS_S_COMPLETE indicates that unprotection processing can begin (or has completed, if single_idu_buffer has non-zero length). o IDUP_S_INCOMPLETE indicates that the unprotection of the P-IDU is not yet complete (i.e., a determination cannot yet be made on the validity of the P-IDU). The application should call IDUP_Form_Complete_PIDU and then should call this function again with the complete P-IDU. (This status code is used in IDUP_Start_Unprotect only if single_idu_buffer has non-zero length) o GSS_S_CONTINUE_NEEDED indicates that at least one of the buffers supplied is too small to hold the generated data. The application should continue calling this routine (until GSS_S_COMPLETE is returned) in order to get all remaining data. o IDUP_S_MORE_PIDU_NEEDED indicates that not enough of the P-IDU has been input yet for the completion of Start_Protect. The application should call this routine again with another buffer of P-IDU in partial_pidu_buffer. o GSS_S_DEFECTIVE_TOKEN indicates that consistency checks performed on the received P-IDU failed, preventing further processing from being performed. o IDUP_S_INAPPROPRIATE_CRED indicates that the credentials supplied do not contain the information necessary for P-IDU unprotection. Adams Document Expiration: 11 Dec. 1996 28 o IDUP_S_MORE_DATA_NEEDED indicates whether unprotection is completed by this call or by IDUP_End_Unprotect() (e.g., whether more data buffers are required for unprotection) o GSS_S_DEFECTIVE_VERIF indicates that consistency checks performed on Service_Verification_Info failed, preventing further processing from being performed with that parameter. o IDUP_S_NO_MATCH indicates that Service_Verification_Info and the P-IDU to be verified do not match. o IDUP_S_SERVICE_UNAVAIL indicates that the underlying mechanism does not support the service requested. o IDUP_S_REQ_TIME_SERVICE_UNAVAIL indicates that the time service requested (TTIME or UTIME) is not available in the environment. o IDUP_S_SERV_VERIF_INFO_NEEDED indicates that the Service_Verification_Info parameter bundle must be input in order for service verification to proceed. The output parameter service_verification_info_id contains an identifier which may be used by the calling application to locate the necessary information. o GSS_S_CREDENTIALS_EXPIRED indicates that the environment is recognized, but that its associated credentials have expired, so that the requested operation cannot be performed. o IDUP_S_NO_ENV indicates that no valid environment was recognized for the env_handle provided. o IDUP_S_UNKNOWN_OPER_ID indicates that the input prot_oper_id value is not recognized or supported in the underlying mechanism. o GSS_S_BAD_QOP indicates that the qop_algs value specified in P-IDU for at least one of the services is unavailable in the local mechanism, so processing cannot continue. o GSS_S_BAD_SIG indicates that the received P-IDU contains an incorrect integrity field (e.g., signature or MAC) for the data. o IDUP_S_BAD_DOA_KEY indicates that the key used to provide IDU data origin auth. / integ. has either expired or been revoked. o IDUP_S_BAD_KE_KEY indicates that the key used to establish a key for confidentiality purposes between originator and target has either expired or been revoked. o IDUP_S_BAD_ENC_IDU indicates that decryption of the received IDU cannot be completed because the encrypted IDU was invalid/defec- tive (e.g., the final block was short or had incorrect padding). o GSS_S_FAILURE indicates that the environment is recognized, but that the requested operation could not be performed for reasons unspecified at the IDUP-GSS-API level. Adams Document Expiration: 11 Dec. 1996 29 Using the security environment referenced by env_handle, initialize the data structures required to begin the process of unprotecting a P-IDU. The caller will be alerted as to which services were applied to the P-IDU in the returned Services_to_Receive set of parameters. If unprotection will be applied more than once to a given P-IDU, it is the responsibility of the calling application to remember if a service solicitation has been responded to previously (i.e., if the requested service has already been generated / sent for that P-IDU) and thus ignore subsequent solicitations on unprotect. The time flags indicate whether to consult trusted, untrusted, or no time (if both flags are FALSE) during the unprotection operation. If the current time is not to be checked, then unprotection may be successful even if the protector's key has expired since the P-IDU was generated (that is, if the Validity period -- as specified in the Quality parameter bundle -- has expired). If the underlying mechanism supports it and if this information is contained in the token, information regarding the originator (that is, the entity which used the protection set of calls to generate this token) is returned in the Prot_Information parameter bundle. 