| Internet-Draft | C509 Certificates | July 2024 |
| Preuß Mattsson, et al. | Expires 9 January 2025 | [Page] |
This document specifies a CBOR encoding of X.509 certificates. The resulting certificates are called C509 Certificates. The CBOR encoding supports a large subset of RFC 5280 and all certificates compatible with the RFC 7925, IEEE 802.1AR (DevID), CNSA, RPKI, GSMA eUICC, and CA/Browser Forum Baseline Requirements profiles. 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% while also significantly reducing memory and code size compared to ASN.1. The CBOR encoded structure can alternatively be signed directly ("natively signed"), which does not require re-encoding for the signature to be verified. The document also specifies C509 Certificate Signing Requests, C509 COSE headers, a C509 TLS certificate type, and a C509 file format.¶
This note is to be removed before publishing as an RFC.¶
Status information for this document may be found at https://datatracker.ietf.org/doc/draft-ietf-cose-cbor-encoded-cert/.¶
Discussion of this document takes place on the CBOR Object Signing and Encryption Working Group mailing list (mailto:[email protected]), which is archived at https://mailarchive.ietf.org/arch/browse/cose/. Subscribe at https://www.ietf.org/mailman/listinfo/cose/.¶
Source for this draft and an issue tracker can be found at https://github.com/cose-wg/CBOR-certificates.¶
This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.¶
Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at https://datatracker.ietf.org/drafts/current/.¶
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This Internet-Draft will expire on 9 January 2025.¶
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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 [RFC9190] [RFC9191] where authenticators typically drop an EAP session after only 40 - 50 round-trips, QUIC [RFC9000] where the latency increases significantly unless the server sends less than three times as many bytes as received prior to validating the client address, and RPKI [RFC6487] where a single certificate can be very large. 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. The use of CBOR also reduces code complexity, code size, memory usage, and CPU usage.¶
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. RFC 8610 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]. We recommend implementors to get used to CBOR by using the CBOR playground [CborMe].¶
CAB Baseline Requirements [CAB-TLS], 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 [RFC9000], DTLS [RFC9147], COSE [RFC9052], 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 RFC 5280. The encoding supports all RFC 7925, IEEE 802.1AR, CAB Baseline [CAB-TLS], [CAB-Code], RPKI [RFC6487], eUICC [GSMA-eUICC] profiled X.509 certificates, and is designed to render a compact encoding of certificates used in constrained environments.¶
The resulting certificates are called C509 Certificates. This document does not specify a certificate profile. Two variants are defined using the same CBOR encoding and differing only in what is being signed:¶
An invertible CBOR re-encoding of DER encoded X.509 certificates [RFC5280], which can be reversed to obtain the original DER encoded X.509 certificate.¶
Natively signed C509 certificates, where the signature is calculated over the CBOR encoding instead of over the DER encoding as in 1. This removes the need for ASN.1 and DER parsing and the associated complexity but they are not backwards compatible with implementations requiring DER encoded X.509.¶
Natively signed C509 certificates can be applied in devices that are only required to authenticate to natively signed C509 certificate compatible servers, which is not a major restriction for many IoT deployments where the parties issuing and verifying certificates can be a restricted ecosystem.¶
This document also specifies C509 Certificate Signing Requests, see Section 4; COSE headers for use of the C509 certificates with COSE, see Section 9.12; and a TLS certificate type for use of the C509 certificates with TLS and QUIC (with or without additional TLS certificate compression), see Section 9.18.¶
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 [RFC2986], [RFC5280], [RFC7228], [RFC8610], and [RFC8949]. When referring to CBOR, this specification always refers to Deterministically Encoded CBOR as specified in Sections 4.2.1 and 4.2.2 of [RFC8949].¶
This section specifies the content and encoding for C509 certificates, with the overall objective to produce a very compact representation supporting large parts of [RFC5280], and everything in [RFC7925], [IEEE-802.1AR], RPKI [RFC6487], GSMA eUICC [GSMA-eUICC], and CAB Baseline [CAB-TLS] [CAB-Code]. In the CBOR encoding, static fields are elided, elliptic curve points and time values are compressed, OID are replaced with short integers or complemented with CBOR OID encoding [RFC9090], and redundant encoding is removed. Combining these different components reduces the certificate size significantly, which is not possible with general purpose compression algorithms, see Figure 5.¶
The C509 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 C509 certificate, in which case the signature is calculated directly on the CBOR encoded data. 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 C509 certificates, see Figure 1.¶
C509 certificates are defined in terms of DER encoded [RFC5280] X.509 certificates:¶
version. The 'version' field is encoded in the 'c509CertificateType' CBOR int. The field 'c509CertificateType' also indicates the type of the C509 certificate. Currently, the type can be a natively signed C509 certificate following X.509 v3 (c509CertificateType = 2) or a CBOR re-encoded X.509 v3 DER certificate (c509CertificateType = 3), see Section 9.1.¶
serialNumber. The 'serialNumber' INTEGER value field is encoded as the unwrapped CBOR unsigned bignum (~biguint) 'certificateSerialNumber'. Any leading 0x00 byte (to indicate that the number is not negative) is therefore omitted.¶
signature. The 'signature' field, containing the signature algorithm including parameters, is encoded as a CBOR int (see Section 9.10) or as an array with an unwrapped CBOR OID tag [RFC9090] optionally followed by the parameters encoded as a CBOR byte string.¶
issuer. In the general case, the sequence of 'Attribute' is encoded as a CBOR array of Attributes. RelativeDistinguishedName with more than one AttributeTypeAndValue is not supported. Each Attribute is encoded as either¶
