diff options
Diffstat (limited to 'crypto/asymmetric_keys')
| -rw-r--r-- | crypto/asymmetric_keys/x509_cert_parser.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c index 2ffe4ae90bea..8df3fa60a44f 100644 --- a/crypto/asymmetric_keys/x509_cert_parser.c +++ b/crypto/asymmetric_keys/x509_cert_parser.c @@ -610,11 +610,14 @@ int x509_process_extension(void *context, size_t hdrlen, /* * Get hold of the basicConstraints * v[1] is the encoding size - * (Expect 0x2 or greater, making it 1 or more bytes) + * (Expect 0x00 for empty SEQUENCE with CA:FALSE, or + * 0x03 or greater for non-empty SEQUENCE) * v[2] is the encoding type * (Expect an ASN1_BOOL for the CA) - * v[3] is the contents of the ASN1_BOOL - * (Expect 1 if the CA is TRUE) + * v[3] is the length of the ASN1_BOOL + * (Expect 1 for a single byte boolean) + * v[4] is the contents of the ASN1_BOOL + * (Expect 0xFF if the CA is TRUE) * vlen should match the entire extension size */ if (v[0] != (ASN1_CONS_BIT | ASN1_SEQ)) @@ -623,8 +626,13 @@ int x509_process_extension(void *context, size_t hdrlen, return -EBADMSG; if (v[1] != vlen - 2) return -EBADMSG; - if (vlen >= 4 && v[1] != 0 && v[2] == ASN1_BOOL && v[3] == 1) + /* Empty SEQUENCE means CA:FALSE (default value omitted per DER) */ + if (v[1] == 0) + return 0; + if (vlen >= 5 && v[2] == ASN1_BOOL && v[3] == 1 && v[4] == 0xFF) ctx->cert->pub->key_eflags |= 1 << KEY_EFLAG_CA; + else + return -EBADMSG; return 0; } |