2.3.8. IDUP_Unprotect call Inputs: o env_handle ENVIRONMENT HANDLE, o input_buffer OCTET STRING Outputs: o major_status INTEGER, o minor_status INTEGER, o output_buffer OCTET STRING Return major_status codes: o GSS_S_COMPLETE indicates that the input_buffer has successfully been included in the unprotection computation. o IDUP_S_NO_ENV indicates that no valid environment was recognized for the env_handle provided. o GSS_S_FAILURE indicates that the environment is recognized, but that the requested operation could not be performed for reasons unspecified at the IDUP-GSS-API level. Using the security environment referenced by env_handle, continue the unprotection processing on the data in input_buffer, putting any resulting IDU data in output_buffer (if required). Adams Document Expiration: 11 Dec. 1996 30 2.3.9. IDUP_End_Unprotect call Inputs: o env_handle ENVIRONMENT HANDLE, Outputs: o major_status INTEGER, o minor_status INTEGER, o Prot_Information PARAMETER BUNDLE, o Services_to_Receive SET OF Unprot_Service, o final_idu_buffer OCTET STRING, o Service_Verification_Info PARAMETER BUNDLE, -- used only if target is on "service_to" list in Unprot_Service o service_verification_info_id INTEGER, -- used only if target is on "service_to" list in Unprot_Service Return major_status codes: o GSS_S_COMPLETE indicates that the unprotect computation was successful. Any residual IDU data will be returned in final_idu_buffer. o IDUP_S_INCOMPLETE indicates that the unprotection of the P-IDU is not yet complete (i.e., a determination cannot yet be made on the validity of the P-IDU). The application should call IDUP_Form_Complete_PIDU and then should call this function again with the complete P-IDU. o GSS_S_CONTINUE_NEEDED indicates that at least one of the buffers supplied is too small to hold the generated data. The application should continue calling this routine (until GSS_S_COMPLETE is returned) in order to get all remaining data. o GSS_S_BAD_SIG indicates that the received P-IDU contains an incorrect integrity field (e.g., signature or MAC) for the data. o IDUP_S_BAD_DOA_KEY indicates that the key used to provide IDU data origin auth. / integ. has either expired or been revoked. o IDUP_S_BAD_KE_KEY indicates that the key used to establish a key for confidentiality purposes between originator and target has either expired or been revoked. o IDUP_S_BAD_ENC_IDU indicates that decryption of the received IDU cannot be completed because the encrypted IDU was invalid/defec- tive (e.g., the final block was short or had incorrect padding). Adams Document Expiration: 11 Dec. 1996 31 o IDUP_S_NO_ENV indicates that no valid environment was recognized for the env_handle provided. o GSS_S_FAILURE indicates that the environment is recognized, but that the requested operation could not be performed for reasons unspecified at the IDUP-GSS-API level. Using the security environment referenced by env_handle, complete the unprotection processing on the data and return the appropriate status code. If there is any residual IDU data it will be returned in final_idu_buffer. If the IDUP_S_INCOMPLETE major status value is returned, all output parameters are conditionally valid; the unprotection set of functions will have to be called again (perhaps with a complete P-IDU, as produced by IDUP_Form_Complete_PIDU) in order to get valid values for all parameters. "Conditional validity" may arise, for example, if all relevant certificates verify correctly, but it is not yet past the time up to which the current policy allows the authorities involved to repudiate their keys. If the underlying mechanism supports it and if this information is contained in the token, information regarding the originator (that is, the entity which used the protection set of calls to generate this token) is returned in the Prot_Information parameter bundle. This information may or may not be omitted if it was returned by the IDUP_Start_Unprotect() call. Note that, unlike GSS-API, IDUP-GSS-API does not incorporate the concept of error tokens transferred between sender and recipient since the protection and unprotection of an IDU may be separated by an indefinite amount of time and may or may not be performed by the same entity. 2.3.10. IDUP_File_Unprotect call Inputs: o env_handle ENVIRONMENT HANDLE, o Mech_Specific_Info PARAMETER BUNDLE, -- NULL selects the mechanism-defined default values o input_filename INTERNAL FILE NAME, o Special_Conditions PARAMETER BUNDLE, Adams Document Expiration: 11 Dec. 1996 32 Outputs: o major_status INTEGER, o minor_status INTEGER, o Services_to_Receive SET OF Unprot_Service, o Prot_Information PARAMETER BUNDLE, o output_filename INTERNAL FILE NAME, o Service_Verification_Info PARAMETER BUNDLE, -- used only if target is on "service_to" list in Unprot_Service o service_verification_info_id INTEGER, -- used only if target is on "service_to" list in Unprot_Service Return major_status codes: o GSS_S_COMPLETE indicates that unprotection processing can begin (or has completed, if single_idu_buffer has non-zero length). o IDUP_S_INCOMPLETE indicates that the unprotection of the P-IDU file is not yet complete (i.e., a determination cannot yet be made on the validity of the P-IDU). The application should call IDUP_Form_Complete_PIDU and then should call this function again with the complete P-IDU. o GSS_S_DEFECTIVE_TOKEN indicates that consistency checks performed on the received P-IDU failed, preventing further processing from being performed. o GSS_S_DEFECTIVE_VERIF indicates that consistency checks performed on Service_Verification_Info failed, preventing further processing from being performed with that parameter. o IDUP_S_NO_MATCH indicates that Service_Verification_Info and the P-IDU to