Certificate Transparency

Certificate Transparency is a set of protocols specified in RFC 6962 which allow X.509 certificates to be sent to append-only logs and have small cryptographic proofs that a certificate has been publicly logged. This allows for external auditing of the certificates that a certificate authority has issued.

class cryptography.x509.certificate_transparency.SignedCertificateTimestamp[source]

New in version 1.9.

SignedCertificateTimestamps (SCTs) are small cryptographically signed assertions that the specified certificate has been submitted to a Certificate Transparency Log, and that it will be part of the public log within some time period, this is called the “maximum merge delay” (MMD) and each log specifies its own.

version
Type:Version

The SCT version as an enumeration. Currently only one version has been specified.

log_id
Type:bytes

An opaque identifier, indicating which log this SCT is from. This is the SHA256 hash of the log’s public key.

timestamp
Type:datetime.datetime

A naïve datetime representing the time in UTC at which the log asserts the certificate had been submitted to it.

entry_type
Type:LogEntryType

The type of submission to the log that this SCT is for. Log submissions can either be certificates themselves or “pre-certificates” which indicate a binding-intent to issue a certificate for the same data, with SCTs embedded in it.

class cryptography.x509.certificate_transparency.Version[source]

New in version 1.9.

An enumeration for SignedCertificateTimestamp versions.

v1

For version 1 SignedCertificateTimestamps.

class cryptography.x509.certificate_transparency.LogEntryType[source]

New in version 1.9.

An enumeration for SignedCertificateTimestamp log entry types.

X509_CERTIFICATE

For SCTs corresponding to X.509 certificates.

PRE_CERTIFICATE

For SCTs corresponding to pre-certificates.