draft-ietf-tls-oob-pubkey-11.txt   rfc7250.txt 
TLS P. Wouters, Ed. Internet Engineering Task Force (IETF) P. Wouters, Ed.
Internet-Draft Red Hat Request for Comments: 7250 Red Hat
Intended status: Standards Track H. Tschofenig, Ed. Category: Standards Track H. Tschofenig, Ed.
Expires: July 22, 2014 ISSN: 2070-1721 ARM Ltd.
J. Gilmore J. Gilmore
Electronic Frontier Foundation
S. Weiler S. Weiler
SPARTA, Inc. Parsons
T. Kivinen T. Kivinen
AuthenTec INSIDE Secure
January 18, 2014 June 2014
Using Raw Public Keys in Transport Layer Security (TLS) and Datagram Using Raw Public Keys in Transport Layer Security (TLS)
Transport Layer Security (DTLS) and Datagram Transport Layer Security (DTLS)
draft-ietf-tls-oob-pubkey-11.txt
Abstract Abstract
This document specifies a new certificate type and two TLS extensions This document specifies a new certificate type and two TLS extensions
for exchanging raw public keys in Transport Layer Security (TLS) and for exchanging raw public keys in Transport Layer Security (TLS) and
Datagram Transport Layer Security (DTLS). The new certificate type Datagram Transport Layer Security (DTLS). The new certificate type
allows raw public keys to be used for authentication. allows raw public keys to be used for authentication.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
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 This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 5741.
This Internet-Draft will expire on July 22, 2014. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7250.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2014 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Structure of the Raw Public Key Extension . . . . . . . . . . 4 3. Structure of the Raw Public Key Extension . . . . . . . . . . 4
4. TLS Client and Server Handshake Behavior . . . . . . . . . . 6 4. TLS Client and Server Handshake Behavior . . . . . . . . . . 7
4.1. Client Hello . . . . . . . . . . . . . . . . . . . . . . 7 4.1. Client Hello . . . . . . . . . . . . . . . . . . . . . . 7
4.2. Server Hello . . . . . . . . . . . . . . . . . . . . . . 8 4.2. Server Hello . . . . . . . . . . . . . . . . . . . . . . 8
4.3. Client Authentication . . . . . . . . . . . . . . . . . . 9 4.3. Client Authentication . . . . . . . . . . . . . . . . . . 9
5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 9 4.4. Server Authentication . . . . . . . . . . . . . . . . . . 9
5.1. TLS Server uses Raw Public Key . . . . . . . . . . . . . 9 5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.2. TLS Client and Server use Raw Public Keys . . . . . . . . 10 5.1. TLS Server Uses a Raw Public Key . . . . . . . . . . . . 10
5.3. Combined Usage of Raw Public Keys and X.509 Certificate . 11 5.2. TLS Client and Server Use Raw Public Keys . . . . . . . . 11
6. Security Considerations . . . . . . . . . . . . . . . . . . . 12 5.3. Combined Usage of Raw Public Keys and X.509 Certificates 12
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 13 6. Security Considerations . . . . . . . . . . . . . . . . . . . 13
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 13 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14
9.1. Normative References . . . . . . . . . . . . . . . . . . 14 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
9.1. Normative References . . . . . . . . . . . . . . . . . . 15
9.2. Informative References . . . . . . . . . . . . . . . . . 15 9.2. Informative References . . . . . . . . . . . . . . . . . 15
Appendix A. Example Encoding . . . . . . . . . . . . . . . . . . 15 Appendix A. Example Encoding . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17
1. Introduction 1. Introduction
Traditionally, TLS client and server public keys are obtained in PKIX Traditionally, TLS client and server public keys are obtained in PKIX
containers in-band as part of the TLS handshake procedure and are containers in-band as part of the TLS handshake procedure and are
validated using trust anchors based on a [PKIX] certification validated using trust anchors based on a [PKIX] certification
authority (CA). This method can add a complicated trust relationship authority (CA). This method can add a complicated trust relationship
that is difficult to validate. Examples of such complexity can be that is difficult to validate. Examples of such complexity can be
seen in [Defeating-SSL]. TLS is, however, also commonly used with seen in [Defeating-SSL]. TLS is, however, also commonly used with
self-signed certificates in smaller deployments where the self-signed self-signed certificates in smaller deployments where the self-signed
certificates are distributed to all involved protocol end points out- certificates are distributed to all involved protocol endpoints out-
of-band. This practice does, however, still requires the overhead of of-band. This practice does, however, still require the overhead of
the certificate generation even though none of the information found the certificate generation even though none of the information found
in the certificate is actually used. in the certificate is actually used.
Alternative methods are available that allow a TLS client/server to Alternative methods are available that allow a TLS client/server to
obtain the TLS server/client public key: obtain the TLS server/client public key:
o The TLS client can obtain the TLS server public key from a DNSSEC o The TLS client can obtain the TLS server public key from a DNSSEC-
secured resource records using DANE [RFC6698]. secured resource record using DNS-Based Authentication of Named
Entities (DANE) [RFC6698].
o The TLS client or server public key is obtained from a [PKIX] o The TLS client or server public key is obtained from a [PKIX]
certificate chain from an Lightweight Directory Access Protocol certificate chain from a Lightweight Directory Access Protocol
(LDAP) [LDAP] server or web page. [LDAP] server or web page.
o The TLS client and server public key is provisioned into the o The TLS client and server public key is provisioned into the
operating system firmware image, and updated via software updates. operating system firmware image and updated via software updates.
For example: For example:
Some smart objects use the UDP-based Constrained Application Some smart objects use the UDP-based Constrained Application
Protocol (CoAP) [I-D.ietf-core-coap] to interact with a Web server Protocol [CoAP] to interact with a Web server to upload sensor
to upload sensor data at a regular intervals, such as temperature data at regular intervals, such as temperature readings. CoAP can
readings. CoAP can utilize DTLS for securing the client-to-server utilize DTLS for securing the client-to-server communication. As
communication. As part of the manufacturing process, the embedded part of the manufacturing process, the embedded device may be
device may be configured with the address and the public key of a configured with the address and the public key of a dedicated CoAP
dedicated CoAP server, as well as a public/private key pair for server, as well as a public/private key pair for the client
the client itself. itself.
