commit ae4c94bb6468078ba16de481991e781e1b486340
Merge: 896d0ebb9 42be1c668
Author: Nick Mathewson <ni...@torproject.org>
Date: Tue Nov 13 08:27:29 2018 -0500
Merge branch 'maint-0.3.4' into maint-0.3.5
changes/bug28413 | 4 ++++
src/lib/crypt_ops/aes_openssl.c | 4 ++--
2 files changed, 6 insertions(+), 2 deletions(-)
diff --cc src/lib/crypt_ops/aes_openssl.c
index f2990fc06,000000000..ac275af33
mode 100644,000000..100644
--- a/src/lib/crypt_ops/aes_openssl.c
+++ b/src/lib/crypt_ops/aes_openssl.c
@@@ -1,410 -1,0 +1,410 @@@
+/* Copyright (c) 2001, Matej Pfajfar.
+ * Copyright (c) 2001-2004, Roger Dingledine.
+ * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
+ * Copyright (c) 2007-2018, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file aes_openssl.c
+ * \brief Use OpenSSL to implement AES_CTR.
+ **/
+
+#include "orconfig.h"
+#include "lib/crypt_ops/aes.h"
+#include "lib/crypt_ops/crypto_util.h"
+#include "lib/log/util_bug.h"
+#include "lib/arch/bytes.h"
+
+#ifdef _WIN32 /*wrkard for dtls1.h >= 0.9.8m of "#include <winsock.h>"*/
+ #include <winsock2.h>
+ #include <ws2tcpip.h>
+#endif
+
+#include "lib/crypt_ops/compat_openssl.h"
+#include <openssl/opensslv.h>
+#include "lib/crypt_ops/crypto_openssl_mgt.h"
+
+#if OPENSSL_VERSION_NUMBER < OPENSSL_V_SERIES(1,0,0)
+#error "We require OpenSSL >= 1.0.0"
+#endif
+
+DISABLE_GCC_WARNING(redundant-decls)
+
+#include <stdlib.h>
+#include <string.h>
+#include <openssl/aes.h>
+#include <openssl/evp.h>
+#include <openssl/engine.h>
+#include <openssl/modes.h>
+
+ENABLE_GCC_WARNING(redundant-decls)
+
+#include "lib/crypt_ops/aes.h"
+#include "lib/log/log.h"
+#include "lib/ctime/di_ops.h"
+
+#ifdef ANDROID
+/* Android's OpenSSL seems to have removed all of its Engine support. */
+#define DISABLE_ENGINES
+#endif
+
+/* We have five strategies for implementing AES counter mode.
+ *
+ * Best with x86 and x86_64: Use EVP_aes_*_ctr() and EVP_EncryptUpdate().
+ * This is possible with OpenSSL 1.0.1, where the counter-mode implementation
+ * can use bit-sliced or vectorized AES or AESNI as appropriate.
+ *
+ * Otherwise: Pick the best possible AES block implementation that OpenSSL
+ * gives us, and the best possible counter-mode implementation, and combine
+ * them.
+ */
+#if OPENSSL_VERSION_NUMBER >= OPENSSL_V_NOPATCH(1,1,0)
+
+/* With newer OpenSSL versions, the older fallback modes don't compile. So
+ * don't use them, even if we lack specific acceleration. */
+
+#define USE_EVP_AES_CTR
+
+#elif OPENSSL_VERSION_NUMBER >= OPENSSL_V_NOPATCH(1,0,1) && \
+ (defined(__i386) || defined(__i386__) || defined(_M_IX86) || \
+ defined(__x86_64) || defined(__x86_64__) || \
+ defined(_M_AMD64) || defined(_M_X64) || defined(__INTEL__))
+
+#define USE_EVP_AES_CTR
+
+#endif /* OPENSSL_VERSION_NUMBER >= OPENSSL_V_NOPATCH(1,1,0) || ... */
+
+/* We have 2 strategies for getting the AES block cipher: Via OpenSSL's
+ * AES_encrypt function, or via OpenSSL's EVP_EncryptUpdate function.
+ *
+ * If there's any hardware acceleration in play, we want to be using EVP_* so
+ * we can get it. Otherwise, we'll want AES_*, which seems to be about 5%
+ * faster than indirecting through the EVP layer.
