7Internet Engineering Task Force (IETF) P. Wouters, Ed.
8Request for Comments: 7250 Red Hat
9Category: Standards Track H. Tschofenig, Ed.
10ISSN: 2070-1721 ARM Ltd.
12 Electronic Frontier Foundation
20 Using Raw Public Keys in Transport Layer Security (TLS)
21 and Datagram Transport Layer Security (DTLS)
25 This document specifies a new certificate type and two TLS extensions
26 for exchanging raw public keys in Transport Layer Security (TLS) and
27 Datagram Transport Layer Security (DTLS). The new certificate type
28 allows raw public keys to be used for authentication.
32 This is an Internet Standards Track document.
34 This document is a product of the Internet Engineering Task Force
35 (IETF). It represents the consensus of the IETF community. It has
36 received public review and has been approved for publication by the
37 Internet Engineering Steering Group (IESG). Further information on
38 Internet Standards is available in Section 2 of RFC 5741.
40 Information about the current status of this document, any errata,
41 and how to provide feedback on it may be obtained at
42 http://www.rfc-editor.org/info/rfc7250.
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60RFC 7250 Using Raw Public Keys in TLS/DTLS June 2014
65 Copyright (c) 2014 IETF Trust and the persons identified as the
66 document authors. All rights reserved.
68 This document is subject to BCP 78 and the IETF Trust's Legal
69 Provisions Relating to IETF Documents
70 (http://trustee.ietf.org/license-info) in effect on the date of
71 publication of this document. Please review these documents
72 carefully, as they describe your rights and restrictions with respect
73 to this document. Code Components extracted from this document must
74 include Simplified BSD License text as described in Section 4.e of
75 the Trust Legal Provisions and are provided without warranty as
76 described in the Simplified BSD License.
80 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
81 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
82 3. Structure of the Raw Public Key Extension . . . . . . . . . . 4
83 4. TLS Client and Server Handshake Behavior . . . . . . . . . . 7
84 4.1. Client Hello . . . . . . . . . . . . . . . . . . . . . . 7
85 4.2. Server Hello . . . . . . . . . . . . . . . . . . . . . . 8
86 4.3. Client Authentication . . . . . . . . . . . . . . . . . . 9
87 4.4. Server Authentication . . . . . . . . . . . . . . . . . . 9
88 5. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . 10
89 5.1. TLS Server Uses a Raw Public Key . . . . . . . . . . . . 10
90 5.2. TLS Client and Server Use Raw Public Keys . . . . . . . . 11
91 5.3. Combined Usage of Raw Public Keys and X.509 Certificates 12
92 6. Security Considerations . . . . . . . . . . . . . . . . . . . 13
93 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
94 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 14
95 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 15
96 9.1. Normative References . . . . . . . . . . . . . . . . . . 15
97 9.2. Informative References . . . . . . . . . . . . . . . . . 15
98 Appendix A. Example Encoding . . . . . . . . . . . . . . . . . . 17
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121 Traditionally, TLS client and server public keys are obtained in PKIX
122 containers in-band as part of the TLS handshake procedure and are
123 validated using trust anchors based on a [PKIX] certification
124 authority (CA). This method can add a complicated trust relationship
125 that is difficult to validate. Examples of such complexity can be
126 seen in [Defeating-SSL]. TLS is, however, also commonly used with
127 self-signed certificates in smaller deployments where the self-signed
128 certificates are distributed to all involved protocol endpoints out-
129 of-band. This practice does, however, still require the overhead of
130 the certificate generation even though none of the information found
131 in the certificate is actually used.
133 Alternative methods are available that allow a TLS client/server to
134 obtain the TLS server/client public key:
136 o The TLS client can obtain the TLS server public key from a DNSSEC-
137 secured resource record using DNS-Based Authentication of Named
138 Entities (DANE) [RFC6698].
140 o The TLS client or server public key is obtained from a [PKIX]
141 certificate chain from a Lightweight Directory Access Protocol
142 [LDAP] server or web page.
144 o The TLS client and server public key is provisioned into the
145 operating system firmware image and updated via software updates.
