commit 24eed8d2d2df4423a63c8761edd0d65a43ff03a3
author Janos Follath <janos.follath@arm.com> Fri Nov 22 13:21:35 2019 +0000
committer Janos Follath <janos.follath@arm.com> Tue Dec 03 16:07:18 2019 +0000
tree fefff85746d2b1296b06cfca0ad6cfcd18aed758
parent a13b905d8dde4d851f1730e62643d1fb775649ca

Initialise return values to an error

Initialising the return values to and error is best practice and makes
the library more robust.

library/ecdsa.c

diff --git a/library/ecdsa.c b/library/ecdsa.c
index bda9262..a6ba75d 100644
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -51,6 +51,7 @@
 #endif
 
 #include "mbedtls/platform_util.h"
+#include "mbedtls/error.h"
 
 /* Parameter validation macros based on platform_util.h */
 #define ECDSA_VALIDATE_RET( cond )    \
@@ -229,7 +230,7 @@
 static int derive_mpi( const mbedtls_ecp_group *grp, mbedtls_mpi *x,
                        const unsigned char *buf, size_t blen )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t n_size = ( grp->nbits + 7 ) / 8;
     size_t use_size = blen > n_size ? n_size : blen;
 
@@ -429,7 +430,7 @@
                     void *p_rng_blind,
                     mbedtls_ecdsa_restart_ctx *rs_ctx )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     mbedtls_hmac_drbg_context rng_ctx;
     mbedtls_hmac_drbg_context *p_rng = &rng_ctx;
     unsigned char data[2 * MBEDTLS_ECP_MAX_BYTES];
@@ -599,7 +600,7 @@
                                      const mbedtls_mpi *r, const mbedtls_mpi *s,
                                      mbedtls_ecdsa_restart_ctx *rs_ctx )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     mbedtls_mpi e, s_inv, u1, u2;
     mbedtls_ecp_point R;
     mbedtls_mpi *pu1 = &u1, *pu2 = &u2;
@@ -723,7 +724,7 @@
 static int ecdsa_signature_to_asn1( const mbedtls_mpi *r, const mbedtls_mpi *s,
                                     unsigned char *sig, size_t *slen )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char buf[MBEDTLS_ECDSA_MAX_LEN];
     unsigned char *p = buf + sizeof( buf );
     size_t len = 0;
@@ -752,7 +753,7 @@
                            void *p_rng,
                            mbedtls_ecdsa_restart_ctx *rs_ctx )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     mbedtls_mpi r, s;
     ECDSA_VALIDATE_RET( ctx  != NULL );
     ECDSA_VALIDATE_RET( hash != NULL );
@@ -845,7 +846,7 @@
                           const unsigned char *sig, size_t slen,
                           mbedtls_ecdsa_restart_ctx *rs_ctx )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     unsigned char *p = (unsigned char *) sig;
     const unsigned char *end = sig + slen;
     size_t len;
@@ -925,7 +926,7 @@
  */
 int mbedtls_ecdsa_from_keypair( mbedtls_ecdsa_context *ctx, const mbedtls_ecp_keypair *key )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     ECDSA_VALIDATE_RET( ctx != NULL );
     ECDSA_VALIDATE_RET( key != NULL );