public static SignerInfo Decode(AsnReader reader)
{
/* SignerInfo ::= SEQUENCE {
* version CMSVersion,
* sid SignerIdentifier,
* digestAlgorithm DigestAlgorithmIdentifier,
* signedAttrs [0] IMPLICIT SignedAttributes OPTIONAL,
* signatureAlgorithm SignatureAlgorithmIdentifier,
* signature SignatureValue,
* unsignedAttrs [1] IMPLICIT UnsignedAttributes OPTIONAL }*/
var sequence = reader.ReadSequence();
// version CMSVersion,
if (!sequence.TryReadInt32(out var version))
{
sequence.ThrowIfNotEmpty();
}
// sid SignerIdentifier,
var sid = SignerIdentifier.Decode(sequence, validateEmpty: false);
// digestAlgorithm DigestAlgorithmIdentifier,
var digestAlgorithm = AlgorithmIdentifier.Decode(sequence);
// signedAttrs [0] IMPLICIT SignedAttributes OPTIONAL,
// SignedAttributes ::= SET SIZE (1..MAX) OF Attribute
var signedAttrs = sequence.ReadOptionalSetOf(0, set => AttributeValue.Decode(set));
// signatureAlgorithm SignatureAlgorithmIdentifier,
var signatureAlgorithm = AlgorithmIdentifier.Decode(sequence);
// signature SignatureValue,
// SignatureValue ::= OCTET STRING
var signature = sequence.ReadPrimitiveOrNotOctetString();
// unsignedAttrs [1] IMPLICIT UnsignedAttributes OPTIONAL
// UnsignedAttributes ::= SET SIZE (1..MAX) OF Attribute
var unsignedAttrs = sequence.ReadOptionalSetOf(1, set => AttributeValue.Decode(set));
sequence.ThrowIfNotEmpty();
return(new()
{
Version = version,
Sid = sid,
DigestAlgorithm = digestAlgorithm,
SignedAttrs = signedAttrs,
SignatureAlgorithm = signatureAlgorithm,
Signature = signature,
UnsignedAttrs = unsignedAttrs,
});
}
public static SignerIdentifier Decode(AsnReader reader, bool validateEmpty = true)
{
/* SignerIdentifier ::= CHOICE {
* issuerAndSerialNumber IssuerAndSerialNumber,
* subjectKeyIdentifier [0] SubjectKeyIdentifier } */
var tag = reader.PeekTag();
if (tag.HasSameClassAndValue(Asn1Tag.Sequence))
{
var result = new SignerIdentifier()
{
IssuerAndSerialNumber = IssuerAndSerialNumber.Decode(reader),
};
if (validateEmpty)
{
reader.ThrowIfNotEmpty();
}
return(result);
}
if (tag.HasSameClassAndValue(new Asn1Tag(TagClass.ContextSpecific, 0)))
{
var result = new SignerIdentifier()
{
SubjectKeyIdentifier = reader.ReadPrimitiveOrNotOctetString(tag),
};
if (validateEmpty)
{
reader.ThrowIfNotEmpty();
}
return(result);
}
throw new CryptographicException();
}
