Internet-Draft | CBOR Encoding of X.509 Certificates (CBO | January 2021 |
Raza, et al. | Expires 23 July 2021 | [Page] |
This document specifies a CBOR encoding of X.509 certificates. The resulting certificates are called CBOR Certificates. The CBOR encoding supports a large subset of RFC 5280 and significantly reduces the size of certificates compatible with e.g. RFC 7925, IEEE 802.1AR (DevID), CNSA, and CA/Browser Forum Baseline Requirements. When used to re-encode DER encoded X.509 certificates, the CBOR encoding can in many cases reduce the size of RFC 7925 profiled certificates with over 50%. The CBOR encoding can also be used to encode "natively signed" CBOR certificates, which does not require re-encoding for the signature to be verified. The document also specifies COSE headers as well as a TLS certificate type for CBOR certificates.¶
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One of the challenges with deploying a Public Key Infrastructure (PKI) for the Internet of Things (IoT) is the size and parsing of X.509 public key certificates [RFC5280], since those are not optimized for constrained environments [RFC7228]. Large certificate chains are also problematic in non-constrained protocols such as EAP-TLS [I-D.ietf-emu-eap-tls13] [I-D.ietf-emu-eaptlscert] where authenticators typically drop an EAP session after only 40 - 50 round-trips and QUIC [I-D.ietf-quic-transport] where the latency increases significantly unless the server only send less than three times as many bytes as received prior to validating the client address. More compact certificate representations are therefore desirable in many use cases. Due to the current PKI usage of DER encoded X.509 certificates, keeping compatibility with DER encoded X.509 is necessary at least for a transition period. However, the use of a more compact encoding with the Concise Binary Object Representation (CBOR) [RFC8949] reduces the certificate size significantly which has known performance benefits in terms of decreased communication overhead, power consumption, latency, storage, etc.¶
CBOR is a data format designed for small code size and small message size. CBOR builds on the JSON data model but extends it by e.g. encoding binary data directly without base64 conversion. In addition to the binary CBOR encoding, CBOR also has a diagnostic notation that is readable and editable by humans. The Concise Data Definition Language (CDDL) [RFC8610] provides a way to express structures for protocol messages and APIs that use CBOR. [RFC8610] also extends the diagnostic notation.¶
CBOR data items are encoded to or decoded from byte strings using a type-length-value encoding scheme, where the three highest order bits of the initial byte contain information about the major type. CBOR supports several different types of data items, in addition to integers (int, uint), simple values (e.g. null), byte strings (bstr), and text strings (tstr), CBOR also supports arrays [] of data items, maps {} of pairs of data items, and sequences of data items. For a complete specification and examples, see [RFC8949], [RFC8610], and [RFC8742].¶
CAB Baseline Requirements [CAB-Baseline], RFC 7925 [RFC7925], IEEE 802.1AR [IEEE-802.1AR], and CNSA [RFC8603] specify certificate profiles which can be applied to certificate based authentication with, e.g., TLS [RFC8446], QUIC [I-D.ietf-quic-transport], DTLS [I-D.ietf-tls-dtls13], COSE [RFC8152], EDHOC [I-D.ietf-lake-edhoc], or Compact TLS 1.3 [I-D.ietf-tls-ctls]. RFC 7925 [RFC7925], RFC7925bis [I-D.ietf-uta-tls13-iot-profile], and IEEE 802.1AR [IEEE-802.1AR] specifically target Internet of Things deployments. This document specifies a CBOR encoding based on [X.509-IoT], which can support large parts of [RFC5280]. The encoding support all [RFC7925] and IEEE 802.1AR [IEEE-802.1AR] and CAB Baseline [CAB-Baseline] profiled X.509 certificates. Two variants are defined using the same CBOR encoding and differing only in what is being signed:¶
This document specifies COSE headers for use of the CBOR certificates with COSE, see Section 9.8. The document also specifies a TLS certificate type for use of the CBOR certificates with TLS and QUIC (with or without additional TLS certificate compression), see Section 9.9.¶
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here.¶
This specification makes use of the terminology in [RFC5280], [RFC7228], [RFC8610], and [RFC8949].¶