This document introduces the use of raw public keys in TLS/DTLS. This document introduces the use of raw public keys in TLS/DTLS.
With raw public keys, only a subset of the information found in With raw public keys, only a subset of the information found in
typical certificates is utilized: namely, the SubjectPublicKeyInfo typical certificates is utilized: namely, the SubjectPublicKeyInfo
structure of a PKIX certificates that carries the parameters structure of a PKIX certificate that carries the parameters necessary
necessary to describe the public key. Other parameters found in PKIX to describe the public key. Other parameters found in PKIX
certificates are omitted. By omitting various certificate-related certificates are omitted. By omitting various certificate-related
structures, the resulting raw public key is kept fairly small in structures, the resulting raw public key is kept fairly small in
comparison to the original certificate, and the code to process the comparison to the original certificate, and the code to process the
keys requires only a minimalistic ASN.1 parser, no code for keys can be simpler. Only a minimalistic ASN.1 parser is needed;
certificate path validation, and other PKIX related processing tasks code for certificate path validation and other PKIX-related
are also omitted. Note, however, the SubjectPublicKeyInfo structure processing is not required. Note, however, the SubjectPublicKeyInfo
is still in an ASN.1 format. To further reduce the size of the structure is still in an ASN.1 format. To further reduce the size of
exchanged information this specification can be combined with the TLS the exchanged information, this specification can be combined with
Cached Info extension [I-D.ietf-tls-cached-info], which enables TLS the TLS Cached Info extension [CACHED-INFO], which enables TLS peers
peers to just exchange fingerprints of their public keys. to exchange just fingerprints of their public keys.
The mechanism defined herein only provides authentication when an The mechanism defined herein only provides authentication when an
out-of-band mechanism is also used to bind the public key to the out-of-band mechanism is also used to bind the public key to the
entity presenting the key. entity presenting the key.
Section 3 defines the structure of the two new TLS extensions Section 3 defines the structure of the two new TLS extensions,
"client_certificate_type" and "server_certificate_type", which can be client_certificate_type and server_certificate_type, which can be
used as part of an extended TLS handshake when raw public keys are to used as part of an extended TLS handshake when raw public keys are to
be used. Section 4 defines the behavior of the TLS client and the be used. Section 4 defines the behavior of the TLS client and the
TLS server. Example exchanges are described in Section 5. Section 6 TLS server. Example exchanges are described in Section 5. Section 6
describes security considerations with this approach. Finally, in describes security considerations with this approach. Finally, in
Section 7 this document also registers a new value to the IANA Section 7 this document registers a new value to the IANA "TLS
certificate types registry for the support of raw public keys. Certificate Types" subregistry for the support of raw public keys.
2. Terminology 2. Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
We use the terms 'TLS server' and 'server' as well as 'TLS client' We use the terms "TLS server" and "server" as well as "TLS client"
and 'client' interchangable. and "client" interchangeably.
3. Structure of the Raw Public Key Extension 3. Structure of the Raw Public Key Extension
This section defines the two TLS extensions 'client_certificate_type' This section defines the two TLS extensions client_certificate_type
and 'server_certificate_type', which can be used as part of an and server_certificate_type, which can be used as part of an extended
extended TLS handshake when raw public keys are used. Section 4 TLS handshake when raw public keys are used. Section 4 defines the
defines the behavior of the TLS client and the TLS server using this behavior of the TLS client and the TLS server using these extensions.
extension.
This specification uses raw public keys whereby the already available This specification uses raw public keys whereby the already available
encoding used in a PKIX certificate in the form of a encoding used in a PKIX certificate in the form of a
SubjectPublicKeyInfo structure is reused. To carry the raw public SubjectPublicKeyInfo structure is reused. To carry the raw public
key within the TLS handshake the Certificate payload is used as a key within the TLS handshake, the Certificate payload is used as a
container, as shown in Figure 1. The shown Certificate structure is container, as shown in Figure 1. The shown Certificate structure is
an adaptation of its original form [RFC5246]. an adaptation of its original form [RFC5246].
opaque ASN.1Cert<1..2^24-1>; opaque ASN.1Cert<1..2^24-1>;
struct { struct {
select(certificate_type){ select(certificate_type){
// certificate type defined in this document. // certificate type defined in this document.
case RawPublicKey: case RawPublicKey:
opaque ASN.1_subjectPublicKeyInfo<1..2^24-1>; opaque ASN.1_subjectPublicKeyInfo<1..2^24-1>;
// X.509 certificate defined in RFC 5246 // X.509 certificate defined in RFC 5246
case X.509: case X.509:
ASN.1Cert certificate_list<0..2^24-1>; ASN.1Cert certificate_list<0..2^24-1>;
// Additional certificate type based on TLS // Additional certificate type based on
// Certificate Type Registry // "TLS Certificate Types" subregistry
}; };
} Certificate; } Certificate;
Figure 1: Certificate Payload as a Container for the Raw Public Key. Figure 1: Certificate Payload as a Container for the Raw Public Key
The SubjectPublicKeyInfo structure is defined in Section 4.1 of RFC The SubjectPublicKeyInfo structure is defined in Section 4.1 of RFC
5280 [PKIX] and does not only contain the raw keys, such as the 5280 [PKIX] and not only contains the raw keys, such as the public
public exponent and the modulus of an RSA public key, but also an exponent and the modulus of an RSA public key, but also an algorithm
algorithm identifier. The algorithm identifier can also include identifier. The algorithm identifier can also include parameters.
parameters. The SubjectPublicKeyInfo value in the Certificate The SubjectPublicKeyInfo value in the Certificate payload MUST
payload MUST contain the DER encoding [X.690] of the contain the DER encoding [X.690] of the SubjectPublicKeyInfo. The
SubjectPublicKeyInfo. The structure, as shown in Figure 2, therefore structure, as shown in Figure 2, therefore also contains length
also contains length information as well. An example is provided in information. An example is provided in Appendix A.
Appendix A.
