/* crypto/rand/md_rand.c */ /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */ /* ==================================================================== * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * openssl-core@openssl.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.openssl.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * */ #ifdef MD_RAND_DEBUG # ifndef NDEBUG # define NDEBUG # endif #endif #include #include #include #include "e_os.h" #if !(defined(OPENSSL_SYS_WIN32) || defined(OPENSSL_SYS_VXWORKS) || defined(OPENSSL_SYSNAME_DSPBIOS)) # include #endif #if defined(OPENSSL_SYS_VXWORKS) # include #endif #include #include #include "rand_lcl.h" #include #ifdef OPENSSL_FIPS # include #endif #ifdef BN_DEBUG # define PREDICT #endif /* #define PREDICT 1 */ #define STATE_SIZE 1023 static int state_num = 0, state_index = 0; static unsigned char state[STATE_SIZE + MD_DIGEST_LENGTH]; static unsigned char md[MD_DIGEST_LENGTH]; static long md_count[2] = { 0, 0 }; static double entropy = 0; static int initialized = 0; static unsigned int crypto_lock_rand = 0; /* may be set only when a thread * holds CRYPTO_LOCK_RAND (to * prevent double locking) */ /* access to lockin_thread is synchronized by CRYPTO_LOCK_RAND2 */ /* valid iff crypto_lock_rand is set */ static CRYPTO_THREADID locking_threadid; #ifdef PREDICT int rand_predictable = 0; #endif const char RAND_version[] = "RAND" OPENSSL_VERSION_PTEXT; static void rand_hw_seed(EVP_MD_CTX *ctx); static void ssleay_rand_cleanup(void); static int ssleay_rand_seed(const void *buf, int num); static int ssleay_rand_add(const void *buf, int num, double add_entropy); static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo); static int ssleay_rand_nopseudo_bytes(unsigned char *buf, int num); static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num); static int ssleay_rand_status(void); static RAND_METHOD rand_ssleay_meth = { ssleay_rand_seed, ssleay_rand_nopseudo_bytes, ssleay_rand_cleanup, ssleay_rand_add, ssleay_rand_pseudo_bytes, ssleay_rand_status }; RAND_METHOD *RAND_SSLeay(void) { return (&rand_ssleay_meth); } static void ssleay_rand_cleanup(void) { OPENSSL_cleanse(state, sizeof(state)); state_num = 0; state_index = 0; OPENSSL_cleanse(md, MD_DIGEST_LENGTH); md_count[0] = 0; md_count[1] = 0; entropy = 0; initialized = 0; } static int ssleay_rand_add(const void *buf, int num, double add) { int i, j, k, st_idx; long md_c[2]; unsigned char local_md[MD_DIGEST_LENGTH]; EVP_MD_CTX m; int do_not_lock; int rv = 0; if (!num) return 1; /* * (Based on the rand(3) manpage) * * The input is chopped up into units of 20 bytes (or less for * the last block). Each of these blocks is run through the hash * function as follows: The data passed to the hash function * is the current 'md', the same number of bytes from the 'state' * (the location determined by in incremented looping index) as * the current 'block', the new key data 'block', and 'count' * (which is incremented after each use). * The result of this is kept in 'md' and also xored into the * 'state' at the same locations that were used as input into the * hash function. */ EVP_MD_CTX_init(&m); /* check if we already have the lock */ if (crypto_lock_rand) { CRYPTO_THREADID cur; CRYPTO_THREADID_current(&cur); CRYPTO_r_lock(CRYPTO_LOCK_RAND2); do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur); CRYPTO_r_unlock(CRYPTO_LOCK_RAND2); } else do_not_lock = 0; if (!do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND); st_idx = state_index; /* * use our own copies of the counters so that even if a concurrent thread * seeds with exactly the same data and uses the same subarray there's * _some_ difference */ md_c[0] = md_count[0]; md_c[1] = md_count[1]; memcpy(local_md, md, sizeof md); /* state_index <= state_num <= STATE_SIZE */ state_index += num; if (state_index >= STATE_SIZE) { state_index %= STATE_SIZE; state_num = STATE_SIZE; } else if (state_num < STATE_SIZE) { if (state_index > state_num) state_num = state_index; } /* state_index <= state_num <= STATE_SIZE */ /* * state[st_idx], ..., state[(st_idx + num - 1) % STATE_SIZE] are what we * will use now, but other threads may use them as well */ md_count[1] += (num / MD_DIGEST_LENGTH) + (num % MD_DIGEST_LENGTH > 0); if (!do_not_lock) CRYPTO_w_unlock(CRYPTO_LOCK_RAND); for (i = 0; i < num; i += MD_DIGEST_LENGTH) { j = (num - i); j = (j > MD_DIGEST_LENGTH) ? MD_DIGEST_LENGTH : j; if (!MD_Init(&m)) goto err; if (!MD_Update(&m, local_md, MD_DIGEST_LENGTH)) goto err; k = (st_idx + j) - STATE_SIZE; if (k > 0) { if (!MD_Update(&m, &(state[st_idx]), j - k)) goto err; if (!MD_Update(&m, &(state[0]), k)) goto err; } else if (!MD_Update(&m, &(state[st_idx]), j)) goto err; /* DO NOT REMOVE THE FOLLOWING CALL TO MD_Update()! */ if (!MD_Update(&m, buf, j)) goto err; /* * We know that line may cause programs such as purify and valgrind * to complain about use of uninitialized data. The problem is not, * it's with the caller. Removing that line will make sure you get * really bad randomness and thereby other problems such as very * insecure keys. */ if (!MD_Update(&m, (unsigned char *)&(md_c[0]), sizeof(md_c))) goto err; if (!MD_Final(&m, local_md)) goto err; md_c[1]++; buf = (const char *)buf + j; for (k = 0; k < j; k++) { /* * Parallel threads may interfere with this, but always each byte * of the new state is the XOR of some previous value of its and * local_md (itermediate values may be lost). Alway using locking * could hurt performance more than necessary given that * conflicts occur only when the total seeding is longer than the * random state. */ state[st_idx++] ^= local_md[k]; if (st_idx >= STATE_SIZE) st_idx = 0; } } if (!do_not_lock) CRYPTO_w_lock(CRYPTO_LOCK_RAND); /* * Don't just copy back local_md into md -- this could mean that other * thread's seeding remains without effect (except for the incremented * counter). By XORing it we keep at least as much entropy as fits into * md. */ for (k = 0; k < (int)sizeof(md); k++) { md[k] ^= local_md[k]; } if (entropy < ENTROPY_NEEDED) /* stop counting when we have enough */ entropy += add; if (!do_not_lock) CRYPTO_w_unlock(CRYPTO_LOCK_RAND); #if !defined(OPENSSL_THREADS) && !defined(OPENSSL_SYS_WIN32) assert(md_c[1] == md_count[1]); #endif rv = 1; err: EVP_MD_CTX_cleanup(&m); return rv; } static int ssleay_rand_seed(const void *buf, int num) { return ssleay_rand_add(buf, num, (double)num); } static int ssleay_rand_bytes(unsigned char *buf, int num, int pseudo) { static volatile int stirred_pool = 0; int i, j, k, st_num, st_idx; int num_ceil; int ok; long md_c[2]; unsigned char local_md[MD_DIGEST_LENGTH]; EVP_MD_CTX m; #ifndef GETPID_IS_MEANINGLESS pid_t curr_pid = getpid(); #endif time_t curr_time = time(NULL); int do_stir_pool = 0; /* time value for various platforms */ #ifdef OPENSSL_SYS_WIN32 FILETIME tv; # ifdef _WIN32_WCE SYSTEMTIME t; GetSystemTime(&t); SystemTimeToFileTime(&t, &tv); # else GetSystemTimeAsFileTime(&tv); # endif #elif defined(OPENSSL_SYS_VXWORKS) struct timespec tv; clock_gettime(CLOCK_REALTIME, &ts); #elif defined(OPENSSL_SYSNAME_DSPBIOS) unsigned long long tv, OPENSSL_rdtsc(); tv = OPENSSL_rdtsc(); #else struct timeval tv; gettimeofday(&tv, NULL); #endif #ifdef PREDICT if (rand_predictable) { static unsigned char val = 0; for (i = 0; i < num; i++) buf[i] = val++; return (1); } #endif if (num <= 0) return 1; EVP_MD_CTX_init(&m); /* round upwards to multiple of MD_DIGEST_LENGTH/2 */ num_ceil = (1 + (num - 1) / (MD_DIGEST_LENGTH / 2)) * (MD_DIGEST_LENGTH / 2); /* * (Based on the rand(3) manpage:) * * For each group of 10 bytes (or less), we do the following: * * Input into the hash function the local 'md' (which is initialized from * the global 'md' before any bytes are generated), the bytes that are to * be overwritten by the random bytes, and bytes from the 'state' * (incrementing looping index). From this digest output (which is kept * in 'md'), the top (up to) 10 bytes are returned to the caller and the * bottom 10 bytes are xored into the 'state'. * * Finally, after we have finished 'num' random bytes for the * caller, 'count' (which is incremented) and the local and global 'md' * are fed into the hash function and the results are kept in the * global 'md'. */ CRYPTO_w_lock(CRYPTO_LOCK_RAND); /* prevent ssleay_rand_bytes() from trying to obtain the lock again */ CRYPTO_w_lock(CRYPTO_LOCK_RAND2); CRYPTO_THREADID_current(&locking_threadid); CRYPTO_w_unlock(CRYPTO_LOCK_RAND2); crypto_lock_rand = 1; if (!initialized) { RAND_poll(); initialized = 1; } if (!stirred_pool) do_stir_pool = 1; ok = (entropy >= ENTROPY_NEEDED); if (!ok) { /* * If the PRNG state is not yet unpredictable, then seeing the PRNG * output may help attackers to determine the new state; thus we have * to decrease the entropy estimate. Once we've had enough initial * seeding we don't bother to adjust the entropy count, though, * because we're not ambitious to provide *information-theoretic* * randomness. NOTE: This approach fails if the program forks before * we have enough entropy. Entropy should be collected in a separate * input pool and be transferred to the output pool only when the * entropy limit has been reached. */ entropy -= num; if (entropy < 0) entropy = 0; } if (do_stir_pool) { /* * In the output function only half of 'md' remains secret, so we * better make sure that the required entropy gets 'evenly * distributed' through 'state', our randomness pool. The input * function (ssleay_rand_add) chains all of 'md', which makes it more * suitable for this purpose. */ int n = STATE_SIZE; /* so that the complete pool gets accessed */ while (n > 0) { #if MD_DIGEST_LENGTH > 20 # error "Please adjust DUMMY_SEED." #endif #define DUMMY_SEED "...................." /* at least MD_DIGEST_LENGTH */ /* * Note that the seed does not matter, it's just that * ssleay_rand_add expects to have something to hash. */ ssleay_rand_add(DUMMY_SEED, MD_DIGEST_LENGTH, 0.0); n -= MD_DIGEST_LENGTH; } if (ok) stirred_pool = 1; } st_idx = state_index; st_num = state_num; md_c[0] = md_count[0]; md_c[1] = md_count[1]; memcpy(local_md, md, sizeof md); state_index += num_ceil; if (state_index > state_num) state_index %= state_num; /* * state[st_idx], ..., state[(st_idx + num_ceil - 1) % st_num] are now * ours (but other threads may use them too) */ md_count[0] += 1; /* before unlocking, we must clear 'crypto_lock_rand' */ crypto_lock_rand = 0; CRYPTO_w_unlock(CRYPTO_LOCK_RAND); while (num > 0) { /* num_ceil -= MD_DIGEST_LENGTH/2 */ j = (num >= MD_DIGEST_LENGTH / 2) ? MD_DIGEST_LENGTH / 2 : num; num -= j; if (!MD_Init(&m)) goto err; #ifndef GETPID_IS_MEANINGLESS if (curr_pid) { /* just in the first iteration to save time */ if (!MD_Update(&m, (unsigned char *)&curr_pid, sizeof curr_pid)) goto err; curr_pid = 0; } #endif if (curr_time) { /* just in the first iteration to save time */ if (!MD_Update(&m, (unsigned char *)&curr_time, sizeof curr_time)) goto err; if (!MD_Update(&m, (unsigned char *)&tv, sizeof tv)) goto err; curr_time = 0; rand_hw_seed(&m); } if (!MD_Update(&m, local_md, MD_DIGEST_LENGTH)) goto err; if (!MD_Update(&m, (unsigned char *)&(md_c[0]), sizeof(md_c))) goto err; #ifndef PURIFY /* purify complains */ /* * The following line uses the supplied buffer as a small source of * entropy: since this buffer is often uninitialised it may cause * programs such as purify or valgrind to complain. So