This section specifies the content and encoding for CBOR certificates, with the overall objective to produce a very compact representation supporting large parts of [RFC5280], and everything in [RFC7925], [IEEE-802.1AR], and CAB Baseline [CAB-Baseline]. In the CBOR encoding, static fields are elided, elliptic curve points and time values are compressed, OID are replaced with short integers, and redundant encoding is removed. Combining these different components reduces the certificate size significantly, which is not possible with general purpose compressions algorithms, see Figure 2.¶
The CBOR certificate can be either a CBOR re-encoding of a DER encoded X.509 certificate, in which case the signature is calculated on the DER encoded ASN.1 data in the X.509 certificate, or a natively signed CBOR certificate, in which case the signature is calculated directly on the CBOR encoded data (see Section 7). In both cases the certificate content is adhering to the restrictions given by [RFC5280]. The re-encoding is known to work with DER encoded certificates but might work with other canonical encodings. The re-encoding does not work for BER encoded certificates.¶
In the encoding described below, the order of elements in arrays are always encoded in the same order as the elements or the corresponding SEQUENCE or SET in the DER encoding.¶
The X.509 fields and their CBOR encodings are listed below, and used in the definition of CBOR Certificates, see Figure 1.¶
CBOR certificates are defined in terms of DER encoded [RFC5280] X.509 certificates:¶
The following Concise Data Definition Language (CDDL) defines CBORCertificate and TBSCertificate, which are encoded as CBOR Sequences [RFC8742]. The member names therefore only have documentary value.¶
For RSA public keys (rsaEncryption), the SEQUENCE and INTEGER type and length fields are omitted and the two INTEGER value fields (modulus, exponent) are encoded as an array of two unwrapped CBOR unsigned bignum (~biguint), i.e. [ modulus : ~biguint, exponent : ~biguint ]. If the exponent is 65537, the array and the exponent is omitted and subjectPublicKey consist of only the modulus encoded as an unwrapped CBOR unsigned bignum (~biguint).¶
For elliptic curve public keys in Weirstrass form (id-ecPublicKey), uncompressed keys are point compressed as defined in Section 2.3.3 of [SECG]. If a DER encoded certificate with a point compressed public key of type id-ecPublicKey is CBOR encoded, the octets 0xfe and 0xfd are used instead of 0x02 and 0x03 in the CBOR encoding to represent even and odd y-coordinate, respectively.¶
For ECDSA signatures, the SEQUENCE and INTEGER type and length fields as well as the any leading 0x00 byte (to indicate that the number is not negative) are omitted. If the two INTEGER value fields have different lengths, the shortest INTEGER value field is padded with zeroes so that the two fields have the same length. The resulting byte string is encoded as a CBOR byte string.¶
This section details the encoding of the 'extensions' field. The 'extensions' field is encoded as a CBOR array where each extensionID is encoded as either a CBOR int or a CBOR OID tag. If 'extensionID' is encoded an int (see Section 9.3),the sign is used to encode if the extension is critical and the 'critical' field is omitted. Critical extensions are encoded with a positive sign and non-critical extensions are encoded with a negative sign.¶
The 'extnValue' OCTET STREAM value field is encoded as the CBOR byte string 'extensionValue' except for the extensions specified below. The 'extensionValue' for the extensions mandated to be supported by [RFC7925], [IEEE-802.1AR], and [CAB-Baseline] are encoded as follows:¶
GeneralNames = [ + GeneralName ] / text GeneralName = ( GeneralNameType : int, GeneralNameValue : any )¶
ExtValueEKU = [ + int / ~oid ] / int¶
ExtValueAKI = [ keyIdentifier: bytes / null, certIssuer: GeneralNames / null, certSerialNumber: CertificateSerialNumber / null ] / bytes¶
ExtValueAIA = [ + ( ocsp : 1 // caIssuers : 2 , uri : text ) ]¶
The examples below use values from Section 9.3, Section 9.4, and Section 9.5:¶
Thus, the extension field of a certificate containing all of the above extensions in the given order would be encoded as the CBOR array [ -1, -1, 2, 17, 3, [ 3, 6 ], 4, "example.com" ].¶
For general purpose applications, the normative requirements of [RFC5280] applies. This section describes the mandatory to implement algorithms and OIDs for constrained IoT application; the values of the OIDs including certificate fields and extensions, time format, attributes in distinguished names, etc.¶
