diff --git a/CMakeLists.txt b/CMakeLists.txt index 7473f15..9e1dde1 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -572,6 +572,8 @@ src/openvpn/shaper.h src/openvpn/sig.c src/openvpn/sig.h + src/openvpn/siphash.h + src/openvpn/siphash_reference.c src/openvpn/socket.c src/openvpn/socket.h src/openvpn/socket_util.c @@ -784,6 +786,7 @@ ) target_sources(test_crypto PRIVATE + tests/unit_tests/openvpn/siphash_openssl.c src/openvpn/crypto_mbedtls.c src/openvpn/crypto_openssl.c src/openvpn/crypto_epoch.c @@ -792,6 +795,7 @@ src/openvpn/packet_id.c src/openvpn/mtu.c src/openvpn/mss.c + src/openvpn/siphash_reference.c ) target_sources(test_ssl PRIVATE diff --git a/src/openvpn/Makefile.am b/src/openvpn/Makefile.am index ff8cc54..1f77384 100644 --- a/src/openvpn/Makefile.am +++ b/src/openvpn/Makefile.am @@ -128,6 +128,7 @@ session_id.c session_id.h \ shaper.c shaper.h \ sig.c sig.h \ + siphash_reference.c siphash.h \ socket.c socket.h \ socket_util.c socket_util.h \ socks.c socks.h \ diff --git a/src/openvpn/siphash.h b/src/openvpn/siphash.h index ef61110..bddddc3 100644 --- a/src/openvpn/siphash.h +++ b/src/openvpn/siphash.h @@ -18,12 +18,26 @@ #ifndef SIPHASH_H #define SIPHASH_H -#include +#include +#include +#include /* siphash always uses 128-bit keys */ #define SIPHASH_KEY_SIZE 16 -int siphash(const void *in, size_t inlen, const void *k, uint8_t *out, - size_t outlen); +/** + * Calculates SIPHASH using the reference implementation + */ +int +siphash_reference(const void *in, size_t inlen, const void *k, + uint8_t *out, size_t outlen); -#endif + +static inline int +siphash(const void *in, size_t inlen, const void *k, + uint8_t *out, size_t outlen) +{ + return siphash_reference(in, inlen, k, out, outlen); +} + +#endif /* ifndef SIPHASH_H */ \ No newline at end of file diff --git a/src/openvpn/siphash_reference.c b/src/openvpn/siphash_reference.c index b21a86e..ad19a51 100644 --- a/src/openvpn/siphash_reference.c +++ b/src/openvpn/siphash_reference.c @@ -100,8 +100,8 @@ * outlen: length of the output in bytes, must be 8 or 16 */ int -siphash(const void *in, const size_t inlen, const void *k, uint8_t *out, - const size_t outlen) +siphash_reference(const void *in, const size_t inlen, const void *k, uint8_t *out, + const size_t outlen) { const unsigned char *ni = (const unsigned char *)in; const unsigned char *kk = (const unsigned char *)k; diff --git a/tests/unit_tests/openvpn/Makefile.am b/tests/unit_tests/openvpn/Makefile.am index d861ef9..ae15759 100644 --- a/tests/unit_tests/openvpn/Makefile.am +++ b/tests/unit_tests/openvpn/Makefile.am @@ -73,6 +73,7 @@ crypto_testdriver_LDFLAGS = @TEST_LDFLAGS@ crypto_testdriver_SOURCES = test_crypto.c \ mock_msg.c mock_msg.h test_common.h \ + siphash_openssl.c siphash_openssl.h \ $(top_srcdir)/src/openvpn/buffer.c \ $(top_srcdir)/src/openvpn/crypto.c \ $(top_srcdir)/src/openvpn/crypto_mbedtls.c \ @@ -84,7 +85,8 @@ $(top_srcdir)/src/openvpn/platform.c \ $(top_srcdir)/src/openvpn/mtu.c \ $(top_srcdir)/src/openvpn/win32-util.c \ - $(top_srcdir)/src/openvpn/mss.c + $(top_srcdir)/src/openvpn/mss.c \ + $(top_srcdir)/src/openvpn/siphash_reference.c dhcp_testdriver_CFLAGS = -I$(top_srcdir)/src/openvpn -I$(top_srcdir)/src/compat @TEST_CFLAGS@ -DDHCP_UNIT_TEST dhcp_testdriver_LDFLAGS = @TEST_LDFLAGS@ -L$(top_srcdir)/src/openvpn diff --git a/tests/unit_tests/openvpn/siphash_openssl.c b/tests/unit_tests/openvpn/siphash_openssl.c new file mode 100644 index 0000000..c301f2d --- /dev/null +++ b/tests/unit_tests/openvpn/siphash_openssl.c @@ -0,0 +1,144 @@ +/* + * OpenVPN -- An application to securely tunnel IP networks + * over a single TCP/UDP port, with support for SSL/TLS-based + * session authentication and key exchange, + * packet encryption, packet authentication, and + * packet