Out-of-Band Public Key Validation for Transport Layer Security (TLS)
draft-ietf-tls-oob-pubkey-07
The information below is for an old version of the document.
| Document | Type | Active Internet-Draft (tls WG) | |
|---|---|---|---|
| Authors | Paul Wouters , Hannes Tschofenig , John IETF Gilmore , Samuel Weiler , Tero Kivinen | ||
| Last updated | 2013-04-24 (Latest revision 2013-02-14) | ||
| Replaces | draft-wouters-tls-oob-pubkey | ||
| Stream | Internet Engineering Task Force (IETF) | ||
| Formats | plain text xml htmlized pdfized bibtex | ||
| Reviews |
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| Stream | WG state | WG Document | |
| Document shepherd | (None) | ||
| IESG | IESG state | AD Evaluation::Revised I-D Needed | |
| Consensus boilerplate | Unknown | ||
| Telechat date | (None) | ||
| Responsible AD | Sean Turner | ||
| IESG note | Joe Salowey (jsalowey@cisco.com) is the Document Shepherd | ||
| Send notices to | tls-chairs@tools.ietf.org, draft-ietf-tls-oob-pubkey@tools.ietf.org |
draft-ietf-tls-oob-pubkey-07
TLS P. Wouters, Ed.
Internet-Draft Red Hat
Intended status: Standards Track H. Tschofenig, Ed.
Expires: August 19, 2013 Nokia Siemens Networks
J. Gilmore
S. Weiler
SPARTA, Inc.
T. Kivinen
AuthenTec
February 15, 2013
Out-of-Band Public Key Validation for Transport Layer Security (TLS)
draft-ietf-tls-oob-pubkey-07.txt
Abstract
This document specifies a new certificate type for exchanging raw
public keys in Transport Layer Security (TLS) and Datagram Transport
Layer Security (DTLS) for use with out-of-band public key validation.
Currently, TLS authentication can only occur via X.509-based Public
Key Infrastructure (PKI) or OpenPGP certificates. By specifying a
minimum resource for raw public key exchange, implementations can use
alternative public key validation methods.
One such alternative public key valiation method is offered by the
DNS-Based Authentication of Named Entities (DANE) together with DNS
Security. Another alternative is to utilize pre-configured keys, as
is the case with sensors and other embedded devices. The usage of
raw public keys, instead of X.509-based certificates, leads to a
smaller code footprint.
This document introduces the support for raw public keys in TLS.
Status of this Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
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
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material or to cite them other than as "work in progress."
This Internet-Draft will expire on August 19, 2013.
Copyright Notice
Copyright (c) 2013 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. New TLS Extension . . . . . . . . . . . . . . . . . . . . . . 5
4. TLS Handshake Extension . . . . . . . . . . . . . . . . . . . 8
4.1. Client Hello . . . . . . . . . . . . . . . . . . . . . . . 8
4.2. Server Hello . . . . . . . . . . . . . . . . . . . . . . . 9
4.3. Certificate Request . . . . . . . . . . . . . . . . . . . 9
4.4. Other Handshake Messages . . . . . . . . . . . . . . . . . 9
4.5. Client authentication . . . . . . . . . . . . . . . . . . 9
5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
6. Security Considerations . . . . . . . . . . . . . . . . . . . 12
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14
9.1. Normative References . . . . . . . . . . . . . . . . . . . 14
9.2. Informative References . . . . . . . . . . . . . . . . . . 14
Appendix A. Example Encoding . . . . . . . . . . . . . . . . . . 15
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16
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1. Introduction
Traditionally, TLS server public keys are obtained in PKIX containers
in-band using the TLS handshake and validated using trust anchors
based on a [PKIX] certification authority (CA). This method can add
a complicated trust relationship that is difficult to validate.
Examples of such complexity can be seen in [Defeating-SSL].
Alternative methods are available that allow a TLS client to obtain
the TLS server public key:
o The TLS server public key is obtained from a DNSSEC secured
resource records using DANE [RFC6698].
o The TLS server public key is obtained from a [PKIX] certificate
chain from an Lightweight Directory Access Protocol (LDAP) [LDAP]
server.
o The TLS client and server public key is provisioned into the
operating system firmware image, and updated via software updates.
