| Message ID | 20220406015337.4000739-3-eric.snowberg@oracle.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | Add CA enforcement keyring restrictions | expand |
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@oracle.com> > --- > 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 > }; > > /*
> On Apr 8, 2022, at 8:39 AM, Mimi Zohar <zohar@linux.ibm.com> wrote: > > 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@oracle.com> >> --- >> 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". I’ll change this name (and also the one you identified in the 3rd patch) in the next round, thanks.
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 */ }; /*
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@oracle.com> --- crypto/asymmetric_keys/x509_cert_parser.c | 9 +++++++++ crypto/asymmetric_keys/x509_parser.h | 1 + 2 files changed, 10 insertions(+)