for those * builds it is not used: the removal of such a small source of * entropy has negligible impact on security. */ if (!MD_Update(&m, buf, j)) goto err; #endif k = (st_idx + MD_DIGEST_LENGTH / 2) - st_num; if (k > 0) { if (!MD_Update(&m, &(state[st_idx]), MD_DIGEST_LENGTH / 2 - k)) goto err; if (!MD_Update(&m, &(state[0]), k)) goto err; } else if (!MD_Update(&m, &(state[st_idx]), MD_DIGEST_LENGTH / 2)) goto err; if (!MD_Final(&m, local_md)) goto err; for (i = 0; i < MD_DIGEST_LENGTH / 2; i++) { /* may compete with other threads */ state[st_idx++] ^= local_md[i]; if (st_idx >= st_num) st_idx = 0; if (i < j) *(buf++) = local_md[i + MD_DIGEST_LENGTH / 2]; } } if (!MD_Init(&m) || !MD_Update(&m, (unsigned char *)&(md_c[0]), sizeof(md_c)) || !MD_Update(&m, local_md, MD_DIGEST_LENGTH)) goto err; CRYPTO_w_lock(CRYPTO_LOCK_RAND); if (!MD_Update(&m, md, MD_DIGEST_LENGTH) || !MD_Final(&m, md)) { CRYPTO_w_unlock(CRYPTO_LOCK_RAND); goto err; } CRYPTO_w_unlock(CRYPTO_LOCK_RAND); EVP_MD_CTX_cleanup(&m); if (ok) return (1); else if (pseudo) return 0; else { RANDerr(RAND_F_SSLEAY_RAND_BYTES, RAND_R_PRNG_NOT_SEEDED); ERR_add_error_data(1, "You need to read the OpenSSL FAQ, " "http://www.openssl.org/support/faq.html"); return (0); } err: EVP_MD_CTX_cleanup(&m); RANDerr(RAND_F_SSLEAY_RAND_BYTES, ERR_R_EVP_LIB); return 0; } static int ssleay_rand_nopseudo_bytes(unsigned char *buf, int num) { return ssleay_rand_bytes(buf, num, 0); } /* * pseudo-random bytes that are guaranteed to be unique but not unpredictable */ static int ssleay_rand_pseudo_bytes(unsigned char *buf, int num) { return ssleay_rand_bytes(buf, num, 1); } static int ssleay_rand_status(void) { CRYPTO_THREADID cur; int ret; int do_not_lock; CRYPTO_THREADID_current(&cur); /* * check if we already have the lock (could happen if a RAND_poll() * implementation calls RAND_status()) */ if (crypto_lock_rand) { CRYPTO_r_lock(CRYPTO_LOCK_RAND2); do_not_lock = !CRYPTO_THREADID_cmp(&locking_threadid, &cur); CRYPTO_r_unlock(CRYPTO_LOCK_RAND2); } else do_not_lock = 0; if (!do_not_lock) { CRYPTO_w_lock(CRYPTO_LOCK_RAND); /* * prevent ssleay_rand_bytes() from trying to obtain the lock again */ CRYPTO_w_lock(CRYPTO_LOCK_RAND2); CRYPTO_THREADID_cpy(&locking_threadid, &cur); CRYPTO_w_unlock(CRYPTO_LOCK_RAND2); crypto_lock_rand = 1; } if (!initialized) { RAND_poll(); initialized = 1; } ret = entropy >= ENTROPY_NEEDED; if (!do_not_lock) { /* before unlocking, we must clear 'crypto_lock_rand' */ crypto_lock_rand = 0; CRYPTO_w_unlock(CRYPTO_LOCK_RAND); } return ret; } /* * rand_hw_seed: get seed data from any available hardware RNG. only * currently supports rdrand. */ /* Adapted from eng_rdrand.c */ #if (defined(__i386) || defined(__i386__) || defined(_M_IX86) || \ defined(__x86_64) || defined(__x86_64__) || \ defined(_M_AMD64) || defined (_M_X64)) && defined(OPENSSL_CPUID_OBJ) # define RDRAND_CALLS 4 size_t OPENSSL_ia32_rdrand(void); extern unsigned int OPENSSL_ia32cap_P[]; static void rand_hw_seed(EVP_MD_CTX *ctx) { int i; if (!(OPENSSL_ia32cap_P[1] & (1 << (62 - 32)))) return; for (i = 0; i < RDRAND_CALLS; i++) { size_t rnd; rnd = OPENSSL_ia32_rdrand(); if (rnd == 0) return; MD_Update(ctx, (unsigned char *)&rnd, sizeof(size_t)); } } /* XOR an existing buffer with random data */ void rand_hw_xor(unsigned char *buf, size_t num) { size_t rnd; if (!(OPENSSL_ia32cap_P[1] & (1 << (62 - 32)))) return; while (num >= sizeof(size_t)) { rnd = OPENSSL_ia32_rdrand(); if (rnd == 0) return; *((size_t *)buf) ^= rnd; buf += sizeof(size_t); num -= sizeof(size_t); } if (num) { rnd = OPENSSL_ia32_rdrand(); if (rnd == 0) return; while (num) { *buf ^= rnd & 0xff; rnd >>= 8; buf++; num--; } } } #else static void rand_hw_seed(EVP_MD_CTX *ctx) { return; } void rand_hw_xor(unsigned char *buf, size_t num) { return; } #endif