148 Some smart objects use the UDP-based Constrained Application
149 Protocol [CoAP] to interact with a Web server to upload sensor
150 data at regular intervals, such as temperature readings. CoAP can
151 utilize DTLS for securing the client-to-server communication. As
152 part of the manufacturing process, the embedded device may be
153 configured with the address and the public key of a dedicated CoAP
154 server, as well as a public/private key pair for the client
157 This document introduces the use of raw public keys in TLS/DTLS.
158 With raw public keys, only a subset of the information found in
159 typical certificates is utilized: namely, the SubjectPublicKeyInfo
160 structure of a PKIX certificate that carries the parameters necessary
161 to describe the public key. Other parameters found in PKIX
162 certificates are omitted. By omitting various certificate-related
163 structures, the resulting raw public key is kept fairly small in
164 comparison to the original certificate, and the code to process the
165 keys can be simpler. Only a minimalistic ASN.1 parser is needed;
166 code for certificate path validation and other PKIX-related
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172RFC 7250 Using Raw Public Keys in TLS/DTLS June 2014
175 processing is not required. Note, however, the SubjectPublicKeyInfo
176 structure is still in an ASN.1 format. To further reduce the size of
177 the exchanged information, this specification can be combined with
178 the TLS Cached Info extension [CACHED-INFO], which enables TLS peers
179 to exchange just fingerprints of their public keys.
181 The mechanism defined herein only provides authentication when an
182 out-of-band mechanism is also used to bind the public key to the
183 entity presenting the key.
185 Section 3 defines the structure of the two new TLS extensions,
186 client_certificate_type and server_certificate_type, which can be
187 used as part of an extended TLS handshake when raw public keys are to
188 be used. Section 4 defines the behavior of the TLS client and the
189 TLS server. Example exchanges are described in Section 5. Section 6
190 describes security considerations with this approach. Finally, in
191 Section 7 this document registers a new value to the IANA "TLS
192 Certificate Types" subregistry for the support of raw public keys.
196 The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
197 "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
198 document are to be interpreted as described in RFC 2119 [RFC2119].
200 We use the terms "TLS server" and "server" as well as "TLS client"
201 and "client" interchangeably.
2033. Structure of the Raw Public Key Extension
205 This section defines the two TLS extensions client_certificate_type
206 and server_certificate_type, which can be used as part of an extended
207 TLS handshake when raw public keys are used. Section 4 defines the
208 behavior of the TLS client and the TLS server using these extensions.
210 This specification uses raw public keys whereby the already available
211 encoding used in a PKIX certificate in the form of a
212 SubjectPublicKeyInfo structure is reused. To carry the raw public
213 key within the TLS handshake, the Certificate payload is used as a
214 container, as shown in Figure 1. The shown Certificate structure is
215 an adaptation of its original form [RFC5246].
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228RFC 7250 Using Raw Public Keys in TLS/DTLS June 2014
231 opaque ASN.1Cert<1..2^24-1>;
234 select(certificate_type){
236 // certificate type defined in this document.
238 opaque ASN.1_subjectPublicKeyInfo<1..2^24-1>;
240 // X.509 certificate defined in RFC 5246
242 ASN.1Cert certificate_list<0..2^24-1>;
244 // Additional certificate type based on
245 // "TLS Certificate Types" subregistry
249 Figure 1: Certificate Payload as a Container for the Raw Public Key
251 The SubjectPublicKeyInfo structure is defined in Section 4.1 of RFC
252 5280 [PKIX] and not only contains the raw keys, such as the public
253 exponent and the modulus of an RSA public key, but also an algorithm
254 identifier. The algorithm identifier can also include parameters.
255 The SubjectPublicKeyInfo value in the Certificate payload MUST
256 contain the DER encoding [X.690] of the SubjectPublicKeyInfo. The
257 structure, as shown in Figure 2, therefore also contains length
258 information. An example is provided in Appendix A.
260 SubjectPublicKeyInfo ::= SEQUENCE {
261 algorithm AlgorithmIdentifier,
262 subjectPublicKey BIT STRING }
264 AlgorithmIdentifier ::= SEQUENCE {
265 algorithm OBJECT IDENTIFIER,
266 parameters ANY DEFINED BY algorithm OPTIONAL }
268 Figure 2: SubjectPublicKeyInfo ASN.1 Structure
270 The algorithm identifiers are Object Identifiers (OIDs). RFC 3279
271 [RFC3279] and RFC 5480 [RFC5480], for example, define the OIDs shown
272 in Figure 3. Note that this list is not exhaustive, and more OIDs
273 may be defined in future RFCs.