TODO: Write this section¶
CBOR certificates can be deployed with legacy X.509 certificates and CA infrastructure. In order to verify the signature, the CBOR certificate is used to recreate the original X.509 data structure to be able to verify the signature.¶
For protocols like TLS/DTLS 1.2, where the handshake is sent unencrypted, the actual encoding and compression can be done at different locations depending on the deployment setting. For example, the mapping between CBOR certificate and standard X.509 certificate can take place in a 6LoWPAN border gateway which allows the server side to stay unmodified. This case gives the advantage of the low overhead of a CBOR certificate over a constrained wireless links. The conversion to X.509 within an IoT device will incur a computational overhead, however, measured in energy this is likely to be negligible compared to the reduced communication overhead.¶
For the setting with constrained server and server-only authentication, the server only needs to be provisioned with the CBOR certificate and does not perform the conversion to X.509. This option is viable when client authentication can be asserted by other means.¶
For protocols like IKEv2, TLS/DTLS 1.3, and EDHOC, where certificates are encrypted, the proposed encoding needs to be done fully end-to-end, through adding the encoding/decoding functionality to the server.¶
The CBOR encoding of the sample certificate given in Appendix A results in the numbers shown in Figure 2. After [RFC7925] profiling, most duplicated information has been removed, and the remaining text strings are minimal in size. Therefore, the further size reduction reached with general compression mechanisms will be small, mainly corresponding to making the ASN.1 encoding more compact. For Brtoli [RFC7932], the brotli command line tool 1.09 was used with the default best compression level.¶
The difference between CBOR encoded X.509 certificate and natively signed CBOR certificate is that the signature is calculated over the CBOR encoding of the CBOR sequence TBSCertficate rather than the DER encoded ASN.1 data. This removes entirely the need for ASN.1 DER and base64 encodings which reduces the processing in the authenticating devices, and avoids known complexities and security issues with these encodings.¶
Natively signed CBOR certificates can be applied in devices that are only required to authenticate to natively signed CBOR certificate compatible servers. This is not a major restriction for many IoT deployments, where the parties issuing and verifying certificates can be a restricted ecosystem which not necessarily involves public CAs.¶
CBOR encoded X.509 certificates provides an intermediate step between [RFC7925] or [IEEE-802.1AR] profiled X.509 certificates and natively signed CBOR certificates: An implementation of CBOR encoded X.509 certificates contains both the CBOR encoding of the X.509 certificate and the signature operations sufficient for natively signed CBOR certificates.¶
The natively signed approach based on DER encoded X.509 certificates described in this document has also other benefits. For example, a CA can use existing ASN.1 machinery to create a DER encoded certificate, the DER encoded certificate can then be transformed to CBOR before signing.¶
The CBOR profiling of X.509 certificates does not change the security assumptions needed when deploying standard X.509 certificates but decreases the number of fields transmitted, which reduces the risk for implementation errors.¶
The use of natively signed CBOR certificates removes the need for ASN.1 encoding, which is a rich source of security vulnerabilities.¶
Conversion between the certificate formats can be made in constant time to reduce risk of information leakage through side channels.¶
The mechanism in this draft does not reveal any additional information compared to X.509. Because of difference in size, it will be possible to detect that this profile is used. The gateway solution described in Section 5 requires unencrypted certificates and is not recommended.¶
This document creates several new registries under the new heading "CBOR Certificate". For all items, the 'Reference' field points to this document.¶
