7.1.3.2 Signature AlgorithmIdentifier

All objects signed by a CA Private Key MUST conform to these requirements on the use of the AlgorithmIdentifier or AlgorithmIdentifier-derived type in the context of signatures.

In particular, it applies to all of the following objects and fields:

    The signatureAlgorithm field of a Certificate.
    The signature field of a TBSCertificate.
    The signatureAlgorithm field of a CertificateList
    The signature field of a TBSCertList
    The signatureAlgorithm field of a BasicOCSPResponse
    The digestAlgorithms field of a SignedData corresponding to a Timestamp token

7.1.3.2.1 RSA

The CA SHALL use one of the following signature algorithms:

    RSASSA-PKCS1-v1_5 with SHA-256
    RSASSA-PKCS1-v1_5 with SHA-384
    RSASSA-PKCS1-v1_5 with SHA-512
    RSASSA-PSS with SHA-256
    RSASSA-PSS with SHA-384
    RSASSA-PSS with SHA-512

In addition, the CA MAY use RSASSA-PKCS1-v1_5 with SHA-1 if one of the following conditions are met:

    It is used within Timestamp Authority Certificate and the date of the notBefore field is not greater than 2022-04-30; or,
    It is used within an OCSP response; or,
    It is used within a CRL; or,
    It is used within a Timestamp Token and the date of the genTime field is not greater than 2022-04-30.

7.1.3.2.2 ECDSA

The CA SHALL use one of the following signature algorithms:

    ECDSA with SHA-256
    ECDSA with SHA-384
    ECDSA with SHA-512

7.1.3.2.3 DSA

The CA SHALL use the following signature algorithm:

    DSA with SHA-256

In addition, the CA MAY use DSA with SHA-1 if one of the following conditions are met:

    It is used within Timestamp Authority Certificate and the date of the notBefore field is not greater than 2022-04-30; or,
    It is used within an OCSP response; or,
    It is used within a CRL; or,
    It is used within a Timestamp Token and the date of the genTime field is not greater than 2022-04-30.