be verified do not match. o IDUP_S_SERVICE_UNAVAIL indicates that the underlying mechanism does not support the service requested. o IDUP_S_REQ_TIME_SERVICE_UNAVAIL indicates that the time service requested (TTIME or UTIME) is not available in the environment. o IDUP_S_SERV_VERIF_INFO_NEEDED indicates that the Service_Verification_Info parameter bundle must be input in order for service verification to proceed. The output parameter service_verification_info_id contains an identifier which may be used by the calling application to locate the necessary information. o IDUP_S_INAPPROPRIATE_CRED indicates that the credentials supplied do not contain the information necessary for P-IDU unprotection. Adams Document Expiration: 11 Dec. 1996 33 o GSS_S_CREDENTIALS_EXPIRED indicates that the environment is recognized, but that its associated credentials have expired, so that the requested operation cannot be performed. o IDUP_S_NO_ENV indicates that no valid environment was recognized for the env_handle provided. o IDUP_S_UNKNOWN_OPER_ID indicates that the input prot_oper_id value is not recognized or supported in the underlying mechanism. o GSS_S_BAD_QOP indicates that the qop_algs value specified in P-IDU for at least one of the services is unavailable in the local mechanism, so processing cannot continue. o GSS_S_BAD_SIG indicates that the received P-IDU contains an incorrect integrity field (e.g., signature or MAC) for the data. o IDUP_S_BAD_DOA_KEY indicates that the key used to provide IDU data origin auth. / integ. has either expired or been revoked. o IDUP_S_BAD_KE_KEY indicates that the key used to establish a key for confidentiality purposes between originator and target has either expired or been revoked. o IDUP_S_BAD_ENC_IDU indicates that decryption of the received IDU cannot be completed because the encrypted IDU was invalid/defec- tive (e.g., the final block was short or had incorrect padding). o GSS_S_FAILURE indicates that the environment is recognized, but that the requested operation could not be performed for reasons unspecified at the IDUP-GSS-API level. This call is almost identical to the IDUP_Start_Unprotect call except that instead of single_pidu_buffer, partial_pidu_buffer, or final_pidu_buffer the input is a filename and instead of single_idu_buffer or initial_idu_buffer the output is again a filename. This can greatly simplify and improve the performance of applications which work primarily with files instead of buffers of data. It is important, however, to note two caveats. Firstly, for reasons of simplicity, unencapsulation is not available to callers of this function (as it is to callers of IDUP_Start_Unprotect); encapsulation is the only option available. Secondly, and more importantly, because of the INTERNAL FILE NAME parameters (input_filename and output_filename), callers of this function are very likely to be non-portable across different computing platforms (since handles to files may differ from platform to platform). Because of the above caveats, this call is specified to be optional, and may not be supported by all underlying mechanisms or implementations. Adams Document Expiration: 11 Dec. 1996 34 2.4. Special-Purpose Calls 2.4.1. Relationship to GSS-API The special-purpose call described in this section has no analog in GSS-API [RFC-1508]. This call is used to complete a P-IDU (that is, to generate a P-IDU which can be unprotected successfully with no additional data at any time during its validity period). This call may not be supported by all underlying IDUP mechanisms or implementations. 2.4.2. IDUP_Form_Complete_PIDU call Inputs: o env_handle ENVIRONMENT HANDLE, o single_pidu_buffer OCTET STRING, o partial_pidu_buffer OCTET STRING, -- an arbitrary-sized piece of the full pidu token. Used if pidu -- will be input a buffer at a time (except that the final buffer -- must be passed in final_pidu_buffer rather than -- partial_pidu_buffer). Only one of single_pidu_buffer and -- partial(final)_pidu_buffer can have nonzero length. o final_pidu_buffer OCTET STRING, Outputs: o major_status INTEGER, o minor_status INTEGER, o pidu_token_out OCTET STRING o call_again_before INTEGER, o call_again_after INTEGER, Adams Document Expiration: 11 Dec. 1996 35 Return major_status codes: o GSS_S_COMPLETE indicates that the completion of P-IDU generation was successful. o GSS_S_CONTINUE_NEEDED indicates that the buffer supplied for pidu_token_out is too small to hold the generated data. The application should continue calling this routine (until GSS_S_COMPLETE is returned) in order to get all remaining data. o IDUP_S_INCOMPLETE indicates that the generation of the P-IDU is not yet complete. The application should call this function again before the time given in call_again_before (if not NULL), or after the time given in call_again_after (if not NULL), or both (if neither are NULL). o IDUP_S_SERVICE_UNAVAIL indicates that the underlying mechanism does not support the service requested. o GSS_S_DEFECTIVE_TOKEN indicates that consistency checks performed on the input P-IDU token failed, preventing further processing from being performed with that token. o GSS_S_FAILURE indicates that the environment is recognized, but that the requested operation could not be performed for reasons unspecified at the IDUP-GSS-API level. Using the