SubjectPublicKeyInfo ::= SEQUENCE { SubjectPublicKeyInfo ::= SEQUENCE {
algorithm AlgorithmIdentifier, algorithm AlgorithmIdentifier,
subjectPublicKey BIT STRING } subjectPublicKey BIT STRING }
AlgorithmIdentifier ::= SEQUENCE { AlgorithmIdentifier ::= SEQUENCE {
algorithm OBJECT IDENTIFIER, algorithm OBJECT IDENTIFIER,
parameters ANY DEFINED BY algorithm OPTIONAL } parameters ANY DEFINED BY algorithm OPTIONAL }
Figure 2: SubjectPublicKeyInfo ASN.1 Structure. Figure 2: SubjectPublicKeyInfo ASN.1 Structure
The algorithm identifiers are Object Identifiers (OIDs). RFC 3279 The algorithm identifiers are Object Identifiers (OIDs). RFC 3279
[RFC3279] and [RFC5480], for example, define the following OIDs shown [RFC3279] and RFC 5480 [RFC5480], for example, define the OIDs shown
in Figure 3. Note that this list is not exhaustive and more OIDs may in Figure 3. Note that this list is not exhaustive, and more OIDs
be defined in future RFCs. RFC 5480 also defines a number of OIDs. may be defined in future RFCs.
Key Type | Document | OID Key Type | Document | OID
RSA | Section 2.3.1 of RFC 3279 | 1.2.840.113549.1.1 --------------------+----------------------------+-------------------
.......................|............................|................... RSA | Section 2.3.1 of RFC 3279 | 1.2.840.113549.1.1
Digital Signature | | ....................|............................|...................
Algorithm (DSA) | Section 2.3.2 of RFC 3279 | 1.2.840.10040.4.1 Digital Signature | |
.......................|............................|................... Algorithm (DSA) | Section 2.3.2 of RFC 3279 | 1.2.840.10040.4.1
Elliptic Curve | | ....................|............................|...................
Digital Signature | | Elliptic Curve | |
Algorithm (ECDSA) | Section 2 of RFC 5480 | 1.2.840.10045.2.1 Digital Signature | |
Algorithm (ECDSA) | Section 2 of RFC 5480 | 1.2.840.10045.2.1
--------------------+----------------------------+-------------------
Figure 3: Example Algorithm Object Identifiers. Figure 3: Example Algorithm Object Identifiers
The extension format for extended client and server hellos, which The extension format for extended client and server hellos, which
uses the "extension_data" field, is used to carry the uses the "extension_data" field, is used to carry the
ClientCertTypeExtension and the ServerCertTypeExtension structures. ClientCertTypeExtension and the ServerCertTypeExtension structures.
These two structures are shown in Figure 4. The CertificateType These two structures are shown in Figure 4. The CertificateType
structure is an enum with values taken from the 'TLS Certificate structure is an enum with values taken from the "TLS Certificate
Type' registry [TLS-Certificate-Types-Registry]. Types" subregistry of the "Transport Layer Security (TLS) Extensions"
registry [TLS-Ext-Registry].
struct { struct {
select(ClientOrServerExtension) { select(ClientOrServerExtension) {
case client: case client:
CertificateType client_certificate_types<1..2^8-1>; CertificateType client_certificate_types<1..2^8-1>;
case server: case server:
CertificateType client_certificate_type; CertificateType client_certificate_type;
} }
} ClientCertTypeExtension; } ClientCertTypeExtension;
struct { struct {
select(ClientOrServerExtension) { select(ClientOrServerExtension) {
case client: case client:
CertificateType server_certificate_types<1..2^8-1>; CertificateType server_certificate_types<1..2^8-1>;
case server: case server:
CertificateType server_certificate_type; CertificateType server_certificate_type;
} }
} ServerCertTypeExtension; } ServerCertTypeExtension;
Figure 4: CertTypeExtension Structure. Figure 4: CertTypeExtension Structure
4. TLS Client and Server Handshake Behavior 4. TLS Client and Server Handshake Behavior
This specification extends the ClientHello and the ServerHello This specification extends the ClientHello and the ServerHello
messages, according to the extension procedures defined in [RFC5246]. messages, according to the extension procedures defined in [RFC5246].
It does not extend or modify any other TLS message. It does not extend or modify any other TLS message.
Note: No new cipher suites are required to use raw public keys. All Note: No new cipher suites are required to use raw public keys. All
existing cipher suites that support a key exchange method compatible existing cipher suites that support a key exchange method compatible
with the defined extension can be used. with the defined extension can be used.
The high-level message exchange in Figure 5 shows the The high-level message exchange in Figure 5 shows the
'client_certificate_type' and 'server_certificate_type' extensions client_certificate_type and server_certificate_type extensions added
added to the client and server hello messages. to the client and server hello messages.
client_hello, client_hello,
client_certificate_type, client_certificate_type,
server_certificate_type -> server_certificate_type ->
<- server_hello, <- server_hello,
client_certificate_type, client_certificate_type,
server_certificate_type, server_certificate_type,
certificate, certificate,
server_key_exchange, server_key_exchange,
skipping to change at page 7, line 27 skipping to change at page 7, line 41
client_key_exchange, client_key_exchange,
certificate_verify, certificate_verify,
change_cipher_spec, change_cipher_spec,
finished -> finished ->
<- change_cipher_spec, <- change_cipher_spec,
finished finished
Application Data <-------> Application Data Application Data <-------> Application Data
Figure 5: Basic Raw Public Key TLS Exchange. Figure 5: Basic Raw Public Key TLS Exchange
4.1. Client Hello 4.1. Client Hello
In order to indicate the support of raw public keys, clients include In order to indicate the support of raw public keys, clients include
the 'client_certificate_type' and/or the 'server_certificate_type' the client_certificate_type and/or the server_certificate_type
extensions in an extended client hello message. The hello extension extensions in an extended client hello message. The hello extension
mechanism is described in Section 7.4.1.4 of TLS 1.2 [RFC5246]. mechanism is described in Section 7.4.1.4 of TLS 1.2 [RFC5246].
The 'client_certificate_type' in the client hello indicates the The client_certificate_type extension in the client hello indicates
certificate types the client is able to provide to the server, when the certificate types the client is able to provide to the server,
requested using a certificate_request message. when requested using a certificate_request message.
The 'server_certificate_type' in the client hello indicates the types The server_certificate_type extension in the client hello indicates
of certificates the client is able to process when provided by the the types of certificates the client is able to process when provided
server in a subsequent certificate payload. by the server in a subsequent certificate payload.
