On Thu, Jan 21, 2021 at 04:32:26PM +0200, Jarkko Sakkinen wrote: > On Thu, Jan 21, 2021 at 12:23:53PM +0800, joeyli wrote: > > Hi Jarkko, > > > > On Thu, Jan 21, 2021 at 01:40:48AM +0200, Jarkko Sakkinen wrote: > > > On Wed, Jan 20, 2021 at 05:05:14PM +0800, Lee, Chun-Yi wrote: > > > > This patch adds the logic for parsing the CodeSign extended key usage > > > > extension in X.509. The parsing result will be set to the eku flag > > > > which is carried by public key. It can be used in the PKCS#7 > > > > verification. > > > > > > > > Signed-off-by: "Lee, Chun-Yi" <j...@suse.com> > > > > --- > > > > crypto/asymmetric_keys/x509_cert_parser.c | 24 ++++++++++++++++++++++++ > > > > include/crypto/public_key.h | 1 + > > > > include/linux/oid_registry.h | 5 +++++ > > > > 3 files changed, 30 insertions(+) > > > > > > > > diff --git a/crypto/asymmetric_keys/x509_cert_parser.c > > > > b/crypto/asymmetric_keys/x509_cert_parser.c > > > > index 52c9b455fc7d..65721313b265 100644 > > > > --- a/crypto/asymmetric_keys/x509_cert_parser.c > > > > +++ b/crypto/asymmetric_keys/x509_cert_parser.c > > > > @@ -497,6 +497,8 @@ int x509_process_extension(void *context, size_t > > > > hdrlen, > > > > struct x509_parse_context *ctx = context; > > > > struct asymmetric_key_id *kid; > > > > const unsigned char *v = value; > > > > + int i = 0; > > > > + enum OID oid; > > > > > > > > pr_debug("Extension: %u\n", ctx->last_oid); > > > > > > > > @@ -526,6 +528,28 @@ int x509_process_extension(void *context, size_t > > > > hdrlen, > > > > return 0; > > > > } > > > > > > > > + if (ctx->last_oid == OID_extKeyUsage) { > > > > + if (v[0] != ((ASN1_UNIV << 6) | ASN1_CONS_BIT | > > > > ASN1_SEQ) || > > > > + v[1] != vlen - 2) > > > > + return -EBADMSG; > > > > + i += 2; > > > > + > > > > + while (i < vlen) { > > > > + /* A 10 bytes EKU OID Octet blob = > > > > + * ASN1_OID + size byte + 8 bytes OID */ > > > > + if (v[i] != ASN1_OID || v[i + 1] != 8 || (i + > > > > 10) > vlen) > > > > + return -EBADMSG; > > > > + > > > > + oid = look_up_OID(v + i + 2, v[i + 1]); > > > > + if (oid == OID_codeSigning) { > > > > + ctx->cert->pub->eku |= EKU_codeSigning; > > > > + } > > > > + i += 10; > > > > + } > > > > + pr_debug("extKeyUsage: %d\n", ctx->cert->pub->eku); > > > > > > With eBPF around, does this make any sense? > > > > > > > I think that the dynamic debug log is still easier for checking the EKU > > setting. > > Why?
There have some certificates may loaded when system boot. In booting stage, using dynamic debug log for checking EKU is easier than eBPF. I am not good on eBPF. Correct me if I missed anything, please! Thanks a lot! Joey Lee