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Versions: 00 01 02 03 04                                                
Internet Draft                             Grigorij Chudov, CRYPTO-PRO
                                          Serguei Leontiev, CRYPTO-PRO
Expires March 8, 2006                                September 8, 2005
Intended Category: Informational

            GOST Cipher Suites for Transport Layer Security

                 <draft-chudov-cryptopro-cptls-02.txt>

Status of this Memo

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Copyright Notice

   Copyright (C) The Internet Society (2005).

Abstract


   This document is intended to register new cipher suites for the
   Transport Layer Security (TLS) protocol, according to the procedure
   specified in section A.5 of [TLS]. These cipher suites are based on
   Russian national cryptographic standards - GOST R 34.10-94 and GOST R
   34.10-2001 public keys, GOST 28147-89 encryption algorithm and GOST R
   34.11-94 digest algorithm.




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Table of Contents

   1     Introduction. . . . . . . . . . . . . . . . . . . . . . .  2
   2     Proposed Ciphersuites . . . . . . . . . . . . . . . . . .  3
   3     CipherSuite Definitions . . . . . . . . . . . . . . . . .  3
   3.1   Key Exchange. . . . . . . . . . . . . . . . . . . . . . .  3
   3.2   PRF, Signature and Hash . . . . . . . . . . . . . . . . .  3
   3.3   Cipher and MAC. . . . . . . . . . . . . . . . . . . . . .  4
   4     Data Structures and Computations. . . . . . . . . . . . .  4
   4.1   Algorithms. . . . . . . . . . . . . . . . . . . . . . . .  4
   4.2   Keys Calculation. . . . . . . . . . . . . . . . . . . . .  5
   4.3   Server Certificate. . . . . . . . . . . . . . . . . . . .  5
   4.4   Server Key Exchange . . . . . . . . . . . . . . . . . . .  5
   4.5   Certificate Request . . . . . . . . . . . . . . . . . . .  5
   4.6   Client Key Exchange Message . . . . . . . . . . . . . . .  5
   4.7   Certificate Verify. . . . . . . . . . . . . . . . . . . .  7
   4.8   Finished. . . . . . . . . . . . . . . . . . . . . . . . .  8
   5     Security Considerations . . . . . . . . . . . . . . . . .  8
   6     Appendix ASN.1 Modules. . . . . . . . . . . . . . . . . .  8
   7     References. . . . . . . . . . . . . . . . . . . . . . . . 10
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 11
   Author's Addresses. . . . . . . . . . . . . . . . . . . . . . . 12
   Full Copyright Statement. . . . . . . . . . . . . . . . . . . . 13

1  Introduction


   This document proposes the addition of new cipher suites to the
   Transport Layer Security (TLS) protocol to support GOST R 34.11-94
   digest, GOST 28147-89 encryption and VKO GOST R 34.10-94/2001 key
   exchange algorithms.  The cipher suites defined here were proposed by
   CRYPTO-PRO Company for the "Russian Cryptographic Software
   Compatibility Agreement" community.

   Algorithms GOST R 34.10-94, GOST R 34.10-2001, GOST 28147-89 and GOST
   R 34.11-94 have been developed by Russian Federal Agency of
   Governmental Communication and Information (FAGCI) and "All-Russian
   Scientific and Research Institute of Standardization". They are
   described in [GOSTR341094], [GOSTR341001], [GOSTR3411] and
   [GOST28147]. Algorithms VKO GOST R 34.10-94/2001 and PRF_GOSTR3411
   are described in [CPALGS].

   This document defines two configurations:
      anonymous client - authenticated server (only server provides a
      certificate);
      authenticated client - authenticated server (client and server
      exchange certificates).




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   The presentation language used here is the same as in [TLS].  Since
   this specification extends TLS, these descriptions should be merged
   with those in the TLS specification and any others that extend TLS.
   This means, that enum types may not specify all possible values and
   structures with multiple formats chosen with a select() clause may
   not indicate all possible cases.