The 'client_certificate_type' and 'server_certificate_type' sent in The client_certificate_type and server_certificate_type extensions
the client hello may carry a list of supported certificate types, sent in the client hello each carry a list of supported certificate
sorted by client preference. It is a list in the case where the types, sorted by client preference. When the client supports only
client supports multiple certificate types. one certificate type, it is a list containing a single element.
The TLS client MUST omit the 'client_certificate_type' extension in The TLS client MUST omit certificate types from the
the client hello if it does not possess a raw public key/certificate client_certificate_type extension in the client hello if it does not
that it can provide to the server when requested using a possess the corresponding raw public key or certificate that it can
certificate_request message or is not configured to use one with the provide to the server when requested using a certificate_request
given TLS server. The TLS client MUST omit the message, or if it is not configured to use one with the given TLS
'server_certificate_type' extension in the client hello if it is server. If the client has no remaining certificate types to send in
unable to process raw public keys or other certificate types the client hello, other than the default X.509 type, it MUST omit the
introduced via this extension. client_certificate_type extension in the client hello.
The TLS client MUST omit certificate types from the
server_certificate_type extension in the client hello if it is unable
to process the corresponding raw public key or other certificate
type. If the client has no remaining certificate types to send in
the client hello, other than the default X.509 certificate type, it
MUST omit the entire server_certificate_type extension from the
client hello.
4.2. Server Hello 4.2. Server Hello
If the server receives a client hello that contains the If the server receives a client hello that contains the
'client_certificate_type' extension and/or the client_certificate_type extension and/or the server_certificate_type
'server_certificate_type' extension then three outcomes are possible: extension, then three outcomes are possible:
1. The server does not support the extension defined in this 1. The server does not support the extension defined in this
document. In this case the server returns the server hello document. In this case, the server returns the server hello
without the extensions defined in this document. without the extensions defined in this document.
2. The server supports the extension defined in this document but it 2. The server supports the extension defined in this document, but
does not have any certificate type in common with the client. it does not have any certificate type in common with the client.
Then, the server terminates the session with a fatal alert of Then, the server terminates the session with a fatal alert of
type "unsupported_certificate". type "unsupported_certificate".
3. The server supports the extensions defined in this document and 3. The server supports the extensions defined in this document and
has at least one certificate type in common with the client. In has at least one certificate type in common with the client. In
this case the processing rules described below are followed. this case, the processing rules described below are followed.
The 'client_certificate_type' in the client hello indicates the The client_certificate_type extension in the client hello indicates
certificate types the client is able to provide to the server, when the certificate types the client is able to provide to the server,
requested using a certificate_request message. If the TLS server when requested using a certificate_request message. If the TLS
wants to request a certificate from the client (via the server wants to request a certificate from the client (via the
certificate_request message) it MUST include the certificate_request message), it MUST include the
'client_certificate_type' extension in the server hello. This client_certificate_type extension in the server hello. This
'client_certificate_type' in the server hello then indicates the type client_certificate_type extension in the server hello then indicates
of certificates the client is requested to provide in a subsequent the type of certificates the client is requested to provide in a
certificate payload. The value conveyed in the subsequent certificate payload. The value conveyed in the
'client_certificate_type' MUST be selected from one of the values client_certificate_type extension MUST be selected from one of the
provided in the 'client_certificate_type' extension sent in the values provided in the client_certificate_type extension sent in the
client hello. The server MUST also include a certificate_request client hello. The server MUST also include a certificate_request
payload in the server hello message. payload in the server hello message.
If the server does not send a certificate_request payload (for If the server does not send a certificate_request payload (for
example, because client authentication happens at the application example, because client authentication happens at the application
layer or no client authentication is required) or none of the layer or no client authentication is required) or none of the
certificates supported by the client (as indicated in the certificates supported by the client (as indicated in the
'client_certificate_type' in the client hello) match the server- client_certificate_type extension in the client hello) match the
supported certificate types then the 'client_certificate_type' server-supported certificate types, then the client_certificate_type
payload in the server hello MUST be omitted. payload in the server hello MUST be omitted.
The 'server_certificate_type' in the client hello indicates the types The server_certificate_type extension in the client hello indicates
of certificates the client is able to process when provided by the the types of certificates the client is able to process when provided
server in a subsequent certificate payload. If the client hello by the server in a subsequent certificate payload. If the client
indicates support of raw public keys in the 'server_certificate_type' hello indicates support of raw public keys in the
extension and the server chooses to use raw public keys then the TLS server_certificate_type extension and the server chooses to use raw
server MUST place the SubjectPublicKeyInfo structure into the public keys, then the TLS server MUST place the SubjectPublicKeyInfo
Certificate payload. With the 'server_certificate_type' in the structure into the Certificate payload. With the
server hello the TLS server indicates the certificate type carried in server_certificate_type extension in the server hello, the TLS server
the Certificate payload. This additional indication allows to avoid indicates the certificate type carried in the Certificate payload.
parsing ambiguities since the Certificate payload may contain either This additional indication enables avoiding parsing ambiguities since
the X.509 certificate or a SubjectPublicKeyInfo structure. Note that the Certificate payload may contain either the X.509 certificate or a
only a single value is permitted in the 'server_certificate_type' SubjectPublicKeyInfo structure. Note that only a single value is
extension when carried in the server hello. permitted in the server_certificate_type extension when carried in
the server hello.
4.3. Client Authentication 4.3. Client Authentication
Authentication of the TLS client to the TLS server is supported only When the TLS server has specified RawPublicKey as the
through authentication of the received client SubjectPublicKeyInfo client_certificate_type, authentication of the TLS client to the TLS
via an out-of-band method. server is supported only through authentication of the received
client SubjectPublicKeyInfo via an out-of-band method.
4.4. Server Authentication
When the TLS server has specified RawPublicKey as the
server_certificate_type, authentication of the TLS server to the TLS
client is supported only through authentication of the received
client SubjectPublicKeyInfo via an out-of-band method.
5. Examples 5. Examples
Figure 6, Figure 7, and Figure 8 illustrate example exchanges. Note Figures 6, 7, and 8 illustrate example exchanges. Note that TLS
that TLS ciphersuites using a Diffie-Hellman exchange offering ciphersuites using a Diffie-Hellman exchange offering forward secrecy
forward secrecy can be used with raw public keys although we do not can be used with a raw public key, although this document does not
show the information exchange at that level with the subsequent show the information exchange at that level with the subsequent
message flows. message flows.
