JcaMTCCosigner (Bouncy Castle Library 1.85 API Specification)

java.lang.Object
- org.bouncycastle.cert.plants.jcajce.JcaMTCCosigner

All Implemented Interfaces:

MTCCosigner
```
public class JcaMTCCosigner
extends java.lang.Object
implements MTCCosigner
```
JCA-side implementation of MTCCosigner for the MTC signature algorithms enumerated in Section 6.1 of draft-ietf-plants-merkle-tree-certs: "ECDSA-P256-SHA256", "ECDSA-P384-SHA384", "Ed25519", "ML-DSA-44", "ML-DSA-65", "ML-DSA-87".
Symmetric counterpart of JcaMTCSignatureVerifier — encapsulates the MTCCosignedMessage encode plus the underlying JCA Signature ceremony. The draft identifiers are mapped to JCA Signature names internally; the plain (r||s) ECDSA encoding used by MTCProof requires SHA256WITHPLAIN-ECDSA / SHA384WITHPLAIN-ECDSA, which BC's JCE provider registers (DER-encoded SHA256withECDSA is wire-incompatible with the MTCProof signature byte format).

Instances are created via JcaMTCCosigner.Builder.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class JcaMTCCosigner.Builder
Builder for JcaMTCCosigner.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`MTCSignature`	`cosignSubtree(MTCLog log, byte[] subtreeHash)`	Cosigns the subtree `[log.getStart(), log.getEnd())` of the issuance log identified by `log.getLogId()`.
`byte[]`	`getCosignerId()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - getCosignerId
```
public byte[] getCosignerId()
```
    Specified by:
    
    getCosignerId in interface MTCCosigner
    
    Returns:
    
    the binary trust anchor ID of this cosigner — the value that appears in MTCSignature.getCosignerId() on every signature produced by this instance. Per Section 5.3 of the draft, when the CA itself is acting as a cosigner this is the CA's own trust anchor ID.
  - cosignSubtree
```
public MTCSignature cosignSubtree(MTCLog log,
                                  byte[] subtreeHash)
                           throws java.io.IOException
```
    Description copied from interface: MTCCosigner
    
    Cosigns the subtree [log.getStart(), log.getEnd()) of the issuance log identified by log.getLogId().
    
    Specified by:
    
    cosignSubtree in interface MTCCosigner
    
    Throws:
    
    java.io.IOException - if the CosignedMessage cannot be encoded or the underlying signing operation fails