The expert reviewers for the registries defined in this document are expected to ensure that the usage solves a valid use case that could not be solved better in a different way, that it is not going to duplicate one that is already registered, and that the registered point is likely to be used in deployments. They are furthermore expected to check the clarity of purpose and use of the requested code points. Experts should take into account the expected usage of entries when approving point assignment, and the length of the encoded value should be weighed against the number of code points left that encode to that size and how constrained the systems it will be used on are. Values in the interval [-24, 23] have a 1 byte encodings, other values in the interval [-256, 255] have a 2 byte encodings, and the remaning values in the interval [-65536, 65535] have 3 byte encodings.¶
IANA has created a new registry titled "CBOR Certificate Types" under the new heading "CBOR Certificate". The columns of the registry are Value, Description, and Reference, where Value is an integer, and the other columns are text strings. For values in the interval [-24, 23] the registration procedure is "IETF Review" and "Expert Review". For all other values the registration procedure is "Expert Review". The initial contents of the registry are:¶
IANA has created a new registry titled "CBOR Certificate Attributes" under the new heading "CBOR Certificate". The columns of the registry are Value, Name, OID, DER, Comments, and Reference, where Value is an integer, and the other columns are text strings. Only non-negative values can be registered. For values in the interval [0, 23] the registration procedure is "IETF Review" and "Expert Review". For all other values the registration procedure is "Expert Review". The initial contents of the registry are:¶
IANA has created a new registry titled "CBOR Certificate Extensions" under the new heading "CBOR Certificate". The columns of the registry are Value, Name, OID, DER, Comments, extensionValue, and Reference, where Value is an integer, and the other columns are text strings. Only non-negative values can be registered. For values in the interval [0, 23] the registration procedure is "IETF Review" and "Expert Review". For all other values the registration procedure is "Expert Review". The initial contents of the registry are:¶
IANA has created a new registry titled "CBOR Certificate Extended Key Usages" under the new heading "CBOR Certificate". The columns of the registry are Value, Name, OID, DER, Comments, and Reference, where Value is an integer, and the other columns are text strings. For values in the interval [-24, 23] the registration procedure is "IETF Review" and "Expert Review". For all other values the registration procedure is "Expert Review". The initial contents of the registry are:¶
IANA has created a new registry titled "CBOR Certificate General Names" under the new heading "CBOR Certificate". The columns of the registry are Value, General Name, and Reference, where Value is an integer, and the other columns are text strings. For values in the interval [-24, 23] the registration procedure is "IETF Review" and "Expert Review". For all other values the registration procedure is "Expert Review". The initial contents of the registry are:¶
IANA has created a new registry titled "CBOR Certificate Signature Algorithms" under the new heading "CBOR Certificate". The columns of the registry are Value, Name, OID, Parameters, DER, Comments, and Reference, where Value is an integer, and the other columns are text strings. For values in the interval [-24, 23] the registration procedure is "IETF Review" and "Expert Review". For all other values the registration procedure is "Expert Review". The initial contents of the registry are:¶
IANA has created a new registry titled "CBOR Certificate Public Key Algorithms" under the new heading "CBOR Certificate". The columns of the registry are Value, Name, OID, Parameters, DER, Comments, and Reference, where Value is an integer, and the other columns are text strings. For values in the interval [-24, 23] the registration procedure is "IETF Review" and "Expert Review". For all other values the registration procedure is "Expert Review". T The initial contents of the registry are:¶
This document registers the following entries in the "COSE Header Parameters" registry under the "CBOR Object Signing and Encryption (COSE)" heading. The formatting and processing are the same as the corresponding x5bag, x5chain, x5t, and x5u defined in [I-D.ietf-cose-x509] except that the certificates are CBOR encoded instead of DER encoded. Note that certificates can also be identified with a 'kid' header parameter by storing 'kid' and the associated bag or chain in a dictionary.¶