5.1. TLS Server uses Raw Public Key 5.1. TLS Server Uses a Raw Public Key
This section shows an example where the TLS client indicates its This section shows an example where the TLS client indicates its
ability to receive and validate raw public keys from the server. In ability to receive and validate a raw public key from the server. In
our example the client is quite restricted since it is unable to this example, the client is quite restricted since it is unable to
process other certificate types sent by the server. It also does not process other certificate types sent by the server. It also does not
have credentials at the TLS layer it could send to the server and have credentials at the TLS layer it could send to the server and
therefore omits the 'client_certificate_type' extension. Hence, the therefore omits the client_certificate_type extension. Hence, the
client only populates the 'server_certificate_type' extension with client only populates the server_certificate_type extension with the
the raw public key type, as shown in [1]. raw public key type, as shown in (1).
When the TLS server receives the client hello it processes the When the TLS server receives the client hello, it processes the
extension. Since it has a raw public key it indicates in [2] that it extension. Since it has a raw public key, it indicates in (2) that
had chosen to place the SubjectPublicKeyInfo structure into the it had chosen to place the SubjectPublicKeyInfo structure into the
Certificate payload [3]. Certificate payload (3).
The client uses this raw public key in the TLS handshake together The client uses this raw public key in the TLS handshake together
with an out-of-band validation technique, such as DANE, to verify it. with an out-of-band validation technique, such as DANE, to verify it.
client_hello, client_hello,
server_certificate_type=(RawPublicKey) // [1] server_certificate_type=(RawPublicKey) // (1)
-> ->
<- server_hello, <- server_hello,
server_certificate_type=(RawPublicKey), // [2] server_certificate_type=RawPublicKey, // (2)
certificate, // [3] certificate, // (3)
server_key_exchange, server_key_exchange,
server_hello_done server_hello_done
client_key_exchange, client_key_exchange,
change_cipher_spec, change_cipher_spec,
finished -> finished ->
<- change_cipher_spec, <- change_cipher_spec,
finished finished
Application Data <-------> Application Data Application Data <-------> Application Data
Figure 6: Example with Raw Public Key provided by the TLS Server. Figure 6: Example with Raw Public Key Provided by the TLS Server
5.2. TLS Client and Server use Raw Public Keys 5.2. TLS Client and Server Use Raw Public Keys
This section shows an example where the TLS client as well as the TLS This section shows an example where the TLS client as well as the TLS
server use raw public keys. This is one of the use case envisioned server use raw public keys. This is one of the use cases envisioned
for smart object networking. The TLS client in this case is an 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 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. TLS and is also able to process a raw public key sent by the server.
Therefore, it indicates these capabilities in [1]. As in the Therefore, it indicates these capabilities in (1). As in the
previously shown example the server fulfills the client's request, previously shown example, the server fulfills the client's request,
indicates this via the "RawPublicKey" value in the indicates this via the RawPublicKey value in the
server_certificate_type payload [2], and provides a raw public key server_certificate_type payload (2), and provides a raw public key in
into the Certificate payload back to the client (see [3]). The TLS the Certificate payload back to the client (see (3)). The TLS server
server, however, demands client authentication and therefore a demands client authentication, and therefore includes a
certificate_request is added [4]. The certificate_type payload in certificate_request (4). The client_certificate_type payload in (5)
[5] indicates that the TLS server accepts raw public keys. The TLS indicates that the TLS server accepts a raw public key. The TLS
client, who has a raw public key pre-provisioned, returns it in the client, which has a raw public key pre-provisioned, returns it in the
Certificate payload [6] to the server. Certificate payload (6) to the server.
client_hello, client_hello,
client_certificate_type=(RawPublicKey) // [1] client_certificate_type=(RawPublicKey) // (1)
server_certificate_type=(RawPublicKey) // [1] server_certificate_type=(RawPublicKey) // (1)
-> ->
<- server_hello, <- server_hello,
server_certificate_type=(RawPublicKey)//[2] server_certificate_type=RawPublicKey // (2)
certificate, // [3] certificate, // (3)
client_certificate_type=(RawPublicKey)//[5] client_certificate_type=RawPublicKey // (5)
certificate_request, // [4] certificate_request, // (4)
server_key_exchange, server_key_exchange,
server_hello_done server_hello_done
certificate, // [6] certificate, // (6)
client_key_exchange, client_key_exchange,
change_cipher_spec, change_cipher_spec,
finished -> finished ->
<- change_cipher_spec, <- change_cipher_spec,
finished finished
Application Data <-------> Application Data Application Data <-------> Application Data
Figure 7: Example with Raw Public Key provided by the TLS Server and Figure 7: Example with Raw Public Key provided by the TLS Server and
the Client. the Client
5.3. Combined Usage of Raw Public Keys and X.509 Certificate 5.3. Combined Usage of Raw Public Keys and X.509 Certificates
This section shows an example combining raw public keys and X.509 This section shows an example combining a raw public key and an X.509
certificates. The client uses a raw public key for client certificate. The client uses a raw public key for client
authentication and the server provides an X.509 certificate. This authentication, and the server provides an X.509 certificate. This
exchange starts with the client indicating its ability to process exchange starts with the client indicating its ability to process an
X.509 certificates and raw public keys, if provided by the server. X.509 certificate, OpenPGP certificate, or a raw public key, if
Additionally, the client indicates that is has a raw public key for provided by the server. It prefers a raw public key, since the
client-side authentication (see [1]). The server provides the X.509 RawPublicKey value precedes the other values in the
certificate in [3] with the indication present in [2]. For client server_certificate_type vector. Additionally, the client indicates
authentication the server indicates in [4] that it selected the raw that it has a raw public key for client-side authentication (see
public key format and requests a certificate from the client in [5]. (1)). The server chooses to provide its X.509 certificate in (3) and
The TLS client provides a raw public key in [6] after receiving and indicates that choice in (2). For client authentication, the server
processing the TLS server hello message. indicates in (4) that it has 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.