The absolute value of the CBOR int (see Figure 8) encodes the attribute type and the sign is used to represent the character string type; positive for utf8String, negative for printableString. The Attribute Email Address and domainComponent (as specified in [RFC3039]) are always an ia5String. In natively signed C509 certificates all text strings are UTF-8 encoded and all attributeType SHALL be non-negative. Text strings SHALL still adhere to any X.509 restrictions, i.e., serialNumber SHALL only contain the 74 character subset of ASCII allowed by printableString and countryName SHALL have length 2. In re-encoded C509 certificates, attribute values of types ia5String (if this is the only allowed type, e.g. emailAddress), printableString and utf8String are allowed, and the string types teletexString, universalString, and bmpString are not supported. If Name contains a single Attribute containing an utf8String encoded 'common name' it is encoded as follows:¶
If the text string has an even length ≥ 2 and contains only the symbols '0'–'9' or 'a'–'f', it is encoded as a CBOR byte string, prefixed with an initial byte set to '00'.¶
If the text string contains an EUI-64 of the form "HH-HH-HH-HH-HH-HH-HH-HH" where 'H' is one of the symbols '0'–'9' or 'A'–'F' it is encoded as a CBOR byte string prefixed with an initial byte set to '01', for a total length of 9. An EUI-64 mapped from a 48-bit MAC address (i.e., of the form "HH-HH-HH-FF-FE-HH-HH-HH) is encoded as a CBOR byte string prefixed with an initial byte set to '01', for a total length of 7.¶
Otherwise it is encoded as a CBOR text string.¶
If the 'issuer' field is identical to the 'subject' field, e.g. in case of self-signed certificates, then it MUST be encoded as CBOR null.¶
validity. The 'notBefore' and 'notAfter' fields are encoded as unwrapped CBOR epoch-based date/time (~time) where the tag content is an unsigned integer. In POSIX time, leap seconds are ignored, with a leap second having the same POSIX time as the second before it. Compression of X.509 certificates with the time 23:59:60 UTC is therefore not supported. Note that RFC 5280 mandates encoding of dates through the year 2049 as UTCTime, and later dates as GeneralizedTime. The value "99991231235959Z" (no expiration date) is encoded as CBOR null.¶
subject. The 'subject' field is encoded exactly like issuer, except that CBOR null is not a valid value.¶
subjectPublicKeyInfo. The 'AlgorithmIdentifier' field including parameters is encoded as the CBOR int 'subjectPublicKeyAlgorithm' (see Section 9.11) or as an array with an unwrapped CBOR OID tag [RFC9090] optionally followed by the parameters encoded as a CBOR byte string. In general, the 'subjectPublicKey' BIT STRING value field is encoded as a CBOR byte string. This specification assumes the BIT STRING has zero unused bits and the unused bits byte is omitted. For rsaEncryption and id-ecPublicKey, the encoding of subjectPublicKey is further optimized as described in Section 3.2.¶
issuerUniqueID. Not supported.¶
subjectUniqueID. Not supported.¶
extensions. The 'extensions' field is encoded as a CBOR array where each extension is encoded as either¶
a CBOR int (see Section 9.4) followed by a CBOR item of any type, or¶
an unwrapped CBOR OID tag [RFC9090] followed by an optional CBOR bool encoding 'critical' and the DER encoded value of the 'extnValue' encoded as a CBOR byte string.¶
If the array contains exactly two ints and the absolute value of the first int is 2 (corresponding to keyUsage), the array is omitted and the extensions is encoded as a single CBOR int with the absolute value of the second int and the sign of the first int. Extensions are encoded as specified in Section 3.3. The extensions mandated to be supported by [RFC7925] and [IEEE-802.1AR] are given special treatment. An omitted 'extensions' field is encoded as an empty CBOR array.¶
signatureAlgorithm. The 'signatureAlgorithm' field is always the same as the 'signature' field and therefore omitted from the CBOR encoding.¶
signatureValue. In general, the 'signatureValue' BIT STRING value field is encoded as the CBOR byte string issuerSignatureValue. This specification assumes the BIT STRING has zero unused bits and the unused bits byte is omitted. For natively signed C509 certificates the signatureValue is calculated over the CBOR sequence TBSCertificate. For ECDSA, the encoding of issuerSignatureValue is further optimized as described in Section 3.2¶
The following Concise Data Definition Language (CDDL) defines the CBOR array C509Certificate and the CBOR sequence [RFC8742] TBSCertificate. The member names therefore only have documentary value. Applications not requiring a CBOR item MAY represent C509 certificates with the CBOR sequence ~C509Certificate (unwrapped C509Certificate).¶
C509Certificate = [
TBSCertificate,
issuerSignatureValue : any,
]
; The elements of the following group are used in a CBOR Sequence:
TBSCertificate = (
c509CertificateType: int,
certificateSerialNumber: CertificateSerialNumber,
issuerSignatureAlgorithm: AlgorithmIdentifier,
issuer: Name / null,
validityNotBefore: ~time,
validityNotAfter: ~time / null,
subject: Name,
subjectPublicKeyAlgorithm: AlgorithmIdentifier,
subjectPublicKey: any,
extensions: Extensions,
)
CertificateSerialNumber = ~biguint
Name = [ * Attribute ] / text / bytes
Attribute = ( attributeType: int, attributeValue: text ) //
( attributeType: ~oid, attributeValue: bytes )
AlgorithmIdentifier = int / ~oid /
[ algorithm: ~oid, parameters: bytes ]
Extensions = [ * Extension ] / int
Extension = ( extensionID: int, extensionValue: any ) //
( extensionID: ~oid, ? critical: true,
extensionValue: bytes )
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 Weierstraß form (id-ecPublicKey), keys may be point compressed as defined in Section 2.3.3 of [SECG]. Native C509 certificates with Weierstraß form keys use the octets 0x02, 0x03, and 0x04 as defined in [SECG]. If a DER encoded certificate with an uncompressed public key of type id-ecPublicKey is CBOR encoded with point compression, 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 shorter 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 either as a CBOR int or as an unwrapped CBOR OID tag. If 'extensionID' is encoded an int (see Section 9.4), the sign is used to encode if the extension is critical and the 'critical' field is omitted. Critical extensions are encoded with a negative sign and non-critical extensions are encoded with a positive sign.¶
The 'extnValue' OCTET STRING value field is encoded as the CBOR byte string 'extensionValue' except for the extensions specified below. For some extensions, only commonly used parts are supported by the CBOR encoding. If unsupported parts are used, the CBOR encoding cannot be used.¶
A note on extension ID naming: in existing OID databases most IDs can be found in versions with and without an 'id-pe' or 'id-ce' prefix. We have excluded the prefix for the commonly used extensions defined in [RFC5280] and included them for extensions defined elsewhere.¶