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
   NOT","SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in
   this document are to be interpreted as described in [RFC 2119].

2  Proposed CipherSuites

   The new cipher suites proposed here have the following definitions:

 CipherSuite TLS_GOST341094_WITH_GOST28147_OFB_GOST28147  = {0x00,0x80}
 CipherSuite TLS_GOST34102001_WITH_GOST28147_OFB_GOST28147= {0x00,0x81}
 CipherSuite TLS_GOST341094_WITH_NULL_GOSTR3411           = {0x00,0x82}
 CipherSuite TLS_GOST34102001_WITH_NULL_GOSTR3411         = {0x00,0x83}

   Note: The above numeric definitions for CipherSuites have not yet
   been registered.

3  CipherSuite Definitions

3.1  Key exchange

   The cipher suites defined here use the following key exchange
   algorithms:

 CipherSuite                                     Key Exchange Algorithm
 TLS_GOST341094_WITH_GOST28147_OFB_GOST28147     VKO GOST R 34.10-94
 TLS_GOST34102001_WITH_GOST28147_OFB_GOST28147   VKO GOST R 34.10-2001
 TLS_GOST341094_WITH_NULL_GOSTR3411              VKO GOST R 34.10-94
 TLS_GOST34102001_WITH_NULL_GOSTR3411            VKO GOST R 34.10-2001

   Key derivation algorithms based on GOST R 3410-94 and GOST R
   3410-2001 public keys (VKO GOST R 34.10-94, VKO GOST R 34.10-2001)
   are described in [CPALGS].

3.2 PRF, Signature and Hash

   For a PRF, described in section 5 of [TLS], the cipher suites
   described here use PRF_GOSTR3411 (refer to section 4.1). The same PRF
   MUST be used for all dependent protocols, such as [EAP-TLS].

   GOST R 3410-94/2001 signature is used for CertificateVerify message.




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   GOST R 34.11 digest algorithm ([GOSTR341194]) is used for
   CertificateVerify.signature.gostR3411_hash and Finished.verify_data
   (see sections 7.4.8 and 7.4.9 of [TLS])

3.3 Cipher and MAC

   The following cipher algorithm and MAC functions are used (for
   details refer to section 4.1):

 CipherSuite                                  Cipher    MAC
 TLS_GOST341094_WITH_GOST28147_OFB_GOST28147   GOST28147 IMIT_GOST28147
 TLS_GOST34102001_WITH_GOST28147_OFB_GOST28147 GOST28147 IMIT_GOST28147
 TLS_GOST341094_WITH_NULL_GOSTR3411               -      HMAC_GOSTR3411
 TLS_GOST34102001_WITH_NULL_GOSTR3411             -      HMAC_GOSTR3411

   For all four cipher suites, the use of MAC is slighttly different
   from the one, described in section 6.2.3.1 of [TLS].  In [TLS], MAC
   is calculated from the following data:

     MACed_data[seq_num] = seq_num +
                           TLSCompressed.type +
                           TLSCompressed.version +
                           TLSCompressed.length +
                           TLSCompressed.fragment;

   These cipher suites use the same input for first record, but for each
   next record the input from all previous records is concatenated:

     MACed_data[0] + ... + MACed_data[n]

4  Data Structures and Computations

4.1  Algorithms

   GOST 28147-89 [GOST28147] uses 256-bit key size and 8-byte IV.
   Cipher suites, defined here, use GOST 28147-89 as a stream cipher in
   OFB mode with S-box from id-Gost28147-89-CryptoPro-A-ParamSet (see
   [CPALGS]) and CryptoPro key meshing algorithm.

   IMIT_GOST28147 is GOST 28147-89 [GOST28147] in "IMITOVSTAVKA" mode (4
   bytes)

   HMAC_GOSTR3411(secret, data) is based on GOST R 34.11 digest and
   described in [CPALGS].

   PRF_GOSTR3411(secret, label, seed) is based on HMAC_GOSTR3411 and
   described in [CPALGS].




