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/ecp_curves.c

diff --git a/library/ecp_curves.c b/library/ecp_curves.c
index dcc7073..a24a50c 100644
--- a/library/ecp_curves.c
+++ b/library/ecp_curves.c
@@ -29,6 +29,7 @@
 
 #include "mbedtls/ecp.h"
 #include "mbedtls/platform_util.h"
+#include "mbedtls/error.h"
 
 #include <string.h>
 
@@ -669,7 +670,7 @@
  */
 static int ecp_use_curve25519( mbedtls_ecp_group *grp )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
     /* Actually ( A + 2 ) / 4 */
     MBEDTLS_MPI_CHK( mbedtls_mpi_read_string( &grp->A, 16, "01DB42" ) );
@@ -709,7 +710,7 @@
 static int ecp_use_curve448( mbedtls_ecp_group *grp )
 {
     mbedtls_mpi Ns;
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
     mbedtls_mpi_init( &Ns );
 
@@ -900,7 +901,7 @@
  */
 static int ecp_mod_p192( mbedtls_mpi *N )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     mbedtls_mpi_uint c = 0;
     mbedtls_mpi_uint *p, *end;
 
@@ -991,7 +992,7 @@
  * (see fix_negative for the motivation of C)
  */
 #define INIT( b )                                                       \
-    int ret;                                                            \
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;                                                            \
     signed char c = 0, cc;                                              \
     uint32_t cur;                                                       \
     size_t i = 0, bits = (b);                                           \
@@ -1027,7 +1028,7 @@
  */
 static inline int fix_negative( mbedtls_mpi *N, signed char c, mbedtls_mpi *C, size_t bits )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 
     /* C = - c * 2^(bits + 32) */
 #if !defined(MBEDTLS_HAVE_INT64)
@@ -1185,7 +1186,7 @@
  */
 static int ecp_mod_p521( mbedtls_mpi *N )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t i;
     mbedtls_mpi M;
     mbedtls_mpi_uint Mp[P521_WIDTH + 1];
@@ -1234,7 +1235,7 @@
  */
 static int ecp_mod_p255( mbedtls_mpi *N )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t i;
     mbedtls_mpi M;
     mbedtls_mpi_uint Mp[P255_WIDTH + 2];
@@ -1291,7 +1292,7 @@
  */
 static int ecp_mod_p448( mbedtls_mpi *N )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t i;
     mbedtls_mpi M, Q;
     mbedtls_mpi_uint Mp[P448_WIDTH + 1], Qp[P448_WIDTH];
@@ -1353,7 +1354,7 @@
 static inline int ecp_mod_koblitz( mbedtls_mpi *N, mbedtls_mpi_uint *Rp, size_t p_limbs,
                                    size_t adjust, size_t shift, mbedtls_mpi_uint mask )
 {
-    int ret;
+    int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
     size_t i;
     mbedtls_mpi M, R;
     mbedtls_mpi_uint Mp[P_KOBLITZ_MAX + P_KOBLITZ_R + 1];