CBOR encoding of the following extension values is fully supported:¶
Subject Key Identifier (subjectKeyIdentifier). The extensionValue is encoded as follows:¶
KeyIdentifier = bytes SubjectKeyIdentifier = KeyIdentifier¶
Key Usage (keyUsage). The 'KeyUsage' BIT STRING is interpreted as an unsigned integer in network byte order and encoded as a CBOR int. See Section 3.1 for special encoding in case keyUsage is the only extension present.¶
KeyUsage = int¶
Policy Mappings (policyMappings). extensionValue is encoded as follows:¶
PolicyMappings = [
+ (issuerDomainPolicy: ~oid, subjectDomainPolicy: ~oid)
]
¶
Basic Constraints (basicConstraints). If 'cA' = false then extensionValue = -2, if 'cA' = true and 'pathLenConstraint' is not present then extensionValue = -1, and if 'cA' = true and 'pathLenConstraint' is present then extensionValue = pathLenConstraint.¶
BasicConstraints = int¶
Policy Constraints (policyConstraints). extensionValue is encoded as follows:¶
PolicyConstraints = [
requireExplicitPolicy: uint / null,
inhibitPolicyMapping: uint / null,
]
¶
Extended Key Usage (extKeyUsage). extensionValue is encoded as an array of CBOR ints (see Section 9.8), or unwrapped CBOR OID tags [RFC9090], where each int or OID encodes a key usage purpose. If the array contains a single KeyPurposeId, the array is omitted.¶
KeyPurposeId = int / ~oid ExtKeyUsageSyntax = [ 2* KeyPurposeId ] / KeyPurposeId¶
Inhibit anyPolicy (inhibitAnyPolicy). extensionValue is encoded as follows:¶
InhibitAnyPolicy = uint¶
CBOR encoding of the following extension values are partly supported:¶
Subject Alternative Name (subjectAltName). If the subject alternative name only contains general names registered in Section 9.9 the extension value can be CBOR encoded. extensionValue is encoded as an array of (int, any) pairs where each pair encodes a general name (see Section 9.9). If subjectAltName contains exactly one dNSName, the array and the int are omitted and extensionValue is the dNSName encoded as a CBOR text string. In addition to the general names defined in [RFC5280], the hardwareModuleName type of otherName has been given its own int due to its mandatory use in IEEE 802.1AR. When 'otherName + hardwareModuleName' is used, then [ ~oid, bytes ] is used to contain the pair ( hwType, hwSerialNum ) directly as specified in [RFC4108]. Only the general names in Section 9.9 are supported.¶
GeneralName = ( GeneralNameType : int, GeneralNameValue : any ) GeneralNames = [ + GeneralName ] SubjectAltName = GeneralNames / text¶
Issuer Alternative Name (issuerAltName). extensionValue is encoded exactly like subjectAltName.¶
IssuerAltName = GeneralNames / text¶
CRL Distribution Points (cRLDistributionPoints). If the CRL Distribution Points is a sequence of DistributionPointName, where each DistributionPointName only contains uniformResourceIdentifiers, the extension value can be CBOR encoded. extensionValue is encoded as follows:¶
DistributionPointName = [ 2* text ] / text CRLDistributionPoints = [ + DistributionPointName ]¶
Freshest CRL (freshestCRL). extensionValue is encoded exactly like cRLDistributionPoints.¶
FreshestCRL = CRLDistributionPoints¶
Authority Information Access (authorityInfoAccess). If all the GeneralNames in authorityInfoAccess are of type uniformResourceIdentifier, the extension value can be CBOR encoded. Each accessMethod is encoded as a CBOR int (see Section 9.7) or an unwrapped CBOR OID tag [RFC9090]. The uniformResourceIdentifiers are encoded as CBOR text strings.¶
AccessDescription = ( accessMethod: int / ~oid , uri: text ) AuthorityInfoAccessSyntax = [ + AccessDescription ]¶
Subject Information Access (subjectInfoAccess). Encoded exactly like authorityInfoAccess.¶
SubjectInfoAccessSyntax = AuthorityInfoAccessSyntax¶
Authority Key Identifier (authorityKeyIdentifier). If the authority key identifier contains all of keyIdentifier, certIssuer, and certSerialNumberm or if only keyIdentifier is present the extension value can be CBOR encoded. If all three are present a CBOR array is used, if only keyIdentifier is present, the array is omitted:¶
KeyIdentifierArray = [
keyIdentifier: KeyIdentifier,
authorityCertIssuer: GeneralNames,
authorityCertSerialNumber: CertificateSerialNumber
]
AuthorityKeyIdentifier = KeyIdentifierArray / KeyIdentifier
¶
Certificate Policies (certificatePolicies). If noticeRef is not used and any explicitText are encoded as UTF8String, the extension value can be CBOR encoded. OIDs registered in Section 9.5 are encoded as an int. The policyQualifierId is encoded as an CBOR int (see Section 9.6) or an unwrapped CBOR OID tag [RFC9090].¶
PolicyIdentifier = int / ~oid
PolicyQualifierInfo = (
policyQualifierId: int / ~oid,
qualifier: text,
)
CertificatePolicies = [
+ ( PolicyIdentifier, ? [ + PolicyQualifierInfo ] )
]
¶
Name Constraints (nameConstraints). If the name constraints only contain general names registered in Section 9.9 the extension value can be CBOR encoded. C509 uses the same additions and restrictions as defined in Section 4.2.1.10 of [RFC5280]. Note that the minimum and maximum fields are not used and therefore omitted.¶
GeneralSubtrees = [ + GeneralName ]
NameConstraints = [
permittedSubtrees: GeneralSubtrees / null,
excludedSubtrees: GeneralSubtrees / null,
]
¶
Subject Directory Attributes (subjectDirectoryAttributes). Encoded as attributes in issuer and subject with the difference that there can be more than one attributeValue.¶
Attributes = ( attributeType: int, attributeValue: [+text] ) //
( attributeType: ~oid, attributeValue: [+bytes] )
SubjectDirectoryAttributes = [+Attributes]
¶
AS Resources (id-pe-autonomousSysIds). If rdi is not present, the extension value can be CBOR encoded. Each ASId is encoded as an uint. With the exception of the first ASId, the ASid is encoded as the difference to the previous ASid.¶
ASIdOrRange = uint / [min:uint, max:uint] ASIdentifiers = [ + ASIdOrRange ] / null¶
AS Resources v2 (id-pe-autonomousSysIds-v2). Encoded exactly like autonomousSysIds.¶
IP Resources (id-pe-ipAddrBlocks). If rdi and SAFI is not present, the extension value can be CBOR encoded. Each AddressPrefix is encoded as a CBOR bytes string (without the unused bits octet) followed by the number of unused bits encoded as a CBOR uint. Each AddressRange is encoded as an array of two CBOR byte strings. The unused bits for min and max are omitted, but the unused bits in max IPAddress is set to ones. With the exception of the first Address, if the byte string has the same length as the previous Address, the Address is encoded as an uint with the the difference to the previous Address. It should be noted that using address differences for compactness prevents encoding an address range larger than 2^64 - 1 corresponding to the cbor integer max value.¶
