From fee7d4bf9e4ea316ea4ff3151bbe52bec1f0745c Mon Sep 17 00:00:00 2001 From: Elichai Turkel Date: Thu, 30 Apr 2020 13:37:52 +0300 Subject: [PATCH 1/6] Add an ECDSA signing and verifying example Co-authored-by: Jonas Nick --- examples/ecdsa.c | 137 ++++++++++++++++++++++++++++++++++++++++++++++ examples/random.h | 73 ++++++++++++++++++++++++ 2 files changed, 210 insertions(+) create mode 100644 examples/ecdsa.c create mode 100644 examples/random.h diff --git a/examples/ecdsa.c b/examples/ecdsa.c new file mode 100644 index 0000000000000..434c856ba0ff2 --- /dev/null +++ b/examples/ecdsa.c @@ -0,0 +1,137 @@ +/************************************************************************* + * Written in 2020-2022 by Elichai Turkel * + * To the extent possible under law, the author(s) have dedicated all * + * copyright and related and neighboring rights to the software in this * + * file to the public domain worldwide. This software is distributed * + * without any warranty. For the CC0 Public Domain Dedication, see * + * EXAMPLES_COPYING or https://creativecommons.org/publicdomain/zero/1.0 * + *************************************************************************/ + +#include +#include +#include + +#include + +#include "random.h" + + + +int main(void) { + /* Instead of signing the message directly, we must sign a 32-byte hash. + * Here the message is "Hello, world!" and the hash function was SHA-256. + * An actual implementation should just call SHA-256, but this example + * hardcodes the output to avoid depending on an additional library. + * See https://bitcoin.stackexchange.com/questions/81115/if-someone-wanted-to-pretend-to-be-satoshi-by-posting-a-fake-signature-to-defrau/81116#81116 */ + unsigned char msg_hash[32] = { + 0x31, 0x5F, 0x5B, 0xDB, 0x76, 0xD0, 0x78, 0xC4, + 0x3B, 0x8A, 0xC0, 0x06, 0x4E, 0x4A, 0x01, 0x64, + 0x61, 0x2B, 0x1F, 0xCE, 0x77, 0xC8, 0x69, 0x34, + 0x5B, 0xFC, 0x94, 0xC7, 0x58, 0x94, 0xED, 0xD3, + }; + unsigned char seckey[32]; + unsigned char randomize[32]; + unsigned char compressed_pubkey[33]; + unsigned char serialized_signature[64]; + size_t len; + int is_signature_valid; + int return_val; + secp256k1_pubkey pubkey; + secp256k1_ecdsa_signature sig; + /* The specification in secp256k1.h states that `secp256k1_ec_pubkey_create` needs + * a context object initialized for signing and `secp256k1_ecdsa_verify` needs + * a context initialized for verification, which is why we create a context + * for both signing and verification with the SECP256K1_CONTEXT_SIGN and + * SECP256K1_CONTEXT_VERIFY flags. */ + secp256k1_context* ctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN | SECP256K1_CONTEXT_VERIFY); + if (!fill_random(randomize, sizeof(randomize))) { + printf("Failed to generate randomness\n"); + return 1; + } + /* Randomizing the context is recommended to protect against side-channel + * leakage See `secp256k1_context_randomize` in secp256k1.h for more + * information about it. This should never fail. */ + return_val = secp256k1_context_randomize(ctx, randomize); + assert(return_val); + + /*** Key Generation ***/ + + /* If the secret key is zero or out of range (bigger than secp256k1's + * order), we try to sample a new key. Note that the probability of this + * happening is negligible. */ + while (1) { + if (!fill_random(seckey, sizeof(seckey))) { + printf("Failed to generate randomness\n"); + return 1; + } + if (secp256k1_ec_seckey_verify(ctx, seckey)) { + break; + } + } + + /* Public