+-----------+-------+----------------+------------------------------+ | Name | Label | Value Type | Description | +===========+=======+================+==============================+ | c5bag | TBD1 | COSE_X509 | An unordered bag of CBOR | | | | | certificates | +-----------+-------+----------------+------------------------------+ | c5chain | TBD2 | COSE_X509 | An ordered chain of CBOR | | | | | certificates | +-----------+-------+----------------+------------------------------+ | c5t | TBD3 | COSE_CertHash | Hash of a CBOR certificate | +-----------+-------+----------------+------------------------------+ | c5u | TBD4 | uri | URI pointing to a CBOR | | | | | certificate | +-----------+-------+----------------+------------------------------+¶
This document registers the following entry in the "TLS Certificate Types" registry under the "Transport Layer Security (TLS) Extensions" heading. The new certificate type can be used with addtional TLS certificate compression [RFC8879].¶
EDITOR'S NOTE: The TLS registrations should be discussed and approved by the TLS WG at a later stage. When COSE WG has adopted work on CBOR certificates, it could perhaps be presented in the TLS WG. The TLS WG might e.g. want a separate draft in the TLS WG.¶
+-------+------------------+-------------+--------------------------+ | Value | Name | Recommended | Comment | +=======+==================+=============+==========================+ | TBD5 | CBOR Certificate | Y | | +-------+------------------+-------------+--------------------------+¶
Example of [RFC7925] profiled X.509 certificate parsed with OpenSSL.¶
Certificate: Data: Version: 3 (0x2) Serial Number: 128269 (0x1f50d) Signature Algorithm: ecdsa-with-SHA256 Issuer: CN=RFC test CA Validity Not Before: Jan 1 00:00:00 2020 GMT Not After : Feb 2 00:00:00 2021 GMT Subject: CN=01-23-45-FF-FE-67-89-AB Subject Public Key Info: Public Key Algorithm: id-ecPublicKey Public-Key: (256 bit) pub: 04:b1:21:6a:b9:6e:5b:3b:33:40:f5:bd:f0:2e:69: 3f:16:21:3a:04:52:5e:d4:44:50:b1:01:9c:2d:fd: 38:38:ab:ac:4e:14:d8:6c:09:83:ed:5e:9e:ef:24: 48:c6:86:1c:c4:06:54:71:77:e6:02:60:30:d0:51: f7:79:2a:c2:06 ASN1 OID: prime256v1 NIST CURVE: P-256 X509v3 extensions: X509v3 Key Usage: Digital Signature Signature Algorithm: ecdsa-with-SHA256 30:44:02:20:44:5d:79:8c:90:e7:f5:00:dc:74:7a:65:4c:ec: 6c:fa:6f:03:72:76:e1:4e:52:ed:07:fc:16:29:4c:84:66:0d: 02:20:5a:33:98:5d:fb:d4:bf:dd:6d:4a:cf:38:04:c3:d4:6e: bf:3b:7f:a6:26:40:67:4f:c0:35:4f:a0:56:db:ae:a6¶
The DER encoding of the above certificate is 314 bytes.¶
30 82 01 36 30 81 DE A0 03 02 01 02 02 03 01 F5 0D 30 0A 06 08 2A 86 48 CE 3D 04 03 02 30 16 31 14 30 12 06 03 55 04 03 0C 0B 52 46 43 20 74 65 73 74 20 43 41 30 1E 17 0D 32 30 30 31 30 31 30 30 30 30 30 30 5A 17 0D 32 31 30 32 30 32 30 30 30 30 30 30 5A 30 22 31 20 30 1E 06 03 55 04 03 0C 17 30 31 2D 32 33 2D 34 35 2D 46 46 2D 46 45 2D 36 37 2D 38 39 2D 41 42 30 59 30 13 06 07 2A 86 48 CE 3D 02 01 06 08 2A 86 48 CE 3D 03 01 07 03 42 00 04 B1 21 6A B9 6E 5B 3B 33 40 F5 BD F0 2E 69 3F 16 21 3A 04 52 5E D4 44 50 B1 01 9C 2D FD 38 38 AB AC 4E 14 D8 6C 09 83 ED 5E 9E EF 24 48 C6 86 1C C4 06 54 71 77 E6 02 60 30 D0 51 F7 79 2A C2 06 A3 0F 30 0D 30 0B 06 03 55 1D 0F 04 04 03 02 07 80 30 0A 06 08 2A 86 48 CE 3D 04 03 02 03 47 00 30 44 02 20 44 5D 79 8C 90 E7 F5 00 DC 74 7A 65 4C EC 6C FA 6F 03 72 76 E1 4E 52 ED 07 FC 16 29 4C 84 66 0D 02 20 5A 33 98 5D FB D4 BF DD 6D 4A CF 38 04 C3 D4 6E BF 3B 7F A6 26 40 67 4F C0 35 4F A0 56 DB AE A6¶
The CBOR encoding of the same X.509 certificate is shown below in CBOR diagnostic format.¶
/This defines a CBOR Sequence (RFC 8742):/ 1, h'01f50d', "RFC test CA", 1577836800, 1612224000, h'0123456789AB', 1, h'02B1216AB96E5B3B3340F5BDF02E693F16213A04525ED44450 B1019C2DFD3838AB', 1, 0, h'445D798C90E7F500DC747A654CEC6CFA6F037276E14E52ED07 FC16294C84660D5A33985DFBD4BFDD6D4ACF3804C3D46EBF3B 7FA62640674FC0354FA056DBAEA6¶
The size of the CBOR encoding (CBOR sequence) is 138 bytes.¶
01 43 01 F5 0D 6B 52 46 43 20 74 65 73 74 20 43 41 1A 5E 0B E1 00 1A 60 18 96 00 46 01 23 45 67 89 AB 01 58 21 02 B1 21 6A B9 6E 5B 3B 33 40 F5 BD F0 2E 69 3F 16 21 3A 04 52 5E D4 44 50 B1 01 9C 2D FD 38 38 AB 01 00 58 40 44 5D 79 8C 90 E7 F5 00 DC 74 7A 65 4C EC 6C FA 6F 03 72 76 E1 4E 52 ED 07 FC 16 29 4C 84 66 0D 5A 33 98 5D FB D4 BF DD 6D 4A CF 38 04 C3 D4 6E BF 3B 7F A6 26 40 67 4F C0 35 4F A0 56 DB AE A6¶