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4.2  Key Calculation

   Key calculation is done according to section 6.3 of [TLS], with
   PRF_GOSTR3411 function used instead of PRF.  The parameters are as
   follows:
      SecurityParameters.hash_size = 32
      SecurityParameters.key_material_length = 32
      SecurityParameters.IV_size = 8
   Length of necessary key material is 144 bytes.

4.3  Server Certificate

   For these cipher suites this message is required and it MUST contain
   a certificate, with a public key algorithm matching
   ServerHello.cipher_suite.

4.4  Server Key Exchange

   This message MUST NOT be used in these cipher suites, because all the
   parameters necessary are present in server certificate (see [CPPK]).

4.3  Certificate Request

   This message is used as described in section 7.4.4 of [TLS], and
   extended as follows:

    enum {
        gost341094(21), gost34102001(22),(255)
    } ClientCertificateType;

   gost341094 and gost34102001 certificate types identify that the
   server accepts GOST R 34.10-94 and GOST R 34.10-2001 public key
   certificates.

   Note: The above numeric definitions for ClientCertificateType have
   not yet been registered.

4.6  Client Key Exchange Message

   This message is used as described in section 7.4.7 of [TLS], it is
   required for these suites, and contains DER-encoded
   TLSGostKeyTransportBlob structure.

    enum { vko_gost } KeyExchangeAlgorithm;

    struct {
        select (KeyExchangeAlgorithm) {
            case vko_gost: TLSGostKeyTransportBlob;



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        } exchange_keys;
    } ClientKeyExchange;

   ASN1-syntax for this structure is:

    TLSGostKeyTransportBlob ::= SEQUENCE {
        keyBlob GostR3410-KeyTransport,
        proxyKeyBlobs SEQUENCE OF TLSProxyKeyTransportBlob OPTIONAL
    }

    TLSProxyKeyTransportBlob ::= SEQUENCE {
        keyBlob GostR3410-KeyTransport,
        cert    OCTET STRING
    }

   GostR3410-KeyTransport is defined in [CPCMS].

   keyBlob.transportParameters MUST be present.

   keyBlob.transportParameters.ephemeralPublicKey MUST be present if the
   server didn't request client certificate or client's public key
   algorithm and parameters do not match those of the recipient. Else it
   SHOULD be omited.

      proxyKeyBlobs   - (optional) contains key exchange for secondary
      recipients (for example, for the firewall, which audits
      connections).
      cert            - contains secondary recipient's certificate.

   Actions of client:

   First, the client generates a random 32-byte premaster_secret.

   Then shared_ukm is calculated as first 8 bytes of digest of
   concatenated client random and server random: shared_ukm =
   GOSTR3411(client_random|server_random)[0..7]

   Then client chooses a sender key.  If
   keyBlob.transportParameters.ephemeralPublicKey is present, the
   corresponding secret key MUST be used as a sender key.  If it is
   missing, the secret key, corresponding to the client certificate MUST
   be used.

   Using the sender key and recipient's public key, algorithm VKO GOST R
   34.10-94 or VKO GOST R 34.10-2001 (described in [CPALGS]) is applied
   to produce KEK.  VKO GOST R 34.10-2001 is used with shared_ukm as
   UKM.




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   Then CryptoPro Key Wrap algorithm is applied to encrypt
   premaster_secret and produce CEK_ENC and CEK_MAC.  Again, shared_ukm
   is used as UKM.  keyBlob.transportParameters.encryptionParamSet is
   used for all encryption operations.

   The resulting encrypted key (CEK_ENC) is placed in
   keyBlob.sessionEncryptedKey.encryptedKey field, it's mac (CEK_MAC) is
   placed in keyBlob.sessionEncryptedKey.macKey field, and shared_ukm
   (UKM) is placed in keyBlob.transportParameters.ukm field.