key creation using a valid context with a verified secret key should never fail */ + return_val = secp256k1_ec_pubkey_create(ctx, &pubkey, seckey); + assert(return_val); + + /* Serialize the pubkey in a compressed form(33 bytes). Should always return 1. */ + len = sizeof(compressed_pubkey); + return_val = secp256k1_ec_pubkey_serialize(ctx, compressed_pubkey, &len, &pubkey, SECP256K1_EC_COMPRESSED); + assert(return_val); + /* Should be the same size as the size of the output, because we passed a 33 byte array. */ + assert(len == sizeof(compressed_pubkey)); + + /*** Signing ***/ + + /* Generate an ECDSA signature `noncefp` and `ndata` allows you to pass a + * custom nonce function, passing `NULL` will use the RFC-6979 safe default. + * Signing with a valid context, verified secret key + * and the default nonce function should never fail. */ + return_val = secp256k1_ecdsa_sign(ctx, &sig, msg_hash, seckey, NULL, NULL); + assert(return_val); + + /* Serialize the signature in a compact form. Should always return 1 + * according to the documentation in secp256k1.h. */ + return_val = secp256k1_ecdsa_signature_serialize_compact(ctx, serialized_signature, &sig); + assert(return_val); + + + /*** Verification ***/ + + /* 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; + } + + /* 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; + } + + /* Verify a signature. This will return 1 if it's valid and 0 if it's not. */ + is_signature_valid = secp256k1_ecdsa_verify(ctx, &sig, msg_hash, &pubkey); + + printf("Is the signature valid? %s\n", is_signature_valid ? "true" : "false"); + printf("Secret Key: "); + print_hex(seckey, sizeof(seckey)); + printf("Public Key: "); + print_hex(compressed_pubkey, sizeof(compressed_pubkey)); + printf("Signature: "); + print_hex(serialized_signature, sizeof(serialized_signature)); + + + /* This will clear everything from the context and free the memory */ + secp256k1_context_destroy(ctx); + + /* It's best practice to try to clear secrets from memory after using them. + * This is done because some bugs can allow an attacker to leak memory, for + * example through "out of bounds" array access (see Heartbleed), Or the OS + * swapping them to disk. Hence, we overwrite the secret key buffer with zeros. + * + * TODO: Prevent these writes from being optimized out, as any good compiler + * will remove any writes that aren't used. */ + memset(seckey, 0, sizeof(seckey)); + + return 0; +} diff --git a/examples/random.h b/examples/random.h new file mode 100644 index 0000000000000..439226f09f5bf --- /dev/null +++ b/examples/random.h @@ -0,0 +1,73 @@ +/************************************************************************* + * Copyright (c) 2020-2021 Elichai Turkel * + * Distributed under the CC0 software license, see the accompanying file * + * EXAMPLES_COPYING or https://creativecommons.org/publicdomain/zero/1.0 * + *************************************************************************/ + +/* + * This file is an attempt at collecting best practice methods for obtaining randomness with different operating systems. + * It may be out-of-date. Consult the documentation of the operating system before considering to use the methods below. + * + * Platform randomness sources: + * Linux -> `getrandom(2)`(`sys/random.h`), if not available `/dev/urandom` should be used. http://man7.org/linux/man-pages/man2/getrandom.2.html, https://linux.die.net/man/4/urandom + * macOS -> `getentropy(2)`(`sys/random.h`), if not available `/dev/urandom` should be used. https://www.unix.com/man-page/mojave/2/getentropy, https://opensource.apple.com/source/xnu/xnu-517.12.7/bsd/man/man4/random.4.auto.html + * FreeBSD -> `getrandom(2)`(`sys/random.h`), if not available `kern.arandom` should be used. https://www.freebsd.org/cgi/man.cgi?query=getrandom, https://www.freebsd.org/cgi/man.cgi?query=random&sektion=4 + * OpenBSD -> `getentropy(2)`(`unistd.h`), if not available `/dev/urandom` should be used. https://man.openbsd.org/getentropy, https://man.openbsd.org/urandom + * Windows -> `BCryptGenRandom`(`bcrypt.h`). https://docs.microsoft.com/en-us/windows/win32/api/bcrypt/nf-bcrypt-bcryptgenrandom + */ + +#if defined(_WIN32) +#include +#include +#include +#elif defined(__linux__) || defined(__APPLE__) || defined(__FreeBSD__) +#include +#elif defined(__OpenBSD__) +#include +#else +#error "Couldn't identify the OS" +#endif + +#include +#include +#include + + +/* Returns 1 on success, and 0 on failure. */ +static int fill_random(unsigned char* data, size_t size) { +#if defined(_WIN32) + NTSTATUS res = BCryptGenRandom(NULL, data, size, BCRYPT_USE_SYSTEM_PREFERRED_RNG); + if (res != STATUS_SUCCESS || size > ULONG_MAX) { + return 0; + } else { + return 1; + } +#elif defined(__linux__) || defined(__FreeBSD__) + /* If `getrandom(2)` is not available you should fallback to /dev/urandom */ + ssize_t res = getrandom(data, size, 0); + if (res < 0 || (size_t)res != size ) { + return 0; + } else { + return 1; + } +#elif defined(__APPLE__) || defined(__OpenBSD__) + /* If `getentropy(2)` is not available you should fallback to either + * `SecRandomCopyBytes` or /dev/urandom */ + int res = getentropy(data, size); + if (res == 0) { + return 1; + } else { + return 0; + } +#endif + return 0; +} + +static void print_hex(unsigned char* data, size_t size) { + size_t i; + printf("0x"); + for (i = 0; i < size; i++) { + printf("%02x", data[i]); + } + printf("\n"); +} From b0cfbcc14347ff6b04ff62a0d935638840a37971 Mon Sep 17 00:00:00 2001 From: Elichai Turkel Date: Mon, 9 Nov 2020 18:11:43 +0200 Subject: [PATCH 2/6] Add a Schnorr signing and verifying example Co-authored-by: Jonas Nick --- examples/schnorr.c | 136 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 136 insertions(+) create mode 100644 examples/schnorr.c diff --git a/examples/schnorr.c b/examples/schnorr.c new file mode 100644 index 0000000000000..a3533b64040e0 --- /dev/null +++ b/examples/schnorr.c @@ -0,0 +1,136 @@ +/************************************************************************* + * Written in 2020-2022 by Elichai Turkel * + * To the extent possible under law, the author(s) have dedicated all * + * copyright and related and neighboring rights to the software in this * + * file to the public domain worldwide. This software is distributed * + * without any warranty. For the CC0 Public Domain Dedication, see * + * EXAMPLES_COPYING or https://creativecommons.org/publicdomain/zero/1.0 * + *************************************************************************/ + +#include +#include +#include + +#include +#include +#include + +#include "random.h" + +int main(void) { + /* Instead of signing the message directly, we must sign a 32-byte hash. + * Here the message is "Hello, world!" and the hash function was SHA-256. + * An actual implementation should just call SHA-256, but this example + * hardcodes the output to avoid depending on an additional library. */ + unsigned char msg_hash[32] = { + 0x31, 0x5F, 0x5B, 0xDB, 0x76, 0xD0, 0x78, 0xC4, + 0x3B, 0x8A, 0xC0, 0x06, 0x4E, 0x4A, 0x01, 0x64, + 0x61, 0x2B, 0x1F, 0xCE, 0x77, 0xC8, 0x69, 0x34, + 0x5B, 0xFC, 0x94, 0xC7, 0x58, 0x94, 0xED, 0xD3, + }; + unsigned char seckey[32]; + unsigned char randomize[32]; + unsigned char auxiliary_rand[32]; + unsigned char serialized_pubkey[32]; + unsigned char signature[64]; + int is_signature_valid; + int return_val; + secp256k1_xonly_pubkey pubkey; + secp256k1_keypair keypair; + /* The specification in secp256k1_extrakeys.h states that `secp256k1_keypair_create` + * needs a context object initialized for signing. And in secp256k1_schnorrsig.h + * they state that `secp256k1_schnorrsig_verify` needs a context initialized for + * verification, which is why we create a context for both signing and verification + * with the SECP256K1_CONTEXT_SIGN and SECP256K1_CONTEXT_VERIFY flags. */ + secp256k1_context* ctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN | SECP256K1_CONTEXT_VERIFY); + if (!fill_random(randomize, sizeof(randomize))) { + printf("Failed to generate randomness\n"); + return 1; + } + /* Randomizing the context is recommended to protect against side-channel + * leakage See `secp256k1_context_randomize` in secp256k1.h for more + * information about it. This should never fail. */ + return_val = secp256k1_context_randomize(ctx, randomize); + assert(return_val); + + /*** Key Generation ***/ + + /* If the secret key is zero or out of range (bigger than secp256k1's + * order), we try to sample a new key. Note that the probability of this + * happening is negligible. */ + while (1) { + if (!fill_random(seckey, sizeof(seckey))) { + printf("Failed to generate randomness\n"); + return 1; + } + /* Try to create a keypair with a valid context, it should only fail if + * the secret key is zero or out of range. */ + if (secp256k1_keypair_create(ctx, &keypair, seckey)) { + break; + } + } + + /* Extract the X-only public key from the keypair. We pass NULL for + * `pk_parity` as the parity isn't needed for signing or verification. + * `secp256k1_keypair_xonly_pub` supports returning the parity for + * other use cases such as tests or verifying Taproot tweaks. + * This should never fail with a valid context and public key. */ + return_val = secp256k1_keypair_xonly_pub(ctx, &pubkey, NULL, &keypair); + assert(return_val); + + /* Serialize the public key. Should always return 1 for a valid public key. */ + return_val = secp256k1_xonly_pubkey_serialize(ctx, serialized_pubkey, &pubkey); + assert(return_val); + + /*** Signing ***/ + + /* 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; + } + + /* Generate a Schnorr signature `noncefp` and `ndata` allows you to pass a + * custom nonce function, passing `NULL` will use the BIP-340 safe default. + * BIP-340 recommends passing 32 bytes of randomness to the nonce function to + * improve security against side-channel attacks. Signing with a valid + * context, verified keypair and the default nonce function should never + * fail. */ + return_val = secp256k1_schnorrsig_sign(ctx, signature, msg_hash, &keypair, auxiliary_rand); + assert(return_val); + + /*** Verification ***/ + + /* Deserialize the public key. This will return 0 if the public key can't + * be parsed correctly */ + if (!secp256k1_xonly_pubkey_parse(ctx, &pubkey, serialized_pubkey)) { + printf("Failed