security environment referenced by env_handle, complete the generation of a P-IDU token and return the appropriate status value along with the completed token (if available). Such a call may be used, for example, for the purpose of batch evidence generation on an "evidence server". A local machine may be able to use the protection set of calls to fill out most of an evidence token and then send a number of these to a batch processor which forms the complete evidence tokens (perhaps by adding a certification path, or a timestamp and signature from a timestamping authority). As another example, on the receiving end an application may make such a call in order to collect all the information necessary to unprotect a P-IDU (such as all relevant certificates and Certificate Revocation Lists); this will ensure that the calls to the unprotection set of operations will be entirely local (i.e., can be performed off-line) and fast. Note that the complete P-IDU generated will be formed using trusted time if this is available in the environment referenced by env_handle and will use untrusted time or no time otherwise (depending on what is available). Adams Document Expiration: 11 Dec. 1996 36 2.5. Support calls 2.5.1. Relationship to GSS-API Support calls in IDUP-GSS-API are to be understood and used as described in GSS-API [RFC-1508]. The calls GSS_Display_status(), GSS_Indicate_mechs(), GSS_Compare_name(), GSS_Display_name(), GSS_Import_name(), GSS_Release_name(), GSS_Release_buffer(), and GSS_Release_oid_set() are unchanged. 2.5.2. IDUP_Parse_token call Inputs: o input_token OCTET STRING Outputs: o major_status INTEGER, o minor_status INTEGER, o mech_type OBJECT IDENTIFIER, Return major_status codes: o GSS_S_COMPLETE indicates that the input_token could be parsed for all relevant fields. o GSS_S_CREDENTIALS_EXPIRED indicates that the environment is recognized, but that its associated credentials have expired, so that the requested operation cannot be performed. o GSS_S_DEFECTIVE_TOKEN indicates that the mechanism type could be parsed, but that either the other fields could not be determined from the input_token, or their values did not correspond to valid values for that mechanism. o GSS_S_FAILURE indicates that the mechanism type could not be parsed (for example, the token may be corrupted). IDUP_Parse_Token() is used to return to an application the attributes which correspond to a given input token. Since IDUP-GSS-API tokens are meant to be opaque to the calling application, this function allows the application to determine information about the token without having to violate the opaqueness intention of IDUP. Of primary importance is the mechanism type, which the application can then use as input to the IDUP_Establish_Env() call in order to establish the correct environment in which to have the token processed. Other token attributes may be added as outputs of this call in future versions of this specification, if required. Adams Document Expiration: 11 Dec. 1996 37 If all tokens are framed as suggested in RFC-1508, Appendix B (mandated in the Kerberos V5 GSS mechanism [KRB5], in the SPKM GSS Mechanism [SPKM], and in this document), then any mechanism implementation should be able to return the mech_type parameter for any uncorrupted input token. If the mechanism implementation whose IDUP_Parse_token() function is being called does recognize the token, it can return other token attributes, if specified. 2.5.3. IDUP_Get_policy_info call Inputs: o policy_id OBJECT IDENTIFIER Outputs: o major_status INTEGER, o minor_status INTEGER, o policy_version INTEGER, o policy_effective_time INTEGER, o policy_expiry_time INTEGER, o supported_services SET OF Service_Descriptor, o supported_mechanisms SET OF Mechanism_Descriptor Return major_status codes: o GSS_S_COMPLETE indicates that the policy_id was recognized and all relevant fields have been returned. o GSS_S_FAILURE indicates that the policy_id was not recognized. This call (which need not be supported by all underlying mechanisms or implementations) allows the application to retrieve information pertaining to a given policy_id. Policies define the following: - rules for the protection of IDUs, such as trusted third parties which may be involved in P-IDU generation, the roles in which they may be involved, and the duration for which the generated P-IDU is valid; Adams Document Expiration: 11 Dec. 1996 38 - rules for the unprotection of P-IDUs, such as the interval during which a trusted third party may legitimately declare its key to have been compromised or revoked; and - rules for adjudication, such as which authorities may be used to adjudicate disputes. The policy itself may be used by an adjudicator when resolving a dispute. For example, the adjudicator might refer to the policy to determine whether the rules for generation of the P-IDU have been followed. The following parameter bundles are associated with this call. o Service_Descriptor PARAMETER BUNDLE, o service_type OBJECT IDENTIFIER, o service_validity_duration INTEGER, o must_use_trusted_time BOOLEAN o Mechanism_Descriptor PARAMETER BUNDLE, o mechanism_type OBJECT IDENTIFIER, o Authority_List PARAMETER BUNDLE, o maximum_time_skew INTEGER -- maximum permissible difference between P-IDU generation -- time and the time of countersignature from a