+ */
+
+/* We have 2 strategies for getting a plug-in counter mode: use our own, or
+ * use OpenSSL's.
+ *
+ * Here we have a counter mode that's faster than the one shipping with
+ * OpenSSL pre-1.0 (by about 10%!). But OpenSSL 1.0.0 added a counter mode
+ * implementation faster than the one here (by about 7%). So we pick which
+ * one to used based on the Openssl version above. (OpenSSL 1.0.0a fixed a
+ * critical bug in that counter mode implementation, so we need to test to
+ * make sure that we have a fixed version.)
+ */
+
+#ifdef USE_EVP_AES_CTR
+
+/* We don't actually define the struct here. */
+
+aes_cnt_cipher_t *
+aes_new_cipher(const uint8_t *key, const uint8_t *iv, int key_bits)
+{
+ EVP_CIPHER_CTX *cipher = EVP_CIPHER_CTX_new();
- const EVP_CIPHER *c;
++ const EVP_CIPHER *c = NULL;
+ switch (key_bits) {
+ case 128: c = EVP_aes_128_ctr(); break;
+ case 192: c = EVP_aes_192_ctr(); break;
+ case 256: c = EVP_aes_256_ctr(); break;
- default: tor_assert(0); // LCOV_EXCL_LINE
++ default: tor_assert_unreached(); // LCOV_EXCL_LINE
+ }
+ EVP_EncryptInit(cipher, c, key, iv);
+ return (aes_cnt_cipher_t *) cipher;
+}
+void
+aes_cipher_free_(aes_cnt_cipher_t *cipher_)
+{
+ if (!cipher_)
+ return;
+ EVP_CIPHER_CTX *cipher = (EVP_CIPHER_CTX *) cipher_;
+#ifdef OPENSSL_1_1_API
+ EVP_CIPHER_CTX_reset(cipher);
+#else
+ EVP_CIPHER_CTX_cleanup(cipher);
+#endif
+ EVP_CIPHER_CTX_free(cipher);
+}
+void
+aes_crypt_inplace(aes_cnt_cipher_t *cipher_, char *data, size_t len)
+{
+ int outl;
+ EVP_CIPHER_CTX *cipher = (EVP_CIPHER_CTX *) cipher_;
+
+ tor_assert(len < INT_MAX);
+
+ EVP_EncryptUpdate(cipher, (unsigned char*)data,
+ &outl, (unsigned char*)data, (int)len);
+}
+int
+evaluate_evp_for_aes(int force_val)
+{
+ (void) force_val;
+ log_info(LD_CRYPTO, "This version of OpenSSL has a known-good EVP "
+ "counter-mode implementation. Using it.");
+ return 0;
+}
+int
+evaluate_ctr_for_aes(void)
+{
+ return 0;
+}
+#else /* !(defined(USE_EVP_AES_CTR)) */
+
+/*======================================================================*/
+/* Interface to AES code, and counter implementation */
+
+/** Implements an AES counter-mode cipher. */
+struct aes_cnt_cipher {
+/** This next element (however it's defined) is the AES key. */
+ union {
+ EVP_CIPHER_CTX evp;
+ AES_KEY aes;
+ } key;
+
+#if !defined(WORDS_BIGENDIAN)
+#define USING_COUNTER_VARS
+ /** These four values, together, implement a 128-bit counter, with
+ * counter0 as the low-order word and counter3 as the high-order word. */
+ uint32_t counter3;
+ uint32_t counter2;
+ uint32_t counter1;
+ uint32_t counter0;
+#endif /* !defined(WORDS_BIGENDIAN) */
+
+ union {
+ /** The counter, in big-endian order, as bytes. */
+ uint8_t buf[16];
+ /** The counter, in big-endian order, as big-endian words. Note that
+ * on big-endian platforms, this is redundant with counter3...0,
+ * so we just use these values instead. */
+ uint32_t buf32[4];
+ } ctr_buf;
+
+ /** The encrypted value of ctr_buf. */
+ uint8_t buf[16];
+ /** Our current stream position within buf. */
+ unsigned int pos;
+
+ /** True iff we're using the evp implementation of this cipher. */
+ uint8_t using_evp;
+};
+
+/** True iff we should prefer the EVP implementation for AES, either because
+ * we're testing it or because we have hardware acceleration configured */
+static int should_use_EVP = 0;
+
+/** Check whether we should use the EVP interface for AES. If <b>force_val</b>
+ * is nonnegative, we use use EVP iff it is true. Otherwise, we use EVP
+ * if there is an engine enabled for aes-ecb. */
+int
+evaluate_evp_for_aes(int force_val)
+{
+ ENGINE *e;
+
+ if (force_val >= 0) {
+ should_use_EVP = force_val;
+ return 0;
+ }
+#ifdef DISABLE_ENGINES
+ should_use_EVP = 0;
+#else
+ e = ENGINE_get_cipher_engine(NID_aes_128_ecb);
+
+ if (e) {
+ log_info(LD_CRYPTO, "AES engine \"%s\" found; using EVP_* functions.",
+ ENGINE_get_name(e));
+ should_use_EVP = 1;
+ } else {
+ log_info(LD_CRYPTO, "No AES engine found; using AES_* functions.");
+ should_use_EVP = 0;
+ }
+#endif /* defined(DISABLE_ENGINES) */
+
+ return 0;
+}
+
+/** Test the OpenSSL counter mode implementation to see whether it has the
+ * counter-mode bug from OpenSSL 1.0.0. If the implementation works, then
+ * we will use it for future encryption/decryption operations.