parsing the public key\n"); + return 1; + } + + /* Verify a signature. This will return 1 if it's valid and 0 if it's not. */ + is_signature_valid = secp256k1_schnorrsig_verify(ctx, signature, msg_hash, 32, &pubkey); + + + printf("Is the signature valid? %s\n", is_signature_valid ? "true" : "false"); + printf("Secret Key: "); + print_hex(seckey, sizeof(seckey)); + printf("Public Key: "); + print_hex(serialized_pubkey, sizeof(serialized_pubkey)); + printf("Signature: "); + print_hex(signature, sizeof(signature)); + + /* This will clear everything from the context and free the memory */ + secp256k1_context_destroy(ctx); + + /* It's best practice to try to clear secrets from memory after using them. + * This is done because some bugs can allow an attacker to leak memory, for + * example through "out of bounds" array access (see Heartbleed), Or the OS + * swapping them to disk. Hence, we overwrite the secret key buffer with zeros. + * + * TODO: Prevent these writes from being optimized out, as any good compiler + * will remove any writes that aren't used. */ + memset(seckey, 0, sizeof(seckey)); + + return 0; +} From 422a7cc86ae86496794c5014028ee249bbe0e072 Mon Sep 17 00:00:00 2001 From: Elichai Turkel Date: Thu, 30 Apr 2020 14:33:22 +0300 Subject: [PATCH 3/6] Add a ecdh shared secret example Co-authored-by: Jonas Nick --- examples/ecdh.c | 127 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 examples/ecdh.c diff --git a/examples/ecdh.c b/examples/ecdh.c new file mode 100644 index 0000000000000..d7e8add361338 --- /dev/null +++ b/examples/ecdh.c @@ -0,0 +1,127 @@ +/************************************************************************* + * Written in 2020-2022 by Elichai Turkel * + * To the extent possible under law, the author(s) have dedicated all * + * copyright and related and neighboring rights to the software in this * + * file to the public domain worldwide. This software is distributed * + * without any warranty. For the CC0 Public Domain Dedication, see * + * EXAMPLES_COPYING or https://creativecommons.org/publicdomain/zero/1.0 * + *************************************************************************/ + +#include +#include +#include + +#include +#include + +#include "random.h" + + +int main(void) { + unsigned char seckey1[32]; + unsigned char seckey2[32]; + unsigned char compressed_pubkey1[33]; + unsigned char compressed_pubkey2[33]; + unsigned char shared_secret1[32]; + unsigned char shared_secret2[32]; + unsigned char randomize[32]; + int return_val; + size_t len; + secp256k1_pubkey pubkey1; + secp256k1_pubkey pubkey2; + + /* The specification in secp256k1.h states that `secp256k1_ec_pubkey_create` + * needs a context object initialized for signing, which is why we create + * a context with the SECP256K1_CONTEXT_SIGN flag. + * (The docs for `secp256k1_ecdh` don't require any special context, just + * some initialized context) */ + secp256k1_context* ctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN); + if (!fill_random(randomize, sizeof(randomize))) { + printf("Failed to generate randomness\n"); + return 1; + } + /* Randomizing the context is recommended to protect against side-channel + * leakage See `secp256k1_context_randomize` in secp256k1.h for more + * information about it. This should never fail. */ + return_val = secp256k1_context_randomize(ctx, randomize); + assert(return_val); + + /*** Key Generation ***/ + + /* If the secret key