time -- service (if required). This parameter is unused if -- trusted time is not required. o Authority_List PARAMETER BUNDLE, o authority_name INTERNAL NAME, o authority_role OCTET STRING, o last_revocation_check_offset INTEGER -- may be greater than 0 or less than 0. The value of -- this parameter is added to P-IDU generation time to -- get latest time at which the mechanism will check to -- see if this authority's key has been revoked. An example of the use of the last parameter in Authority_List is as follows. If an authority has a defined last_revocation_check_offset of negative one hour, then all revocations taking effect earlier than one hour before the generation of a P-IDU will render that P-IDU invalid; no revocation taking place later than one hour before the generation of the P-IDU will affect the P-IDU's validity. Note that both the maximum_time_skew and the last_revocation_check_offset values are given in minutes. Adams Document Expiration: 11 Dec. 1996 39 3. Related Activities In order to implement the IDUP-GSS-API atop existing, emerging, and future security mechanisms, the following is necessary: - object identifiers must be assigned to candidate IDUP-GSS-API mechanisms and the name types which they support; and - concrete data element (i.e., token and parameter bundle) formats must be defined for candidate mechanisms. Calling applications must implement formatting conventions which will enable them to distinguish IDUP-GSS-API P-IDUs from other IDUs in their environment. Concrete language bindings are required for the programming environments in which the IDUP-GSS-API is to be employed; such a binding for the C language are available in the Internet Draft [IDUP-C]. 4. Acknowledgments Many thanks are due to Warwick Ford, Paul Van Oorschot, and Tim Moses of Bell-Northern Research, and to Denis Pinkas of Bull, for a number of helpful comments. 5. Security Considerations Security issues are discussed throughout this memo. Adams Document Expiration: 11 Dec. 1996 40 6. REFERENCES [MSP]: U.S. National Security Agency, "Message Security Protocol", Secure Data Network System SDN.701, March 1994. [RFC-1421]: J. Linn, "Privacy Enhancement for Internet Electronic Mail: Part I: Message Encryption and Authentication Procedures", RFC 1421. [RFC-1508]: J. Linn, "Generic Security Service Application Program Interface", RFC 1508. [GSSv2]: J. Linn, "Generic Security Service Application Program Interface, Version 2", Internet Draft draft-ietf-cat-gssv2-0x.txt (work in progress). [KRB5]: J. Linn, "The Kerberos Version 5 GSS-API Mechanism", Internet Draft draft-ietf-cat-kerb5gss-0x.txt (work in progress). [SPKM]: C. Adams, "The Simple Public-Key GSS-API Mechanism (SPKM)", Internet Draft draft-ietf-cat-spkmgss-0x.txt (work in progress). [IDUP-C]: D. Thakkar, D. Grebovich, "Independent Data Unit Protection Generic Security Service Application Program Interface: C- bindings", Internet Draft draft-ietf-cat-idup-cbind-0x.txt (work in progress). [ISO/IEC]: 2nd ISO/IEC CD 13888-1, "Information technology - Security techniques - Non-repudiation - Part 1: General Model", ISO/IEC JTC 1/SC 27, May 30, 1995 7. Author's Address Carlisle Adams NORTEL Secure Networks P.O.Box 3511, Station C Ottawa, Ontario, CANADA K1Y 4H7 Phone: +1 613.763.9008 E-mail: cadams@nortel.ca Adams Document Expiration: 11 Dec. 1996 41 APPENDIX A MECHANISM-INDEPENDENT TOKEN FORMAT This appendix specifies a mechanism-independent level of encapsulating representation for IDUP-GSS-API tokens, incorporating an identifier of the mechanism type to be used when processing those tokens. Use of this format (with ASN.1-encoded data elements represented in BER, constrained in the interests of parsing simplicity to the Distinguished Encoding Rule (DER) BER subset defined in X.509, clause 8.7) is recommended to the designers of IDUP-GSS-API implementations based on various mechanisms, so that tokens can be interpreted unambiguously at IDUP-GSS-API peers. There is no requirement that the mechanism-specific token data element be encoded in ASN.1 BER. -- top-level token definition to frame different mechanisms IDUP-GSS-API DEFINITIONS ::= BEGIN MechType ::= OBJECT IDENTIFIER Token ::= [APPLICATION 0] IMPLICIT SEQUENCE { thisMech MechType, token ANY DEFINED BY thisMech -- contents mechanism-specific } END APPENDIX B MECHANISM DESIGN CONSTRAINTS The following constrain on IDUP-GSS-API mechanism designs is adopted in response to observed caller protocol requirements, and adherence thereto is anticipated in subsequent descriptions of IDUP-GSS-API mechanisms to be documented in standards-track Internet specifications. Use of the approach defined in Appendix A of this specification, applying a mechanism type tag to the Token is required. Adams Document Expiration: 11 Dec. 1996 42 APPENDIX C EXAMPLES OF IDUP USE This appendix provides examples of the use of IDUP to do IDU protec- tion and unprotection. It should not be regarded as constrictive to implementations or as defining the only means through which IDUP-GSS-API functions can be realized with particular underlying technology, and does not demonstrate all IDUP-GSS-API features. C.1. Simple Mechanism, Single Buffer To illustrate the simplest possible case, consider an underlying IDUP mechanism which does straightforward encryption/decryption and