Address = bytes / uint, AddressPrefix = (Address, unusedBits: uint) AddressRange = [min:Address, max:Address] IPAddressOrRange = AddressPrefix / AddressRange IPAddressChoice = [ + IPAddressOrRange ] / null IPAddrBlocks = [ AFI: uint, IPAddressChoice ]¶
IP Resources v2 (id-pe-ipAddrBlocks-v2). Encoded exactly like id-pe-ipAddrBlocks.¶
Signed Certificate Timestamp. If all the SCTs are version 1, and there are no SCT extensions, the extension value can be CBOR encoded. LogIDs are encoded as CBOR byte strings, the timestamp is encoded as a CBOR int (milliseconds since validityNotBefore), and the signature is encoded with an (AlgorithmIdentifier, any) pair in the same way as issuerSignatureAlgorithm and issuerSignatureValue.¶
SignedCertificateTimestamp = (
logID: bytes,
timestamp: int,
sigAlg: AlgorithmIdentifier,
sigValue: any,
)
SignedCertificateTimestamps = [ + SignedCerticateTimestamp ]
¶
The examples below use values from Section 9.4, Section 9.8, and Section 9.9:¶
A critical basicConstraints ('cA' = true) without pathLenConstraint is encoded as the two CBOR ints -4, -1.¶
A non-critical keyUsage with digitalSignature (0), nonRepudiation (1), keyEncipherment (2) and keyAgreement (4) asserted is encoded as the two CBOR ints 2, 23 (2^0 + 2^1 + 2^2 + 2^4 = 23).¶
A non-critical extKeyUsage containing id-kp-codeSigning and id-kp-OCSPSigning is encoded as the CBOR int 8 followed by the CBOR array [ 3, 9 ].¶
A non-critical subjectAltName containing only the dNSName example.com is encoded as the CBOR int 3 followed by the CBOR text string "example.com".¶
Thus, the extension field of a certificate containing all of the above extensions in the given order would be encoded as the CBOR array [ -4, -1, 2, 23, 8, [ 3, 9 ], 3, "example.com" ].¶
The formatting and processing for c5b, c5c, and c5t, and c5u, defined in Table 1 are similar to x5bag, x5chain, x5t, x5u defined in [RFC9360] except that the certificates are C509 instead of DER encoded X.509 and uses a COSE_C509 structure instead of COSE_X509. c5u provides an alternative way to identify an untrusted certificate bag/chain by reference with a URI. The content is a COSE_C509 item served with the application/cose-c509-cert media type, see Section 9.13, with corresponding CoAP Content-Format defined in Section 9.17. A stored file format is defined in [RFC9277], with "magic number" TBD8 composed of the reserved CBOR tag 55799 concatenated with the CBOR tag calculated from the CoAP Content-Format value.¶
The COSE_C509 structure used in c5b, c5c, and c5u is defined as:¶
COSE_C509 = C509Certificate / [ 2* C509Certificate ]¶
As the contents of c5b, c5c, c5t, and c5u are untrusted input, the header parameters can be in either the protected or unprotected header bucket. The trust mechanism MUST process any certificates in the c5b, c5c, and c5u parameters as untrusted input. The presence of a self-signed certificate in the parameter MUST NOT cause the update of the set of trust anchors without some out-of-band confirmation.¶
| Name | Label | Value Type | Description |
|---|---|---|---|
| c5b | TBD1 | COSE_C509 | An unordered bag of C509 certificates |
| c5c | TBD2 | COSE_C509 | An ordered chain of C509 certificates |
| c5t | TBD3 | COSE_CertHash | Hash of a C509Certificate |
| c5u | TBD4 | uri | URI pointing to a COSE_C509 containing a ordered chain of certificates |
Note that certificates can also be identified with a 'kid' header parameter by storing 'kid' and the associated bag or chain in a dictionary.¶
Certificate management also makes use of data structures including private keys, see e.g. [RFC7468]. This section defines the following CBOR encoded structures:¶
C509PrivateKey = [ subjectPrivateKeyAlgorithm: AlgorithmIdentifier, subjectPrivateKey: any, ]¶
The C509PrivateKey item is served with the application/cose-c509-privkey media type, see Section 9.15, with corresponding CoAP Content-Format defined in Section 9.17. A stored file format is defined in [RFC9277], with "magic number" TBD12 composed of the reserved CBOR tag 55799 concatenated with the CBOR tag calculated from the CoAP Content-Format value.¶
C509PEM = [ C509PrivateKey, COSE_C509 / null, ]¶
The C509PEM item is served with the application/cose-c509-pem media type, see Section 9.16, with corresponding CoAP Content-Format defined in Section 9.17. A stored file format is defined in [RFC9277], with "magic number" TBD13 composed of the reserved CBOR tag 55799 concatenated with the CBOR tag calculated from the CoAP Content-Format value.¶
Editor's note: Include further details for encoding of subjectPrivateKey.¶
This section defines the format of a C509 Certificate Signing Request (CSR), also known as a C509 Certificate Request, based on and compatible with RFC 2986 [RFC2986], and reusing the formatting of C509 certificates defined in Section 3. The media type is application/cose-c509-pkcs10, see Section 9.14, with corresponding CoAP Content-Format defined in Section 9.17. The "magic number" TBD9 is composed of the reserved CBOR tag 55799 concatenated with the CBOR tag calculated from the CoAP Content-Format value, see [RFC9277].¶
Different types of C509 Certificate Requests are defined, see Section 9.2, all using the same CBOR encoding and differing only in what is being signed and what type of C509 certificate is being requested:¶
The C509 Certificate Request can either be an invertible CBOR re-encoding of a DER encoded RFC 2986 certification request, or it can be natively signed where the signature is calculated over the CBOR encoding instead of the DER encoding.¶
The requested C509 certificate in the C509 Certificate Request can either be of type 2 or of type 3, see Section 9.1.¶
Combining these options enables the four instances of c509CertificateRequestType defined in Section 9.2 and illustrated in Figure 2.¶
An implementation MAY only support c509CertificateRequestType = 0. The most common variants are expected to be:¶
c509CertificateRequestType = 0. This type indicates that the C509 Certificate Request is natively signed, and that the requested certificate format has c509CertificateType = 2. This encoding removes the need for ASN.1 and DER parsing and re-encoding in the requesting party.¶
c509CertificateRequestType = 3. This type indicates that the C509 Certificate Request is CBOR re-encoded RFC 2986 certification requests, and that the requested certificate formate has c509CertificateType = 3. This encoding is backwards compatible with legacy RFC 2986 certification requests and X.509 certificates, but enables a reduced transport overhead.¶