+ *
+ * We can't just look at the OpenSSL version, since some distributions update
+ * their OpenSSL packages without changing the version number.
+ **/
+int
+evaluate_ctr_for_aes(void)
+{
+ /* Result of encrypting an all-zero block with an all-zero 128-bit AES key.
+ * This should be the same as encrypting an all-zero block with an all-zero
+ * 128-bit AES key in counter mode, starting at position 0 of the stream.
+ */
+ static const unsigned char encrypt_zero[] =
+ "\x66\xe9\x4b\xd4\xef\x8a\x2c\x3b\x88\x4c\xfa\x59\xca\x34\x2b\x2e";
+ unsigned char zero[16];
+ unsigned char output[16];
+ unsigned char ivec[16];
+ unsigned char ivec_tmp[16];
+ unsigned int pos, i;
+ AES_KEY key;
+ memset(zero, 0, sizeof(zero));
+ memset(ivec, 0, sizeof(ivec));
+ AES_set_encrypt_key(zero, 128, &key);
+
+ pos = 0;
+ /* Encrypting a block one byte at a time should make the error manifest
+ * itself for known bogus openssl versions. */
+ for (i=0; i<16; ++i)
+ AES_ctr128_encrypt(&zero[i], &output[i], 1, &key, ivec, ivec_tmp, &pos);
+
+ if (fast_memneq(output, encrypt_zero, 16)) {
+ /* Counter mode is buggy */
+ /* LCOV_EXCL_START */
+ log_err(LD_CRYPTO, "This OpenSSL has a buggy version of counter mode; "
+ "quitting tor.");
+ exit(1); // exit ok: openssl is broken.
+ /* LCOV_EXCL_STOP */
+ }
+ return 0;
+}
+
+#if !defined(USING_COUNTER_VARS)
+#define COUNTER(c, n) ((c)->ctr_buf.buf32[3-(n)])
+#else
+#define COUNTER(c, n) ((c)->counter ## n)
+#endif
+
+static void aes_set_key(aes_cnt_cipher_t *cipher, const uint8_t *key,
+ int key_bits);
+static void aes_set_iv(aes_cnt_cipher_t *cipher, const uint8_t *iv);
+
+/**
+ * Return a newly allocated counter-mode AES128 cipher implementation,
+ * using the 128-bit key <b>key</b> and the 128-bit IV <b>iv</b>.
+ */
+aes_cnt_cipher_t*
+aes_new_cipher(const uint8_t *key, const uint8_t *iv, int bits)
+{
+ aes_cnt_cipher_t* result = tor_malloc_zero(sizeof(aes_cnt_cipher_t));
+
+ aes_set_key(result, key, bits);
+ aes_set_iv(result, iv);
+
+ return result;
+}
+
+/** Set the key of <b>cipher</b> to <b>key</b>, which is
+ * <b>key_bits</b> bits long (must be 128, 192, or 256). Also resets
+ * the counter to 0.