signing/verification only; none of the other possible services, such as creation of proof-of-origin evidence, requests for proof-of- delivery evidence, or use of trusted time, are supported. PEM [RFC-1421] is one example of a mechanism which fits this description. Furthermore (again for simplicity), assume that encapsulation is chosen by the calling application during IDU protection. The following parameter bundle uses and defaults would therefore be specified in the relevant IDUP mechanism document. Mech_Specific_Info - NOT USED (the only acceptable input, therefore, is NULL) Idu_Sensitivity - NOT USED (the only acceptable input, therefore, is NULL) Service_Creation_Info - NOT USED (the only acceptable input, therefore, is NULL) Service_Verification_Info - NOT USED (the only acceptable input, therefore, is NULL) Quality - the qop_algs parameter must be supported, with a suitable DEFAULT value specified; - suitable DEFAULT values for validity, policy_id, and allow_policy_mapping must be specified (it may be an implementation option as to whether these parameters are explicitly modifiable by the calling application, or whether NULLs are the only acceptable input) Idu_Information - the idu_type parameter must have a value representing a suitable IDU type (for example, in PEM a value representing the string "RFC822" or some other valid "Content-Domain" would be used), with a suitable DEFAULT value specified; - the idu_title parameter is NOT USED (the only acceptable input, therefore, is NULL) Adams Document Expiration: 11 Dec. 1996 43 Prot_Information - the originator_name and idu_type (in Idu_Information) parameters are read from the encapsulating information and output by IDUP_Start_Unprotect; - all other parameters are NOT USED (and therefore NULL) Special_Conditions - NOT USED (the only acceptable input, therefore, is NULL) Target_Info - this bundle is used as described in IDUP; no DEFAULT values are specified General_Service_Data - the unencapsulated_token parameter is used if encapsulation_request is FALSE; - the minor_status parameter is used to return minor status values as specified by the mechanism document Prot_Service - the prot_service_type parameter may have a value of "1" ("perform unsolicited service") or NULL (which specifies the DEFAULT value of "1"); - the service_id parameter must have a value representing "PER_CONF" or "PER_DOA"; - the parameters Service_Creation_Info, service_to, Service_Verification_Info, and service_verification_info_id are NOT USED (and therefore NULL) Unprot_Service - the unprot_service_type parameter will always have a value of "1" ("receive unsolicited service"); - the service_id parameter will have a value representing "REC_CONF" or "REC_DOA"; - the parameters service_verification_info_id, Service_Verification_Info, service_to, and Service_Creation_Info, are NOT USED (and therefore NULL) Assuming that the calling application has only a single buffer of data to protect/unprotect, the following sequence of operations must be performed by the sender and receivers (subsequent to environment establishment). SENDER (any parameters not listed below are given the value NULL): Set env_handle = environment handle in use; encapsulation_request = TRUE; single_idu_buffer = data buffer; Target_Info.targ_names = receiver names; P_Services.Prot_Service_1.service_id = PER_CONF; P_Services.Prot_Service_2.service_id = PER_DOA; Adams Document Expiration: 11 Dec. 1996 44 Call IDUP_Start_Protect() with above input parameters Check major_status. If not GSS_S_COMPLETE, check minor_status, Target_Info.bad_targ_names / Target_Info.bad_targ_status, P_Services.Prot_Service_1.General_Service_Data.minor_status, P_Services.Prot_Service_2.General_Service_Data.minor_status (as required) for more detailed information. Send Output parameter pidu_buffer to receiver. RECEIVER (any parameters not listed below are given the value NULL): Set env_handle = environment handle in use; single_pidu_buffer = received data buffer; Call IDUP_Start_Unprotect() with above input parameters Check major_status. If not GSS_S_COMPLETE, check minor_status, R_Services.Unprot_Service_1.General_Service_Data.minor_status, R_Services.Unprot_Service_2.General_Service_Data.minor_status (as required) for more detailed information Utilize R_Services.Unprot_Service_1/2.service_id, (to determine which services were applied by the originator) R_Services.Unprot_Service_1/2.Quality, (to determine the corresponding qualities of the services) Prot_Information.originator_name, (to determine the name of the originator) single_idu_buffer (to retrieve the unprotected data). Adams Document Expiration: 11 Dec. 1996 45 C.2. Simple Mechanism, Multiple Buffers To illustrate the next step up in complexity, consider the use of the simple IDUP mechanism described above with multiple data buffers. In particular, consider the case in which a large data file is to be signed. For this example, assume that the calling application does not wish to use encapsulation. Note that the parameter bundle uses and defaults are as specified in C.1. above. SENDER (any parameters not listed below are given the value NULL): Set env_handle = environment handle in use; encapsulation_request = FALSE; P_Services.Prot_Service.service_id = PER_DOA; Call IDUP_Start_Protect() with above input parameters Check major_status. If