TLS Working Group B. Lonc
Internet-Draft Renault
Intended status: Informational June 12, 2015
Expires: December 14, 2015
Transport Layer Security (TLS) Authentication using ITS ETSI and IEEE
certificates
draft-lonc-tls-certieee1609-01.txt
Abstract
This document specifies the use of two new certificate types to
authenticate TLS entities. The first type enables the use of a
certificate specified by the Institute of Electrical and Electronics
Engineers (IEEE) [IEEE-ITS] and the second by the European
Telecommunications Standards Institute (ETSI) [ETSI-ITS].
Status of This Memo
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Requirements Terminology . . . . . . . . . . . . . . . . . . 3
3. Extension Overview . . . . . . . . . . . . . . . . . . . . . 3
4. Security Considerations . . . . . . . . . . . . . . . . . . . 3
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
6. Cipher Suites . . . . . . . . . . . . . . . . . . . . . . . . 5
7. Message Flow . . . . . . . . . . . . . . . . . . . . . . . . 5
7.1. Client Hello . . . . . . . . . . . . . . . . . . . . . . 6
7.2. Server Hello . . . . . . . . . . . . . . . . . . . . . . 7
7.3. Client Authentication . . . . . . . . . . . . . . . . . . 7
8. Certificate Verification . . . . . . . . . . . . . . . . . . 8
8.1. IEEE 1609.2 certificates . . . . . . . . . . . . . . . . 8
8.2. ETSI TS 103 097 certificates . . . . . . . . . . . . . . 9
9. IEEE - ETSI comparison . . . . . . . . . . . . . . . . . . . 10
9.1. Certificate Encoding . . . . . . . . . . . . . . . . . . 10
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
10.1. Normative References . . . . . . . . . . . . . . . . . . 10
10.2. Informative References . . . . . . . . . . . . . . . . . 11
Appendix A. ETSI Encoding Example . . . . . . . . . . . . . . . 12
Appendix B. IEEE Encoding Example . . . . . . . . . . . . . . . 15
Appendix C. Co-authors' Addresses . . . . . . . . . . . . . . . 17
1. Introduction
At present, TLS protocol uses X509 [RFC5246] and OpenPGP digital
certificates [RFC6091] in order to authenticate servers and clients.
This document describes the use of certificates specified either by
the Institute of Electrical and Electronics Engineers (IEEE) [IEEE-
ITS] or the European Telecommunications Standards Institute (ETSI)
[ETSI-ITS]. These standards were defined in order to secure
communications in vehicular environments. Existing certificates,
such as X509 and OpenPGPG, are designed for Internet use,
particularly for flexibility and extensibility, and are not optimized
for bandwidth and processing time to support delay-sensitive
applications. This is why size-optimized certificates that meet the
ITS requirements were designed and standardized.
In addition, the purpose of these certificates is to provide privacy
relying on geographical and/or temporal validity criteria, and
minimizing the exchange of private data.
Two new values referring the previously mentioned certificated are
added to the "cert_type" extension defined in [RFC6091].
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2. Requirements 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 [RFC2119].
3. Extension Overview
In order to negotiate the support of IEEE or ETSI certificate-based
authentication, clients MAY include an extension of type "cert_type"
in the extended client hello. The "extension_data" field of this
extension SHALL contain a list of supported certificate types
proposed by the client, where:
enum {
X.509(0), OpenPGP(1), RawPublicKey(2),
IEEE(3), ETSI(4), (255)
}CertificateType;
In case where the TLS server accepts the described extension, it
selects one of the certificate types in the extension described here.
The same extension type and structure will be used for the server's
response to the extension described here. Note that a server MAY
send no certificate type if it either does not support it or wishes
to authenticate the client using other authentication methods. The
client MAY at its discretion either continue the handshake, or
respond with a fatal message alert.
The end-entity certificate's public key has to be compatible with one
of the certificate types listed in extension described here.
Servers aware of the extension described here but not wishing to use
it, SHOULD gracefully revert to a classical TLS handshake or decide
not to proceed with the negotiation.
4. Security Considerations
This section provides an overview of the basic security
considerations which need to be taken into account before
implementing the necessary security mechanisms. The security
considerations described throughout [RFC5246] apply here as well.
