Prefer initializing ret to error values

gilles-peskine-arm · gilles-peskine-arm · commit 006c1b5f4e8d · 2019-09-30T17:29:54.000+02:00
These initial values shouldn't be used, but in case they accidentally
get used after a code change, fail safe.
diff --git a/library/entropy.c b/library/entropy.c
@@ -258,7 +258,9 @@ int mbedtls_entropy_update_manual( mbedtls_entropy_context *ctx,
  */
 static int entropy_gather_internal( mbedtls_entropy_context *ctx )
 {
-    int ret = 0, i, have_one_strong = 0;
+    int ret = MBEDTLS_ERR_ENTROPY_SOURCE_FAILED;
+    int i;
+    int have_one_strong = 0;
     unsigned char buf[MBEDTLS_ENTROPY_MAX_GATHER];
     size_t olen;
 
diff --git a/library/hmac_drbg.c b/library/hmac_drbg.c
@@ -74,7 +74,7 @@ int mbedtls_hmac_drbg_update_ret( mbedtls_hmac_drbg_context *ctx,
     unsigned char rounds = ( additional != NULL && add_len != 0 ) ? 2 : 1;
     unsigned char sep[1];
     unsigned char K[MBEDTLS_MD_MAX_SIZE];
-    int ret = 0;
+    int ret = MBEDTLS_ERR_MD_BAD_INPUT_DATA;
 
     for( sep[0] = 0; sep[0] < rounds; sep[0]++ )
     {

Original file line number	Diff line number	Diff line change
`@@ -74,7 +74,7 @@ int mbedtls_hmac_drbg_update_ret( mbedtls_hmac_drbg_context *ctx,`
`74`	`74`	`unsigned char rounds = ( additional != NULL && add_len != 0 ) ? 2 : 1;`
`75`	`75`	`unsigned char sep[1];`
`76`	`76`	`unsigned char K[MBEDTLS_MD_MAX_SIZE];`
`77`		`- int ret = 0;`
	`77`	`+ int ret = MBEDTLS_ERR_MD_BAD_INPUT_DATA;`
`78`	`78`
`79`	`79`	`for( sep[0] = 0; sep[0] < rounds; sep[0]++ )`
`80`	`80`	`{`