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287 Key Type | Document | OID
288 --------------------+----------------------------+-------------------
289 RSA | Section 2.3.1 of RFC 3279 | 1.2.840.113549.1.1
290 ....................|............................|...................
291 Digital Signature | |
292 Algorithm (DSA) | Section 2.3.2 of RFC 3279 | 1.2.840.10040.4.1
293 ....................|............................|...................
295 Digital Signature | |
296 Algorithm (ECDSA) | Section 2 of RFC 5480 | 1.2.840.10045.2.1
297 --------------------+----------------------------+-------------------
299 Figure 3: Example Algorithm Object Identifiers
301 The extension format for extended client and server hellos, which
302 uses the "extension_data" field, is used to carry the
303 ClientCertTypeExtension and the ServerCertTypeExtension structures.
304 These two structures are shown in Figure 4. The CertificateType
305 structure is an enum with values taken from the "TLS Certificate
306 Types" subregistry of the "Transport Layer Security (TLS) Extensions"
307 registry [TLS-Ext-Registry].
310 select(ClientOrServerExtension) {
312 CertificateType client_certificate_types<1..2^8-1>;
314 CertificateType client_certificate_type;
316 } ClientCertTypeExtension;
319 select(ClientOrServerExtension) {
321 CertificateType server_certificate_types<1..2^8-1>;
323 CertificateType server_certificate_type;
325 } ServerCertTypeExtension;
327 Figure 4: CertTypeExtension Structure
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3434. TLS Client and Server Handshake Behavior
345 This specification extends the ClientHello and the ServerHello
346 messages, according to the extension procedures defined in [RFC5246].
347 It does not extend or modify any other TLS message.
349 Note: No new cipher suites are required to use raw public keys. All
350 existing cipher suites that support a key exchange method compatible
351 with the defined extension can be used.
353 The high-level message exchange in Figure 5 shows the
354 client_certificate_type and server_certificate_type extensions added
355 to the client and server hello messages.
358 client_certificate_type,
359 server_certificate_type ->
362 client_certificate_type,
363 server_certificate_type,
374 <- change_cipher_spec,
377 Application Data <-------> Application Data
379 Figure 5: Basic Raw Public Key TLS Exchange
383 In order to indicate the support of raw public keys, clients include
384 the client_certificate_type and/or the server_certificate_type
385 extensions in an extended client hello message. The hello extension
386 mechanism is described in Section 7.4.1.4 of TLS 1.2 [RFC5246].
388 The client_certificate_type extension in the client hello indicates
389 the certificate types the client is able to provide to the server,
390 when requested using a certificate_request message.
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399 The server_certificate_type extension in the client hello indicates
400 the types of certificates the client is able to process when provided
401 by the server in a subsequent certificate payload.
403 The client_certificate_type and server_certificate_type extensions
404 sent in the client hello each carry a list of supported certificate
405 types, sorted by client preference. When the client supports only
406 one certificate type, it is a list containing a single element.
408 The TLS client MUST omit certificate types from the
409 client_certificate_type extension in the client hello if it does not
410 possess the corresponding raw public key or certificate that it can
411 provide to the server when requested using a certificate_request
412 message, or if it is not configured to use one with the given TLS
413 server. If the client has no remaining certificate types to send in
414 the client hello, other than the default X.509 type, it MUST omit the
415 client_certificate_type extension in the client hello.
417 The TLS client MUST omit certificate types from the
418 server_certificate_type extension in the client hello if it is unable
419 to process the corresponding raw public key or other certificate
420 type. If the client has no remaining certificate types to send in
421 the client hello, other than the default X.509 certificate type, it
422 MUST omit the entire server_certificate_type extension from the
427 If the server receives a client hello that contains the
428 client_certificate_type extension and/or the server_certificate_type
429 extension, then three outcomes are possible:
431 1. The server does not support the extension defined in this
432 document. In this case, the server returns the server hello
433 without the extensions defined in this document.
435 2. The server supports the extension defined in this document, but
436 it does not have any certificate type in common with the client.
437 Then, the server terminates the session with a fatal alert of
438 type "unsupported_certificate".
440 3. The server supports the extensions defined in this document and
441 has at least one certificate type in common with the client. In
442 this case, the processing rules described below are followed.
