Interface FixedLengthContentSigner

  • All Superinterfaces:
    ContentSigner

    public interface FixedLengthContentSigner
    extends ContentSigner
    Extension of ContentSigner for signers whose signature encoding has a fixed, predictable length — RSA (PKCS#1 v1.5 and PSS: the modulus size), Ed25519/Ed448 and ML-DSA qualify; DER-encoded ECDSA/DSA do not (the INTEGER components vary in length).

    This enables definite-length (DL/DER) streaming of CMS SignedData with encapsulated content: the SignerInfos trail the content in the encoding but their length feeds the enclosing headers, which are written before any content flows — so the signature length has to be committed up front.

    • Method Detail

      • getSignatureLength

        int getSignatureLength()
        Return the exact length in octets of the signature this signer will produce.
        Returns:
        the signature length, or -1 if it cannot be fixed in advance