Merge #1654: use EXIT_ constants over magic numbers for indicating …

…program execution status

13d3896 CONTRIBUTING: mention that `EXIT_` codes should be used (Sebastian Falbesoner)
c855581 test, bench, precompute_ecmult: use `EXIT_...` constants for `main` return values (Sebastian Falbesoner)
965393f examples: use `EXIT_...` constants for `main` return values (Sebastian Falbesoner)

Pull request description:

  This simple PR addresses #1609 for all example and internal binaries. Alternative to #1618, which is stale (the author confirmed to me that they are not working on that PR anymore). The last commits adds a suggestion to CONTRIBUTING.md, not sure though if we want to go that far.

ACKs for top commit:
  jonasnick:
    ACK 13d3896
  real-or-random:
    utACK 13d3896

Tree-SHA512: 513eba4b712ba3d5f23a5fdc51cb27c5347b29bcaba39501345913c220be6f093a41186911032d2ddc898b848de84f05f374b3554ffcf92610728b2a23c0bb36

CONTRIBUTING.md

@@ -74,6 +74,7 @@ In addition, libsecp256k1 tries to maintain the following coding conventions:
 * User-facing comment lines in headers should be limited to 80 chars if possible.
 * All identifiers in file scope should start with `secp256k1_`.
 * Avoid trailing whitespace.
+* Use the constants `EXIT_SUCCESS`/`EXIT_FAILURE` (defined in `stdlib.h`) to indicate program execution status for examples and other binaries.
 
 ### Tests
 

examples/ecdh.c

@@ -8,6 +8,7 @@
  *************************************************************************/
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <assert.h>
 #include <string.h>
 
@@ -33,7 +34,7 @@ int main(void) {
     secp256k1_context* ctx = secp256k1_context_create(SECP256K1_CONTEXT_NONE);
     if (!fill_random(randomize, sizeof(randomize))) {
         printf("Failed to generate randomness\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     /* Randomizing the context is recommended to protect against side-channel
      * leakage See `secp256k1_context_randomize` in secp256k1.h for more
@@ -44,14 +45,14 @@ int main(void) {
     /*** Key Generation ***/
     if (!fill_random(seckey1, sizeof(seckey1)) || !fill_random(seckey2, sizeof(seckey2))) {
         printf("Failed to generate randomness\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     /* If the secret key is zero or out of range (greater than secp256k1's
     * order), we fail. Note that the probability of this occurring is negligible
     * with a properly functioning random number generator. */
     if (!secp256k1_ec_seckey_verify(ctx, seckey1) || !secp256k1_ec_seckey_verify(ctx, seckey2)) {
         printf("Generated secret key is invalid. This indicates an issue with the random number generator.\n");
-        return 1;
+        return EXIT_FAILURE;
     }
 
     /* Public key creation using a valid context with a verified secret key should never fail */
@@ -116,5 +117,5 @@ int main(void) {
     secure_erase(shared_secret1, sizeof(shared_secret1));
     secure_erase(shared_secret2, sizeof(shared_secret2));
 
-    return 0;
+    return EXIT_SUCCESS;
 }

examples/ecdsa.c

@@ -8,6 +8,7 @@
  *************************************************************************/
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <assert.h>
 #include <string.h>
 
@@ -40,7 +41,7 @@ int main(void) {
     secp256k1_context* ctx = secp256k1_context_create(SECP256K1_CONTEXT_NONE);
     if (!fill_random(randomize, sizeof(randomize))) {
         printf("Failed to generate randomness\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     /* Randomizing the context is recommended to protect against side-channel
      * leakage See `secp256k1_context_randomize` in secp256k1.h for more
@@ -51,14 +52,14 @@ int main(void) {
     /*** Key Generation ***/
     if (!fill_random(seckey, sizeof(seckey))) {
         printf("Failed to generate randomness\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     /* If the secret key is zero or out of range (greater than secp256k1's
     * order), we fail. Note that the probability of this occurring is negligible
     * with a properly functioning random number generator. */
     if (!secp256k1_ec_seckey_verify(ctx, seckey)) {
         printf("Generated secret key is invalid. This indicates an issue with the random number generator.\n");
-        return 1;
+        return EXIT_FAILURE;
     }
 