   Actions of server:

   Server MUST verify, that keyBlob.transportParameters.ukm is equal to
   GOSTR3411(client_random|server_random)[0..7], before decrypting the
   premaster_secret.

   Server applies VKO GOST R 34.10-94 or VKO GOST R 34.10-2001,
   (depending on the client public key type), and CryptoPro Key Unwrap
   algorithm in the simillar manner to decrypt the premaster_secret.

   Server MUST verify keyBlob.sessionEncryptedKey.macKey after
   decrypting the premaster_secret.

4.7  Certificate Verify

   This message is used as described in section 7.4.8 of [TLS].  If the
   client have sent both a client certificate and an ephemeral public
   key, it MUST send a certificate verify message, as a proof of
   possession of the private key for provided certificate.

   The TLS structures are extended as follows:

    enum { gost341094, gost34102001 }
        SignatureAlgorithm;

    select (SignatureAlgorithm) {
        case gost341094:
            digitally-signed struct {
                opaque gost341194_hash[32];
            };
        case gost34102001:
            digitally-signed struct {
                opaque gost341194_hash[32];
            };
    } Signature;

    CertificateVerify.signature.gostR3411_hash =
        GOSTR3411(handshake_messages)



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4.8  Finished

   This message is used as described in section 7.4.9 of [TLS].

   Finished.verify_data = PRF_GOSTR3411(master_secret, finished_label +
                              GOSTR3411(handshake_messages)) [0..11]

5  Security Considerations

   It is RECOMMENDED that software applications verify signature values,
   subject public keys and algorithm parameters to conform to
   [GOSTR341001], [GOSTR341094] standards prior to their use.

   Use of the same key for signature and key derivation is NOT
   RECOMMENDED.

   It is RECOMMENDED for both client and server to verify the private
   key usage period, if this extension is present in the certificate.

   The cipher suites TLS_GOST341094_WITH_GOST28147_OFB_GOST28147 and
   TLS_GOST34102001_WITH_GOST28147_OFB_GOST28147 proposed hereby, have
   been analyzed by special certification laboratory of Scientific and
   Technical Centre "ATLAS" in appropriate levels of
   target_of_evaluation (TOE).

   It is RECOMMENDED to subject the implementations of these cipher
   suites to examination by an authorized agency with approved methods
   of cryptographic analysis.

6  Appendix ASN.1 Modules

   Additional ASN.1 modules, referenced here, can be found in [CPALGS]
   and [CPCMS].


6.1  Gost-CryptoPro-TLS

Gost-CryptoPro-TLS
    { iso(1) member-body(2) ru(643) rans(2)
      cryptopro(2) other(1) modules(1) gost-CryptoPro-TLS(16) 1 }
DEFINITIONS ::=
BEGIN
-- EXPORTS All --
-- The types and values defined in this module are exported for
-- use in the other ASN.1 modules contained within the Russian
-- Cryptography "GOST" & "GOST R" Specifications, and for the use
-- of other applications which will use them to access Russian
-- Cryptography services. Other applications may use them for