For security considerations in a vehicular environment, the minimal
use of any TLS extensions is recommended such as :
o The "cert_type" [IANA value 9] extension who's purpose was
previously described in Section 3.
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o The "elliptic_curves" [IANA value 10] extension which indicates
the set of elliptic curves supported by the client.
o The "SessionTicket" [IANA value 35] extension for session
resumption.
In addition, servers SHOULD not support renegotiation [RFC5746] which
presented Man-In-The-Middle (MITM) type attacks over the past years.
The ETSI and IEEE Standards propose the use of secp256r1 (aka NIST
P-256) recommended by the NIST FIPS 186-4 standard [FIPS186].
Elliptic curve algorithms require significantly shorter public keys
to achieve the same security strength. ECC is the digital signature
algorithm of choice in the IEEE 1609.2 standard that specifies
security services and procedures designed for vehicle communications.
The ECDSA is specified in American National Standard (ANS) X9.62 .
NIST approved the use of ECDSA and specified additional requirements
in the FIPS Publication 186-4.
ECDSA also produces smaller signatures than RSA. The smaller key
sizes and signature sizes of ECDSA mean lower message overheads when
transporting ECDSA public keys over wireless networks compared with
transporting RSA or DSA public keys. This is important in a large
vehicle network where vehicles may often have to exchange their
public keys over bandwidth - limited wireless channels. The smaller
ECDSA key lengths can also translate into savings on computing power,
storage and memory space, and energy required to achieve the same
security strength [KARGL] [SCHUTZE] [PETIT] [ICSI]. This makes ECDSA
attractive for resource - constrained mobile devices, such as vehicle
on-board communication units.
The Standard defines ECIES as the encryption algorithm. Seen that
this RFC aims to client authentication, the use of this algorithm can
be optional for future use but not required.
AES-CCM provides both authentication and confidentiality (encryption
and decryption) and uses as its only primitive the AES encrypt block
cipher operation. This makes it amenable to compact implementations,
which are advantageous in constrained envrionments. Adoption outside
of constrained environments is necessary to enable interoperability,
such as that between web clients and embedded servers, or between
embedded clients and web servers.
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5. IANA Considerations
Existing IANA references have not been updated yet to point to this
document.
IANA is asked to register two new values in the "TLS Certificate
Types" registry of Transport Layer Security (TLS) Extensions [TLS-
Certificate-Types-Registry], as follows:
o Value: 3 Description: IEEE Reference: [THIS RFC]
o Value: 4 Description: ETSI Reference: [THIS RFC]
6. Cipher Suites
The table below defines ECC cipher suites that should be used
[RFC7251]:
CipherSuite TLS_ECDHE_ECDSA_WITH_AES_128_CCM = {0xC0,0xAC}
CipherSuite TLS_ECDHE_ECDSA_WITH_AES_256_CCM = {0xC0,0xAD}
CipherSuite TLS_ECDHE_ECDSA_WITH_AES_128_CCM_8 = {0xC0,0xAE}
CipherSuite TLS_ECDHE_ECDSA_WITH_AES_256_CCM_8 = {0xC0,0xAF}
Figure 1: TLS ECC cipher suites
Server implementations SHOULD support all of the previous cipher
suites, and client implementations SHOULD support at least one of
them. Note that the versions "*_CCM_8" of cipher suites use a 64
bits tag rather than a 128 bits tag. Such cipher suites MAY be
preferred in ITS networks to gain in bandwidth and message size but
at the cost of a loss in integrity.
7. Message Flow
The "cert_type" message MUST be sent as the first handshake message
as illustrated in Figure 1 below.
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Client Server
ClientHello
/* with
certificate type */ -------->
ServerHello
/* with
certificate type */
Certificate*
ServerKeyExchange*
CertificateRequest*
<-------- ServerHelloDone
Certificate
ClientKeyExchange
CertificateVerify*
[ChangeCipherSpec]
Finished -------->
[ChangeCipherSpec]
<-------- Finished
Application Data <-------> Application Data
* Indicates optional or situation-dependent messages that are not
always sent.
Figure 2: Message Flow with certificate type extension
7.1. Client Hello
In order to indicate the support of IEEE or ETSI certificates,
clients MUST include an extension of type "cert_type" to the extended
client hello message. The hello extension mechanism is described in
Section 7.4.1.4 of TLS 1.2 [RFC5246].
