Peer review feedback. Adjust README.md and fix possible use of un-init variable.

pk/ecc/README.md

@@ -20,8 +20,12 @@ The `ecc_keys.c` example shows how to work with storing and loading keys after t
 
 ## ecc_sign
 
-The `ecc_verify.c` example uses NIST test vectors to demonstrate hashing a message and verifying an ECC signature.
+The `ecc_sign.c:` example takes a random message and private key, creates a signature then verifies it.
 
 ## ecc_verify
 
-The `ecc_sign.c:` example takes a random message and private key, creates a signature then verifies it.
+The `ecc_verify.c` example uses NIST test vectors to demonstrate hashing a message and verifying an ECC signature.
+
+## ecc_pub
+
+The `ecc_pub` example code shows how to extracting an ECC public key from private key.

pk/ecc/ecc_sign.c

@@ -295,7 +295,7 @@ int main()
     int ret;
     uint8_t hash[WC_SHA256_DIGEST_SIZE];
     uint8_t sig[ECC_CURVE_SZ*2];
-    uint32_t sigSz = sizeof(sig);
+    uint32_t sigSz = 0;
 
 #ifdef DEBUG_WOLFSSL
     wolfSSL_Debugging_ON();
@@ -303,6 +303,8 @@ int main()
 
     printf("Running NIST P-256,SHA-256 Sign Test\n");
 
+    memset(sig, 0, sizeof(sig));
+
     ret = crypto_sha256(
         kMsg, sizeof(kMsg), /* input message */
         hash, sizeof(hash), /* hash digest result */
@@ -313,6 +315,7 @@ int main()
         /* Note: result of an ECC sign varies for each call even with same 
             private key and hash. This is because a new random public key is 
             used for each operation. */ 
+        sigSz = sizeof(sig);
         ret = crypto_ecc_sign(
             kPrivKey, sizeof(kPrivKey), /* private key */
             hash, sizeof(hash),         /* computed hash digest */
@@ -333,16 +336,18 @@ int main()
         );
     }
 
-    printf("Signature %d\n", sigSz);
-    print_hex(sig, sigSz);
+    if (ret == 0) {
+        printf("Signature %d\n", sigSz);
+        print_hex(sig, sigSz);
 
-    if (ret != 0) {
-        printf("Failure %d: %s\n", ret, wc_GetErrorString(ret));
-        return -1;
+        printf("Success\n");
+    }
+    else {
+        printf("Failure %d: %s\n", ret, wc_GetErrorString(ret));
+        ret = -1;
     }
-    printf("Success\n");
 
-    return 0;
+    return ret;
 #else
     printf("wolfSSL requires ECC and SHA256\n");
     return -1;

pk/ecc/ecc_verify.c

@@ -231,11 +231,13 @@ int main()
         );
     }
 
-    if (ret != 0) {
-        printf("Failure %d: %s\n", ret, wc_GetErrorString(ret));
-        return -1;
+    if (ret == 0) {
+        printf("Success\n");
+    }
+    else {
+        printf("Failure %d: %s\n", ret, wc_GetErrorString(ret));
+        ret = -1;
     }
-    printf("Success\n");
 
     return ret;
 #else