Struct CmsSignedData 

pub struct CmsSignedData<'a> {
    pub signer_key_id: &'a [u8],
    pub cd_content: &'a [u8],
    pub signature_raw: [u8; 64],
}

Parsed contents of a CMS SignedData envelope

Fields

signer_key_id: &'a [u8]

SubjectKeyIdentifier from the SignerInfo (identifies the signing key)

cd_content: &'a [u8]

Raw TLV CD payload (the encapsulated content)

signature_raw: [u8; 64]

ECDSA signature in raw (r || s) format, 64 bytes

Implementations

impl<'a> CmsSignedData<'a>

pub fn parse(cms_message: &'a [u8]) -> Result<CmsSignedData<'a>, Error>

Parse a CMS SignedData message, extracting the signer key ID, encapsulated CD content, and ECDSA signature (converted from DER to raw).

Expects the profiled CMS structure used by Matter CDs (Matter Spec): https://www.rfc-editor.org/rfc/rfc5652#section-5.2

ContentInfo ::= SEQUENCE {
  contentType OBJECT IDENTIFIER id-signedData (1.2.840.113549.1.7.2),
  content [0] EXPLICIT SignedData
}

SignedData ::= SEQUENCE {
  version INTEGER (v3(3)),
  digestAlgorithms SET { OBJECT IDENTIFIER sha256 (2.16.840.1.101.3.4.2.1) },
  encapContentInfo EncapsulatedContentInfo,
  signerInfos SET { SignerInfo }
}

EncapsulatedContentInfo ::= SEQUENCE {
  eContentType OBJECT IDENTIFIER pkcs7-data (1.2.840.113549.1.7.1),
  eContent [0] EXPLICIT OCTET STRING cd_content
}

SignerInfo ::= SEQUENCE {
  version INTEGER (v3(3)),
  subjectKeyIdentifier [0] IMPLICIT OCTET STRING,
  digestAlgorithm OBJECT IDENTIFIER sha256 (2.16.840.1.101.3.4.2.1),
  signatureAlgorithm OBJECT IDENTIFIER ecdsa-with-SHA256 (1.2.840.10045.4.3.2),
  signature OCTET STRING
}