444 The client_certificate_type extension in the client hello indicates
445 the certificate types the client is able to provide to the server,
446 when requested using a certificate_request message. If the TLS
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452RFC 7250 Using Raw Public Keys in TLS/DTLS June 2014
455 server wants to request a certificate from the client (via the
456 certificate_request message), it MUST include the
457 client_certificate_type extension in the server hello. This
458 client_certificate_type extension in the server hello then indicates
459 the type of certificates the client is requested to provide in a
460 subsequent certificate payload. The value conveyed in the
461 client_certificate_type extension MUST be selected from one of the
462 values provided in the client_certificate_type extension sent in the
463 client hello. The server MUST also include a certificate_request
464 payload in the server hello message.
466 If the server does not send a certificate_request payload (for
467 example, because client authentication happens at the application
468 layer or no client authentication is required) or none of the
469 certificates supported by the client (as indicated in the
470 client_certificate_type extension in the client hello) match the
471 server-supported certificate types, then the client_certificate_type
472 payload in the server hello MUST be omitted.
474 The server_certificate_type extension in the client hello indicates
475 the types of certificates the client is able to process when provided
476 by the server in a subsequent certificate payload. If the client
477 hello indicates support of raw public keys in the
478 server_certificate_type extension and the server chooses to use raw
479 public keys, then the TLS server MUST place the SubjectPublicKeyInfo
480 structure into the Certificate payload. With the
481 server_certificate_type extension in the server hello, the TLS server
482 indicates the certificate type carried in the Certificate payload.
483 This additional indication enables avoiding parsing ambiguities since
484 the Certificate payload may contain either the X.509 certificate or a
485 SubjectPublicKeyInfo structure. Note that only a single value is
486 permitted in the server_certificate_type extension when carried in
4894.3. Client Authentication
491 When the TLS server has specified RawPublicKey as the
492 client_certificate_type, authentication of the TLS client to the TLS
493 server is supported only through authentication of the received
494 client SubjectPublicKeyInfo via an out-of-band method.
4964.4. Server Authentication
498 When the TLS server has specified RawPublicKey as the
499 server_certificate_type, authentication of the TLS server to the TLS
500 client is supported only through authentication of the received
501 client SubjectPublicKeyInfo via an out-of-band method.
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513 Figures 6, 7, and 8 illustrate example exchanges. Note that TLS
514 ciphersuites using a Diffie-Hellman exchange offering forward secrecy
515 can be used with a raw public key, although this document does not
516 show the information exchange at that level with the subsequent
5195.1. TLS Server Uses a Raw Public Key
521 This section shows an example where the TLS client indicates its
522 ability to receive and validate a raw public key from the server. In
523 this example, the client is quite restricted since it is unable to
524 process other certificate types sent by the server. It also does not
525 have credentials at the TLS layer it could send to the server and
526 therefore omits the client_certificate_type extension. Hence, the
527 client only populates the server_certificate_type extension with the
528 raw public key type, as shown in (1).
530 When the TLS server receives the client hello, it processes the
531 extension. Since it has a raw public key, it indicates in (2) that
532 it had chosen to place the SubjectPublicKeyInfo structure into the
533 Certificate payload (3).
535 The client uses this raw public key in the TLS handshake together
536 with an out-of-band validation technique, such as DANE, to verify it.
539 server_certificate_type=(RawPublicKey) // (1)
542 server_certificate_type=RawPublicKey, // (2)
551 <- change_cipher_spec,
554 Application Data <-------> Application Data
556 Figure 6: Example with Raw Public Key Provided by the TLS Server
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5675.2. TLS Client and Server Use Raw Public Keys
569 This section shows an example where the TLS client as well as the TLS
570 server use raw public keys. This is one of the use cases envisioned
571 for smart object networking. The TLS client in this case is an
572 embedded device that is configured with a raw public key for use with
573 TLS and is also able to process a raw public key sent by the server.
574 Therefore, it indicates these capabilities in (1). As in the
575 previously shown example, the server fulfills the client's request,
576 indicates this via the RawPublicKey value in the
577 server_certificate_type payload (2), and provides a raw public key in
578 the Certificate payload back to the client (see (3)). The TLS server
579 demands client authentication, and therefore includes a
580 certificate_request (4). The client_certificate_type payload in (5)
