Introduce compute_hash() function
This allows callers not to worry with md_info and makes it easier to
provide a PSA version for when MD_C is not available.
Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/library/rsa.c b/library/rsa.c
index af1a9d5..7e7af2a 100644
--- a/library/rsa.c
+++ b/library/rsa.c
@@ -1163,7 +1163,7 @@
* \param hlen length of the input hash
* \param salt the input salt
* \param slen length of the input salt
- * \param out the output buffer - must be large enough for \c md_alg
+ * \param out the output buffer - must be large enough for \p md_alg
* \param md_alg message digest to use
*/
static int hash_mprime( const unsigned char *hash, size_t hlen,
@@ -1197,6 +1197,27 @@
return( ret );
}
+
+/**
+ * Compute a hash.
+ *
+ * \param md_alg algorithm to use
+ * \param input input message to hash
+ * \param ilen input length
+ * \param output the output buffer - must be large enough for \p md_alg
+ */
+static int compute_hash( mbedtls_md_type_t md_alg,
+ const unsigned char *input, size_t ilen,
+ unsigned char *output )
+{
+ const mbedtls_md_info_t *md_info;
+
+ md_info = mbedtls_md_info_from_type( md_alg );
+ if( md_info == NULL )
+ return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
+
+ return( mbedtls_md( md_info, input, ilen, output ) );
+}
#endif /* MBEDTLS_PKCS1_V21 */
#if defined(MBEDTLS_PKCS1_V21)
@@ -1247,7 +1268,8 @@
p += hlen;
/* Construct DB */
- if( ( ret = mbedtls_md( md_info, label, label_len, p ) ) != 0 )
+ ret = compute_hash( (mbedtls_md_type_t) ctx->hash_id, label, label_len, p );
+ if( ret != 0 )
return( ret );
p += hlen;
p += olen - 2 * hlen - 2 - ilen;
@@ -1428,7 +1450,9 @@
}
/* Generate lHash */
- if( ( ret = mbedtls_md( md_info, label, label_len, lhash ) ) != 0 )
+ ret = compute_hash( (mbedtls_md_type_t) ctx->hash_id,
+ label, label_len, lhash );
+ if( ret != 0 )
goto cleanup;
/*