is zero or out of range (bigger than secp256k1's + * order), we try to sample a new key. Note that the probability of this + * happening is negligible. */ + while (1) { + if (!fill_random(seckey1, sizeof(seckey1)) || !fill_random(seckey2, sizeof(seckey2))) { + printf("Failed to generate randomness\n"); + return 1; + } + if (secp256k1_ec_seckey_verify(ctx, seckey1) && secp256k1_ec_seckey_verify(ctx, seckey2)) { + break; + } + } + + /* Public key creation using a valid context with a verified secret key should never fail */ + return_val = secp256k1_ec_pubkey_create(ctx, &pubkey1, seckey1); + assert(return_val); + return_val = secp256k1_ec_pubkey_create(ctx, &pubkey2, seckey2); + assert(return_val); + + /* Serialize pubkey1 in a compressed form (33 bytes), should always return 1 */ + len = sizeof(compressed_pubkey1); + return_val = secp256k1_ec_pubkey_serialize(ctx, compressed_pubkey1, &len, &pubkey1, SECP256K1_EC_COMPRESSED); + assert(return_val); + /* Should be the same size as the size of the output, because we passed a 33 byte array. */ + assert(len == sizeof(compressed_pubkey1)); + + /* Serialize pubkey2 in a compressed form (33 bytes) */ + len = sizeof(compressed_pubkey2); + return_val = secp256k1_ec_pubkey_serialize(ctx, compressed_pubkey2, &len, &pubkey2, SECP256K1_EC_COMPRESSED); + assert(return_val); + /* Should be the same size as the size of the output, because we passed a 33 byte array. */ + assert(len == sizeof(compressed_pubkey2)); + + /*** Creating the shared secret ***/ + + /* Perform ECDH with seckey1 and pubkey2. Should never fail with a verified + * seckey and valid pubkey */ + return_val = secp256k1_ecdh(ctx, shared_secret1, &pubkey2, seckey1, NULL, NULL); + assert(return_val); + + /* Perform ECDH with seckey2 and pubkey1. Should never fail with a verified + * seckey and valid pubkey */ + return_val = secp256k1_ecdh(ctx, shared_secret2, &pubkey1, seckey2, NULL, NULL); + assert(return_val); + + /* Both parties should end up with the same shared secret */ + return_val = memcmp(shared_secret1, shared_secret2, sizeof(shared_secret1)); + assert(return_val == 0); + + printf("Secret Key1: "); + print_hex(seckey1, sizeof(seckey1)); + printf("Compressed Pubkey1: "); + print_hex(compressed_pubkey1, sizeof(compressed_pubkey1)); + printf("\nSecret Key2: "); + print_hex(seckey2, sizeof(seckey2)); + printf("Compressed Pubkey2: "); + print_hex(compressed_pubkey2, sizeof(compressed_pubkey2)); + printf("\nShared Secret: "); + print_hex(shared_secret1, sizeof(shared_secret1)); + + /* This will clear everything from the context and free the memory */ + secp256k1_context_destroy(ctx); + + /* It's best practice to try to clear secrets from memory after using them. + * This is done because some bugs can allow an attacker to leak memory, for + * example through "out of bounds" array access (see Heartbleed), Or the OS + * swapping them to disk. Hence, we overwrite the secret key buffer with zeros. + * + * TODO: Prevent these writes from being optimized out, as any good compiler + * will remove any writes that aren't used. */ + memset(seckey1, 0, sizeof(seckey1)); + memset(seckey2, 0, sizeof(seckey2)); + memset(shared_secret1, 0, sizeof(shared_secret1)); + memset(shared_secret2, 0, sizeof(shared_secret2)); + + return 0; +} From 517644eab14ef397e1f0bc2b45f2dff8b1a473ec Mon Sep 17 00:00:00 2001 From: Elichai Turkel Date: Thu, 30 Apr 2020 14:34:24 +0300 Subject: [PATCH 4/6] Optionally