not GSS_S_COMPLETE, check minor_status, P_Services.Prot_Service.General_Service_Data.minor_status (as required) for more detailed information. For each buffer of input data: Set input_buffer = buffer Call IDUP_Protect() with above input parameter Check major_status. If not GSS_S_COMPLETE, check minor_status Call IDUP_End_Protect() Check major_status. If not GSS_S_COMPLETE, check minor_status, P_Services.Prot_Service.General_Service_Data.minor_status (as required) for more detailed information. Send P_Services.Prot_Service.General_Service_Data.unencapsulated_token, the file for which the signature was calculated (if required) to receiver. Adams Document Expiration: 11 Dec. 1996 46 RECEIVER (any parameters not listed below are given the value NULL): Set env_handle = environment handle in use; partial_pidu_buffer = received unencapsulated token; Call IDUP_Start_Unprotect() with above input parameters Check major_status. If not GSS_S_COMPLETE, check minor_status, R_Services.Unprot_Service_1.General_Service_Data.minor_status, (as required) for more detailed information For each buffer of input data: Set input_buffer = buffer Call IDUP_Unprotect() with above input parameter Check major_status. If not GSS_S_COMPLETE, check minor_status Call IDUP_End_Unprotect() Check major_status. If not GSS_S_COMPLETE, check minor_status, R_Services.Unprot_Service_1.General_Service_Data.minor_status, (as required) for more detailed information. Utilize R_Services.Unprot_Service_1.service_id, (to determine which service was applied by the originator; note that Unprot_Service_2 will have NULL in unprot_service_type to indicate that it is not used) R_Services.Unprot_Service_1.Quality, (to determine the corresponding quality of the service) Prot_Information.originator_name, (from IDUP_Start_Unprotect) (to determine the name of the signer) major_status (from IDUP_End_Unprotect) (to determine pass/fail status of signature verification). Adams Document Expiration: 11 Dec. 1996 47 C.3. More Sophisticated Mechanism, Small Application Buffers To illustrate a higher level of complexity, consider the use of a more sophisticated IDUP mechanism and a calling application with small data buffers. In particular, consider the case in which a very small e-mail message is to be encrypted for a relatively large receiver list (R), some subset of whom (r) will be asked to send proofs of receipt of the message to some other subset (L) (which includes the originator). So that the example is not unnecessarily complicated, assume again that the originating application uses encapsulation. The uses and defaults for the various parameter bundles for this mechanism would be specified in the relevant IDUP mechanism document as follows. Mech_Specific_Info - NOT USED (the only acceptable input, therefore, is NULL) Idu_Sensitivity - NOT USED (the only acceptable input, therefore, is NULL) Service_Creation_Info - used to create "proof of delivery" evidence (but actual structure is opaque to calling application) Service_Verification_Info - used to verify "proof of delivery" evidence (but actual structure is opaque to calling application) Quality - the qop_algs parameter must be supported, with a suitable DEFAULT value specified; - suitable DEFAULT values for validity, policy_id, and allow_policy_mapping must be specified (it may be an implementation option as to whether these parameters are explicitly modifiable by the calling application, or whether NULLs are the only acceptable input) Idu_Information - the idu_type parameter must have a value representing a suitable IDU type, with a suitable DEFAULT value specified; - the idu_title parameter must have a value representing a suitable IDU title, with a suitable DEFAULT value specified Prot_Information - the originator_name, protection_time, and idu_type / idu_title (in Idu_Information) parameters are read from the contained header information and output by IDUP_Start_Unprotect; Special_Conditions - the parameter prot_oper_id is NOT USED (the only acceptable input, therefore, is NULL); - trusted or untrusted time may be selected by the calling application, with a suitable DEFAULT value specified Adams Document Expiration: 11 Dec. 1996 48 Target_Info - this bundle is used as described in IDUP; no DEFAULT values are specified General_Service_Data - the unencapsulated_token parameter is used if encapsulation_request is FALSE; - the minor_status parameter is used to return minor status values as specified by the mechanism document Prot_Service - the prot_service_type parameter may have a value of "1" ("perform unsolicited service"), "2" ("perform solicited service"), "3" (perform service solicitation), or NULL (which specifies the DEFAULT value of "1"); - the service_id parameter must have a value representing "PER_CONF", "PER_DOA", "PER_POO", or "PER_POD"; - the parameters Service_Creation_Info, service_to, Service_Verification_Info, and service_verification_info_id are used when required by the IDUP operation Unprot_Service - the unprot_service_type parameter may have a value of "1" ("receive unsolicited service"), "2" ("receive solicited service"), or "3" (receive service solicitation); - the service_id parameter will have a value representing "REC_CONF", "REC_DOA", "REC_POO", or "REC_POD"; - the parameters service_verification_info_id, Service_Verification_Info, service_to, and