Some smart objects use the UDP-based Constrained Application Protocol
(CoAP) [I-D.ietf-core-coap] to interact with a Web server to upload
sensor data at a regular intervals, such as temperature readings.
CoAP [I-D.ietf-core-coap] can utilize DTLS for securing the client-
to-server communication. As part of the manufacturing process, the
embeded device may be configured with the address and the public key
of a dedicated CoAP server, as well as a public key for the client
itself. The usage of X.509-based PKIX certificates [PKIX] may not
suit all smart object deployments and would therefore be an
unneccesarry burden.
The Transport Layer Security (TLS) Protocol Version 1.2 [RFC5246]
provides a framework for extensions to TLS as well as guidelines for
designing such extensions. This document registers a new value to
the IANA certificate types registry for the support of raw public
keys.
2. Terminology
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 [RFC2119].
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3. New TLS Extension
This section describes the changes to the TLS handshake message
contents when raw public key certificates are to be used. Figure 4
illustrates the exchange of messages as described in the sub-sections
below. The client and the server exchange make use of two new TLS
extensions, namely 'client_certificate_type' and
'server_certificate_type', and an already available IANA TLS
Certificate Type registry [TLS-Certificate-Types-Registry] to
indicate their ability and desire to exchange raw public keys. These
raw public keys, in the form of a SubjectPublicKeyInfo structure, are
then carried inside the Certificate payload. The Certificate and the
SubjectPublicKeyInfo structure is shown in Figure 1.
opaque ASN.1Cert<1..2^24-1>;
struct {
select(certificate_type){
// certificate type defined in this document.
case RawPublicKey:
opaque ASN.1_subjectPublicKeyInfo<1..2^24-1>;
// X.509 certificate defined in RFC 5246
case X.509:
ASN.1Cert certificate_list<0..2^24-1>;
// Additional certificate type based on TLS
// Certificate Type Registry
};
} Certificate;
Figure 1: TLS Certificate Structure.
The SubjectPublicKeyInfo structure is defined in Section 4.1 of RFC
5280 [PKIX] and does not only contain the raw keys, such as the
public exponent and the modulus of an RSA public key, but also an
algorithm identifier. The structure, as shown in Figure 2, is
encoded in an ASN.1 format and therefore contains length information
as well. An example is provided in Appendix A.
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SubjectPublicKeyInfo ::= SEQUENCE {
algorithm AlgorithmIdentifier,
subjectPublicKey BIT STRING }
Figure 2: SubjectPublicKeyInfo ASN.1 Structure.
The algorithm identifiers are Object Identifiers (OIDs). RFC 3279
[RFC3279], for example, defines the following OIDs shown in Figure 3.
Key Type | Document | OID
-----------------------+----------------------------+-------------------
RSA | Section 2.3.1 of RFC 3279 | 1.2.840.113549.1.1
.......................|............................|...................
Digital Signature | |
Algorithm (DSS) | Section 2.3.2 of RFC 3279 | 1.2.840.10040.4.1
.......................|............................|...................
Elliptic Curve | |
Digital Signature | |
Algorithm (ECDSA) | Section 2.3.5 of RFC 3279 | 1.2.840.10045.2.1
-----------------------+----------------------------+-------------------
Figure 3: Example Algorithm Identifiers.
The message exchange in Figure 4 shows the 'client_certificate_type'
and 'server_certificate_type' extensions added to the client and
server hello messages.
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client_hello,
client_certificate_type
server_certificate_type ->
<- server_hello,
client_certificate_type,
server_certificate_type,
certificate,
server_key_exchange,
certificate_request,
server_hello_done
certificate,
client_key_exchange,
certificate_verify,
change_cipher_spec,
finished ->
<- change_cipher_spec,
finished
Application Data <-------> Application Data
Figure 4: Basic Raw Public Key TLS Exchange.