compile the examples in autotools, compile+run in travis --- .cirrus.yml | 2 ++ .gitignore | 5 +++++ Makefile.am | 35 +++++++++++++++++++++++++++++++++++ ci/cirrus.sh | 1 + configure.ac | 13 +++++++++++++ 5 files changed, 56 insertions(+) diff --git a/.cirrus.yml b/.cirrus.yml index ffbd820710527..8e18c6ea588d8 100644 --- a/.cirrus.yml +++ b/.cirrus.yml @@ -23,6 +23,8 @@ env: BENCH: yes SECP256K1_BENCH_ITERS: 2 CTIMETEST: yes + # Compile and run the tests + EXAMPLES: yes cat_logs_snippet: &CAT_LOGS always: diff --git a/.gitignore b/.gitignore index cb52998ad6ef2..53941f23a540a 100644 --- a/.gitignore +++ b/.gitignore @@ -6,11 +6,16 @@ exhaustive_tests precompute_ecmult_gen precompute_ecmult valgrind_ctime_test +ecdh_example +ecdsa_example +schnorr_example *.exe *.so *.a *.csv !.gitignore +*.log +*.trs Makefile configure diff --git a/Makefile.am b/Makefile.am index f87852974fae1..51c5960301a49 100644 --- a/Makefile.am +++ b/Makefile.am @@ -63,6 +63,7 @@ noinst_HEADERS += contrib/lax_der_parsing.h noinst_HEADERS += contrib/lax_der_parsing.c noinst_HEADERS += contrib/lax_der_privatekey_parsing.h noinst_HEADERS += contrib/lax_der_privatekey_parsing.c +noinst_HEADERS += examples/random.h PRECOMPUTED_LIB = libsecp256k1_precomputed.la noinst_LTLIBRARIES = $(PRECOMPUTED_LIB) @@ -139,6 +140,40 @@ exhaustive_tests_LDFLAGS = -static TESTS += exhaustive_tests endif +if USE_EXAMPLES +noinst_PROGRAMS += ecdsa_example +ecdsa_example_SOURCES = examples/ecdsa.c +ecdsa_example_CPPFLAGS = -I$(top_srcdir)/include +ecdsa_example_LDADD = libsecp256k1.la +ecdsa_example_LDFLAGS = -static +if BUILD_WINDOWS +ecdsa_example_LDFLAGS += -lbcrypt +endif +TESTS += ecdsa_example +if ENABLE_MODULE_ECDH +noinst_PROGRAMS += ecdh_example +ecdh_example_SOURCES = examples/ecdh.c +ecdh_example_CPPFLAGS = -I$(top_srcdir)/include +ecdh_example_LDADD = libsecp256k1.la +ecdh_example_LDFLAGS = -static +if BUILD_WINDOWS +ecdh_example_LDFLAGS += -lbcrypt +endif +TESTS += ecdh_example +endif +if ENABLE_MODULE_SCHNORRSIG +noinst_PROGRAMS += schnorr_example +schnorr_example_SOURCES = examples/schnorr.c +schnorr_example_CPPFLAGS = -I$(top_srcdir)/include +schnorr_example_LDADD = libsecp256k1.la +schnorr_example_LDFLAGS = -static +if BUILD_WINDOWS +schnorr_example_LDFLAGS += -lbcrypt +endif +TESTS += schnorr_example +endif +endif + ### Precomputed tables EXTRA_PROGRAMS = precompute_ecmult precompute_ecmult_gen CLEANFILES = $(EXTRA_PROGRAMS) diff --git a/ci/cirrus.sh b/ci/cirrus.sh index 4379e25047b09..b85f012d3f3c0 100755 --- a/ci/cirrus.sh +++ b/ci/cirrus.sh @@ -19,6 +19,7 @@ valgrind --version || true --with-ecmult-gen-precision="$ECMULTGENPRECISION" \ --enable-module-ecdh="$ECDH" --enable-module-recovery="$RECOVERY" \ --enable-module-schnorrsig="$SCHNORRSIG" \ + --enable-examples="$EXAMPLES" \ --with-valgrind="$WITH_VALGRIND" \ --host="$HOST" $EXTRAFLAGS diff --git a/configure.ac b/configure.ac index 92e497df8b39a..4a78b88b6a849 100644 --- a/configure.ac +++ b/configure.ac @@ -45,6 +45,8 @@ if test x"$ac_cv_prog_cc_c89" = x"no"; then fi AM_PROG_AS +build_windows=no + case $host_os in *darwin*) if test x$cross_compiling != xyes; then @@ -68,6 +70,9 @@ case $host_os in fi fi ;; + cygwin*|mingw*) + build_windows=yes + ;; esac # Try if some desirable compiler flags are supported and append them to SECP_CFLAGS. @@ -135,6 +140,11 @@ AC_ARG_ENABLE(exhaustive_tests, [use_exhaustive_tests=$enableval], [use_exhaustive_tests=yes]) +AC_ARG_ENABLE(examples, + AS_HELP_STRING([--enable-examples],[compile