     /* Public key creation using a valid context with a verified secret key should never fail */
@@ -92,13 +93,13 @@ int main(void) {
     /* Deserialize the signature. This will return 0 if the signature can't be parsed correctly. */
     if (!secp256k1_ecdsa_signature_parse_compact(ctx, &sig, serialized_signature)) {
         printf("Failed parsing the signature\n");
-        return 1;
+        return EXIT_FAILURE;
     }
 
     /* Deserialize the public key. This will return 0 if the public key can't be parsed correctly. */
     if (!secp256k1_ec_pubkey_parse(ctx, &pubkey, compressed_pubkey, sizeof(compressed_pubkey))) {
         printf("Failed parsing the public key\n");
-        return 1;
+        return EXIT_FAILURE;
     }
 
     /* Verify a signature. This will return 1 if it's valid and 0 if it's not. */
@@ -133,5 +134,5 @@ int main(void) {
      * will remove any writes that aren't used. */
     secure_erase(seckey, sizeof(seckey));
 
-    return 0;
+    return EXIT_SUCCESS;
 }

examples/ellswift.c

@@ -13,6 +13,7 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <assert.h>
 #include <string.h>
 
@@ -38,7 +39,7 @@ int main(void) {
     ctx = secp256k1_context_create(SECP256K1_CONTEXT_NONE);
     if (!fill_random(randomize, sizeof(randomize))) {
         printf("Failed to generate randomness\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     /* Randomizing the context is recommended to protect against side-channel
      * leakage. See `secp256k1_context_randomize` in secp256k1.h for more
@@ -49,22 +50,22 @@ int main(void) {
     /*** Generate secret keys ***/
     if (!fill_random(seckey1, sizeof(seckey1)) || !fill_random(seckey2, sizeof(seckey2))) {
         printf("Failed to generate randomness\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     /* If the secret key is zero or out of range (greater than secp256k1's
     * order), we fail. Note that the probability of this occurring is negligible
     * with a properly functioning random number generator. */
     if (!secp256k1_ec_seckey_verify(ctx, seckey1) || !secp256k1_ec_seckey_verify(ctx, seckey2)) {
         printf("Generated secret key is invalid. This indicates an issue with the random number generator.\n");
-        return 1;
+        return EXIT_FAILURE;
     }
 
     /* Generate ElligatorSwift public keys. This should never fail with valid context and
        verified secret keys. Note that providing additional randomness (fourth parameter) is
        optional, but recommended. */
     if (!fill_random(auxrand1, sizeof(auxrand1)) || !fill_random(auxrand2, sizeof(auxrand2))) {
         printf("Failed to generate randomness\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     return_val = secp256k1_ellswift_create(ctx, ellswift_pubkey1, seckey1, auxrand1);
     assert(return_val);
@@ -117,5 +118,5 @@ int main(void) {
     secure_erase(shared_secret1, sizeof(shared_secret1));
     secure_erase(shared_secret2, sizeof(shared_secret2));
 
-    return 0;
+    return EXIT_SUCCESS;
 }

examples/musig.c

@@ -12,6 +12,7 @@
  */
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <assert.h>
 #include <string.h>
 
@@ -193,7 +194,7 @@ int main(void) {
     for (i = 0; i < N_SIGNERS; i++) {
         if (!create_keypair(ctx, &signer_secrets[i], &signers[i])) {
             printf("FAILED\n");
-            return 1;
+            return EXIT_FAILURE;
         }
         pubkeys_ptr[i] = &signers[i].pubkey;
     }
@@ -208,7 +209,7 @@ int main(void) {
     fflush(stdout);
     if (!secp256k1_ec_pubkey_sort(ctx, pubkeys_ptr, N_SIGNERS)) {
         printf("FAILED\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("ok\n");
 