The semantic of the two extensions is defined as follows:
The 'client_certificate_type' and 'server_certificate_type' sent
in the client hello, may carry a list of supported certificate
types, sorted by client preference. It is a list in the case
where the client supports multiple certificate types. These
extension MUST be omitted if the client only supports X.509
certificates. The 'client_certificate_type' sent in the client
hello indicates the certificate types the client is able to
provide to the server, when requested using a certificate_request
message. The 'server_certificate_type' in the client hello
indicates the type of certificates the client is able to process
when provided by the server in a subsequent certificate payload.
The 'client_certificate_type' returned in the server hello
indicates the certificate type found in the attached certificate
payload. Only a single value is permitted. The
'server_certificate_type' in the server hello indicates the type
of certificates the client is requested to provide in a subsequent
certificate payload. The value conveyed in the
'server_certificate_type' MUST be selected from one of the values
provided in the 'server_certificate_type' sent in the client
hello. If the server does not send a certificate_request payload
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or none of the certificates supported by the client (as indicated
in the 'server_certificate_type' in the client hello) match the
server-supported certificate types the 'server_certificate_type'
payload sent in the server hello is omitted.
The "extension_data" field of this extension contains the
ClientCertTypeExtension or the ServerCertTypeExtension structure, as
shown in Figure 5. The CertificateType structure is an enum with
with values from TLS Certificate Type Registry.
struct {
select(ClientOrServerExtension)
case client:
CertificateType client_certificate_types<1..2^8-1>;
case server:
CertificateType client_certificate_type;
}
} ClientCertTypeExtension;
struct {
select(ClientOrServerExtension)
case client:
CertificateType server_certificate_types<1..2^8-1>;
case server:
CertificateType server_certificate_type;
}
} ServerCertTypeExtension;
Figure 5: CertTypeExtension Structure.
No new cipher suites are required to use raw public keys. All
existing cipher suites that support a key exchange method compatible
with the defined extension can be used.
4. TLS Handshake Extension
4.1. Client Hello
In order to indicate the support of out-of-band raw public keys,
clients MUST include the 'client_certificate_type' and
'server_certificate_type' extensions extended client hello message.
The hello extension mechanism is described in TLS 1.2 [RFC5246].
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4.2. Server Hello
If the server receives a client hello that contains the
'client_certificate_type' and 'server_certificate_type' extensions
and chooses a cipher suite then three outcomes are possible:
1. The server does not support the extension defined in this
document. In this case the server returns the server hello
without the extensions defined in this document.
2. The server supports the extension defined in this document and
has at least one certificate type in common with the client. In
this case it returns the 'server_certificate_type' and indicates
the selected certificate type value.
3. The server supports the extension defined in this document but
does not have a certificate type in common with the client. In
this case the server terminate the session with a fatal alert of
type "unsupported_certificate".
If the TLS server also requests a certificate from the client (via
the certificate_request) it MUST include the
'client_certificate_type' extension with a value chosen from the list
of client-supported certificates types (as provided in the
'client_certificate_type' of the client hello).
If the client indicated the support of raw public keys in the
'client_certificate_type' extension in the client hello and the
server is able to provide such raw public key then the TLS server
MUST place the SubjectPublicKeyInfo structure into the Certificate
payload. The public key algorithm MUST match the selected key
exchange algorithm.
4.3. Certificate Request
The semantics of this message remain the same as in the TLS
specification.
4.4. Other Handshake Messages
All the other handshake messages are identical to the TLS
specification.
4.5. Client authentication
Client authentication by the TLS server is supported only through
authentication of the received client SubjectPublicKeyInfo via an
out-of-band method.
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5. Examples
Figure 6, Figure 7, and Figure 8 illustrate example exchanges.
The first example shows an exchange where the TLS client indicates
its ability to receive and validate raw public keys from the server.