client_hello, client_hello,
server_certificate_type=(X.509, RawPublicKey) server_certificate_type=(RawPublicKey, X.509, OpenPGP)
client_certificate_type=(RawPublicKey) // [1] client_certificate_type=(RawPublicKey) // (1)
-> ->
<- server_hello, <- server_hello,
server_certificate_type=(X.509)//[2] server_certificate_type=X.509 // (2)
certificate, // [3] certificate, // (3)
client_certificate_type=(RawPublicKey)//[4] client_certificate_type=RawPublicKey // (4)
certificate_request, // [5] certificate_request, // (5)
server_key_exchange, server_key_exchange,
server_hello_done server_hello_done
certificate, // [6] certificate, // (6)
client_key_exchange, client_key_exchange,
change_cipher_spec, change_cipher_spec,
finished -> finished ->
<- change_cipher_spec, <- change_cipher_spec,
finished finished
Application Data <-------> Application Data Application Data <-------> Application Data
Figure 8: Hybrid Certificate Example. Figure 8: Hybrid Certificate Example
6. Security Considerations 6. Security Considerations
The transmission of raw public keys, as described in this document, The transmission of raw public keys, as described in this document,
provides benefits by lowering the over-the-air transmission overhead provides benefits by lowering the over-the-air transmission overhead
since raw public keys are naturally smaller than an entire since raw public keys are naturally smaller than an entire
certificate. There are also advantages from a code size point of certificate. There are also advantages from a code-size point of
view for parsing and processing these keys. The cryptographic view for parsing and processing these keys. The cryptographic
procedures for associating the public key with the possession of a procedures for associating the public key with the possession of a
private key also follows standard procedures. private key also follows standard procedures.
The main security challenge is, however, how to associate the public However, the main security challenge is how to associate the public
key with a specific entity. Without a secure binding between key with a specific entity. Without a secure binding between
identifier and key, the protocol will be vulnerable to man-in-the- identifier and key, the protocol will be vulnerable to man-in-the-
middle attacks. This document assumes that such binding can be made middle attacks. This document assumes that such binding can be made
out-of-band and we list a few examples in Section 1. DANE [RFC6698] out-of-band, and we list a few examples in Section 1. DANE [RFC6698]
offers one such approach. In order to address these vulnerabilities, offers one such approach. In order to address these vulnerabilities,
specifications that make use of the extension need to specify how the specifications that make use of the extension need to specify how the
identifier and public key are bound. In addition to ensuring the identifier and public key are bound. In addition to ensuring the
binding is done out-of-band an implementation also needs to check the binding is done out-of-band, an implementation also needs to check
status of that binding. the status of that binding.
If public keys are obtained using DANE, these public keys are If public keys are obtained using DANE, these public keys are
authenticated via DNSSEC. Pre-configured keys is another out-of-band authenticated via DNSSEC. Using pre-configured keys is another out-
method for authenticating raw public keys. While pre-configured keys of-band method for authenticating raw public keys. While pre-
are not suitable for a generic Web-based e-commerce environment such configured keys are not suitable for a generic Web-based e-commerce
keys are a reasonable approach for many smart object deployments environment, such keys are a reasonable approach for many smart
where there is a close relationship between the software running on object deployments where there is a close relationship between the
the device and the server-side communication endpoint. Regardless of software running on the device and the server-side communication
the chosen mechanism for out-of-band public key validation an endpoint. Regardless of the chosen mechanism for out-of-band public
assessment of the most suitable approach has to be made prior to the key validation, an assessment of the most suitable approach has to be
start of a deployment to ensure the security of the system. made prior to the start of a deployment to ensure the security of the
system.
An attacker might try to influence the handshake exchange to make the An attacker might try to influence the handshake exchange to make the
parties select different certificate types than they would normally parties select different certificate types than they would normally
choose. choose.
For this attack, an attacker must actively change one or more For this attack, an attacker must actively change one or more
handshake messages. If this occurs, the client and server will handshake messages. If this occurs, the client and server will
compute different values for the handshake message hashes. As a compute different values for the handshake message hashes. As a
result, the parties will not accept each others' Finished messages. result, the parties will not accept each others' Finished messages.
Without the master_secret, the attacker cannot repair the Finished Without the master_secret, the attacker cannot repair the Finished
messages, so the attack will be discovered. messages, so the attack will be discovered.
7. IANA Considerations 7. IANA Considerations
IANA is asked to register a new value in the "TLS Certificate Types" IANA has registered a new value in the "TLS Certificate Types"
registry of Transport Layer Security (TLS) Extensions subregistry of the "Transport Layer Security (TLS) Extensions"
[TLS-Certificate-Types-Registry], as follows: registry [TLS-Ext-Registry], as follows:
Value: 2 Value: 2
Description: Raw Public Key Description: Raw Public Key
Reference: [[THIS RFC]] Reference: RFC 7250
This document asks IANA to allocate two new TLS extensions, IANA has allocated two new TLS extensions, client_certificate_type
"client_certificate_type" and "server_certificate_type", from the TLS and server_certificate_type, from the "TLS ExtensionType Values"
ExtensionType registry defined in [RFC5246]. These extensions are subregistry defined in [RFC5246]. These extensions are used in both
used in both the client hello message and the server hello message. the client hello message and the server hello message. The new
The new extension type is used for certificate type negotiation. The extension types are used for certificate type negotiation. The
values carried in these extensions are taken from the TLS Certificate values carried in these extensions are taken from the "TLS
Types registry [TLS-Certificate-Types-Registry]. Certificate Types" subregistry of the "Transport Layer Security (TLS)
Extensions" registry [TLS-Ext-Registry].
8. Acknowledgements 8. Acknowledgements
The feedback from the TLS working group meeting at IETF#81 has The feedback from the TLS working group meeting at IETF 81 has
substantially shaped the document and we would like to thank the substantially shaped the document, and we would like to thank the
meeting participants for their input. The support for hashes of meeting participants for their input. The support for hashes of
public keys has been moved to [I-D.ietf-tls-cached-info] after the public keys has been moved to [CACHED-INFO] after the discussions at
discussions at the IETF#82 meeting. the IETF 82 meeting.