The extension 'cert_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.
In a vehicular environment, privacy is important. In order to
preserve anonymity, a client MUST include IEEE or ETSI certificate
types in the "cert_type" extension prior to other supported
certificates.
A TLS client that proposes ECC algorithms in its ClientHello message
SHOULD include "elliptic_curves" extension [RFC4492].
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Clients respond along with their certificates by sending a
"Certificate" message immediately followed by the "ClientKeyExchange"
message. The premaster secret is generated according to the cipher
algorithm selected by the server in the ServerHello.cipher_suite.
7.2. Server Hello
If the server receives a client hello that contains the "cert_type"
extension and chooses a cipher suite that requires a certificate,
then two outcomes are possible. The server MUST either, select a
certificate type from the certificate_types field in the extended
client hello and must take into account the client list priority, or
terminate the session with a fatal alert of type
"unsupported_certificate".
The certificate type selected by the server is encoded in a
CertificateTypeExtension structure, which is included in the extended
server hello message using an extension of type "cert_type".
Servers implementing ECC cipher suites MUST support "elliptic_curves"
extension, and when a client uses this extension, servers MUST NOT
negotiate the use of an ECC cipher suite unless they can complete the
handshake while respecting the choice of curves and compression
techniques specified by the client [RFC4492].
7.3. Client Authentication
Client authentication is done upon specific request of the server.
This procedure SHALL be done as described in section 7.4.4 of
[RFC5246].
The figure below depicts the format of the CertificateRequest
message.
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enum {
rsa_sign(1), dss_sign(2), rsa_fixed_dh(3),
dss_fixed_dh(4), rsa_ephemeral_dh_RESERVED(5),
dss_ephemeral_dh_RESERVED(6), fortezza_dms_RESERVED(20),
ECDSA_sign(64), (255)
} ClientCertificateType;
opaque DistinguishedName<1..2^16-1>;
struct {
ClientCertificateType certificate_types<1..2^8-1>;
SignatureAndHashAlgorithm
supported_signature_algorithms<2^16-1>;
DistinguishedName certificate_authorities<0..2^16-1>;
} CertificateRequest;
Figure 3: Structure of the CertificateRequest message
The CertificateRequest SHALL be filled as follow:
ClientCertificateType ECDSA_sign(64)
SignatureAndHashAlgorithm {0x04,0x03} (ECDSA-SHA256)
DistinguishedName It MAY be used by the server to specify a
list of certificate authorities it trusts
(i.e. AA/PCA or EA/LTCA). If possible,
the client SHOULD then reply with a
certificate signed by one of the
certificate authorities trusted by the
server in order to avoid sending the
certificate chain. A certificate authority
is identified by its HashedId8 as defined
in section 4.2.12 of [ETSI-ITS]. That is,
DistinguishedName is a list of HashedId8.
If not used this field MUST be empty.
8. Certificate Verification
8.1. IEEE 1609.2 certificates
Verification of an IEEE 1609.2 certificate or certificate chain is
described in section 5.5.2 of [IEEE-ITS].
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8.2. ETSI TS 103 097 certificates
The format of an ETSI TS 103 097 certificate is depicted in the
figure below.
+------+-------+--------+----------+-------+-----+----------+------+
| | | | verifi- |assu- |its | validity | |
| ver- |signer |subject | cation/ |rance |_aid | _restri- |sign- |
| sion |_info |_info | encryp- |_level |_ssp | ctions |ature |
| | | | tion key | | | | |
+------+-------+--------+----------+-------+-----+----------+------+
Figure 4: ETSI TS 103 097 certificate format
The verification process of an ETSI TS 103 097 certificate SHALL
follow these steps:
1. Verify that the certificate content is conform to one of ETSI
profiles (RCA, EA, AA, EC, AT). If not, the verification has
failed and the message SHALL be discarded.
2. Verify the certificate's signer identity:
* If the certificate digest included in "signer_info" is known,
goto step 3.
* Else:
+ If it is a root certificate digest, the verification has
failed (error - untrusted RCA) and the message SHALL be
discarded.