Service_Creation_Info, are used when required by the IDUP operation SENDER (any parameters not listed below are given the value NULL): Set env_handle = environment handle in use; Idu_Information.idu_type = value for "e-mail document"; Idu_Information.idu_title = "Contract 1234"; Special_Conditions.use_trusted_time = TRUE; encapsulation_request = TRUE; single_idu_buffer = very small e-mail message; Target_Info.targ_names = receiver names (R); Prot_Service_1.prot_service_type = "1"; Prot_Service_1.service_id = PER_CONF; Prot_Service_2.prot_service_type = "3"; Prot_Service_2.service_id = PER_POD; Prot_Service_2.General_Service_Data.Target_Info.targ_names = "receipts from" list (r); Prot_Service_2.service_to = "receipts to" list (L); P_Services.Prot_Service_1 = Prot_Service_1; P_Services.Prot_Service_2 = Prot_Service_2; Adams Document Expiration: 11 Dec. 1996 49 Call IDUP_Start_Protect() with above input parameters Check major_status. If not GSS_S_COMPLETE, while major_status == GSS_S_CONTINUE_NEEDED Save pidu_buffer, Call IDUP_Start_Protect() (to get next portion of pidu_buffer) Check major_status, minor_status, Target_Info.bad_targ_names / Target_Info.bad_targ_status, P_Services.Prot_Service_1.General_Service_Data.minor_status, P_Services.Prot_Service_2.General_Service_Data.minor_status (as required) for more detailed information. Save Prot_Service_2.Service_Verification_Info, Prot_Service_2.service_verification_info_id Send All saved buffers of pidu_buffer to receiver list (R). RECEIVER (ON RECEIVER LIST (R)): (any parameters not listed below are given the value NULL) Set env_handle = environment handle in use; partial_pidu_buffer = initial buffer of received p-idu; Call IDUP_Start_Unprotect() with above input parameters While major_status == IDUP_S_MORE_PIDU_NEEDED, Set partial_pidu_buffer = next buffer of p-idu Call IDUP_Start_Unprotect() Check major_status, minor_status, R_Services.Unprot_Service_1.General_Service_Data.minor_status, R_Services.Unprot_Service_2.General_Service_Data.minor_status, (as required) for more detailed information Save initial_idu_buffer (if non-empty) Adams Document Expiration: 11 Dec. 1996 50 Set input_buffer = remaining p-idu buffer Call IDUP_Unprotect() with above input parameter Check major_status. If not GSS_S_COMPLETE, check minor_status Save output_buffer Call IDUP_End_Unprotect() Check major_status. If not GSS_S_COMPLETE, check minor_status, R_Services.Unprot_Service_1.General_Service_Data.minor_status, R_Services.Unprot_Service_2.General_Service_Data.minor_status, (as required) for more detailed information. Utilize R_Services.Unprot_Service_1/2.service_id, (to determine which services were applied by the originator) R_Services.Unprot_Service_1/2.Quality, (to determine the corresponding qualities of the service) Prot_Information.originator_name/protection_time and Prot_Information.Idu_Information.idu_type/idu_title, (from IDUP_Start_Unprotect) (to determine originator info.) R_Services.Unprot_Service_2.General_Service_Data.Target_Info. targ.names, (to determine if rec. is in "receipts from" (r)) Service_Verification_Info/service_verification_info_id (to determine if receiver is in "receipts to" list (L)) If receiver is in "receipts from" list (r) Save R_Services.Unprot_Service_2.service_to, R_Services.Unprot_Service_2.Service_Creation_Info If receiver is in "receipts to" list (L) Save Service_Verification_Info, service_verification_info_id Adams Document Expiration: 11 Dec. 1996 51 RECEIVER (ON "RECEIPTS FROM" LIST (r)): (procedure to generate receipt) Set env_handle = environment handle in use; Target_Info.targ_names = service_to Prot_Service_1.prot_service_type = "2"; Prot_Service_1.service_id = "PER_POD"; Prot_Service_1.Service_Creation_Info = Service_Creation_Info; P_Services.Prot_Service_1 = Prot_Service_1 Call IDUP_Start_Protect() with above input parameters Check major_status. If not GSS_S_COMPLETE, check minor_status, P_Services.Prot_Service_1.General_Service_Data.minor_status (as required) for more detailed information. Send pidu_buffer to "receipts to" list (L) RECEIVER (ON "RECEIPTS TO" LIST (L)): (procedure to process received receipt) Set env_handle = environment handle in use; single_pidu_buffer = received p-idu buffer (if it fits in a single buffer; otherwise use partial_pidu_buffer and make multiple calls, as above) Call IDUP_Start_Unprotect() with above input parameters If major_status == IDUP_S_SERV_VERIF_INFO_NEEDED Utilize R_Services.Unprot_Service_1.service_verification_info.id (to assist in locating necessary Service_Verification_Info) Set R_Services.Unprot_Service_1.Service_Verification_Info = Service_Verification_Info Call IDUP_Start_Unprotect() with above input parameters Check major_status, minor_status, R_Services.Unprot_Service_1.General_Service_Data.minor_status (as required) for more detailed information. Utilize R_Services.Unprot_Service_1.service_id, (to determine that this is a "proof of delivery" evidence) R_Services.Unprot_Service_1.Quality, Prot_Information.originator_name, (for evidence generator info.) major_status (to determine pass/fail status of evi. verif.). Adams Document Expiration: 11 Dec. 1996 52
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draft-ietf-cat-idup-gss-05
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