org.bouncycastle.cert.plants

Class MTCContentSigner

java.lang.Object

org.bouncycastle.cert.plants.MTCContentSigner

All Implemented Interfaces:

ContentSigner

public class MTCContentSigner
extends java.lang.Object
implements ContentSigner

Issuer-side ContentSigner that emits an MTC signatureValue (an encoded MTCProof) for an EE Merkle Tree certificate per Section 6.1 of draft-ietf-plants-merkle-tree-certs.

The signer is plugged into the standard X509v3CertificateBuilder.build(ContentSigner) flow. As the TBSCertificate DER bytes stream out of the builder into getOutputStream(), this class captures them; when getSignature() is invoked it:

1. Derives the MerkleTreeCertEntry leaf hash and climbs one Merkle level using the single-sibling inclusionProof via MerkleTreeCertificateValidator.computeSubtreeHash(byte[], byte[], org.bouncycastle.cert.plants.MerkleTreeHash).
2. Delegates to MTCCosigner.cosignSubtree(org.bouncycastle.cert.plants.MTCLog, byte[]) to produce the cosigner's MTCSignature.
3. Wraps the inclusion proof and the cosigner signature in an MTCProof and returns its TLS wire encoding.

This is the simple-case binding used by the worked examples: a standalone certificate (Section 6.2 of the draft) over the minimal subtree [0, 2) — the EE's log entry at index 0, one sibling leaf at index 1, and a single-node inclusion proof — carrying one cosigner signature. Issuers with multi-level inclusion proofs or multiple cosigners should compose the MTCCosigner, MTCProof and MerkleTreeHash primitives directly; landmark-relative certificates (Section 6.3, no signatures) are built via LandmarkCertificateManager.buildLandmarkCertificate(long, long, org.bouncycastle.asn1.x509.TBSCertificateLogEntry, org.bouncycastle.asn1.x509.SubjectPublicKeyInfo, org.bouncycastle.cert.plants.MerkleTreePrimitives.SubtreeInfo, java.util.List<byte[]>, org.bouncycastle.cert.plants.MerkleTreeHash).

Constructor Summary

Constructors

Constructor and Description
MTCContentSigner(MTCLog log, byte[] inclusionProof, MTCCosigner cosigner) The cosigner's identity is taken from MTCCosigner.getCosignerId() — the CA-as-cosigner case is just a MTCCosigner constructed with log.getCa().getCaId() as its cosigner ID (Section 5.3 of the draft).

Method Summary

Modifier and Type	Method and Description
org.bouncycastle.asn1.x509.AlgorithmIdentifier	getAlgorithmIdentifier() Return the algorithm identifier describing the signature algorithm and parameters this signer generates.
java.io.OutputStream	getOutputStream() Returns a stream that will accept data for the purpose of calculating a signature.
byte[]	getSignature() Returns a signature based on the current data written to the stream, since the start or the last call to getSignature().

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MTCContentSigner

public MTCContentSigner(MTCLog log,
                        byte[] inclusionProof,
                        MTCCosigner cosigner)

The cosigner's identity is taken from MTCCosigner.getCosignerId() — the CA-as-cosigner case is just a MTCCosigner constructed with log.getCa().getCaId() as its cosigner ID (Section 5.3 of the draft). Witnesses, regulators, federated peers or any other entity with a distinct trust anchor ID work via the same constructor by constructing the cosigner with their own ID.

Parameters:

log - issuance log + subtree window [log.getStart(), log.getEnd()) — also supplies the CA (via MTCLog.getCa()) and therefore the hash function and log ID

inclusionProof - the single sibling leaf hash that, combined with the EE's leaf hash, yields the subtree hash — same bytes that land in the resulting MTCProof

cosigner - cosigner driver bound to its trust anchor ID, signature algorithm and key

Method Detail

getAlgorithmIdentifier

public org.bouncycastle.asn1.x509.AlgorithmIdentifier getAlgorithmIdentifier()

Description copied from interface: ContentSigner

Return the algorithm identifier describing the signature algorithm and parameters this signer generates.

Specified by:

getAlgorithmIdentifier in interface ContentSigner

Returns:

algorithm oid and parameters.

getOutputStream

public java.io.OutputStream getOutputStream()

Description copied from interface: ContentSigner

Returns a stream that will accept data for the purpose of calculating a signature. Use org.bouncycastle.util.io.TeeOutputStream if you want to accumulate the data on the fly as well.

Specified by:

getOutputStream in interface ContentSigner

Returns:

an OutputStream

getSignature

public byte[] getSignature()

Description copied from interface: ContentSigner

Returns a signature based on the current data written to the stream, since the start or the last call to getSignature().

Specified by:

getSignature in interface ContentSigner

Returns:

bytes representing the signature.