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-- their own purposes, but this will not constrain extensions and
-- modifications needed to maintain or improve the Russian
-- Cryptography service.
    IMPORTS
        Certificate,
        AlgorithmIdentifier
        FROM PKIX1Explicit88 {iso(1) identified-organization(3)
        dod(6) internet(1) security(5) mechanisms(5) pkix(7)
        id-mod(0) id-pkix1-explicit-88(1)}
        id-CryptoPro-algorithms, gostR3410-EncryptionSyntax
        FROM Cryptographic-Gost-Useful-Definitions
            { iso(1) member-body(2) ru(643) rans(2)
              cryptopro(2) other(1) modules(1)
              cryptographic-Gost-Useful-Definitions(0) 1 }
        GostR3410-KeyTransport
        FROM GostR3410-EncryptionSyntax
             gostR3410-EncryptionSyntax
    ;
    id-PRF-GostR3411-94 OBJECT IDENTIFIER ::=
        { id-CryptoPro-algorithms prf-gostr3411-94(23) }
    TLSProxyKeyTransportBlob ::=
        SEQUENCE {
            keyBlob GostR3410-KeyTransport,
            cert    OCTET STRING
        }
    TLSGostKeyTransportBlob ::=
        SEQUENCE {
            keyBlob GostR3410-KeyTransport,
            proxyKeyBlobs SEQUENCE OF
                TLSProxyKeyTransportBlob OPTIONAL
        }
    TLSGostSrvKeyExchange ::=
        SEQUENCE OF
            OCTET STRING (CONSTRAINED BY {Certificate})
    TLSGostExtensionHashHMACSelect ::=
        SEQUENCE {
            hashAlgorithm AlgorithmIdentifier,
            hmacAlgorithm AlgorithmIdentifier,
            prfAlgorithm AlgorithmIdentifier
        }
    TLSGostExtensionHashHMACSelectClient ::=
        SEQUENCE OF
            TLSGostExtensionHashHMACSelect
    TLSGostExtensionHashHMACSelectServer ::=
        TLSGostExtensionHashHMACSelect

END -- Gost-CryptoPro-TLS




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7  References

   Normative references:


   [CPALGS]      V. Popov, I. Kurepkin, S. Leontiev, "Additional crypto-
                 graphic algorithms for use with GOST 28147-89, GOST R
                 34.10-94, GOST R 34.10-2001, and GOST R 34.11-94 algo-
                 rithms.", September 2005, draft-popov-cryptopro-
                 cpalgs-04.txt

   [CPPK]        S. Leontiev, D. Shefanovskij, "Algorithms and Identi-
                 fiers for the Internet X.509 Public Key Infrastructure
                 Certificates and Certificate Revocation List (CRL),
                 corresponding to the algorithms GOST R 34.10-94, GOST R
                 34.10-2001, GOST R 34.11-94", September 2005, draft-
                 ietf-pkix-gost-cppk-03.txt

   [CPCMS]       S. Leontiev, G. Chudov, "Using the GOST 28147-89, GOST
                 R 34.11-94, GOST R 34.10-94 and GOST R 34.10-2001 algo-
                 rithms with the Cryptographic Message Syntax (CMS)",
                 September 2005, draft-ietf-smime-gost-05.txt

   [GOST28147]   "Cryptographic Protection for Data Processing System",
                 GOST 28147-89, Gosudarstvennyi Standard of USSR, Gov-
                 ernment Committee of the USSR for Standards, 1989. (In
                 Russian);

   [GOSTR341094] "Information technology. Cryptographic Data Security.
                 Produce and check procedures of Electronic Digital Sig-
                 natures based on Asymmetric Cryptographic Algorithm.",
                 GOST R 34.10-94, Gosudarstvennyi Standard of Russian
                 Federation, Government Committee of the Russia for
                 Standards, 1994. (In Russian);

   [GOSTR341001] "Information technology. Cryptographic Data Secu-
                 rity.Signature and verification processes of [elec-
                 tronic] digital signature.", GOST R 34.10-2001, Gosu-
                 darstvennyi Standard of Russian Federation, Government
                 Committee of the Russia for Standards, 2001. (In Rus-
                 sian);

   [GOSTR341194] "Information technology. Cryptographic Data Security.
                 Hashing function.", GOST R 34.10-94, Gosudarstvennyi
                 Standard of Russian Federation, Government Committee of
                 the Russia for Standards, 1994. (In Russian);





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   [TLS]         The TLS Protocol Version 1.0.  T.  Dierks, C.  Allen.
                 January 1999, RFC 2246.

   Informative references:


   [RFC 2119]    Bradner, S., "Key Words for Use in RFCs to Indicate
                 Requirement Levels", BCP 14, RFC 2119, March 1997.

   [Schneier95]  B.  Schneier, Applied cryptography, second edition,
                 John Wiley & Sons, Inc., 1995;

   [TLSEXT]      Blake-Wilson, S., Nystrom, M., Hopwood, D., Mikkelsen,
                 J. and T. Wright, "Transport Layer Security (TLS)
                 Extensions", RFC 3546, June 2003.