+ */
+static void
+aes_set_key(aes_cnt_cipher_t *cipher, const uint8_t *key, int key_bits)
+{
+ if (should_use_EVP) {
+ const EVP_CIPHER *c = 0;
+ switch (key_bits) {
+ case 128: c = EVP_aes_128_ecb(); break;
+ case 192: c = EVP_aes_192_ecb(); break;
+ case 256: c = EVP_aes_256_ecb(); break;
+ default: tor_assert(0); // LCOV_EXCL_LINE
+ }
+ EVP_EncryptInit(&cipher->key.evp, c, key, NULL);
+ cipher->using_evp = 1;
+ } else {
+ AES_set_encrypt_key(key, key_bits,&cipher->key.aes);
+ cipher->using_evp = 0;
+ }
+
+#ifdef USING_COUNTER_VARS
+ cipher->counter0 = 0;
+ cipher->counter1 = 0;
+ cipher->counter2 = 0;
+ cipher->counter3 = 0;
+#endif /* defined(USING_COUNTER_VARS) */
+
+ memset(cipher->ctr_buf.buf, 0, sizeof(cipher->ctr_buf.buf));
+
+ cipher->pos = 0;
+
+ memset(cipher->buf, 0, sizeof(cipher->buf));
+}
+
+/** Release storage held by <b>cipher</b>
+ */
+void
+aes_cipher_free_(aes_cnt_cipher_t *cipher)
+{
+ if (!cipher)
+ return;
+ if (cipher->using_evp) {
+ EVP_CIPHER_CTX_cleanup(&cipher->key.evp);
+ }
+ memwipe(cipher, 0, sizeof(aes_cnt_cipher_t));
+ tor_free(cipher);
+}
+
+#if defined(USING_COUNTER_VARS)
+#define UPDATE_CTR_BUF(c, n) STMT_BEGIN \
+ (c)->ctr_buf.buf32[3-(n)] = htonl((c)->counter ## n); \
+ STMT_END
+#else
+#define UPDATE_CTR_BUF(c, n)
+#endif /* defined(USING_COUNTER_VARS) */
+
+/* Helper function to use EVP with openssl's counter-mode wrapper. */
+static void
+evp_block128_fn(const uint8_t in[16],
+ uint8_t out[16],
+ const void *key)
+{
+ EVP_CIPHER_CTX *ctx = (void*)key;
+ int inl=16, outl=16;
+ EVP_EncryptUpdate(ctx, out, &outl, in, inl);
+}
+
+/** Encrypt <b>len</b> bytes from <b>input</b>, storing the results in place.
+ * Uses the key in <b>cipher</b>, and advances the counter by <b>len</b> bytes
+ * as it encrypts.
+ */
+void
+aes_crypt_inplace(aes_cnt_cipher_t *cipher, char *data, size_t len)
+{
+ /* Note that the "128" below refers to the length of the counter,
+ * not the length of the AES key. */
+ if (cipher->using_evp) {
+ /* In openssl 1.0.0, there's an if'd out EVP_aes_128_ctr in evp.h. If
+ * it weren't disabled, it might be better just to use that.
+ */
+ CRYPTO_ctr128_encrypt((const unsigned char *)data,
+ (unsigned char *)data,
+ len,
+ &cipher->key.evp,
+ cipher->ctr_buf.buf,
+ cipher->buf,
+ &cipher->pos,
+ evp_block128_fn);
+ } else {
+ AES_ctr128_encrypt((const unsigned char *)data,
+ (unsigned char *)data,
+ len,
+ &cipher->key.aes,
+ cipher->ctr_buf.buf,
+ cipher->buf,
+ &cipher->pos);
+ }
+}
+
+/** Reset the 128-bit counter of <b>cipher</b> to the 16-bit big-endian value
+ * in <b>iv</b>. */
+static void
+aes_set_iv(aes_cnt_cipher_t *cipher, const uint8_t *iv)
+{
+#ifdef USING_COUNTER_VARS
+ cipher->counter3 = tor_ntohl(get_uint32(iv));
+ cipher->counter2 = tor_ntohl(get_uint32(iv+4));
+ cipher->counter1 = tor_ntohl(get_uint32(iv+8));
+ cipher->counter0 = tor_ntohl(get_uint32(iv+12));
+#endif /* defined(USING_COUNTER_VARS) */
+ cipher->pos = 0;
+ memcpy(cipher->ctr_buf.buf, iv, 16);
+}
+
+#endif /* defined(USE_EVP_AES_CTR) */
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