result_t
x509_verify_cert_eku (x509_crt *cert, const char * const expected_oid)
{
result_t fFound = FAILURE;
if (!(cert->ext_types & EXT_EXTENDED_KEY_USAGE))
{
msg (D_HANDSHAKE, "Certificate does not have extended key usage extension");
}
else
{
x509_sequence *oid_seq = &(cert->ext_key_usage);
msg (D_HANDSHAKE, "Validating certificate extended key usage");
while (oid_seq != NULL)
{
x509_buf *oid = &oid_seq->buf;
char oid_num_str[1024];
const char *oid_str;
if (0 == oid_get_extended_key_usage( oid, &oid_str ))
{
msg (D_HANDSHAKE, "++ Certificate has EKU (str) %s, expects %s",
oid_str, expected_oid);
if (!strcmp (expected_oid, oid_str))
{
fFound = SUCCESS;
break;
}
}
if (0 < oid_get_numeric_string( oid_num_str,
sizeof (oid_num_str), oid))
{
msg (D_HANDSHAKE, "++ Certificate has EKU (oid) %s, expects %s",
oid_num_str, expected_oid);
if (!strcmp (expected_oid, oid_num_str))
{
fFound = SUCCESS;
break;
}
}
oid_seq = oid_seq->next;
}
}
return fFound;
}
int x509_oid_get_numeric_string( char *buf, size_t size, x509_buf *oid )
{
return oid_get_numeric_string( buf, size, oid );
}
static int x509_get_crt_ext_data(const unsigned char **ext_data,
size_t *ext_len,
x509_crt *crt,
const char *oid)
{
int ret;
size_t len;
unsigned char *end_ext_data, *end_ext_octet;
unsigned char *p;
const unsigned char *end;
char oid_str[64];
p = crt->v3_ext.p;
end = crt->v3_ext.p + crt->v3_ext.len;
ret = asn1_get_tag(&p, end, &len, ASN1_CONSTRUCTED | ASN1_SEQUENCE);
if (ret != 0)
return POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret;
if (end != p + len)
return POLARSSL_ERR_X509_INVALID_EXTENSIONS +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH;
while (p < end) {
/*
* Extension ::= SEQUENCE {
* extnID OBJECT IDENTIFIER,
* critical BOOLEAN DEFAULT FALSE,
* extnValue OCTET STRING }
*/
x509_buf extn_oid = {0, 0, NULL};
int is_critical = 0; /* DEFAULT FALSE */
ret = asn1_get_tag(&p, end, &len,
ASN1_CONSTRUCTED | ASN1_SEQUENCE);
if (ret != 0)
return POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret;
end_ext_data = p + len;
/* Get extension ID */
extn_oid.tag = *p;
ret = asn1_get_tag(&p, end, &extn_oid.len, ASN1_OID);
if (ret != 0)
return POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret;
extn_oid.p = p;
p += extn_oid.len;
if ((end - p) < 1)
return POLARSSL_ERR_X509_INVALID_EXTENSIONS +
POLARSSL_ERR_ASN1_OUT_OF_DATA;
/* Get optional critical */
ret = asn1_get_bool(&p, end_ext_data, &is_critical);
if (ret != 0 && (ret != POLARSSL_ERR_ASN1_UNEXPECTED_TAG))
return POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret;
/* Data should be octet string type */
ret = asn1_get_tag(&p, end_ext_data, &len, ASN1_OCTET_STRING);
if (ret != 0)
return POLARSSL_ERR_X509_INVALID_EXTENSIONS + ret;
end_ext_octet = p + len;
if (end_ext_octet != end_ext_data)
return POLARSSL_ERR_X509_INVALID_EXTENSIONS +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH;
/* Detect requested extension */
oid_get_numeric_string(oid_str, 64, &extn_oid);
if (memcmp(oid, oid_str, sizeof(oid)) == 0) {
*ext_data = p;
*ext_len = len;
return 0;
}
/* Next */
p = end_ext_octet;
}
if (p != end)
return POLARSSL_ERR_X509_INVALID_EXTENSIONS +
POLARSSL_ERR_ASN1_LENGTH_MISMATCH;
return POLARSSL_ERR_X509_UNKNOWN_OID;
}