@@ -219,29 +220,29 @@ int main(void) {
      * while providing a non-NULL agg_pk argument. */
     if (!secp256k1_musig_pubkey_agg(ctx, NULL, &cache, pubkeys_ptr, N_SIGNERS)) {
         printf("FAILED\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("ok\n");
     printf("Tweaking................");
     fflush(stdout);
     /* Optionally tweak the aggregate key */
     if (!tweak(ctx, &agg_pk, &cache)) {
         printf("FAILED\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("ok\n");
     printf("Signing message.........");
     fflush(stdout);
     if (!sign(ctx, signer_secrets, signers, &cache, msg, sig)) {
         printf("FAILED\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("ok\n");
     printf("Verifying signature.....");
     fflush(stdout);
     if (!secp256k1_schnorrsig_verify(ctx, sig, msg, 32, &agg_pk)) {
         printf("FAILED\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     printf("ok\n");
 
@@ -256,5 +257,5 @@ int main(void) {
         secure_erase(&signer_secrets[i], sizeof(signer_secrets[i]));
     }
     secp256k1_context_destroy(ctx);
-    return 0;
+    return EXIT_SUCCESS;
 }

examples/schnorr.c

@@ -8,6 +8,7 @@
  *************************************************************************/
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <assert.h>
 #include <string.h>
 
@@ -34,7 +35,7 @@ int main(void) {
     secp256k1_context* ctx = secp256k1_context_create(SECP256K1_CONTEXT_NONE);
     if (!fill_random(randomize, sizeof(randomize))) {
         printf("Failed to generate randomness\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     /* Randomizing the context is recommended to protect against side-channel
      * leakage See `secp256k1_context_randomize` in secp256k1.h for more
@@ -45,15 +46,15 @@ int main(void) {
     /*** Key Generation ***/
     if (!fill_random(seckey, sizeof(seckey))) {
         printf("Failed to generate randomness\n");
-        return 1;
+        return EXIT_FAILURE;
     }
     /* Try to create a keypair with a valid context. This only fails if the
      * secret key is zero or out of range (greater than secp256k1's order). Note
      * that the probability of this occurring is negligible with a properly
      * functioning random number generator. */
     if (!secp256k1_keypair_create(ctx, &keypair, seckey)) {
         printf("Generated secret key is invalid. This indicates an issue with the random number generator.\n");
-        return 1;
+        return EXIT_FAILURE;
     }
 
     /* Extract the X-only public key from the keypair. We pass NULL for
@@ -90,7 +91,7 @@ int main(void) {
     /* Generate 32 bytes of randomness to use with BIP-340 schnorr signing. */
     if (!fill_random(auxiliary_rand, sizeof(auxiliary_rand))) {
         printf("Failed to generate randomness\n");
-        return 1;
+        return EXIT_FAILURE;
     }
 
     /* Generate a Schnorr signature.
@@ -110,7 +111,7 @@ int main(void) {
      * be parsed correctly */
     if (!secp256k1_xonly_pubkey_parse(ctx, &pubkey, serialized_pubkey)) {
         printf("Failed parsing the public key\n");
-        return 1;
+        return EXIT_FAILURE;
     }
 
     /* Compute the tagged hash on the received messages using the same tag as the signer. */
@@ -149,5 +150,5 @@ int main(void) {
      * Here we are preventing these writes from being optimized out, as any good compiler
      * will remove any writes that aren't used. */
     secure_erase(seckey, sizeof(seckey));
-    return 0;
+    return EXIT_SUCCESS;
 }

src/bench.c

@@ -5,6 +5,7 @@
  ***********************************************************************/
 
