| Message ID | 20211124044124.998170-6-eric.snowberg@oracle.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | Enroll kernel keys thru MOK | expand |
On Tue, 2021-11-23 at 23:41 -0500, 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 a new public_key field call key_is_ca. > 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@oracle.com> You could extend the description to state why kernel needs X.509 Basic Constraints support. /Jarkko > --- > v7: Initial version > v8: Moved key_is_ca after key_is_private, recommended by Mimi > --- > crypto/asymmetric_keys/x509_cert_parser.c | 9 +++++++++ > include/crypto/public_key.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 6d003096b5bc..f4299b8a4926 100644 > --- a/crypto/asymmetric_keys/x509_cert_parser.c > +++ b/crypto/asymmetric_keys/x509_cert_parser.c > @@ -571,6 +571,15 @@ int x509_process_extension(void *context, size_t hdrlen, > return 0; > } > > + if (ctx->last_oid == OID_basicConstraints) { > + if (v[0] != (ASN1_CONS_BIT | ASN1_SEQ)) > + return -EBADMSG; > + if (v[1] != vlen - 2) > + return -EBADMSG; > + if (v[1] != 0 && v[2] == ASN1_BOOL && v[3] == 1) > + ctx->cert->pub->key_is_ca = true; > + } > + > return 0; > } > > diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h > index a9b2e600b7cc..72dcbc06ef9c 100644 > --- a/include/crypto/public_key.h > +++ b/include/crypto/public_key.h > @@ -26,6 +26,7 @@ struct public_key { > void *params; > u32 paramlen; > bool key_is_private; > + bool key_is_ca; > const char *id_type; > const char *pkey_algo; > };
diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c index 6d003096b5bc..f4299b8a4926 100644 --- a/crypto/asymmetric_keys/x509_cert_parser.c +++ b/crypto/asymmetric_keys/x509_cert_parser.c @@ -571,6 +571,15 @@ int x509_process_extension(void *context, size_t hdrlen, return 0; } + if (ctx->last_oid == OID_basicConstraints) { + if (v[0] != (ASN1_CONS_BIT | ASN1_SEQ)) + return -EBADMSG; + if (v[1] != vlen - 2) + return -EBADMSG; + if (v[1] != 0 && v[2] == ASN1_BOOL && v[3] == 1) + ctx->cert->pub->key_is_ca = true; + } + return 0; } diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h index a9b2e600b7cc..72dcbc06ef9c 100644 --- a/include/crypto/public_key.h +++ b/include/crypto/public_key.h @@ -26,6 +26,7 @@ struct public_key { void *params; u32 paramlen; bool key_is_private; + bool key_is_ca; const char *id_type; const char *pkey_algo; };
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 a new public_key field call key_is_ca. 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@oracle.com> --- v7: Initial version v8: Moved key_is_ca after key_is_private, recommended by Mimi --- crypto/asymmetric_keys/x509_cert_parser.c | 9 +++++++++ include/crypto/public_key.h | 1 + 2 files changed, 10 insertions(+)