581 indicates that the TLS server accepts a raw public key. The TLS
582 client, which has a raw public key pre-provisioned, returns it in the
583 Certificate payload (6) to the server.
586client_certificate_type=(RawPublicKey) // (1)
587server_certificate_type=(RawPublicKey) // (1)
590 server_certificate_type=RawPublicKey // (2)
592 client_certificate_type=RawPublicKey // (5)
593 certificate_request, // (4)
602 <- change_cipher_spec,
605Application Data <-------> Application Data
607 Figure 7: Example with Raw Public Key provided by the TLS Server and
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6235.3. Combined Usage of Raw Public Keys and X.509 Certificates
625 This section shows an example combining a raw public key and an X.509
626 certificate. The client uses a raw public key for client
627 authentication, and the server provides an X.509 certificate. This
628 exchange starts with the client indicating its ability to process an
629 X.509 certificate, OpenPGP certificate, or a raw public key, if
630 provided by the server. It prefers a raw public key, since the
631 RawPublicKey value precedes the other values in the
632 server_certificate_type vector. Additionally, the client indicates
633 that it has a raw public key for client-side authentication (see
634 (1)). The server chooses to provide its X.509 certificate in (3) and
635 indicates that choice in (2). For client authentication, the server
636 indicates in (4) that it has selected the raw public key format and
637 requests a certificate from the client in (5). The TLS client
638 provides a raw public key in (6) after receiving and processing the
639 TLS server hello message.
642server_certificate_type=(RawPublicKey, X.509, OpenPGP)
643client_certificate_type=(RawPublicKey) // (1)
646 server_certificate_type=X.509 // (2)
648 client_certificate_type=RawPublicKey // (4)
649 certificate_request, // (5)
657 <- change_cipher_spec,
660Application Data <-------> Application Data
662 Figure 8: Hybrid Certificate Example
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676RFC 7250 Using Raw Public Keys in TLS/DTLS June 2014
6796. Security Considerations
681 The transmission of raw public keys, as described in this document,
682 provides benefits by lowering the over-the-air transmission overhead
683 since raw public keys are naturally smaller than an entire
684 certificate. There are also advantages from a code-size point of
685 view for parsing and processing these keys. The cryptographic
686 procedures for associating the public key with the possession of a
687 private key also follows standard procedures.
689 However, the main security challenge is how to associate the public
690 key with a specific entity. Without a secure binding between
691 identifier and key, the protocol will be vulnerable to man-in-the-
692 middle attacks. This document assumes that such binding can be made
693 out-of-band, and we list a few examples in Section 1. DANE [RFC6698]
694 offers one such approach. In order to address these vulnerabilities,
695 specifications that make use of the extension need to specify how the
696 identifier and public key are bound. In addition to ensuring the
697 binding is done out-of-band, an implementation also needs to check
698 the status of that binding.
700 If public keys are obtained using DANE, these public keys are
701 authenticated via DNSSEC. Using pre-configured keys is another out-
702 of-band method for authenticating raw public keys. While pre-
703 configured keys are not suitable for a generic Web-based e-commerce
704 environment, such keys are a reasonable approach for many smart
705 object deployments where there is a close relationship between the
706 software running on the device and the server-side communication
707 endpoint. Regardless of the chosen mechanism for out-of-band public
708 key validation, an assessment of the most suitable approach has to be
709 made prior to the start of a deployment to ensure the security of the
712 An attacker might try to influence the handshake exchange to make the
713 parties select different certificate types than they would normally
716 For this attack, an attacker must actively change one or more
717 handshake messages. If this occurs, the client and server will
718 compute different values for the handshake message hashes. As a
719 result, the parties will not accept each others' Finished messages.
720 Without the master_secret, the attacker cannot repair the Finished
721 messages, so the attack will be discovered.
