Class SctVerifier

java.lang.Object

zeroecho.pki.server.ct.SctVerifier

public final class SctVerifier
extends Object

Verifies Signed Certificate Timestamps collected from CT logs before they may be embedded in a final certificate.

Verification enforces two invariants per RFC 9162 §4.9 and the operator policy:

1. Timestamp freshness: SCTs with a timestamp more than 10 minutes in the future are rejected. A future timestamp indicates a misbehaving or malicious log.
2. Signature validity: The SCT's DigitallySigned structure must verify against the corresponding log's public key using the pre-certificate as input. Any SCT whose cryptographic signature is invalid is discarded.

SCTs from logs not present in the supplied logPublicKeys map are silently discarded (the log is not trusted by the operator for this authority).

After filtering, the verifyAll(List, Map, byte[], int) method enforces a minimum SCT count. If fewer than minScts SCTs survive verification the issuance is aborted by throwing CtSubmissionException.

Thread safety

This class is stateless and thread-safe.

Since:

1.0

Field Summary

Fields

Modifier and Type	Field	Description
static final int	MAX_FUTURE_DRIFT_MINUTES	Maximum allowed clock skew between a CT log and the local clock.

Method Summary

Modifier and Type	Method	Description
static List<SignedCertificateTimestamp>	verifyAll(List<SignedCertificateTimestamp> scts, Map<String, PublicKey> logPublicKeys, byte[] preCertDer, int minScts)	Verifies all collected SCTs and returns the subset that are cryptographically valid, enforcing the minimum count required for issuance.

Methods inherited from class Object

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

Field Details

MAX_FUTURE_DRIFT_MINUTES

public static final int MAX_FUTURE_DRIFT_MINUTES

Maximum allowed clock skew between a CT log and the local clock.

See Also:

• Constant Field Values

Method Details

verifyAll

public static List<SignedCertificateTimestamp> verifyAll(List<SignedCertificateTimestamp> scts,
 Map<String, PublicKey> logPublicKeys,
 byte[] preCertDer,
 int minScts)
                                                  throws CtSubmissionException

Verifies all collected SCTs and returns the subset that are cryptographically valid, enforcing the minimum count required for issuance.

Steps performed for each SCT:

1. Reject if the SCT's log ID is not in logPublicKeys.
2. Reject if the SCT's timestamp is more than 10 minutes in the future.
3. Reject if Pkix.verifySct(SignedCertificateTimestamp, PublicKey, byte[]) returns false for the corresponding log public key and pre-certificate.

If the number of surviving SCTs is less than minScts, this method throws CtSubmissionException. Otherwise the verified SCTs are returned.

Parameters:

scts - SCTs collected by CtLogSubmitter.submitAll(byte[], List, List, Instant); must not be null

logPublicKeys - map from hex log ID to the corresponding CT log's public key; must not be null

preCertDer - DER-encoded pre-certificate that was submitted; must not be null

minScts - minimum number of valid SCTs required for issuance (typically ≥ 2)

Returns:

immutable list of verified SCTs; never fewer than minScts elements

Throws:

CtSubmissionException - if fewer than minScts SCTs survive verification

NullPointerException - if any argument is null

Since:

1.0