subjectSignatureAlgorithm can be a signature algorithm or a non-signature proof-of-possession algorithm, e.g., as defined in [RFC6955]. In the latter case, the signature is replaced by a MAC and requires a public Diffie-Hellman key of the verifier distributed out-of-band. Both kinds are listed in the C509 Signature Algorithms Registry, see Section 9.10. Note that a key agreement key pair may be used with a signature algorithm in a certificate request, see Appendix A.1.3.¶
Certificate request attributes, i.e. attributes for use with certificate requests providing additional information about the subject of the certificate, are defined in Section 5.4 of [RFC2985]. The attribute extensionRequest is supported with a dedicated element. Other certificate request attributes are included using the same Extensions structure as in extensionsRequest, both extensions and attributes are listed in the C509 Extensions Registry, see Figure 9. The only other certificate request attribute specified in this document is challengePassword which is defined for printableString or utf8String values and encoded as CBOR text string, except if the text string has an even length ≥ 2 and contains only the symbols '0'–'9' or 'a'–'f', in which case it is encoded as a CBOR byte string. The sign of extensionID of challengePassword indicates the string type (instead the criticalness in other extensions): positive for utf8String and negative for printableString. In the native certificate request (types 0 and 2), only utf8String is allowed.¶
C509CertificateRequest = [ TBSCertificateRequest, subjectSignatureValue: any, ] ; The elements of the following group are used in a CBOR Sequence: TBSCertificateRequest = ( c509CertificateRequestType: int, subjectSignatureAlgorithm: AlgorithmIdentifier, subject: Name, subjectPublicKeyAlgorithm: AlgorithmIdentifier, subjectPublicKey: any, extensionsRequest: Extensions, ) challengePassword: tstr / bstr
After verifying the subjectSignatureValue, the CA MAY transform the C509CertificateRequest into a [RFC2986] CertificationRequestInfo for compatibility with existing procedures and code.¶
It is straightforward to integrate the C509 format into legacy X.509 processing during certificate issuance. C509 processing can be performed as an isolated function of the CA, or as a separate function trusted by the CA.¶
The Certificate Signing Request (CSR) format defined in Section 4 follows the PKCS#10 format to enable a direct mapping to the certification request information, see Section 4.1 of [RFC2986].¶
When a certificate request is received, the CA, or function trusted by the CA, needs to perform some limited C509 processing and verify the proof-of-possession corresponding to the public key, before normal certificate generation can take place.¶
In the reverse direction, in case c509CertificateType = 3 was requested, a separate C509 processing function can perform the conversion from a generated X.509 certificate to C509 as a bump-in-the-wire. In case c509CertificateType = 2 was requested, the C509 processing needs to be performed before signing the certificate, in which case a tighter integration with the CA may be needed.¶
C509 certificates can be deployed with legacy X.509 certificates and CA infrastructure. An existing CA can continue to use its existing procedures and code for PKCS#10, and DER encoded X.509 and only implement C509 as a thin processing layer on top. When receiving a C509 CSR, the CA transforms it into a DER encoded RFC 2986 CertificationRequestInfo and use that with existing processes and code to produce an RFC 5280 DER encoded X.509 certificate. The DER encoded X.509 is then transformed into a C509 certificate. At any later point, the C509 certificate can be used to recreate the original X.509 data structure needed 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 C509 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 C509 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 C509 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 chains given in Appendix A results in the numbers shown in Figure 4 and Figure 5. COSE_X509 is defined in [RFC9360] and COSE_C509 is defined in Section 9.12. After RFC 7925 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 such as Brotli will be small, mainly corresponding to making the ASN.1 encoding more compact. CBOR encoding can however significantly compress RFC 7925 profiled certificates. For the example HTTPS certificate chains (www.ietf.org and tools.ietf.org) both C509 and Brotli perform well complementing each other. C509 use dedicated information to compress individual certificates, while Brotli can compress duplicate information in the entire chain. Note that C509 certificates of type 2 and 3 have the same size. For Brotli [RFC7932], the Rust crate Brotli 3.3.0 was used with compression level 11 and window size 22.¶
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 C509 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 6 requires unencrypted certificates and is not recommended.¶
This document creates several new registries under the new heading "CBOR Encoded X.509 (C509) Parameters". 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 remaining values in the interval [-65536, 65535] have 3 byte encodings.¶
IANA has created a new registry titled "C509 Certificate Types" under the new heading "CBOR Encoded X.509 (C509) Parameters". 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 "C509 Certificate Request Types" under the new heading "CBOR Encoded X.509 (C509) Parameters". 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 "C509 Attributes" under the new heading "CBOR Encoded X.509 (C509) Parameters". The columns of the registry are Value, Name, Identifiers, OID, DER, Comments, and Reference, where Value is an non-negative integer, and the other columns are text strings. For values in the interval [0, 23] the registration procedure is "IETF Review" and "Expert Review". Values ≥ 32768 are reserved for Private Use. For all other values the registration procedure is "Expert Review". The initial contents of the registry are:¶
IANA has created a new registry titled "C509 Extensions Registry" under the new heading "CBOR Encoded X.509 (C509) Parameters". The columns of the registry are Value, Name, Identifiers, OID, DER, Comments, extensionValue, and Reference, where Value is an positive integer, and the other columns are text strings. The registry also contains CSR attributes for use in Certificate Requests, see Section 4. For values in the interval [1, 23] the registration procedure is "IETF Review" and "Expert Review". Values ≥ 32768 are reserved for Private Use. For all other values the registration procedure is "Expert Review". The initial contents of the registry are:¶
