Add single function to parse ASN.1 AlgorithmIdentifier to x509.c
diff --git a/include/mbedtls/x509.h b/include/mbedtls/x509.h
index c02c7c8..8297910 100644
--- a/include/mbedtls/x509.h
+++ b/include/mbedtls/x509.h
@@ -305,6 +305,10 @@
                                 int *salt_len );
 #endif
 int mbedtls_x509_get_sig( unsigned char **p, const unsigned char *end, mbedtls_x509_buf *sig );
+int mbedtls_x509_get_sig_alg_raw( unsigned char **p, unsigned char const *end,
+                                  mbedtls_md_type_t *md_alg,
+                                  mbedtls_pk_type_t *pk_alg,
+                                  void **sig_opts );
 int mbedtls_x509_get_sig_alg( const mbedtls_x509_buf *sig_oid, const mbedtls_x509_buf *sig_params,
                       mbedtls_md_type_t *md_alg, mbedtls_pk_type_t *pk_alg,
                       void **sig_opts );