 #include <stdio.h>
+#include <stdlib.h>
 #include <string.h>
 
 #include "../include/secp256k1.h"
@@ -188,11 +189,11 @@ int main(int argc, char** argv) {
            || have_flag(argc, argv, "--help")
            || have_flag(argc, argv, "help")) {
             help(default_iters);
-            return 0;
+            return EXIT_SUCCESS;
         } else if (invalid_args) {
             fprintf(stderr, "./bench: unrecognized argument.\n\n");
             help(default_iters);
-            return 1;
+            return EXIT_FAILURE;
         }
     }
 
@@ -201,23 +202,23 @@ int main(int argc, char** argv) {
     if (have_flag(argc, argv, "ecdh")) {
         fprintf(stderr, "./bench: ECDH module not enabled.\n");
         fprintf(stderr, "Use ./configure --enable-module-ecdh.\n\n");
-        return 1;
+        return EXIT_FAILURE;
     }
 #endif
 
 #ifndef ENABLE_MODULE_RECOVERY
     if (have_flag(argc, argv, "recover") || have_flag(argc, argv, "ecdsa_recover")) {
         fprintf(stderr, "./bench: Public key recovery module not enabled.\n");
         fprintf(stderr, "Use ./configure --enable-module-recovery.\n\n");
-        return 1;
+        return EXIT_FAILURE;
     }
 #endif
 
 #ifndef ENABLE_MODULE_SCHNORRSIG
     if (have_flag(argc, argv, "schnorrsig") || have_flag(argc, argv, "schnorrsig_sign") || have_flag(argc, argv, "schnorrsig_verify")) {
         fprintf(stderr, "./bench: Schnorr signatures module not enabled.\n");
         fprintf(stderr, "Use ./configure --enable-module-schnorrsig.\n\n");
-        return 1;
+        return EXIT_FAILURE;
     }
 #endif
 
@@ -227,7 +228,7 @@ int main(int argc, char** argv) {
         have_flag(argc, argv, "ellswift_ecdh")) {
         fprintf(stderr, "./bench: ElligatorSwift module not enabled.\n");
         fprintf(stderr, "Use ./configure --enable-module-ellswift.\n\n");
-        return 1;
+        return EXIT_FAILURE;
     }
 #endif
 
@@ -275,5 +276,5 @@ int main(int argc, char** argv) {
     run_ellswift_bench(iters, argc, argv);
 #endif
 
-    return 0;
+    return EXIT_SUCCESS;
 }

src/bench.h

@@ -24,7 +24,7 @@ static int64_t gettime_i64(void) {
     struct timespec tv;
     if (!timespec_get(&tv, TIME_UTC)) {
         fputs("timespec_get failed!", stderr);
-        exit(1);
+        exit(EXIT_FAILURE);
     }
     return (int64_t)tv.tv_nsec / 1000 + (int64_t)tv.tv_sec * 1000000LL;
 #else

src/bench_ecmult.c

@@ -4,6 +4,7 @@
  * file COPYING or https://www.opensource.org/licenses/mit-license.php.*
  ***********************************************************************/
 #include <stdio.h>
+#include <stdlib.h>
 
 #include "secp256k1.c"
 #include "../include/secp256k1.h"
@@ -287,7 +288,7 @@ int main(int argc, char **argv) {
            || have_flag(argc, argv, "--help")
            || have_flag(argc, argv, "help")) {
             help(argv);
-            return 0;
+            return EXIT_SUCCESS;
         } else if(have_flag(argc, argv, "pippenger_wnaf")) {
             printf("Using pippenger_wnaf:\n");
             data.ecmult_multi = secp256k1_ecmult_pippenger_batch_single;
@@ -299,7 +300,7 @@ int main(int argc, char **argv) {
         } else {
             fprintf(stderr, "%s: unrecognized argument '%s'.\n\n", argv[0], argv[1]);
             help(argv);
-            return 1;
+            return EXIT_FAILURE;
         }
     }
 
@@ -363,5 +364,5 @@ int main(int argc, char **argv) {
     free(data.output);
     free(data.expected_output);
 
-    return(0);
+    return EXIT_SUCCESS;
 }