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 Summary

Modifier and Type	Method	Description
int	getSignatureLength()	Return the exact length in octets of the signature this signer will produce.

Methods inherited from interface ContentSigner

getAlgorithmIdentifier, getOutputStream, getSignature

Method Details

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