We would like to thank the following persons for their review We would like to thank the following persons for their review
comments: Martin Rex, Bill Frantz, Zach Shelby, Carsten Bormann, comments: Martin Rex, Bill Frantz, Zach Shelby, Carsten Bormann,
Cullen Jennings, Rene Struik, Alper Yegin, Jim Schaad, Barry Leiba, Cullen Jennings, Rene Struik, Alper Yegin, Jim Schaad, Barry Leiba,
Paul Hoffman, Robert Cragie, Nikos Mavrogiannopoulos, Phil Hunt, John Paul Hoffman, Robert Cragie, Nikos Mavrogiannopoulos, Phil Hunt, John
Bradley, Klaus Hartke, Stefan Jucker, Kovatsch Matthias, Daniel Kahn Bradley, Klaus Hartke, Stefan Jucker, Kovatsch Matthias, Daniel Kahn
Gillmor, Peter Sylvester, Hauke Mehrtens, Alexey Melnikov, Stephen Gillmor, Peter Sylvester, Hauke Mehrtens, Alexey Melnikov, Stephen
Farrell, Richard Barnes, and James Manger. Nikos Mavrogiannopoulos Farrell, Richard Barnes, and James Manger. Nikos Mavrogiannopoulos
contributed the design for re-using the certificate type registry. contributed the design for reusing the certificate type registry.
Barry Leiba contributed guidance for the IANA consideration text. Barry Leiba contributed guidance for the IANA Considerations text.
Stefan Jucker, Kovatsch Matthias, and Klaus Hartke provided Stefan Jucker, Kovatsch Matthias, and Klaus Hartke provided
implementation feedback regarding the SubjectPublicKeyInfo structure. implementation feedback regarding the SubjectPublicKeyInfo structure.
Christer Holmberg provided the General Area (Gen-Art) review, Yaron Christer Holmberg provided the General Area (Gen-Art) review, Yaron
Sheffer provided the Security Directorate (SecDir) review, Bert Sheffer provided the Security Directorate (SecDir) review, Bert
Greevenbosch provided the Applications Area Directorate review, and Greevenbosch provided the Applications Area Directorate review, and
Linda Dunbar provided the Operations Directorate review. Linda Dunbar provided the Operations Directorate review.
We would like to thank our TLS working group chairs, Eric Rescorla We would like to thank our TLS working group chairs, Eric Rescorla
and Joe Salowey, for their guidance and support. Finally, we would and Joe Salowey, for their guidance and support. Finally, we would
like to thank Sean Turner, who is the responsible security area like to thank Sean Turner, who is the responsible Security Area
director for this work for his review comments and suggestions. Director for this work, for his review comments and suggestions.
9. References 9. References
9.1. Normative References 9.1. Normative References
[PKIX] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., [PKIX] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
Housley, R., and W. Polk, "Internet X.509 Public Key Housley, R., and W. Polk, "Internet X.509 Public Key
Infrastructure Certificate and Certificate Revocation List Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 5280, May 2008. (CRL) Profile", RFC 5280, May 2008.
skipping to change at page 14, line 51 skipping to change at page 15, line 29
Infrastructure Certificate and Certificate Revocation List Infrastructure Certificate and Certificate Revocation List
(CRL) Profile", RFC 3279, April 2002. (CRL) Profile", RFC 3279, April 2002.
[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", RFC 5246, August 2008. (TLS) Protocol Version 1.2", RFC 5246, August 2008.
[RFC5480] Turner, S., Brown, D., Yiu, K., Housley, R., and T. Polk, [RFC5480] Turner, S., Brown, D., Yiu, K., Housley, R., and T. Polk,
"Elliptic Curve Cryptography Subject Public Key "Elliptic Curve Cryptography Subject Public Key
Information", RFC 5480, March 2009. Information", RFC 5480, March 2009.
[TLS-Certificate-Types-Registry] [TLS-Ext-Registry]
"TLS Certificate Types Registry", February 2013, IANA, "Transport Layer Security (TLS) Extensions",
<http://www.iana.org/assignments/ <http://www.iana.org/assignments/
tls-extensiontype-values#tls-extensiontype-values-2>. tls-extensiontype-values>.
[X.690] "Information technology - ASN.1 encoding rules: > [X.690] ITU-T, "Information technology - ASN.1 encoding rules:
Specification of Basic Encoding Rules (BER), Canonical > Specification of Basic Encoding Rules (BER), Canonical
Encoding Rules (CER) and Distinguished Encoding Rules > Encoding Rules (CER) and Distinguished Encoding Rules
(DER).", RFC 5280, 2002. (DER)", ITU-T Recommendation X.690, ISO/IEC 8825-1:2002,
2002.
9.2. Informative References 9.2. Informative References
[ASN.1-Dump] [ASN.1-Dump]
Gutmann, P., "ASN.1 Object Dump Program", February 2013, Gutmann, P., "ASN.1 Object Dump Program", February 2013,
<http://www.cs.auckland.ac.nz/~pgut001/>. <http://www.cs.auckland.ac.nz/~pgut001/>.
[CACHED-INFO]
Santesson, S. and H. Tschofenig, "Transport Layer Security
(TLS) Cached Information Extension", Work in Progress,
February 2014.
[CoAP] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
Application Protocol (CoAP)", RFC 7252, June 2014.
[Defeating-SSL] [Defeating-SSL]
Marlinspike, M., "New Tricks for Defeating SSL in Marlinspike, M., "New Tricks for Defeating SSL in
Practice", February 2009, <http://www.blackhat.com/ Practice", February 2009, <http://www.blackhat.com/
presentations/bh-dc-09/Marlinspike/ presentations/bh-dc-09/Marlinspike/
BlackHat-DC-09-Marlinspike-Defeating-SSL.pdf>. BlackHat-DC-09-Marlinspike-Defeating-SSL.pdf>.
[I-D.ietf-core-coap]
Shelby, Z., Hartke, K., and C. Bormann, "Constrained
Application Protocol (CoAP)", draft-ietf-core-coap-18
(work in progress), June 2013.
[I-D.ietf-tls-cached-info]
Santesson, S. and H. Tschofenig, "Transport Layer Security
(TLS) Cached Information Extension", draft-ietf-tls-
cached-info-15 (work in progress), October 2013.
[LDAP] Sermersheim, J., "Lightweight Directory Access Protocol [LDAP] Sermersheim, J., "Lightweight Directory Access Protocol
(LDAP): The Protocol", RFC 4511, June 2006. (LDAP): The Protocol", RFC 4511, June 2006.