IANA has created a new registry titled "C509 Certificate Policies Registry" under the new heading "CBOR Encoded X.509 (C509) Parameters". The columns of the registry are Value, Name, Identifiers, 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". Values ≥ 32768 are reserved for Private Use. For all other values the registration procedure is "Expert Review". The initial contents of the registry are:¶
IANA has created a new registry titled "C509 Policies Qualifiers Registry" under the new heading "CBOR Encoded X.509 (C509) Parameters". The columns of the registry are Value, Name, Identifiers, 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". Values ≥ 32768 are reserved for Private Use. For all other values the registration procedure is "Expert Review". The initial contents of the registry are:¶
IANA has created a new registry titled "C509 Information Access Registry" under the new heading "CBOR Encoded X.509 (C509) Parameters". The columns of the registry are Value, Name, Identifiers, 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 "C509 Extended Key Usages Registry" under the new heading "CBOR Encoded X.509 (C509) Parameters". The columns of the registry are Value, Name, Identifiers, 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". Values ≥ 32768 are reserved for Private Use. For all other values the registration procedure is "Expert Review". The initial contents of the registry are:¶
IANA has created a new registry titled "C509 General Names Registry" under the new heading "CBOR Encoded X.509 (C509) Parameters". 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 "C509 Signature Algorithms" under the new heading "CBOR Encoded X.509 (C509) Parameters". The registry includes both signature algorithms and non-signature proof-of-possession algorithms. The columns of the registry are Value, Name, Identifiers, 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 "C509 Public Key Algorithms" under the new heading "CBOR Encoded X.509 (C509) Parameters". The columns of the registry are Value, Name, Identifiers, 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:¶
The public key algorithms registry Section 9.11 specify a number of algorithms, not all which are suitable for usage with constrained devices. RSA requires large keys and large signature sizes compared to elliptic curve cryptography (ECC), which together with resource-efficient implementations of named elliptic curves (Montgomery, Edwards and Weierstraß curves), make them suitable candidates for IoT public key usage. These curves are represented by ids 1–11 and 24–28 in Section 9.11.¶
IANA is requested to assign the entries in Table 1 to the "COSE Header Parameters" registry under the "CBOR Object Signing and Encryption (COSE)" heading with this document as reference.¶
When the application/cose-c509-cert media type is used, the data is a COSE_C509 structure. If the parameter "usage" is set to "chain", this sequence indicates a certificate chain.¶
IANA has registered the following media type [RFC6838]:¶
Type name: application¶
Subtype name: cose-c509-cert¶
Required parameters: N/A¶
Optional parameters: usage¶
Can be absent to provide no further information about the intended meaning of the order in the CBOR sequence of certificates.¶
Can be set to "chain" to indicate that the sequence of data items is to be interpreted as a certificate chain.¶
Encoding considerations: binary¶
Security considerations: See the Security Considerations section of [[this document]].¶
Interoperability considerations: N/A¶
Published specification: [[this document]]¶
Applications that use this media type: Applications that employ COSE and use C509 as a certificate type.¶
Fragment identifier considerations: N/A¶
Additional information:¶
Deprecated alias names for this type: N/A¶
Magic number(s): TBD8¶
File extension(s): .c509¶
Macintosh file type code(s): N/A¶
Person & email address to contact for further information: [email protected]¶
Intended usage: COMMON¶
Restrictions on usage: N/A¶
Author: COSE WG¶
Change controller: IESG¶
When the application/cose-c509-pkcs10 media type is used, the data is a C509CertificateRequest structure.¶
IANA has registered the following media type [RFC6838]:¶
Type name: application¶
Subtype name: cose-c509-pkcs10¶
Required parameters: N/A¶
Optional parameters: N/A¶
Encoding considerations: binary¶
Security considerations: See the Security Considerations section of [[this document]].¶
Interoperability considerations: N/A¶
Published specification: [[this document]]¶
Applications that use this media type: Applications that employ COSE and C509 Certificate Request.¶
Fragment identifier considerations: N/A¶
Additional information:¶
Deprecated alias names for this type: N/A¶
Magic number(s): TBD9¶
File extension(s): .c509¶
Macintosh file type code(s): N/A¶
Person & email address to contact for further information: [email protected]¶
Intended usage: COMMON¶
Restrictions on usage: N/A¶
Author: COSE WG¶
Change controller: IESG¶
When the application/cose-c509-privkey media type is used, the data is a C509PrivateKey structure.¶
IANA has registered the following media type [RFC6838]:¶
Type name: application¶
Subtype name: cose-c509-privkey¶
Required parameters: N/A¶
Optional parameters: usage¶
Encoding considerations: binary¶
Security considerations: See the Security Considerations section of [[this document]].¶
Interoperability considerations: N/A¶
Published specification: [[this document]]¶
Applications that use this media type: Applications that employ COSE and use C509 as a certificate type.¶
Fragment identifier considerations: N/A¶
Additional information:¶
Deprecated alias names for this type: N/A¶
Magic number(s): TBD12¶
File extension(s): .c509¶
Macintosh file type code(s): N/A¶
Person & email address to contact for further information: [email protected]¶
Intended usage: COMMON¶
Restrictions on usage: N/A¶
Author: COSE WG¶
Change controller: IESG¶
When the application/cose-c509-pem media type is used, the data is a C509PEM structure.¶
IANA has registered the following media type [RFC6838]:¶
Type name: application¶
Subtype name: cose-c509-pem¶
Required parameters: N/A¶
Optional parameters: usage¶
Encoding considerations: binary¶
Security considerations: See the Security Considerations section of [[this document]].¶
Interoperability considerations: N/A¶
Published specification: [[this document]]¶
Applications that use this media type: Applications that employ COSE and use C509 as a certificate type.¶
Fragment identifier considerations: N/A¶
Additional information:¶
Deprecated alias names for this type: N/A¶
Magic number(s): TBD13¶
File extension(s): .c509¶
Macintosh file type code(s): N/A¶
Person & email address to contact for further information: [email protected]¶
Intended usage: COMMON¶
Restrictions on usage: N/A¶
Author: COSE WG¶
Change controller: IESG¶