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7357. IANA Considerations
737 IANA has registered a new value in the "TLS Certificate Types"
738 subregistry of the "Transport Layer Security (TLS) Extensions"
739 registry [TLS-Ext-Registry], as follows:
742 Description: Raw Public Key
745 IANA has allocated two new TLS extensions, client_certificate_type
746 and server_certificate_type, from the "TLS ExtensionType Values"
747 subregistry defined in [RFC5246]. These extensions are used in both
748 the client hello message and the server hello message. The new
749 extension types are used for certificate type negotiation. The
750 values carried in these extensions are taken from the "TLS
751 Certificate Types" subregistry of the "Transport Layer Security (TLS)
752 Extensions" registry [TLS-Ext-Registry].
756 The feedback from the TLS working group meeting at IETF 81 has
757 substantially shaped the document, and we would like to thank the
758 meeting participants for their input. The support for hashes of
759 public keys has been moved to [CACHED-INFO] after the discussions at
762 We would like to thank the following persons for their review
763 comments: Martin Rex, Bill Frantz, Zach Shelby, Carsten Bormann,
764 Cullen Jennings, Rene Struik, Alper Yegin, Jim Schaad, Barry Leiba,
765 Paul Hoffman, Robert Cragie, Nikos Mavrogiannopoulos, Phil Hunt, John
766 Bradley, Klaus Hartke, Stefan Jucker, Kovatsch Matthias, Daniel Kahn
767 Gillmor, Peter Sylvester, Hauke Mehrtens, Alexey Melnikov, Stephen
768 Farrell, Richard Barnes, and James Manger. Nikos Mavrogiannopoulos
769 contributed the design for reusing the certificate type registry.
770 Barry Leiba contributed guidance for the IANA Considerations text.
771 Stefan Jucker, Kovatsch Matthias, and Klaus Hartke provided
772 implementation feedback regarding the SubjectPublicKeyInfo structure.
774 Christer Holmberg provided the General Area (Gen-Art) review, Yaron
775 Sheffer provided the Security Directorate (SecDir) review, Bert
776 Greevenbosch provided the Applications Area Directorate review, and
777 Linda Dunbar provided the Operations Directorate review.
779 We would like to thank our TLS working group chairs, Eric Rescorla
780 and Joe Salowey, for their guidance and support. Finally, we would
781 like to thank Sean Turner, who is the responsible Security Area
782 Director for this work, for his review comments and suggestions.
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788RFC 7250 Using Raw Public Keys in TLS/DTLS June 2014
7939.1. Normative References
795 [PKIX] Cooper, D., Santesson, S., Farrell, S., Boeyen, S.,
796 Housley, R., and W. Polk, "Internet X.509 Public Key
797 Infrastructure Certificate and Certificate Revocation List
798 (CRL) Profile", RFC 5280, May 2008.
800 [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
801 Requirement Levels", BCP 14, RFC 2119, March 1997.
803 [RFC3279] Bassham, L., Polk, W., and R. Housley, "Algorithms and
804 Identifiers for the Internet X.509 Public Key
805 Infrastructure Certificate and Certificate Revocation List
806 (CRL) Profile", RFC 3279, April 2002.
808 [RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
809 (TLS) Protocol Version 1.2", RFC 5246, August 2008.
811 [RFC5480] Turner, S., Brown, D., Yiu, K., Housley, R., and T. Polk,
812 "Elliptic Curve Cryptography Subject Public Key
813 Information", RFC 5480, March 2009.
816 IANA, "Transport Layer Security (TLS) Extensions",
817 <http://www.iana.org/assignments/
818 tls-extensiontype-values>.
820 [X.690] ITU-T, "Information technology - ASN.1 encoding rules:
821 Specification of Basic Encoding Rules (BER), Canonical
822 Encoding Rules (CER) and Distinguished Encoding Rules
823 (DER)", ITU-T Recommendation X.690, ISO/IEC 8825-1:2002,
8269.2. Informative References
829 Gutmann, P., "ASN.1 Object Dump Program", February 2013,
830 <http://www.cs.auckland.ac.nz/~pgut001/>.
833 Santesson, S. and H. Tschofenig, "Transport Layer Security
834 (TLS) Cached Information Extension", Work in Progress,
837 [CoAP] Shelby, Z., Hartke, K., and C. Bormann, "The Constrained
838 Application Protocol (CoAP)", RFC 7252, June 2014.
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844RFC 7250 Using Raw Public Keys in TLS/DTLS June 2014
848 Marlinspike, M., "New Tricks for Defeating SSL in
849 Practice", February 2009, <http://www.blackhat.com/
850 presentations/bh-dc-09/Marlinspike/
851 BlackHat-DC-09-Marlinspike-Defeating-SSL.pdf>.
853 [LDAP] Sermersheim, J., "Lightweight Directory Access Protocol
854 (LDAP): The Protocol", RFC 4511, June 2006.