[RFC6698] Hoffman, P. and J. Schlyter, "The DNS-Based Authentication [RFC6698] Hoffman, P. and J. Schlyter, "The DNS-Based Authentication
of Named Entities (DANE) Transport Layer Security (TLS) of Named Entities (DANE) Transport Layer Security (TLS)
Protocol: TLSA", RFC 6698, August 2012. Protocol: TLSA", RFC 6698, August 2012.
Appendix A. Example Encoding Appendix A. Example Encoding
For example, the hex sequence shown in Figure 9 describes a For example, the hex sequence shown in Figure 9 describes a
skipping to change at page 16, line 25 skipping to change at page 17, line 30
9 | 0xe1, 0xda, 0xe7, 0x09, 0xbf, 0x0d, 0x57, 0x41, 0x86, 0x60, 9 | 0xe1, 0xda, 0xe7, 0x09, 0xbf, 0x0d, 0x57, 0x41, 0x86, 0x60,
10 | 0xa1, 0xc1, 0x27, 0x91, 0x5b, 0x0a, 0x98, 0x46, 0x1b, 0xf6, 10 | 0xa1, 0xc1, 0x27, 0x91, 0x5b, 0x0a, 0x98, 0x46, 0x1b, 0xf6,
11 | 0xa2, 0x84, 0xf8, 0x65, 0xc7, 0xce, 0x2d, 0x96, 0x17, 0xaa, 11 | 0xa2, 0x84, 0xf8, 0x65, 0xc7, 0xce, 0x2d, 0x96, 0x17, 0xaa,
12 | 0x91, 0xf8, 0x61, 0x04, 0x50, 0x70, 0xeb, 0xb4, 0x43, 0xb7, 12 | 0x91, 0xf8, 0x61, 0x04, 0x50, 0x70, 0xeb, 0xb4, 0x43, 0xb7,
13 | 0xdc, 0x9a, 0xcc, 0x31, 0x01, 0x14, 0xd4, 0xcd, 0xcc, 0xc2, 13 | 0xdc, 0x9a, 0xcc, 0x31, 0x01, 0x14, 0xd4, 0xcd, 0xcc, 0xc2,
14 | 0x37, 0x6d, 0x69, 0x82, 0xd6, 0xc6, 0xc4, 0xbe, 0xf2, 0x34, 14 | 0x37, 0x6d, 0x69, 0x82, 0xd6, 0xc6, 0xc4, 0xbe, 0xf2, 0x34,
15 | 0xa5, 0xc9, 0xa6, 0x19, 0x53, 0x32, 0x7a, 0x86, 0x0e, 0x91, 15 | 0xa5, 0xc9, 0xa6, 0x19, 0x53, 0x32, 0x7a, 0x86, 0x0e, 0x91,
16 | 0x82, 0x0f, 0xa1, 0x42, 0x54, 0xaa, 0x01, 0x02, 0x03, 0x01, 16 | 0x82, 0x0f, 0xa1, 0x42, 0x54, 0xaa, 0x01, 0x02, 0x03, 0x01,
17 | 0x00, 0x01 17 | 0x00, 0x01
Figure 9: Example SubjectPublicKeyInfo Structure Byte Sequence. Figure 9: Example SubjectPublicKeyInfo Structure Byte Sequence
The decoded byte-sequence shown in Figure 9 (for example using The decoded byte sequence shown in Figure 9 (for example, using Peter
Peter's ASN.1 decoder [ASN.1-Dump]) illustrates the structure, as Gutmann's ASN.1 decoder [ASN.1-Dump]) illustrates the structure, as
shown in Figure 10. shown in Figure 10.
Offset Length Description Offset Length Description
------------------------------------------------------------------- -------------------------------------------------------------------
0 3+159: SEQUENCE { 0 3+159: SEQUENCE {
3 2+13: SEQUENCE { 3 2+13: SEQUENCE {
5 2+9: OBJECT IDENTIFIER Value (1 2 840 113549 1 1 1) 5 2+9: OBJECT IDENTIFIER Value (1 2 840 113549 1 1 1)
: PKCS #1, rsaEncryption : PKCS #1, rsaEncryption
16 2+0: NULL 16 2+0: NULL
: } : }
18 3+141: BIT STRING, encapsulates { 18 3+141: BIT STRING, encapsulates {
22 3+137: SEQUENCE { 22 3+137: SEQUENCE {
25 3+129: INTEGER Value (1024 bit) 25 3+129: INTEGER Value (1024 bit)
157 2+3: INTEGER Value (65537) 157 2+3: INTEGER Value (65537)
: } : }
: } : }
: } : }
Figure 10: Decoding of Example SubjectPublicKeyInfo Structure. Figure 10: Decoding of Example SubjectPublicKeyInfo Structure
Authors' Addresses Authors' Addresses
Paul Wouters (editor) Paul Wouters (editor)
Red Hat Red Hat
Email: paul@nohats.ca EMail: pwouters@redhat.com
Hannes Tschofenig (editor) Hannes Tschofenig (editor)
Cambridge CBI 9NJ ARM Ltd.
UK 6060 Hall in Tirol
Austria
Email: Hannes.Tschofenig@gmx.net EMail: Hannes.tschofenig@gmx.net
URI: http://www.tschofenig.priv.at URI: http://www.tschofenig.priv.at
John Gilmore John Gilmore
Electronic Frontier Foundation
PO Box 170608 PO Box 170608
San Francisco, California 94117 San Francisco, California 94117
USA USA
Phone: +1 415 221 6524 Phone: +1 415 221 6524
Email: gnu@toad.com EMail: gnu@toad.com
URI: https://www.toad.com/ URI: https://www.toad.com/
Samuel Weiler Samuel Weiler
SPARTA, Inc. Parsons
7110 Samuel Morse Drive 7110 Samuel Morse Drive
Columbia, Maryland 21046 Columbia, Maryland 21046
US US
Email: weiler@tislabs.com EMail: weiler@tislabs.com
Tero Kivinen Tero Kivinen
AuthenTec INSIDE Secure
Eerikinkatu 28 Eerikinkatu 28
HELSINKI FI-00180 Helsinki FI-00180
FI FI
Email: kivinen@iki.fi EMail: kivinen@iki.fi
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