On Tue, 2022-04-05 at 21:53 -0400, Eric Snowberg wrote:
> Parse the X.509 Basic Constraints. The basic constraints extension
> identifies whether the subject of the certificate is a CA.
>
> BasicConstraints ::= SEQUENCE {
> cA BOOLEAN DEFAULT FALSE,
> pathLenConstraint INTEGER (0..MAX) OPTIONAL }
>
> If the CA is true, store it in the x509_certificate. This will be used
> in a follow on patch that requires knowing if the public key is a CA.
>
> Signed-off-by: Eric Snowberg <eric.snowberg@xxxxxxxxxx>
> ---
> crypto/asymmetric_keys/x509_cert_parser.c | 9 +++++++++
> crypto/asymmetric_keys/x509_parser.h | 1 +
> 2 files changed, 10 insertions(+)
>
> diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c
> index 2899ed80bb18..30f7374ea9c0 100644
> --- a/crypto/asymmetric_keys/x509_cert_parser.c
> +++ b/crypto/asymmetric_keys/x509_cert_parser.c
> @@ -583,6 +583,15 @@ int x509_process_extension(void *context, size_t hdrlen,
> return 0;
> }
>
> + if (ctx->last_oid == OID_basicConstraints) {
> + if (vlen < 2 || v[0] != (ASN1_CONS_BIT | ASN1_SEQ))
> + return -EBADMSG;
> + if (v[1] != vlen - 2)
> + return -EBADMSG;
> + if (vlen >= 4 && v[1] != 0 && v[2] == ASN1_BOOL && v[3] == 1)
> + ctx->cert->is_root_ca = true;
> + }
> +
> return 0;
> }
>
> diff --git a/crypto/asymmetric_keys/x509_parser.h b/crypto/asymmetric_keys/x509_parser.h
> index 97a886cbe01c..dc45df9f6594 100644
> --- a/crypto/asymmetric_keys/x509_parser.h
> +++ b/crypto/asymmetric_keys/x509_parser.h
> @@ -38,6 +38,7 @@ struct x509_certificate {
> bool self_signed; /* T if self-signed (check unsupported_sig too) */
> bool unsupported_sig; /* T if signature uses unsupported crypto */
> bool blacklisted;
> + bool is_root_ca; /* T if basic constraints CA is set */
There's no need to prefix variables with "is_". Similar to the
variable "self_signed" simply name this variable "root_ca".
thanks,
Mimi
> };
>
> /*