The corresponding natively signed CBOR certificate in CBOR diagnostic format is identical, except for cborCertificateType and signatureValue.¶
/This defines a CBOR Sequence (RFC 8742):/ 0, h'01f50d', "RFC test CA", 1577836800, 1612224000, h'0123456789AB', 1, h'02B1216AB96E5B3B3340F5BDF02E693F16213A04525ED44450 B1019C2DFD3838AB', 1, 6, h'B27A0B781455F71B68290F6C2EC9A897F18FDE9B6C59575953 BC67268AB0E4DDE99D273E04E4715383AB2257C6AAA35284E5 ED18BDB91247E9F2C433136480B9'¶
The size of the CBOR encoding (CBOR sequence) is 138 bytes.¶
00 43 01 F5 0D 6B 52 46 43 20 74 65 73 74 20 43 41 1A 5E 0B E1 00 1A 60 18 96 00 46 01 23 45 67 89 AB 01 58 21 02 B1 21 6A B9 6E 5B 3B 33 40 F5 BD F0 2E 69 3F 16 21 3A 04 52 5E D4 44 50 B1 01 9C 2D FD 38 38 AB 01 00 58 40 B2 7A 0B 78 14 55 F7 1B 68 29 0F 6C 2E C9 A8 97 F1 8F DE 9B 6C 59 57 59 53 BC 67 26 8A B0 E4 DD E9 9D 27 3E 04 E4 71 53 83 AB 22 57 C6 AA A3 52 84 E5 ED 18 BD B9 12 47 E9 F2 C4 33 13 64 80 B9¶
Below are the issuer key pair and the subject private key belonging to the above example certificates. The private keys are encoded as in COSE [RFC8152]. These issuer key pair can be used to sign or verify the example certificates and the subject private key allows the example certificates to be used in test vectors for other protocols like EDHOC.¶
issuerPublicKeyAlgorithm : 1 (EC Public Key (Weierstraß) with secp256r1) issuerPublicKey : h'02AE4CDB01F614DEFC7121285FDC7F5C6D1D42C95647F061BA0080DF678867845E' issuerPrivateKey : h'DC66B3415456D649429B53223DF7532B942D6B0E0842C30BCA4C0ACF91547BB2'¶
subjectPrivateKey : h'D718111F3F9BD91B92FF6877F386BDBFCEA7154268FD7F2FB56EE17D99EA16D4'¶
EDITOR'S NOTE: To do¶
The www.ietf.org HTTPS server replies with a certificate message with 2 certificates. The DER encoding of the first certificate is 1209 bytes.¶
30 82 04 b5 30 82 04 5a a0 03 02 01 02 02 10 04 7f a1 e3 19 28 ee 40 3b a0 b8 3a 39 56 73 fc 30 0a 06 08 2a 86 48 ce 3d 04 03 02 30 4a 31 0b 30 09 06 03 55 04 06 13 02 55 53 31 19 30 17 06 03 55 04 0a 13 10 43 6c 6f 75 64 66 6c 61 72 65 2c 20 49 6e 63 2e 31 20 30 1e 06 03 55 04 03 13 17 43 6c 6f 75 64 66 6c 61 72 65 20 49 6e 63 20 45 43 43 20 43 41 2d 33 30 1e 17 0d 32 30 30 37 32 39 30 30 30 30 30 30 5a 17 0d 32 31 30 37 32 39 31 32 30 30 30 30 5a 30 6d 31 0b 30 09 06 03 55 04 06 13 02 55 53 31 0b 30 09 06 03 55 04 08 13 02 43 41 31 16 30 14 06 03 55 04 07 13 0d 53 61 6e 20 46 72 61 6e 63 69 73 63 6f 31 19 30 17 06 03 55 04 0a 13 10 43 6c 6f 75 64 66 6c 61 72 65 2c 20 49 6e 63 2e 31 1e 30 1c 06 03 55 04 03 13 15 73 6e 69 2e 63 6c 6f 75 64 66 6c 61 72 65 73 73 6c 2e 63 6f 6d 30 59 30 13 06 07 2a 86 48 ce 3d 02 01 06 08 2a 86 48 ce 3d 03 01 07 03 42 00 04 96 3e cd d8 4d cd 1b 93 a1 cf 43 2d 1a 72 17 d6 c6 3b de 33 55 a0 2f 8c fb 5a d8 99 4c d4 4e 20 5f 15 f6 e3 d2 3b 38 2b a6 49 9b b1 7f 34 1f a5 92 fa 21 86 1f 16 d3 12 06 63 24 05 fd 70 42 bd a3 82 02 fd 30 82 02 f9 30 1f 06 03 55 1d 23 04 18 30 16 80 14 a5 ce 37 ea eb b0 75 0e 94 67 88 b4 45 fa d9 24 10 87 96 1f 30 1d 06 03 55 1d 0e 04 16 04 14 cc 0b 50 e7 d8 37 db f2 43 f3 85 3d 48 60 f5 3b 39 be 9b 2a 30 2e 06 03 55 1d 11 04 27 30 25 82 15 73 6e 69 2e 63 6c 6f 75 64 66 6c 61 72 65 73 73 6c 2e 63 6f 6d 82 0c 77 77 77 2e 69 65 74 66 2e 6f 72 67 30 0e 06 03 55 1d 0f 01 01 ff 04 04 03 02 07 80 30 1d 06 03 55 1d 25 04 16 30 14 06 08 2b 06 01 05 05 07 03 01 06 08 2b 06 01 05 05 07 03 02 30 7b 06 03 55 1d 1f 04 74 30 72 30 37 a0 35 a0 33 86 31 68 74 74 70 3a 2f 2f 63 72 6c 33 2e 64 69 67 69 63 65 72 74 2e 63 6f 6d 2f 43 6c 6f 75 64 66 6c 61 72 65 49 6e 63 45 43 43 43 41 2d 33 2e 63 72 6c 30 37 a0 35 a0 33 86 31 68 74 74 70 3a 2f 2f 63 72 6c 34 2e 64 69 67 69 63 65 72 74 2e 63 6f 6d 2f 43 6c 6f 75 64 66 6c 61 72 65 49 6e 63 45 43 43 43 41 2d 33 2e 63 72 6c 30 4c 06 03 55 1d 20 04 45 30 43 30 37 06 09 60 86 48 01 86 fd 6c 01 01 30 2a 30 28 06 08 2b 06 01 05 05 07 02 01 16 1c 68 74 74 70 73 3a 2f 2f 77 77 77 2e 64 69 67 69 63 65 72 74 2e 63 6f 6d 2f 43 50 53 30 08 06 06 67 81 0c 01 02 02 30 76 06 08 2b 06 01 05 05 07 01 01 04 6a 30 68 30 24 06 08 2b 06 01 05 05 07 30 01 86 18 68 74 74 70 3a 2f 2f 6f 63 73 70 2e 64 69 67 69 63 65 72 74 2e 63 6f 6d 30 40 06 08 2b 06 01 05 05 07 30 02 86 34 68 74 74 70 3a 2f 2f 63 61 63 65 72 74 73 2e 64 69 67 69 63 65 72 74 2e 63 6f 6d 2f 43 6c 6f 75 64 66 6c 61 72 65 49 6e 63 45 43 43 43 41 2d 33 2e 63 72 74 30 0c 06 03 55 1d 13 01 01 ff 04 