+ Else: pause the current certificate verification process
and start verification of the next certificate in the chain
(which SHALL be the signer's certificate) recursively by
restarting from step 1. Once verified, resume the
certificate verification previously paused.
3. Verify that the certificate is not in the Certificate Revocation
List (CRL). If it is, the verification has failed (error -
certificate in CRL) and the message SHALL be discarded.
4. Verify the signature of the certificate (see [RFC4492] for
details).
5. Verify "subject_info": "subject_name" SHALL be a 32 bytes hash of
the server URL. Note that this step is only done by clients that
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are verifying a server's certificate. In the opposite case this
step SHALL be ignored.
6. Verify "validity_restrictions": only the validity of time is
checked, the validity of space (i.e. geographical region) is
ignored.
7. Verify the "its_aid_ssp": ITS-AID included in the certificate
SHALL be consistent with those included in the signer's
certificate (heritage).
9. IEEE - ETSI comparison
The ETSI and IEEE 1609.2 represent the active standardization groups
in Europe and U.S those dealing with the security of vehicular
communications. Although defined for the same purpose, the different
security requirements have led to the definition of different
certificate formats.
9.1. Certificate Encoding
As described in the IEEE 1609.2 and ETSI standards, the internal
representation of the certificate structure is encoded into a flat
octet string in network byte order (i.e. big-endian).
IEEE 1609.2 is developing for future an ASN.1 version of the standard
using X.696 (OER) [X696].
10. References
10.1. Normative References
[ETSI-ITS]
ETSI, , "ETSI TS 103 097 v1.1.1 (2013-04): Intelligent
Transport Systems (ITS); Security; Security header and
certificate formats", April 2013.
[IEEE-ITS]
IEEE 1609.2, , "IEEE Standard for Wireless Access in
Vehicular Environments - Security Services for
Applications and Management Messages", 2013.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", March 1997.
[RFC4492] Blake-Wilson, S., Bolyard, N., Gupta, V., Hawk, C., and B.
Moeller, "Elliptic Curve Cryptography (ECC) Cipher Suites
for Transport Layer Security (TLS)", May 2006.
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[RFC5246] Dierks, T. and E. Rescorla, "The Transport Layer Security
(TLS) Protocol Version 1.2", August 2008.
[RFC5746] Rescorla, E., Ray, M., Dispensa, S., and N. Oskov,
"Transport Layer Security (TLS) Renegotiation Indication
Extension"", February 2010.
[RFC6091] Mavrogiannopoulos, N. and D. Gillmor, "Using OpenPGP Keys
for Transport Layer Security (TLS) Authentication",
February 2011.
[RFC7251] McGrew, D., Bailey, D., Campagna, M., and R. Dugal, "AES-
CCM Elliptic Curve Cryptography (ECC) Cipher Suites for
TLS", June 2014.
10.2. Informative References
[FIPS186] FIPS 186-4, , "Digital Signature Standard", July 2013.
[KARGL] Kargl, F., Papadimitratos, P., Buttyan, L., Muter, M.,
Schoch, E., Wiedersheim, B., Thong, T., Calandriello, G.,
Held, A., Kung, A., and J. Hubaux, "Secure Vehicular
Communications: Implementation, Performance, and Research
Challenges", November 2008.
[SCHUTZE] Schutze, T., "Automotive security: Cryptography for Car2X
communication", March 2011.
[PETIT] Petit, J., "Analysis of ECDSA authentication processing in
VANETs", December 2009.
[ICSI] ICST project, , "Analysis of timeliness of communication
for IEEE 1609.2", 2013.
[X696] ITU-T X.696, , "Information Technology - ASN.1 encoding
rules: Specification of Octet Encoding Rules (OER)",
august 2014.
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Appendix A. ETSI Encoding Example
The hex sequence shown in Figure 5 presents an encoded secured
message with signed payload as a generic encoded octet string.