IANA is requested to add the media types "application/cose-c509-cert", "application/cose-c509-pkcs10", "application/cose-c509-privkey" and "application/cose-c509-pem" to the "CoAP Content-Formats" registry under the registry group "Constrained RESTful Environments (CoRE) Parameters".¶
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 additional TLS certificate compression [RFC8879]. C509 is defined in the same way as as X.509, but uses a different value and instead of DER-encoded X.509 certificate, opaque cert_data<1..2^24-1> contains a the CBOR sequence ~C509Certificate (an unwrapped C509Certificate).¶
Editor's Note: The TLS registrations should be discussed and approved by the TLS WG at a later stage. The TLS WG might e.g. want a separate draft in the TLS WG.¶
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 2023 GMT
Not After : Jan 1 00:00:00 2026 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
30:46:02:21:00:d4:32:0b:1d:68:49:e3:09:21:9d:30:03:7e:
13:81:66:f2:50:82:47:dd:da:e7:6c:ce:ea:55:05:3c:10:8e:
90:02:21:00:d5:51:f6:d6:01:06:f1:ab:b4:84:cf:be:62:56:
c1:78:e4:ac:33:14:ea:19:19:1e:8b:60:7d:a5:ae:3b:da:16
¶
The DER encoding of the above certificate is 316 bytes.¶
30 82 01 38 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 33 30 31 30 31 30 30 30 30 30 30 5a 17 0d 32 36 30 31 30 31 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 49 00 30 46 02 21 00 d4 32 0b 1d 68 49 e3 09 21 9d 30 03 7e 13 81 66 f2 50 82 47 dd da e7 6c ce ea 55 05 3c 10 8e 90 02 21 00 d5 51 f6 d6 01 06 f1 ab b4 84 cf be 62 56 c1 78 e4 ac 33 14 ea 19 19 1e 8b 60 7d a5 ae 3b da 16¶
The CBOR encoding (~C509Certificate) of the same X.509 certificate is shown below in CBOR diagnostic format.¶
/This defines a CBOR Sequence (RFC 8742):/
3, / version and certificate type /
h'01f50d', / serialNumber /
0, / signatureAlgorithm /
"RFC test CA", / issuer /
1672531200, / notBefore /
1767225600, / notAfter /
h'010123456789AB', / subject, EUI-64 /
1, / subjectPublicKeyAlgorithm /
h'FEB1216AB96E5B3B3340F5BDF02E693F16213A04525ED44450
B1019C2DFD3838AB',
1, / single extension:
non-critical keyUsage
digitalSignature /
h'D4320B1D6849E309219D30037E138166F2508247DDDAE76CCE
EA55053C108E90D551F6D60106F1ABB484CFBE6256C178E4AC
3314EA19191E8B607DA5AE3BDA16'
¶
The size of the CBOR encoding (CBOR sequence) is 139 bytes. The point compressed public key is represented as described in Section 3.2.1.¶
03 43 01 F5 0D 00 6B 52 46 43 20 74 65 73 74 20 43 41 1A 63 B0 CD 00 1A 69 55 B9 00 47 01 01 23 45 67 89 AB 01 58 21 FE 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 58 40 D4 32 0B 1D 68 49 E3 09 21 9D 30 03 7E 13 81 66 F2 50 82 47 DD DA E7 6C CE EA 55 05 3C 10 8E 90 D5 51 F6 D6 01 06 F1 AB B4 84 CF BE 62 56 C1 78 E4 AC 33 14 EA 19 19 1E 8B 60 7D A5 AE 3B DA 16¶
The corresponding natively signed C509 certificate in CBOR diagnostic format is identical, except for c509CertificateType, encoding of point compression (see Section 3.2.1), and signatureValue.¶
/This defines a CBOR Sequence (RFC 8742):/
2,
h'01f50d',
0,
"RFC test CA",
1672531200,
1767225600,
h'010123456789AB',
1,
h'02B1216AB96E5B3B3340F5BDF02E693F16213A04525ED44450
B1019C2DFD3838AB',
1,
h'357B3D83F4ECD1B4E1D225A85C6BE2EADA3134375E72E5B6E2
C311FC9F3DD5962585ABF644D68415194C245A579E134A7CA5
313B90AEAFCAA7AF0DE440302146'
¶
The size of the CBOR encoding (CBOR sequence) is 139 bytes.¶
02 43 01 F5 0D 00 6B 52 46 43 20 74 65 73 74 20 43 41 1A 63 B0 CD 00 1A 69 55 B9 00 47 01 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 58 40 35 7B 3D 83 F4 EC D1 B4 E1 D2 25 A8 5C 6B E2 EA DA 31 34 37 5E 72 E5 B6 E2 C3 11 FC 9F 3D D5 96 25 85 AB F6 44 D6 84 15 19 4C 24 5A 57 9E 13 4A 7C A5 31 3B 90 AE AF CA A7 AF 0D E4 40 30 21 46¶
The two previous examples illustrate the common key usage digitalSignature. A C509 certificate for a public Diffie-Hellman key would instead have key usage keyAgreement encoded according to Section 3.3 (in this case of single extension encoded as integer 16 instead of 1 for digital signature) but otherwise identical in format. Note that Section 5.6.3.2 of [SP-800-56A] allows a key agreement key pair to be used to sign a certificate request.¶
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 [RFC9052]. 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'¶
An example of an IEEE 802.1AR profiled X.509 certificate (Secure Device Identifier, DevID) is provided in Appendix C.2 of [RFC9148]. The certificate is shown below including details of the hardwareModuleName type of otherName in subjectAltName, see Section 3.3.¶
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 9112578475118446130 (0x7e7661d7b54e4632)
Signature Algorithm: ecdsa-with-SHA256
Issuer: C=US, ST=CA, O=Example Inc, OU=certification, CN=802.1AR CA
Validity
Not Before: Jan 31 11:29:16 2019 GMT
Not After : Dec 31 23:59:59 9999 GMT
Subject: C=US, ST=CA, L=LA, O=example Inc, OU=IoT/serialNumber=Wt1234
Subject Public Key Info:
Public Key Algorithm: id-ecPublicKey
Public-Key: (256 bit)
pub:
04:c8:b4:21:f1:1c:25:e4:7e:3a:c5:71:23:bf:2d:
9f:dc:49:4f:02:8b:c3:51:cc:80:c0:3f:15:0b:f5:
0c:ff:95:8d:75:41:9d:81:a6:a2:45:df:fa:e7:90:
be:95:cf:75:f6:02:f9:15:26:18:f8:16:a2:b2:3b:
56:38:e5:9f:d9
ASN1 OID: prime256v1
NIST CURVE: P-256
X509v3 extensions:
X509v3 Basic Constraints:
CA:FALSE
X509v3 Subject Key Identifier:
96:60:0D:87:16:BF:7F:D0:E7:52:D0:AC:76:07:77:AD:66:5D:02:A0
X509v3 Authority Key Identifier:
68:D1:65:51:F9:51:BF:C8:2A:43:1D:0D:9F:08:BC:2D:20:5B:11:60
X509v3 Key Usage: critical
Digital Signature, Key Encipherment
X509v3 Subject Alternative Name:
otherName:
type-id: 1.3.6.1.5.5.7.8.4 (id-on-hardwareModuleName)
value:
hwType: 1.3.6.1.4.1.6175.10.1
hwSerialNum: 01:02:03:04
Signature Algorithm: ecdsa-with-SHA256
Signature Value:
30:46:02:21:00:c0:d8:19:96:d2:50:7d:69:3f:3c:48:ea:a5:
ee:94:91:bd:a6:db:21:40:99:d9:81:17:c6:3b:36:13:74:cd:
86:02:21:00:a7:74:98:9f:4c:32:1a:5c:f2:5d:83:2a:4d:33:
6a:08:ad:67:df:20:f1:50:64:21:18:8a:0a:de:6d:34:92:36
¶
The DER encoding of the certificate is 577 bytes:¶
30 82 02 3D 30 82 01 E2 A0 03 02 01 02 02 08 7E 76 61 D7 B5 4E 46 32 30 0A 06 08 2A 86 48 CE 3D 04 03 02 30 5D 31 0B 30 09 06 03 55 04 06 13 02 55 53 31 0B 30 09 06 03 55 04 08 0C 02 43 41 31 14 30 12 06 03 55 04 0A 0C 0B 45 78 61 6D 70 6C 65 20 49 6E 63 31 16 30 14 06 03 55 04 0B 0C 0D 63 65 72 74 69 66 69 63 61 74 69 6F 6E 31 13 30 11 06 03 55 04 03 0C 0A 38 30 32 2E 31 41 52 20 43 41 30 20 17 0D 31 39 30 31 33 31 31 31 32 39 31 36 5A 18 0F 39 39 39 39 31 32 33 31 32 33 35 39 35 39 5A 30 5C 31 0B 30 09 06 03 55 04 06 13 02 55 53 31 0B 30 09 06 03 55 04 08 0C 02 43 41 31 0B 30 09 06 03 55 04 07 0C 02 4C 41 31 14 30 12 06 03 55 04 0A 0C 0B 65 78 61 6D 70 6C 65 20 49 6E 63 31 0C 30 0A 06 03 55 04 0B 0C 03 49 6F 54 31 0F 30 0D 06 03 55 04 05 13 06 57 74 31 32 33 34 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 C8 B4 21 F1 1C 25 E4 7E 3A C5 71 23 BF 2D 9F DC 49 4F 02 8B C3 51 CC 80 C0 3F 15 0B F5 0C FF 95 8D 75 41 9D 81 A6 A2 45 DF FA E7 90 BE 95 CF 75 F6 02 F9 15 26 18 F8 16 A2 B2 3B 56 38 E5 9F D9 A3 81 8A 30 81 87 30 09 06 03 55 1D 13 04 02 30 00 30 1D 06 03 55 1D 0E 04 16 04 14 96 60 0D 87 16 BF 7F D0 E7 52 D0 AC 76 07 77 AD 66 5D 02 A0 30 1F 06 03 55 1D 23 04 18 30 16 80 14 68 D1 65 51 F9 51 BF C8 2A 43 1D 0D 9F 08 BC 2D 20 5B 11 60 30 0E 06 03 55 1D 0F 01 01 FF 04 04 03 02 05 A0 30 2A 06 03 55 1D 11 04 23 30 21 A0 1F 06 08 2B 06 01 05 05 07 08 04 A0 13 30 11 06 09 2B 06 01 04 01 B4 3B 0A 01 04 04 01 02 03 04 30 0A 06 08 2A 86 48 CE 3D 04 03 02 03 49 00 30 46 02 21 00 C0 D8 19 96 D2 50 7D 69 3F 3C 48 EA A5 EE 94 91 BD A6 DB 21 40 99 D9 81 17 C6 3B 36 13 74 CD 86 02 21 00 A7 74 98 9F 4C 32 1A 5C F2 5D 83 2A 4D 33 6A 08 AD 67 DF 20 F1 50 64 21 18 8A 0A DE 6D 34 92 36¶