02 30 00 30 82 01 05 06 0a 2b 06 01 04 01 d6 79 02 04 02 04 81 f6 04 81 f3 00 f1 00 76 00 f6 5c 94 2f d1 77 30 22 14 54 18 08 30 94 56 8e e3 4d 13 19 33 bf df 0c 2f 20 0b cc 4e f1 64 e3 00 00 01 73 9c 83 5f 8e 00 00 04 03 00 47 30 45 02 21 00 f8 d1 b4 a9 3d 2f 0d 4c 41 76 df b4 88 bc c7 3b 86 44 3d 7d e0 0e 6a c8 17 4d 89 48 a8 84 36 68 02 20 29 ff 5a 34 06 8a 24 0c 69 50 27 88 e8 ee 25 ab 7e d2 cb cf 68 6e ce 7b 5f 96 b4 31 a9 07 02 fa 00 77 00 5c dc 43 92 fe e6 ab 45 44 b1 5e 9a d4 56 e6 10 37 fb d5 fa 47 dc a1 73 94 b2 5e e6 f6 c7 0e ca 00 00 01 73 9c 83 5f be 00 00 04 03 00 48 30 46 02 21 00 e8 91 c1 97 bf b0 e3 d3 0c b6 ce e6 0d 94 c3 c7 5f d1 17 53 36 93 11 08 d8 98 12 d4 d2 9d 81 d0 02 21 00 a1 59 d1 6c 46 47 d1 48 37 57 fc d6 ce 4e 75 ec 7b 5e f6 57 ef e0 28 f8 e5 cc 47 92 68 2d ac 43 30 0a 06 08 2a 86 48 ce 3d 04 03 02 03 49 00 30 46 02 21 00 bd 63 cf 4f 7e 5c fe 6c 29 38 5e a7 1c fb fc 1e 3f 7b 1c d0 72 51 a2 21 f7 77 69 c0 f4 71 df ea 02 21 00 b5 c0 6c c4 58 54 fa 30 b2 82 88 b1 d3 bb 9a 66 61 ed 50 31 72 5b 1a 82 02 e0 da 5b 59 f9 54 02¶
The CBOR encoding of the first X.509 certificate is shown below in CBOR diagnostic format.¶
/This defines a CBOR Sequence (RFC 8742):/ 1, h'047FA1E31928EE403BA0B83A395673FC', [ -4, "IE", -8, "Baltimore", -9, "CyberTrust", -1, "Baltimore CyberTrust Root" ], 1595980800, 1627560000, [ -4, "US", -6, "CA", -5, "San Francisco", -8, "Cloudflare, Inc.", -1, "sni.cloudflaressl.com" ], 1, h'03963ECDD84DCD1B93A1CF432D1A7217D6C63BDE3355A02F8CFB5AD8994CD44E20', [ 6, h'A5CE37EAEBB0750E946788B445FAD9241087961F', 0, h'CC0B50E7D837DBF243F3853D4860F53B39BE9B2A', 2, [2, "sni.cloudflaressl.com", 2, "www.ietf.org"], -1, 1, 7, [1, 2], 4, ["http://crl3.digicert.com/CloudflareIncECCCA-3.crl", "http://crl4.digicert.com/CloudflareIncECCCA-3.crl"], 5, [h'6086480186FD6C0101', "https://www.digicert.com/CPS", 2], 8, [1, "http://ocsp.digicert.com", 2, "http://cacerts.digicert.com/CloudflareIncECCCA-3.crt"], -3, -2, 9, ... ], 0, h'BD63CF4F7E5CFE6C29385EA71CFBFC1E3F7B1CD07251A221F77769C0F471DFEAB5C06CC45854FA30B28288B1D3BB9A6661ED5031725B1A8202E0DA5B59F95402'¶
The tools.ietf.org HTTPS server replies with a certificate message with 4 certificates. The DER encoding of the first certificate is 1647 bytes.¶
30 82 06 6b 30 82 05 53 a0 03 02 01 02 02 09 00 a6 a5 5c 87 0e 39 b4 0e 30 0d 06 09 2a 86 48 86 f7 0d 01 01 0b 05 00 30 81 c6 31 0b 30 09 06 03 55 04 06 13 02 55 53 31 10 30 0e 06 03 55 04 08 13 07 41 72 69 7a 6f 6e 61 31 13 30 11 06 03 55 04 07 13 0a 53 63 6f 74 74 73 64 61 6c 65 31 25 30 23 06 03 55 04 0a 13 1c 53 74 61 72 66 69 65 6c 64 20 54 65 63 68 6e 6f 6c 6f 67 69 65 73 2c 20 49 6e 63 2e 31 33 30 31 06 03 55 04 0b 13 2a 68 74 74 70 3a 2f 2f 63 65 72 74 73 2e 73 74 61 72 66 69 65 6c 64 74 65 63 68 2e 63 6f 6d 2f 72 65 70 6f 73 69 74 6f 72 79 2f 31 34 30 32 06 03 55 04 03 13 2b 53 74 61 72 66 69 65 6c 64 20 53 65 63 75 72 65 20 43 65 72 74 69 66 69 63 61 74 65 20 41 75 74 68 6f 72 69 74 79 20 2d 20 47 32 30 1e 17 0d 32 30 31 30 30 31 31 39 33 38 33 36 5a 17 0d 32 31 31 31 30 32 31 39 33 38 33 36 5a 30 3e 31 21 30 1f 06 03 55 04 0b 13 18 44 6f 6d 61 69 6e 20 43 6f 6e 74 72 6f 6c 20 56 61 6c 69 64 61 74 65 64 31 19 30 17 06 03 55 04 03 0c 10 2a 2e 74 6f 6f 6c 73 2e 69 65 74 66 2e 6f 72 67 30 82 01 22 30 0d 06 09 2a 86 48 86 f7 0d 01 01 01 05 00 03 82 01 0f 00 30 82 01 0a 02 82 01 01 00 b1 e1 37 e8 eb 82 d6 89 fa db f5 c2 4b 77 f0 2c 4a de 72 6e 3e 13 60 d1 a8 66 1e c4 ad 3d 32 60 e5 f0 99 b5 f4 7a 7a 48 55 21 ee 0e 39 12 f9 ce 0d ca f5 69 61 c7 04 ed 6e 0f 1d 3b 1e 50 88 79 3a 0e 31 41 16 f1 b1 02 64 68 a5 cd f5 4a 0a ca 99 96 35 08 c3 7e 27 5d d0 a9 cf f3 e7 28 af 37 d8 b6 7b dd f3 7e ae 6e 97 7f f7 ca 69 4e cc d0 06 df 5d 27 9b 3b 12 e7 e6 fe 08 6b 52 7b 82 11 7c 72 b3 46 eb c1 e8 78 b8 0f cb e1 eb bd 06 44 58 dc 83 50 b2 a0 62 5b dc 81 b8 36 e3 9e 7c 79 b2 a9 53 8a e0 0b c9 4a 2a 13 39 31 13 bd 2c cf a8 70 cf 8c 8d 3d 01 a3 88 ae 12 00 36 1d 1e 24 2b dd 79 d8 53 01 26 ed 28 4f c9 86 94 83 4e c8 e1 14 2e 85 b3 af d4 6e dd 69 46 af 41 25 0e 7a ad 8b f2 92 ca 79 d9 7b 32 4f f7 77 e8 f9 b4 4f 23 5c d4 5c 03 ae d8 ab 3a ca 13 5f 5d 5d 5d a1 02 03 01 00 01 a3 82 02 e1 30 82 02 dd 30 0c 06 03 55 1d 13 01 01 ff 04 02 30 00 30 1d 06 03 55 1d 25 04 16 30 14 06 08 2b 06 01 05 05 07 03 01 06 08 2b 06 01 05 05 07 03 02 30 0e 06 03 55 1d 0f 01 01 ff 04 04 03 02 05 a0 30 3d 06 03 55 1d 1f 04 36 30 34 30 32 a0 30 a0 2e 86 2c 68 74 74 70 3a 2f 2f 63 72 6c 2e 73 74 61 72 66 69 65 6c 