compression. + * + * Copyright (C) 2002-2026 OpenVPN Inc + * Copyright (C) 2026 Arne Schwabe + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, see . + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include "siphash.h" + +#ifdef ENABLE_CRYPTO_OPENSSL +#include +#endif + +/* OpenSSL siphash is currently 2-3 times slower than the reference + * implementation, so we only use it for unit testing that our implementation + * and OpenSSL agree */ +#if defined(ENABLE_CRYPTO_OPENSSL) && OPENSSL_VERSION_NUMBER >= 0x30000000L +#include +#include "crypto_openssl.h" +#include "crypto_backend.h" +#include "buffer.h" + +struct siphash_context +{ + EVP_MAC *mac; + EVP_MAC_CTX *ctx; + size_t size; + OSSL_PARAM params[3]; +}; + +/* + * Computes a SipHash value + * in: pointer to input data (read-only) + * inlen: input data length in bytes (any size_t value) + * k: pointer to the key data (read-only), must be 16 bytes + * out: pointer to output data (write-only), outlen bytes must be allocated + * outlen: length of the output in bytes, must be 8 or 16 + */ +int +siphash_openssl(void *sip_context, const void *in, const size_t inlen, + const void *k, uint8_t *out, const size_t outlen) +{ + struct siphash_context *sip = sip_context; + + + sip->params[1] = OSSL_PARAM_construct_octet_string("key", (void *)k, + SIPHASH_KEY_SIZE); + if (!EVP_MAC_init(sip->ctx, NULL, 0, sip->params)) + { + crypto_msg(M_FATAL, "EVP_MAC_init failed"); + } + EVP_MAC_update(sip->ctx, in, inlen); + + size_t outl = 0; + EVP_MAC_final(sip->ctx, out, &outl, outlen); + return 0; +} + +void * +siphash_openssl_init(size_t hash_size) +{ + struct siphash_context *sip; + ALLOC_OBJ(sip, struct siphash_context); + + sip->mac = EVP_MAC_fetch(NULL, "SIPHASH", NULL); + if (!sip->mac) + { + /* Our OpenSSL library does not support SIPHASH */ + return sip; + } + sip->ctx = EVP_MAC_CTX_new(sip->mac); + + /* OpenSSL will truly hold a pointer to an int in that parameter */ + sip->size = hash_size; + sip->params[0] = OSSL_PARAM_construct_size_t("size", &sip->size); + /* params[1] will hold the key that changes which each invocation */ + sip->params[2] = OSSL_PARAM_construct_end(); + return sip; +} + +bool +siphash_openssl_available(void *sip_context) +{ + struct siphash_context *sip = sip_context; + + return (bool)(sip->mac); +} + +void +siphash_openssl_uninit(void *sip_context) +{ + struct siphash_context *sip = sip_context; + EVP_MAC_CTX_free(sip->ctx); + EVP_MAC_free(sip->mac); + free(sip_context); +} +#else +/* Do avoid a lot more ifdefs in the test we put dummy functions here */ +int +siphash_openssl(void *sip_context, const void *in, const size_t inlen, + const void *k, uint8_t *out, const size_t outlen) +{ + return -1; +} + +bool +siphash_openssl_available(void *sip_context) +{ + return false; +} + +void * +siphash_openssl_init(size_t hash_size) +{ + return NULL; +} + +void +siphash_openssl_uninit(void *sip_context) +{ +} + + +#endif /* if defined(ENABLE_CRYPTO_OPENSSL) && OPENSSL_VERSION_NUMBER >= 0x30000000L */ diff --git a/tests/unit_tests/openvpn/siphash_openssl.h b/tests/unit_tests/openvpn/siphash_openssl.h new file mode 100644 index 0000000..0f1d329 --- /dev/null +++ b/tests/unit_tests/openvpn/siphash_openssl.h @@ -0,0 +1,64 @@ +/* + * OpenVPN -- An application to securely tunnel IP networks + * over a single TCP/UDP port, with support for SSL/TLS-based + * session authentication and key exchange, + * packet encryption, packet authentication, and + * packet compression. + * + * Copyright (C) 2002-2026 OpenVPN Inc + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, see . + */ +#ifndef SIPHASH_OPENSSL_H +#define SIPHASH_OPENSSL_H + +#include +#include +#include + + +/* Prototypes for an implementation of SIPHASH in a crypto library */ +/** + * + * @param hash_size the size