the examples [default=no]]), + [use_examples=$enableval], + [use_examples=no]) + AC_ARG_ENABLE(module_ecdh, AS_HELP_STRING([--enable-module-ecdh],[enable ECDH shared secret computation]), [enable_module_ecdh=$enableval], @@ -393,6 +403,7 @@ AC_SUBST(SECP_CFLAGS) AM_CONDITIONAL([ENABLE_COVERAGE], [test x"$enable_coverage" = x"yes"]) AM_CONDITIONAL([USE_TESTS], [test x"$use_tests" != x"no"]) AM_CONDITIONAL([USE_EXHAUSTIVE_TESTS], [test x"$use_exhaustive_tests" != x"no"]) +AM_CONDITIONAL([USE_EXAMPLES], [test x"$use_examples" != x"no"]) AM_CONDITIONAL([USE_BENCHMARK], [test x"$use_benchmark" = x"yes"]) AM_CONDITIONAL([ENABLE_MODULE_ECDH], [test x"$enable_module_ecdh" = x"yes"]) AM_CONDITIONAL([ENABLE_MODULE_RECOVERY], [test x"$enable_module_recovery" = x"yes"]) @@ -400,6 +411,7 @@ AM_CONDITIONAL([ENABLE_MODULE_EXTRAKEYS], [test x"$enable_module_extrakeys" = x" AM_CONDITIONAL([ENABLE_MODULE_SCHNORRSIG], [test x"$enable_module_schnorrsig" = x"yes"]) AM_CONDITIONAL([USE_EXTERNAL_ASM], [test x"$use_external_asm" = x"yes"]) AM_CONDITIONAL([USE_ASM_ARM], [test x"$set_asm" = x"arm"]) +AM_CONDITIONAL([BUILD_WINDOWS], [test "$build_windows" = "yes"]) AC_SUBST(LIB_VERSION_CURRENT, _LIB_VERSION_CURRENT) AC_SUBST(LIB_VERSION_REVISION, _LIB_VERSION_REVISION) AC_SUBST(LIB_VERSION_AGE, _LIB_VERSION_AGE) @@ -417,6 +429,7 @@ echo " with external callbacks = $use_external_default_callbacks" echo " with benchmarks = $use_benchmark" echo " with tests = $use_tests" echo " with coverage = $enable_coverage" +echo " with examples = $use_examples" echo " module ecdh = $enable_module_ecdh" echo " module recovery = $enable_module_recovery" echo " module extrakeys = $enable_module_extrakeys" From 42e03432e6be7f0bf18c7f86130d3930bdf4038d Mon Sep 17 00:00:00 2001 From: Elichai Turkel Date: Thu, 30 Apr 2020 15:08:50 +0300 Subject: [PATCH 5/6] Add usage examples to the readme --- README.md | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/README.md b/README.md index 5fc07dd4fa468..f1ae215c8cce1 100644 --- a/README.md +++ b/README.md @@ -69,6 +69,14 @@ libsecp256k1 is built using autotools: $ make check # run the test suite $ sudo make install # optional +Usage examples +----------- + Usage examples can be found in the [examples](examples) directory. To compile them you need to configure with `--enable-examples`. + For experimental modules, you will also need `--enable-experimental` as well as a flag for each individual module, e.g. `--enable-module-ecdh`. + * [ECDSA example](examples/ecdsa.c) + * [Schnorr Signatures example](examples/schnorr.c) + * [Deriving a shared secret(ECDH) example](examples/ecdh.c) + Test coverage ----------- From 7c9502cece9c9e8d811333f7ab5bb22f4eb01c04 Mon Sep 17 00:00:00 2001 From: Elichai Turkel Date: Sun, 4 Jul 2021 17:42:30 +0300 Subject: [PATCH 6/6] Add a copy of the CC0 license to the examples --- examples/EXAMPLES_COPYING | 121 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 121 insertions(+) create mode 100644 examples/EXAMPLES_COPYING diff --git a/examples/EXAMPLES_COPYING b/examples/EXAMPLES_COPYING new file mode 100644 index 0000000000000..0e259d42c9967 --- /dev/null +++ b/examples/EXAMPLES_COPYING @@ -0,0 +1,121 @@ +Creative Commons Legal Code + +CC0 1.0 Universal + + CREATIVE COMMONS CORPORATION IS NOT A LAW FIRM AND DOES NOT PROVIDE + LEGAL SERVICES. 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