64 74 65 63 68 2e 63 6f 6d 2f 73 66 69 67 32 73 31 2d 32 34 32 2e 63 72 6c 30 63 06 03 55 1d 20 04 5c 30 5a 30 4e 06 0b 60 86 48 01 86 fd 6e 01 07 17 01 30 3f 30 3d 06 08 2b 06 01 05 05 07 02 01 16 31 68 74 74 70 3a 2f 2f 63 65 72 74 69 66 69 63 61 74 65 73 2e 73 74 61 72 66 69 65 6c 64 74 65 63 68 2e 63 6f 6d 2f 72 65 70 6f 73 69 74 6f 72 79 2f 30 08 06 06 67 81 0c 01 02 01 30 81 82 06 08 2b 06 01 05 05 07 01 01 04 76 30 74 30 2a 06 08 2b 06 01 05 05 07 30 01 86 1e 68 74 74 70 3a 2f 2f 6f 63 73 70 2e 73 74 61 72 66 69 65 6c 64 74 65 63 68 2e 63 6f 6d 2f 30 46 06 08 2b 06 01 05 05 07 30 02 86 3a 68 74 74 70 3a 2f 2f 63 65 72 74 69 66 69 63 61 74 65 73 2e 73 74 61 72 66 69 65 6c 64 74 65 63 68 2e 63 6f 6d 2f 72 65 70 6f 73 69 74 6f 72 79 2f 73 66 69 67 32 2e 63 72 74 30 1f 06 03 55 1d 23 04 18 30 16 80 14 25 45 81 68 50 26 38 3d 3b 2d 2c be cd 6a d9 b6 3d b3 66 63 30 2b 06 03 55 1d 11 04 24 30 22 82 10 2a 2e 74 6f 6f 6c 73 2e 69 65 74 66 2e 6f 72 67 82 0e 74 6f 6f 6c 73 2e 69 65 74 66 2e 6f 72 67 30 1d 06 03 55 1d 0e 04 16 04 14 ad 8a b4 1c 07 51 d7 92 89 07 b0 b7 84 62 2f 36 55 7a 5f 4d 30 82 01 06 06 0a 2b 06 01 04 01 d6 79 02 04 02 04 81 f7 04 81 f4 00 f2 00 77 00 f6 5c 94 2f d1 77 30 22 14 54 18 08 30 94 56 8e e3 4d 13 19 33 bf df 0c 2f 20 0b cc 4e f1 64 e3 00 00 01 74 e5 ac 71 13 00 00 04 03 00 48 30 46 02 21 00 8c f5 48 52 ce 56 35 43 39 11 cf 10 cd b9 1f 52 b3 36 39 22 3a d1 38 a4 1d ec a6 fe de 1f e9 0f 02 21 00 bc a2 25 43 66 c1 9a 26 91 c4 7a 00 b5 b6 53 ab bd 44 c2 f8 ba ae f4 d2 da f2 52 7c e6 45 49 95 00 77 00 5c dc 43 92 fe e6 ab 45 44 b1 5e 9a d4 56 e6 10 37 fb d5 fa 47 dc a1 73 94 b2 5e e6 f6 c7 0e ca 00 00 01 74 e5 ac 72 3c 00 00 04 03 00 48 30 46 02 21 00 a5 e0 90 6e 63 e9 1d 4f dd ef ff 03 52 b9 1e 50 89 60 07 56 4b 44 8a 38 28 f5 96 dc 6b 28 72 6d 02 21 00 fc 91 ea ed 02 16 88 66 05 4e e1 8a 2e 53 46 c4 cc 51 fe b3 fa 10 a9 1d 2e db f9 91 25 f8 6c e6 30 0d 06 09 2a 86 48 86 f7 0d 01 01 0b 05 00 03 82 01 01 00 14 04 3f a0 be d2 ee 3f a8 6e 3a 1f 78 8e a0 4c 35 53 0f 11 06 1f ff 60 a1 6d 0b 83 e9 d9 2a db b3 3f 9d b3 d7 e0 59 4c 19 a8 e4 19 a5 0c a7 70 72 77 63 d5 fe 64 51 0a d2 7a d6 50 a5 8a 92 38 ec cb 2f 0f 5a c0 64 58 4d 5c 06 b9 73 63 68 27 8b 89 34 dc 79 c7 1d 3a fd 34 5f 83 14 41 58 49 80 68 29 80 39 8a 86 72 69 cc 79 37 ce e3 97 f7 dc f3 95 88 ed 81 03 29 00 d2 a2 c7 ba ab d6 3a 8e ca 09 0b d9 fb 39 26 4b ff 03 d8 8e 2d 3f 6b 21 ca 8a 7d d8 5f fb 94 ba 83 de 9c fc 15 8d 61 fa 67 2d b0 c7 db 3d 25 0a 41 4a 85 d3 7f 49 46 37 3c f4 b1 75 d0 52 f3 dd c7 66 f1 4b fd aa 00 ed bf e4 7e ed 01 ec 7b e4 f6 46 fc 31 fd 72 fe 03 d2 f2 65 af 4d 7e e2 81 9b 7a fd 30 3c f5 52 f4 05 34 a0 8a 3e 19 41 58 c8 a8 e0 51 71 84 09 15 ae ec a5 77 75 fa 18 f7 d5 77 d5 31 cc c7 2d¶
The CBOR encoding of the first X.509 certificate is shown below in CBOR diagnostic format.¶
/This defines a CBOR Sequence (RFC 8742):/ 1, h'A6A55C870E39B40E', [ -4, "US", -6, "Arizona", -5, "Scottsdale", -8, "Starfield Technologies, Inc.", -9, "http://certs.starfieldtech.com/repository/", -1, "Starfield Secure Certificate Authority - G2" ], 1601581116, 1635881916, [ -9, "Domain Control Validated", 1, "*.tools.ietf.org" ], 0, h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http://crl.starfieldtech.com/sfig2s1-242.crl", 5, [ h'6086480186fd6e01071701', "http://certificates.starfieldtech.com/repository/", 1 ], 8, [ 1, "http://ocsp.starfieldtech.com/", 2, "http://certificates.starfieldtech.com/repository/sfig2.crt" ], 6, h'254581685026383D3B2D2CBECD6AD9B63DB36663', 2, [ 2, "*.tools.ietf.org", 2, "tools.ietf.org" ], 0, h'AD8AB41C0751D7928907B0B784622F36557A5F4D', 9, [ h'F65C942FD1773022145418083094568EE34D131933BFDF0C2F200BCC4EF164E3', 1715, 1, h'8CF54852CE5635433911CF10CDB91F52B33639223AD138A41DECA6FEDE1FE90FBCA2254366C19A2691C47A00B5B653ABBD44C2F8BAAEF4D2DAF2527CE6454995', h'5CDC4392FEE6AB4544B15E9AD456E61037FBD5FA47DCA17394B25EE6F6C70ECA', 2012, 1, h'A5E0906E63E91D4FDDEFFF0352B91E50896007564B448A3828F596DC6B28726DFC91EAED02168866054EE18A2E5346C4CC51FEB3FA10A91D2EDBF99125F86CE6' ] ], 23, h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¶
The size of the CBOR encoding (CBOR sequence) is 1242 bytes.¶
The authors want to thank Henk Birkholz, Carsten Bormann, Russ Housley, Olle Johansson, Benjamin Kaduk, Ilari Liusvaara, Laurence Lundblade, Thomas Peterson, Michael Richardson, Stefan Santesson, Jim Schaad, Fraser Tweedale, and Rene Struik for reviewing and commenting on intermediate versions of the draft.¶