In our example the client is quite restricted since it is unable to
process other certificate types sent by the server. It also does not
have credentials (at the TLS layer) it could send. The
'client_certificate_type' extension indicates this in [1]. When the
TLS server receives the client hello it processes the
'client_certificate_type' extension. Since it also has a raw public
key it indicates in [2] that it had choosen to place the
SubjectPublicKeyInfo structure into the Certificate payload [3]. The
client uses this raw public key in the TLS handshake and an out-of-
band technique, such as DANE, to verify its validity.
client_hello,
server_certificate_type=(RawPublicKey) -> // [1]
<- server_hello,
server_certificate_type=(RawPublicKey), // [2]
certificate, // [3]
server_key_exchange,
server_hello_done
client_key_exchange,
change_cipher_spec,
finished ->
<- change_cipher_spec,
finished
Application Data <-------> Application Data
Figure 6: Example with Raw Public Key provided by the TLS Server
In our second example the TLS client as well as the TLS server use
raw public keys. This is a use case envisioned for smart object
networking. The TLS client in this case is an embedded device that
is configured with a raw public key for use with TLS and is also able
to process raw public keys sent by the server. Therefore, it
indicates these capabilities in [1]. As in the previously shown
example the server fulfills the client's request, indicates this via
the "RawPublicKey" value in the server_certificate_type payload, and
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provides a raw public key into the Certificate payload back to the
client (see [3]). The TLS server, however, demands client
authentication and therefore a certificate_request is added [4]. The
certificate_type payload in [2] indicates that the TLS server accepts
raw public keys. The TLS client, who has a raw public key pre-
provisioned, returns it in the Certificate payload [5] to the server.
client_hello,
client_certificate_type=(RawPublicKey) // [1]
server_certificate_type=(RawPublicKey) // [1]
->
<- server_hello,
server_certificate_type=(RawPublicKey)//[2]
certificate, // [3]
client_certificate_type=(RawPublicKey)//[4]
certificate_request, // [4]
server_key_exchange,
server_hello_done
certificate, // [5]
client_key_exchange,
change_cipher_spec,
finished ->
<- change_cipher_spec,
finished
Application Data <-------> Application Data
Figure 7: Example with Raw Public Key provided by the TLS Server and
the Client
In our last example we illustrate a combination of raw public key and
X.509 usage. The client uses a raw public key for client
authentication but the server provides an X.509 certificate. This
exchange starts with the client indicating its ability to process
X.509 certificates provided by the server, and the ability to send
raw public keys (see [1]). The server provides the X.509 certificate
in [3] with the indication present in [2]. For client authentication
the server indicates in [4] that it selected the raw public key
format and requests a certificate from the client in [5]. The TLS
client provides a raw public key in [6] after receiving and
processing the TLS server hello message.
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client_hello,
server_certificate_type=(X.509)
client_certificate_type=(RawPublicKey) // [1]
->
<- server_hello,
server_certificate_type=(X.509)//[2]
certificate, // [3]
client_certificate_type=(RawPublicKey)//[4]
certificate_request, // [5]
server_key_exchange,
server_hello_done
certificate, // [6]
client_key_exchange,
change_cipher_spec,
finished ->
<- change_cipher_spec,
finished
Application Data <-------> Application Data
Figure 8: Hybrid Certificate Example
6. Security Considerations
The transmission of raw public keys, as described in this document,
provides benefits by lowering the over-the-air transmission overhead
since raw public keys are quite naturally smaller than an entire
certificate. There are also advantages from a codesize point of view
for parsing and processing these keys. The crytographic procedures
for assocating the public key with the possession of a private key
also follows standard procedures.
The main security challenge is, however, how to associate the public
key with a specific entity. This information will be needed to make
authorization decisions. Without a secure binding, man-in-the-middle
attacks may be the consequence. This document assumes that such
binding can be made out-of-band and we list a few examples in
Section 1. DANE [RFC6698] offers one such approach. If public keys
are obtained using DANE, these public keys are authenticated via
DNSSEC. Pre-configured keys is another out of band method for
authenticating raw public keys. While pre-configured keys are not
suitable for a generic Web-based e-commerce environment such keys are
a reasonable approach for many smart object deployments where there
is a close relationship between the software running on the device
and the server-side communication endpoint. Regardless of the chosen
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mechanism for out-of-band public key validation an assessment of the
most suitable approach has to be made prior to the start of a
deployment to ensure the security of the system.