856 [RFC6698] Hoffman, P. and J. Schlyter, "The DNS-Based Authentication
857 of Named Entities (DANE) Transport Layer Security (TLS)
858 Protocol: TLSA", RFC 6698, August 2012.
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900RFC 7250 Using Raw Public Keys in TLS/DTLS June 2014
903Appendix A. Example Encoding
905 For example, the hex sequence shown in Figure 9 describes a
906 SubjectPublicKeyInfo structure inside the certificate payload.
909 +------+-----+-----+-----+-----+-----+-----+-----+-----+-----
910 1 | 0x30, 0x81, 0x9f, 0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48,
911 2 | 0x86, 0xf7, 0x0d, 0x01, 0x01, 0x01, 0x05, 0x00, 0x03, 0x81,
912 3 | 0x8d, 0x00, 0x30, 0x81, 0x89, 0x02, 0x81, 0x81, 0x00, 0xcd,
913 4 | 0xfd, 0x89, 0x48, 0xbe, 0x36, 0xb9, 0x95, 0x76, 0xd4, 0x13,
914 5 | 0x30, 0x0e, 0xbf, 0xb2, 0xed, 0x67, 0x0a, 0xc0, 0x16, 0x3f,
915 6 | 0x51, 0x09, 0x9d, 0x29, 0x2f, 0xb2, 0x6d, 0x3f, 0x3e, 0x6c,
916 7 | 0x2f, 0x90, 0x80, 0xa1, 0x71, 0xdf, 0xbe, 0x38, 0xc5, 0xcb,
917 8 | 0xa9, 0x9a, 0x40, 0x14, 0x90, 0x0a, 0xf9, 0xb7, 0x07, 0x0b,
918 9 | 0xe1, 0xda, 0xe7, 0x09, 0xbf, 0x0d, 0x57, 0x41, 0x86, 0x60,
919 10 | 0xa1, 0xc1, 0x27, 0x91, 0x5b, 0x0a, 0x98, 0x46, 0x1b, 0xf6,
920 11 | 0xa2, 0x84, 0xf8, 0x65, 0xc7, 0xce, 0x2d, 0x96, 0x17, 0xaa,
921 12 | 0x91, 0xf8, 0x61, 0x04, 0x50, 0x70, 0xeb, 0xb4, 0x43, 0xb7,
922 13 | 0xdc, 0x9a, 0xcc, 0x31, 0x01, 0x14, 0xd4, 0xcd, 0xcc, 0xc2,
923 14 | 0x37, 0x6d, 0x69, 0x82, 0xd6, 0xc6, 0xc4, 0xbe, 0xf2, 0x34,
924 15 | 0xa5, 0xc9, 0xa6, 0x19, 0x53, 0x32, 0x7a, 0x86, 0x0e, 0x91,
925 16 | 0x82, 0x0f, 0xa1, 0x42, 0x54, 0xaa, 0x01, 0x02, 0x03, 0x01,
928 Figure 9: Example SubjectPublicKeyInfo Structure Byte Sequence
930 The decoded byte sequence shown in Figure 9 (for example, using Peter
931 Gutmann's ASN.1 decoder [ASN.1-Dump]) illustrates the structure, as
934 Offset Length Description
935 -------------------------------------------------------------------
938 5 2+9: OBJECT IDENTIFIER Value (1 2 840 113549 1 1 1)
939 : PKCS #1, rsaEncryption
942 18 3+141: BIT STRING, encapsulates {
944 25 3+129: INTEGER Value (1024 bit)
945 157 2+3: INTEGER Value (65537)
950 Figure 10: Decoding of Example SubjectPublicKeyInfo Structure
954Wouters, et al. Standards Track [Page 17]
956RFC 7250 Using Raw Public Keys in TLS/DTLS June 2014
961 Paul Wouters (editor)
964 EMail: pwouters@redhat.com
967 Hannes Tschofenig (editor)
972 EMail: Hannes.tschofenig@gmx.net
973 URI: http://www.tschofenig.priv.at
977 Electronic Frontier Foundation
979 San Francisco, California 94117
982 Phone: +1 415 221 6524
984 URI: https://www.toad.com/
989 7110 Samuel Morse Drive
990 Columbia, Maryland 21046
993 EMail: weiler@tislabs.com
1002 EMail: kivinen@iki.fi
1010Wouters, et al. Standards Track [Page 18]