of the output hash size + * @return initialised context for siphash + */ +void * +siphash_openssl_init(size_t hash_size); + + +/** + * Calculates SIPHASH using the crypto library function. + */ +int +siphash_openssl(void *sip_context, const void *in, size_t inlen, + const void *k, uint8_t *out, size_t outlen); + +/** + * Free the siphash context used for the crypto library + * @param sip_context + */ +void +siphash_openssl_uninit(void *sip_context); + +/** + * Returns if the crypto library is available (and should be used) + * + * This returns if there is a crypto library version of Siphash24 is + * available and should be used (OpenSSL 3/4 version is quite slow, so + * we prefer the reference implementation) + * + */ +bool +siphash_openssl_available(void *sip_context); +#endif /* ifndef SIPHASH_OPENSSL_H */ \ No newline at end of file diff --git a/tests/unit_tests/openvpn/test_crypto.c b/tests/unit_tests/openvpn/test_crypto.c index cb4eaa2..77cf295 100644 --- a/tests/unit_tests/openvpn/test_crypto.c +++ b/tests/unit_tests/openvpn/test_crypto.c @@ -31,12 +31,15 @@ #include #include #include +#include #include #include "crypto.h" #include "crypto_epoch.h" #include "options.h" #include "ssl_backend.h" +#include "siphash.h" +#include "siphash_openssl.h" #include "mss.h" #include "test_common.h" @@ -923,6 +926,69 @@ assert_memory_equal(key_parameters.hmac, exp_impl_iv, sizeof(exp_impl_iv)); } +/* Use a define here since some c compilers don't like array initialisation + * with an integer */ +#define UT_SIPHASH_HASH_SIZE 16 + +static const char *ut_message = "Look behind you, a Three-Headed Monkey!"; +static const uint8_t ut_key[SIPHASH_KEY_SIZE] = { 0x11, 0x22, 0x33, 0x44, 0x55, 0x66 }; +const uint8_t expected_hash[UT_SIPHASH_HASH_SIZE] = { 0x3e, 0xea, 0x95, 0xb2, 0x6d, 0x5c, 0x4e, 0xfa, + 0x20, 0x47, 0x65, 0x7e, 0xdd, 0xcd, 0x62, 0x51 }; + +static void +test_siphash(void **state) +{ + uint8_t out[UT_SIPHASH_HASH_SIZE] = { 0 }; + siphash_reference(ut_message, strlen(ut_message), ut_key, out, UT_SIPHASH_HASH_SIZE); + assert_memory_equal(out, expected_hash, UT_SIPHASH_HASH_SIZE); +} + +static void +test_siphash_openssl(void **state) +{ + void *sipctx = siphash_openssl_init(UT_SIPHASH_HASH_SIZE); + + if (!siphash_openssl_available(sipctx)) + { + siphash_openssl_uninit(sipctx); + skip(); + } + + uint8_t out[UT_SIPHASH_HASH_SIZE] = { 0 }; + + siphash_openssl(sipctx, ut_message, strlen(ut_message), ut_key, out, + UT_SIPHASH_HASH_SIZE); + assert_memory_equal(out, expected_hash, UT_SIPHASH_HASH_SIZE); + + /* check that calling the function twice is safe */ + siphash_openssl(sipctx, ut_message, strlen(ut_message), ut_key, out, + UT_SIPHASH_HASH_SIZE); + assert_memory_equal(out, expected_hash, UT_SIPHASH_HASH_SIZE); + + /* Test a few random strings and ensure that our implementation behave the + * same */ + for (int i = 0; i < 1000; i++) + { + size_t len = random() % 1000u; + uint8_t buf[1024] = { 0 }; + uint8_t key[SIPHASH_KEY_SIZE] = { 0 }; + + assert_true(rand_bytes(buf, (int)len)); + assert_true(rand_bytes(key, sizeof(key))); + + + siphash_openssl(sipctx, buf, len, key, out, UT_SIPHASH_HASH_SIZE); + + uint8_t outref[UT_SIPHASH_HASH_SIZE] = { 0 }; + siphash_reference(buf, len, key, outref, UT_SIPHASH_HASH_SIZE); + + assert_memory_equal(out, outref, UT_SIPHASH_HASH_SIZE); + } + + siphash_openssl_uninit(sipctx); +} + + int main(void) { @@ -960,7 +1026,9 @@ cmocka_unit_test_prestate_setup_teardown(crypto_test_epoch_edge, crypto_test_epoch_setup, crypto_test_epoch_teardown, &prestate_num13), - cmocka_unit_test(epoch_test_derive_data_key) + cmocka_unit_test(epoch_test_derive_data_key), + cmocka_unit_test(test_siphash), + cmocka_unit_test(test_siphash_openssl) }; return cmocka_run_group_tests_name("crypto tests", tests, NULL, NULL);