7. IANA Considerations
IANA is asked to register a new value in the "TLS Certificate Types"
registry of Transport Layer Security (TLS) Extensions
[TLS-Certificate-Types-Registry], as follows:
Value: 2
Description: Raw Public Key
Reference: [[THIS RFC]]
This document asks IANA to allocate two new TLS extensions,
"client_certificate_type" and "server_certificate_type", from the TLS
ExtensionType registry defined in [RFC5246]. These extensions are
used in both the client hello message and the server hello message.
The new extension type is used for certificate type negotiation. The
values carried in these extensions are taken from the TLS Certificate
Types registry [TLS-Certificate-Types-Registry].
8. Acknowledgements
The feedback from the TLS working group meeting at IETF#81 has
substantially shaped the document and we would like to thank the
meeting participants for their input. The support for hashes of
public keys has been moved to [I-D.ietf-tls-cached-info] after the
discussions at the IETF#82 meeting.
We would like to thank the following persons for their review
comments: Martin Rex, Bill Frantz, Zach Shelby, Carsten Bormann,
Cullen Jennings, Rene Struik, Alper Yegin, Jim Schaad, Barry Leiba,
Paul Hoffman, Robert Cragie, Nikos Mavrogiannopoulos, Phil Hunt, John
Bradley, Klaus Hartke, Stefan Jucker, Kovatsch Matthias, Daniel Kahn
Gillmor, and James Manger. Nikos Mavrogiannopoulos contributed the
design for re-using the certificate type registry. Barry Leiba
contributed guidance for the IANA consideration text. Stefan Jucker,
Kovatsch Matthias, and Klaus Hartke provided implementation feedback
regarding the SubjectPublicKeyInfo structure.
Finally, we would like to thank our TLS working group chairs, Eric
Rescorla and Joe Salowey, for their guidance and support.
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9. References
9.1. Normative References
[PKIX] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, May 2008.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, August 2008.
[TLS-Certificate-Types-Registry]
"TLS Certificate Types Registry", February 2013, <http://
www.iana.org/assignments/
tls-extensiontype-values#tls-extensiontype-values-2>.
9.2. Informative References
[ASN.1-Dump]
Gutmann, P., "ASN.1 Object Dump Program", February 2013,
<http://www.cs.auckland.ac.nz/~pgut001/>.
[Defeating-SSL]
Marlinspike, M., "New Tricks for Defeating SSL in
Practice", February 2009, <http://www.blackhat.com/
presentations/bh-dc-09/Marlinspike/
BlackHat-DC-09-Marlinspike-Defeating-SSL.pdf>.
[I-D.ietf-core-coap]
Shelby, Z., Hartke, K., Bormann, C., and B. Frank,
"Constrained Application Protocol (CoAP)",
draft-ietf-core-coap-13 (work in progress), December 2012.
[I-D.ietf-tls-cached-info]
Santesson, S. and H. Tschofenig, "Transport Layer Security
(TLS) Cached Information Extension",
draft-ietf-tls-cached-info-13 (work in progress),
September 2012.
[LDAP] Sermersheim, J., "Lightweight Directory Access Protocol
(LDAP): The Protocol", RFC 4511, June 2006.
[RFC3279] Bassham, L., Polk, W., and R. Housley, "Algorithms and
Identifiers for the Internet X.509 Public Key
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Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 3279, April 2002.
[RFC6698] Hoffman, P. and J. Schlyter, "The DNS-Based Authentication
of Named Entities (DANE) Transport Layer Security (TLS)
Protocol: TLSA", RFC 6698, August 2012.
