Class CmsAttribute

Namespace

SimpleSign.Core.Crypto

Assembly

SimpleSign.Core.dll

Represents a pre-encoded CMS signed attribute (OID + DER value). Used to inject custom CAdES attributes into the CMS SignedData.

public sealed class CmsAttribute

Inheritance

object

CmsAttribute

Inherited Members

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Properties

DerValue

The DER-encoded value (the content of SET OF { value }).

public byte[] DerValue { get; }

Property Value

byte[]

Oid

The OID of the attribute.

public string Oid { get; }

Property Value

string

Methods

CertValues(params byte[][])

Creates a cert-values attribute (CAdES-XL, RFC 5126 §5.5.1). Embeds the full DER-encoded signer and CA certificates.

public static CmsAttribute CertValues(params byte[][] certDerBytes)

Parameters

certDerBytes byte[][]

DER-encoded certificates. Must contain at least one certificate.

Returns

CmsAttribute

CertificateRefs(params (byte[] Hash, string HashOid, byte[]? IssuerSerial)[])

Creates a certificate-refs attribute (CAdES-X/L, RFC 5126 §5.4.2).

CompleteCertificateRefs ::= SEQUENCE OF OtherCertID
OtherCertID ::= OtherHash { issuerSerial OPTIONAL }

public static CmsAttribute CertificateRefs(params (byte[] Hash, string HashOid, byte[]? IssuerSerial)[] certHashes)

Parameters

certHashes (byte[] Hash, string HashOid, byte[] IssuerSerial)[]

Array of (certHash, hashAlgorithmOid, issuerSerialBytes) tuples. The issuerSerial must be DER-encoded IssuerSerial bytes when provided.

Returns

CmsAttribute

CommitmentTypeIndication(CommitmentType)

Creates a commitment-type-indication attribute (RFC 5126 §5.11.1).

CommitmentTypeIndication ::= SEQUENCE {
  commitmentTypeId  CommitmentTypeIdentifier }
CommitmentTypeIdentifier ::= OID

public static CmsAttribute CommitmentTypeIndication(CommitmentType type)

Parameters

type CommitmentType

Returns

CmsAttribute

Create(string, byte[])

Creates a custom attribute from an OID and a DER-encoded attribute value. The derValue will be wrapped in SET OF by the CMS rendering code.

public static CmsAttribute Create(string oid, byte[] derValue)

Parameters

oid string

The attribute OID.

derValue byte[]

The DER-encoded attribute value (content of SET OF).

Returns

CmsAttribute

Raw(string, byte[])

Creates a CmsAttribute from raw OID and DER-encoded value.

public static CmsAttribute Raw(string oid, byte[] derValue)

Parameters

oid string

derValue byte[]

Returns

CmsAttribute

RevocationRefs(params byte[][])

Creates a revocation-refs attribute (CAdES-X/L, RFC 5126 §5.4.3). Each CRL is SHA-256 hashed and wrapped in a CrlValidatedID inside a single CRLListID.

CompleteRevocationRefs ::= SEQUENCE OF CrlOcspRef
CrlOcspRef ::= CHOICE { crl [0] CRLListID }
CRLListID ::= SEQUENCE OF CrlValidatedID
CrlValidatedID ::= SEQUENCE { crlHash  OtherHash }
OtherHash ::= SEQUENCE { hashAlgorithm  AlgorithmIdentifier,
                         hashValue      OCTET STRING }

public static CmsAttribute RevocationRefs(params byte[][] crlDerBytes)

Parameters

crlDerBytes byte[][]

Array of DER-encoded CRL bytes.

Returns

CmsAttribute

RevocationValues(byte[][]?, byte[][]?)

Creates a revocation-values attribute (CAdES-XL, RFC 5126 §5.5.2). Embeds CRLs and/or OCSP responses.

public static CmsAttribute RevocationValues(byte[][]? ocspDerResponses = null, byte[][]? crlDerBytes = null)

Parameters

ocspDerResponses byte[][]

DER-encoded OCSP responses.

crlDerBytes byte[][]

DER-encoded CRLs.

Returns

CmsAttribute

Exceptions

ArgumentException

Both parameters are null or empty — at least one revocation source is required.

SignatureManifestAttr(byte[])

Creates a signature manifest attribute containing JSON-encoded evidence. The data is embedded as an OCTET STRING (UTF-8 JSON) under OID 2.16.76.1.12.1.1.

public static CmsAttribute SignatureManifestAttr(byte[] manifestJsonUtf8)

Parameters

manifestJsonUtf8 byte[]

UTF-8 encoded JSON bytes of the manifest.

Returns

CmsAttribute

SignaturePolicyIdentifier(string, string?)

Creates a signature-policy-identifier attribute (RFC 5126 §5.8.1).

SignaturePolicyIdentifier ::= SEQUENCE {
  signaturePolicyId    SignaturePolicyId,
  sigPolicyHash        SigPolicyHash OPTIONAL }
SignaturePolicyId ::= OID
SigPolicyHash ::= OtherHashAlgAndValue (SEQUENCE { algorithm, hash })

public static CmsAttribute SignaturePolicyIdentifier(string policyOid, string? policyUri = null)

Parameters

policyOid string

OID of the signature policy.

policyUri string

Optional URI of the policy document (encoded as SigPolicyQualifier).

Returns

CmsAttribute