The CBOR encoding (~C509Certificate) of the same X.509 certificate is shown below in CBOR diagnostic format.¶
/This defines a CBOR Sequence (RFC 8742):/ 3, h'7E7661D7B54E4632', 0, [ -4, "US", 6, "CA", 8, "Example Inc", 9, "certification", 1, "802.1AR CA" ], 1548934156, null, [ -4, "US", 6, "CA", 5, "LA", 8, "example Inc", 9, "IoT", -3, "Wt1234" ], 1, h'FDC8B421F11C25E47E3AC57123BF2D9FDC494F028BC351CC80C03F150BF50CFF95', [ 4, -2, 1, h'96600D8716BF7FD0E752D0AC760777AD665D02A0', 7, h'68D16551F951BFC82A431D0D9F08BC2D205B1160', -2, 5, 3, [-1, [h'2B06010401B01F0A01', h'01020304']] / subjectAltName w. hardwareModuleName / ], h'C0D81996D2507D693F3C48EAA5EE9491BDA6DB214099D98117C63B361374CD86A7 74989F4C321A5CF25D832A4D336A08AD67DF20F1506421188A0ADE6D349236'¶
The size of the CBOR encoding (CBOR sequence) is 275 bytes:¶
03 48 7E 76 61 D7 B5 4E 46 32 8A 23 62 55 53 06 62 43 41 08 6B 45 78 61 6D 70 6C 65 20 49 6E 63 09 6D 63 65 72 74 69 66 69 63 61 74 69 6F 6E 01 6A 38 30 32 2E 31 41 52 20 43 41 1A 5C 52 DC 0C F6 8C 23 62 55 53 06 62 43 41 05 62 4C 41 08 6B 65 78 61 6D 70 6C 65 20 49 6E 63 09 63 49 6F 54 22 66 57 74 31 32 33 34 01 58 21 FD C8 B4 21 F1 1C 25 E4 7E 3A C5 71 23 BF 2D 9F DC 49 4F 02 8B C3 51 CC 80 C0 3F 15 0B F5 0C FF 95 8A 04 21 01 54 96 60 0D 87 16 BF 7F D0 E7 52 D0 AC 76 07 77 AD 66 5D 02 A0 07 54 68 D1 65 51 F9 51 BF C8 2A 43 1D 0D 9F 08 BC 2D 20 5B 11 60 21 05 03 82 20 82 49 2B 06 01 04 01 B0 1F 0A 01 44 01 02 03 04 00 58 40 C0 D8 19 96 D2 50 7D 69 3F 3C 48 EA A5 EE 94 91 BD A6 DB 21 40 99 D9 81 17 C6 3B 36 13 74 CD 86 A7 74 98 9F 4C 32 1A 5C F2 5D 83 2A 4D 33 6A 08 AD 67 DF 20 F1 50 64 21 18 8A 0A DE 6D 34 92 36¶
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 (~C509Certificate) of the first X.509 certificate is shown below in CBOR diagnostic format.¶
/This defines a CBOR Sequence (RFC 8742):/
3,
h'047FA1E31928EE403BA0B83A395673FC',
0,
[
-4, "US",
-8, "Cloudflare, Inc.",
-1, "Cloudflare Inc ECC CA-3"
],
1595980800,
1627560000,
[
-4, "US",
-6, "CA",
-5, "San Francisco",
-8, "Cloudflare, Inc.",
-1, "sni.cloudflaressl.com"
],
1,
h'FD963ECDD84DCD1B93A1CF432D1A7217D6C63BDE3355A02F8CFB5AD8994CD44E20',
[
7, h'A5CE37EAEBB0750E946788B445FAD9241087961F',
1, h'CC0B50E7D837DBF243F3853D4860F53B39BE9B2A',
3, [2, "sni.cloudflaressl.com", 2, "www.ietf.org"],
-2, 1,
8, [1, 2],
5, ["http://crl3.digicert.com/CloudflareIncECCCA-3.crl",
"http://crl4.digicert.com/CloudflareIncECCCA-3.crl"],
6, [h'6086480186FD6C0101', [1, "https://www.digicert.com/CPS"], 2],
9, [1, "http://ocsp.digicert.com",
2, "http://cacerts.digicert.com/CloudflareIncECCCA-3.crt"],
-4, -2,
10, [
h'F65C942FD1773022145418083094568EE34D131933BFDF0C2F200BCC4EF164E3',
77922190,
0,
h'F8D1B4A93D2F0D4C4176DFB488BCC73B86443D7DE00E6AC8174D8948A8843668
29FF5A34068A240C69502788E8EE25AB7ED2CBCF686ECE7B5F96B431A90702FA',
h'5CDC4392FEE6AB4544B15E9AD456E61037FBD5FA47DCA17394B25EE6F6C70ECA',
77922238,
0,
h'E891C197BFB0E3D30CB6CEE60D94C3C75FD1175336931108D89812D4D29D81D0
A159D16C4647D1483757FCD6CE4E75EC7B5EF657EFE028F8E5CC4792682DAC43'
]
],
h'BD63CF4F7E5CFE6C29385EA71CFBFC1E3F7B1CD07251A221F77769C0F471DFEA
B5C06CC45854FA30B28288B1D3BB9A6661ED5031725B1A8202E0DA5B59F95402'
¶
The size of the CBOR encoding (CBOR sequence) is 783 bytes.¶
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 (~C509Certificate) of the first X.509 certificate is shown below in CBOR diagnostic format.¶
/This defines a CBOR Sequence (RFC 8742):/
3,
h'A6A55C870E39B40E',
23,
[
-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'B1E137E8EB82D689FADBF5C24B77F02C4ADE726E3E1360D1A8661EC4AD3D3260
E5F099B5F47A7A485521EE0E3912F9CE0DCAF56961C704ED6E0F1D3B1E508879
3A0E314116F1B1026468A5CDF54A0ACA99963508C37E275DD0A9CFF3E728AF37
D8B67BDDF37EAE6E977FF7CA694ECCD006DF5D279B3B12E7E6FE086B527B8211
7C72B346EBC1E878B80FCBE1EBBD064458DC8350B2A0625BDC81B836E39E7C79
B2A9538AE00BC94A2A13393113BD2CCFA870CF8C8D3D01A388AE1200361D1E24
2BDD79D8530126ED284FC98694834EC8E1142E85B3AFD46EDD6946AF41250E7A
AD8BF292CA79D97B324FF777E8F9B44F235CD45C03AED8AB3ACA135F5D5D5DA1',
[
-4, -2,
8, [ 1, 2 ],
-2, 5,
5, ["http://crl.starfieldtech.com/sfig2s1-242.crl"],
6, [ h'6086480186fd6e01071701',
[1, "http://certificates.starfieldtech.com/repository/"], 1 ],
9, [ 1, "http://ocsp.starfieldtech.com/",
2, "http://certificates.starfieldtech.com/repository/sfig2.crt" ],
7, h'254581685026383D3B2D2CBECD6AD9B63DB36663',
3, [ 2, "*.tools.ietf.org", 2, "tools.ietf.org" ],
1, h'AD8AB41C0751D7928907B0B784622F36557A5F4D',
10, [
h'F65C942FD1773022145418083094568EE34D131933BFDF0C2F200BCC4EF164E3',
1715,
0,
h'8CF54852CE5635433911CF10CDB91F52B33639223AD138A41DECA6FEDE1FE90F
BCA2254366C19A2691C47A00B5B653ABBD44C2F8BAAEF4D2DAF2527CE6454995',
h'5CDC4392FEE6AB4544B15E9AD456E61037FBD5FA47DCA17394B25EE6F6C70ECA',
2012,
0,
h'A5E0906E63E91D4FDDEFFF0352B91E50896007564B448A3828F596DC6B28726D
FC91EAED02168866054EE18A2E5346C4CC51FEB3FA10A91D2EDBF99125F86CE6'
]
],
h'14043FA0BED2EE3FA86E3A1F788EA04C35530F11061FFF60A16D0B83E9D92ADB
B33F9DB3D7E0594C19A8E419A50CA770727763D5FE64510AD27AD650A58A9238
ECCB2F0F5AC064584D5C06B9736368278B8934DC79C71D3AFD345F8314415849
80682980398A867269CC7937CEE397F7DCF39588ED81032900D2A2C7BAABD63A
8ECA090BD9FB39264BFF03D88E2D3F6B21CA8A7DD85FFB94BA83DE9CFC158D61
FA672DB0C7DB3D250A414A85D37F4946373CF4B175D052F3DDC766F14BFDAA00
EDBFE47EED01EC7BE4F646FC31FD72FE03D2F265AF4D7EE2819B7AFD303CF552
F40534A08A3E194158C8A8E05171840915AEECA57775FA18F7D577D531CCC72D'
¶
The size of the CBOR encoding (CBOR sequence) is 1245 bytes.¶
The authors want to thank Henk Birkholz, Carsten Bormann, Russ Housley, Olle Johansson, Benjamin Kaduk, Ilari Liusvaara, Laurence Lundblade, Francesca Palombini, Thomas Peterson, Michael Richardson, Stefan Santesson, Jim Schaad, Brian Sipos, Fraser Tweedale, and Rene Struik for reviewing and commenting on intermediate versions of the draft and helping with GitHub. The authors are especially grateful to Lijun Liao for his many detailed improvement proposals.¶