00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
+---+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--
01 | 02 80 ba 80 02 02 01 53 88 de c6 40 c6 e1 9e 01
02 | 00 52 00 00 04 d4 81 34 8a cd d1 d9 9c 1f fb a4
03 | c7 0e 6d 2a 5d 13 ca b0 a1 e6 cf 63 22 9f 69 79
04 | b4 53 c0 15 c7 da 3a 12 7c 8f 39 44 59 b1 2f 94
05 | d4 cb 9a 12 ce e1 1d 87 40 8d 91 ac 95 6c 90 c8
06 | b3 b2 9f 4c 22 02 e0 21 0b 24 03 01 00 00 25 04
07 | 01 00 00 00 0b 01 15 04 39 83 15 4c bc 02 03 00
08 | 00 00 71 ff 9a 0d 80 16 ca cb cd d8 1c d1 4f 81
09 | 94 3c dd c7 74 51 1e 2b f7 15 7b 33 e5 4f 7b 6b
10 | 6e 5b 5d 07 94 70 be 40 a6 46 e0 55 9c 19 89 28
11 | b5 b8 ed cf bd c2 29 70 53 95 1d bc 51 cb d6 a3
12 | e1 d0 00 00 01 41 ae 0f 26 64 c0 05 24 01 55 20
13 | 50 02 80 00 31 01 00 14 00 30 14 4a d9 f8 7e 59
14 | 9e 09 2b 00 00 00 00 00 00 00 00 80 00 00 00 00
15 | 00 00 00 07 d1 00 00 01 02 00 00 00 02 09 2b 40
16 | 56 b4 9d 20 0d 69 3a 40 1f ff ff fc 22 30 d4 1e
17 | 40 00 0f c0 00 7e 02 76 ea 87 33 a9 d7 4f ff d0
18 | 84 14 00 00 43 01 00 00 61 6d 42 37 dd 2c ea b7
19 | 27 31 c2 3b cb 5d 61 8f 88 17 df 0d a8 7b d2 b8
20 | d3 54 8f 71 09 8a f1 88 d2 43 04 a8 61 6a 95 bf
21 | 5e 07 45 a1 06 e9 33 9f 9e 69 ba b3 3c bc 68 28
22 | 93 5a 66 ea 11 a0 37 69
Figure 5: Example of encoded ETSI secured message with signed payload
In the parsed data structure, the contents are presented in the form:
struct SecuredMessage {
uint8 protocol_version: 2
HeaderField<186> header_fields {
struct HeaderField {
HeaderFieldType type: signer_info (128)
struct SignerInfo signer {
SignerInfoType type: certificate (2)
struct Certificate certificate {
uint8 version: 2
struct SignerInfo signer_info {
SignerInfoType type: certificate_digest_with_sha256 (1)
HashedId8 digest: 5388DEC640C6E19E
}
struct SubjectInfo subject_info {
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SubjectType subject_type: authorization_ticket (1)
opaque<0> subject_name:
}
SubjectAttribute<82> subject_attributes {
struct SubjectAttribute {
SubjectAttributeType type: verification_key (0)
struct PublicKey key {
PublicKeyAlgorithm algorithm: ecdsa_nistp256_with_
sha256 (0)
struct EccPoint public_key {
EccPointType type: uncompressed (4)
opaque[32] x: D481348ACDD1D99C1FFBA4C70E6D2A5D
13CAB0A1E6CF63229F6979B453C015C7
opaque[32] y: DA3A127C8F394459B12F94D4CB9A12CE
E11D87408D91AC956C90C8B3B29F4C22
}
}
}
struct SubjectAttribute {
SubjectAttributeType type: assurance_level (2)
SubjectAssurance assurance_level: assurance level = 7,
confidence = 0
(bitmask = 11100000)
}
struct SubjectAttribute {
SubjectAttributeType type: its_aid_ssp_list (33)
ItsAidSsp<11> its_aid_ssp_list {
struct ItsAidSsp {
IntX its_aid: 36
opaque<3> service_specific_permissions: 010000
}
struct ItsAidSsp {
IntX its_aid: 37
opaque<4> service_specific_permissions: 01000000
}
}
}
}
ValidityRestriction<11> validity_restrictions {
struct ValidityRestriction {
ValidityRestrictionType type: time_start_and_end (1)
Time32 start_validity: 2015-03-05 00:00:00 UTC
Time32 end_validity: 2015-04-28 23:59:59 UTC