Appendix A. Example Encoding
For example, the following hex sequence describes a
SubjectPublicKeyInfo structure inside the certificate payload:
0 1 2 3 4 5 6 7 8 9
---+------+-----+-----+-----+-----+-----+-----+-----+-----+-----
1 | 0x30, 0x81, 0x9f, 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48,
2 | 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x01, 0x05, 0x00, 0x03, 0x81,
3 | 0x8d, 0x00, 0x30, 0x81, 0x89, 0x02, 0x81, 0x81, 0x00, 0xcd,
4 | 0xfd, 0x89, 0x48, 0xbe, 0x36, 0xb9, 0x95, 0x76, 0xd4, 0x13,
5 | 0x30, 0x0e, 0xbf, 0xb2, 0xed, 0x67, 0x0a, 0xc0, 0x16, 0x3f,
6 | 0x51, 0x09, 0x9d, 0x29, 0x2f, 0xb2, 0x6d, 0x3f, 0x3e, 0x6c,
7 | 0x2f, 0x90, 0x80, 0xa1, 0x71, 0xdf, 0xbe, 0x38, 0xc5, 0xcb,
8 | 0xa9, 0x9a, 0x40, 0x14, 0x90, 0x0a, 0xf9, 0xb7, 0x07, 0x0b,
9 | 0xe1, 0xda, 0xe7, 0x09, 0xbf, 0x0d, 0x57, 0x41, 0x86, 0x60,
10 | 0xa1, 0xc1, 0x27, 0x91, 0x5b, 0x0a, 0x98, 0x46, 0x1b, 0xf6,
11 | 0xa2, 0x84, 0xf8, 0x65, 0xc7, 0xce, 0x2d, 0x96, 0x17, 0xaa,
12 | 0x91, 0xf8, 0x61, 0x04, 0x50, 0x70, 0xeb, 0xb4, 0x43, 0xb7,
13 | 0xdc, 0x9a, 0xcc, 0x31, 0x01, 0x14, 0xd4, 0xcd, 0xcc, 0xc2,
14 | 0x37, 0x6d, 0x69, 0x82, 0xd6, 0xc6, 0xc4, 0xbe, 0xf2, 0x34,
15 | 0xa5, 0xc9, 0xa6, 0x19, 0x53, 0x32, 0x7a, 0x86, 0x0e, 0x91,
16 | 0x82, 0x0f, 0xa1, 0x42, 0x54, 0xaa, 0x01, 0x02, 0x03, 0x01,
17 | 0x00, 0x01
Figure 9: Example SubjectPublicKeyInfo Structure Byte Sequence.
The decoded byte-sequence shown in Figure 9 (for example using
Peter's ASN.1 decoder [ASN.1-Dump]) illustrates the structure, as
shown in Figure 10.
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Offset Length Description
-------------------------------------------------------------------
0 3+159: SEQUENCE {
3 2+13: SEQUENCE {
5 2+9: OBJECT IDENTIFIER Value (1 2 840 113549 1 1 1)
: PKCS #1, rsaEncryption
16 2+0: NULL
: }
18 3+141: BIT STRING, encapsulates {
22 3+137: SEQUENCE {
25 3+129: INTEGER Value (1024 bit)
157 2+3: INTEGER Value (65537)
: }
: }
: }
Figure 10: Decoding of Example SubjectPublicKeyInfo Structure.
Authors' Addresses
Paul Wouters (editor)
Red Hat
Email: paul@nohats.ca
Hannes Tschofenig (editor)
Nokia Siemens Networks
Linnoitustie 6
Espoo 02600
Finland
Phone: +358 (50) 4871445
Email: Hannes.Tschofenig@gmx.net
URI: http://www.tschofenig.priv.at
Wouters, et al. Expires August 19, 2013 [Page 16]
Internet-Draft TLS OOB Public Key Validation February 2013
John Gilmore
PO Box 170608
San Francisco, California 94117
USA
Phone: +1 415 221 6524
Email: gnu@toad.com
URI: https://www.toad.com/
Samuel Weiler
SPARTA, Inc.
7110 Samuel Morse Drive
Columbia, Maryland 21046
US
Email: weiler@tislabs.com
Tero Kivinen
AuthenTec
Eerikinkatu 28
HELSINKI FI-00180
FI
Email: kivinen@iki.fi
Wouters, et al. Expires August 19, 2013 [Page 17]