   [X.660]       ITU-T Recommendation X.660 Information Technology -
                 ASN.1 encoding rules: Specification of Basic Encoding
                 Rules (BER), Canonical Encoding Rules (CER) and Distin-
                 guished Encoding Rules (DER), 1997.

   [EAP-TLS]     B. Aboba, D. Simon, "PPP EAP TLS Authentication Proto-
                 col", RFC 2716, October 1999.


Acknowledgments

   This document was created in accordance with "Russian Cryptographic
   Software Compatibility Agreement", signed by FGUE STC "Atlas",
   CRYPTO-PRO, Factor-TS, MD PREI, Infotecs GmbH, SPRCIS (SPbRCZI),
   Cryptocom, R-Alpha.  The aim of this agreement is to achieve mutual
   compatibility of the products and solutions.

   The authors wish to thank:

      Microsoft Corporation Russia for provided information about
      company products and solutions, and also for technical consulting
      in PKI.

      RSA Security Russia and Demos Co Ltd for active colaboration and
      critical help in creation of this document.

      NIP Informzachita for compatibility testing of the proposed data
      formats while incorporating them into company products.

      Citrix Inc for help in compatibility testing Citrix products for
      Microsoft Windows.




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      Russ Hously (Vigil Security, LLC, housley@vigilsec.com) and
      Vasilij Sakharov (DEMOS Co Ltd, svp@dol.ru) for initiative,
      creating this document.

   This document is based on a contribution of CRYPTO-PRO company.  Any
   substantial use of the text from this document must acknowledge
   CRYPTO-PRO.  CRYPTO-PRO requests that all material mentioning or
   referencing this document identify this as "CRYPTO-PRO CPTLS".

Author's Addresses

   Grigorij Chudov
   CRYPTO-PRO
   38, Obraztsova,
   Moscow, 127018, Russian Federation
   EMail: chudov@cryptopro.ru

   Serguei Leontiev
   CRYPTO-PRO
   38, Obraztsova,
   Moscow, 127018, Russian Federation
   EMail: lse@cryptopro.ru

   Alexandr Afanasiev
   Factor-TS
   office 711, 14, Presnenskij val,
   Moscow, 123557, Russian Federation
   EMail: afa1@factor-ts.ru

   Nikolaj Nikishin
   Infotecs GmbH
   p/b 35, 80-5, Leningradskij prospekt,
   Moscow, 125315, Russian Federation
   EMail: nikishin@infotecs.ru

   Boleslav Izotov
   FGUE STC "Atlas"
   38, Obraztsova,
   Moscow, 127018, Russian Federation
   EMail: izotov@nii.voskhod.ru

   Elena Minaeva
   MD PREI
   build 3, 6A, Vtoroj Troitskij per.,
   Moscow, Russian Federation
   EMail: evminaeva@mail.ru

   Serguei Murugov



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   R-Alpha
   4/1, Raspletina,
   Moscow, 123060, Russian Federation
   EMail: msm@top-cross.ru

   Igor Ustinov
   Cryptocom
   office 239, 51, Leninskij prospekt,
   Moscow, 119991, Russian Federation
   EMail: igus@cryptocom.ru

   Anatolij Erkin
   SPRCIS (SPbRCZI)
   1, Obrucheva,
   St.Petersburg, 195220, Russian Federation
   EMail: erkin@nevsky.net


Disclaimer of Validity

   This document and the information contained herein are provided on an
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   OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
   ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
   INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
   INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
   WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

Full Copyright Statement

   Copyright (C) The Internet Society (2005).  This document is subject
   to the rights, licenses and restrictions contained in BCP 78, and
   except as set forth therein, the authors retain all their rights.

Acknowledgment

   Funding for the RFC Editor function is currently provided by the
   Internet Society.













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