}
struct ValidityRestriction {
ValidityRestrictionType type: region (3)
struct GeographicRegion region {
RegionType region_type: none (0)
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}
}
}
struct Signature {
PublicKeyAlgorithm algorithm: ecdsa_nistp256_with_sha256 (0)
struct EcdsaSignature ecdsa_signature {
struct EccPoint R {
EccPointType type: x_coordinate_only (0)
opaque[32] x: 71FF9A0D8016CACBCDD81CD14F81943C
DDC774511E2BF7157B33E54F7B6B6E5B
}
opaque[32] s: 5D079470BE40A646E0559C198928B5B8
EDCFBDC2297053951DBC51CBD6A3E1D0
}
}
}
}
}
struct HeaderField {
HeaderFieldType type: generation_time (0)
Time64 generation_time: 2015-03-17 15:26:48.000 UTC
}
struct HeaderField {
HeaderFieldType type: its_aid (5)
IntX its_aid: 36
}
}
struct Payload payload_field {
PayloadType type: signed (1)
opaque<85> data: 2050028000310100140030144AD9F87E
599E092B000000000000000080000000
0000000007D10000010200000002092B
4056B49D200D693A401FFFFFFC2230D4
1E40000FC0007E0276EA8733A9D74FFF
D084140000
}
TrailerField<67> trailer_fields {
struct TrailerField {
TrailerFieldType type: signature (1)
struct Signature signature {
PublicKeyAlgorithm algorithm: ecdsa_nistp256_with_sha256 (0)
struct EcdsaSignature ecdsa_signature {
struct EccPoint R {
EccPointType type: x_coordinate_only (0)
opaque[32] x: 616D4237DD2CEAB72731C23BCB5D618F
8817DF0DA87BD2B8D3548F71098AF188
}
opaque[32] s: D24304A8616A95BF5E0745A106E9339F
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9E69BAB33CBC6828935A66EA11A03769
}
}
}
}
}
Figure 6: Example of parsed ETSI secured message with signed payload
Appendix B. IEEE Encoding Example
The hex sequence shown in Figure 7 presents an encoded signed data
structure as a flat encoded octet string.
00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
+---+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--
01 | 02 01 03 02 02 04 f3 db 4f 6f ca b6 49 65 01 09
02 | 63 65 72 74 4e 61 6d 65 31 01 05 e0 00 00 01 00
03 | 04 00 00 00 00 00 00 00 01 00 02 d4 a8 61 1d ce
04 | d8 8c a7 a2 e9 6a 8d 7e 49 0f 3c 9a 46 27 c0 72
05 | 26 ed 67 8d 04 74 41 02 00 03 9c b6 6f 87 4a 40
06 | 7c 21 83 40 22 db 6d 0a 80 d0 14 cb df 24 fc a0
07 | 83 f8 e2 00 81 b0 7c 14 b8 e7 02 19 90 d0 57 4b
08 | 14 d2 80 29 1f c4 e6 a6 73 12 68 74 96 77 c2 52
09 | 34 ae bb e4 29 da 16 60 61 19 74 c6 b3 53 98 0e
10 | 70 e3 3d 4f b9 03 99 76 05 44 e9 74 70 d9 92 bb
11 | 3c 37 92 c3 51 d4 7d 8e ea b1 03 0a e0 00 00 01
12 | 0c 73 6f 6d 65 20 63 6f 6e 74 65 6e 74 00 00 e7
13 | 2a dc 3e dc 09 00 00 00 00 00 00 00 00 00 00 00
14 | 02 ca bf a2 0d 82 ae 3e 25 a3 8c 9c dd 2e cf 94
15 | 9f cc 7c 7f d9 d8 83 89 f5 08 f7 aa bb 5b ef 21
16 | bd 7a 2e 79 6c c7 de 01 af b1 93 35 5b e2 f5 88
17 | 19 76 70 e4 ae 09 cf 3b ee
Figure 7: Example of encoded IEEE 1609.2 signed data structure
In the parsed data structure, the contents are presented in the form:
protocol_version (0, 1): 02
type (1, 1): 01 (signed)
signed_data (2, 263):
signer (2, 169):
type (2, 1): 03 (certificate)
certificates (3, 168):
version_and_type (3, 1): 02 (explicit)
unsigned_certificate (4, 102):
holder_type (4, 1): 02 (identified localized)
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cf (5, 1): 04 (encryption_key)
signer_id (6, 8): f3 db 4f 6f ca b6 49 65
signature_alg (14, 1): 01 (ECDSA NIST P256)
scope (15, 18):
id_scope (15, 18):
name_len (15, 1): 09
name (16, 9): 63 65 72 74 4e 61 6d 65 31
permissions (25, 7):
type (25, 1): 01 (specified)
permissions_list_len (26, 1): 05
permissions_list (27, 5):
psid (27, 4): e0 00 00 01
service_specific_permissions_len (31, 1): 00
region (32, 1):
region_type (32, 1): 04 (none)
expiration (33, 4): 00 00 00 00 (00:00:34 01 Jan 2004 UTC)
crl_series (37, 4): 00 00 00 01
verification_key (41, 30):
algorithm (41, 1): 00 (ECDSA NIST P224)
public_key (42, 29):
type (42, 1): 02 (compressed, lsb of y is 0)
x (43, 28):
d4 a8 61 1d ce d8 8c a7 a2 e9 6a 8d 7e 49 0f 3c
9a 46 27 c0 72 26 ed 67 8d 04 74 41
encryption_key (71, 35):
algorithm (71, 1): 02 (ECIES NIST P256)
supported_symm_alg (72, 1): 00 (AES 128 CCM)
public_key (73, 33):
type (73, 1): 03 (compressed, lsb of y is 1)
x (74, 32):
9c b6 6f 87 4a 40 7c 21 83 40 22 db 6d 0a 80 d0
14 cb df 24 fc a0 83 f8 e2 00 81 b0 7c 14 b8 e7
signature (106, 65):
ecdsa_signature (106, 65):
R (106, 33):
type (106, 1): 02 (compressed, lsb of y is 0)
x (107, 32):
19 90 d0 57 4b 14 d2 80 29 1f c4 e6 a6 73 12 68
74 96 77 c2 52 34 ae bb e4 29 da 16 60 61 19 74
s (139, 32):
c6 b3 53 98 0e 70 e3 3d 4f b9 03 99 76 05 44 e9
74 70 d9 92 bb 3c 37 92 c3 51 d4 7d 8e ea b1 03
unsigned_data (171, 37):
tf (171, 1): 0a (use_generation_time, use_location)
psid (172, 4): e0 00 00 01
data_len (176, 1): 0c
data (177, 12): 73 6f 6d 65 20 63 6f 6e 74 65 6e 74
generation_time (189, 9):
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time (189, 8): 00 00 e7 2a dc 3e dc 09
(19:08:23 20 Jan 2012 UTC)
log_std_dev (197, 1): 00 (1.134666 ns or less)
generation_location (198, 10):
latitude (198, 4): 00 00 00 00
longitude (202, 4): 00 00 00 00
elevation (206, 2): 00 00
signature (208, 57):
ecdsa_signature (208, 57):
R (208, 29):
type (208, 1): 02 (compressed, lsb of y is 0)
x (209, 28):
ca bf a2 0d 82 ae 3e 25 a3 8c 9c dd 2e cf 94 9f
cc 7c 7f d9 d8 83 89 f5 08 f7 aa bb
s (237, 28):
5b ef 21 bd 7a 2e 79 6c c7 de 01 af b1 93 35 5b
e2 f5 88 19 76 70 e4 ae 09 cf 3b ee
Figure 8: Example of parsed IEEE 1609.2 signed data structure
Appendix C. Co-authors' Addresses
Houda Labiod
Telecom Paristech
46 rue Barrault
75634 Paris cedex 13
France
Email: houda.labiod@telecom-paristech.fr
Francois Lonc
Telecom Paristech
46 rue Barrault
75634 Paris cedex 13
France
Email: francois.lonc@telecom-paristech.fr
Ahmed Serhrouchni
Telecom Paristech
46 rue Barrault
75634 Paris cedex 13
France
Email: ahmed.serhrouchni@telecom-paristech.fr
Arnaud Kaiser
IRT SystemX
8 avenue de la Vauve
91120 Palaiseau
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France
Email: arnaud.kaiser@irt-systemx.fr
Author's Address
Brigitte Lonc
Renault
1 avenue du Golf
78288 Guyancourt
France
EMail: brigitte.lonc@renault.com
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