X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Futil%2Fcrypto_random.c;h=29b25524dc84913b2b69057a18a52fd0e79d5398;hb=9b0414d6f98f33d7e1c33dafe105eb58da0bf79b;hp=719acf07c6107e6e78b097f0eb16b76c4e247e47;hpb=e1196c2c76e6a4a142a91bb9e0a0fae1a06f68fc;p=oweals%2Fgnunet.git diff --git a/src/util/crypto_random.c b/src/util/crypto_random.c index 719acf07c..29b25524d 100644 --- a/src/util/crypto_random.c +++ b/src/util/crypto_random.c @@ -1,6 +1,6 @@ /* This file is part of GNUnet. - (C) 2001, 2002, 2003, 2004, 2005, 2006 Christian Grothoff (and other contributing authors) + (C) 2001, 2002, 2003, 2004, 2005, 2006, 2012 Christian Grothoff (and other contributing authors) GNUnet is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published @@ -34,18 +34,77 @@ #define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "util", syscall) + +/** + * GNUNET_YES if we are using a 'weak' (low-entropy) PRNG. + */ +static int weak_random; + + + +/* TODO: ndurner, move this to plibc? */ +/* The code is derived from glibc, obviously */ +#if MINGW +#ifdef RANDOM +#undef RANDOM +#endif +#ifdef SRANDOM +#undef SRANDOM +#endif +#define RANDOM() glibc_weak_rand32() +#define SRANDOM(s) glibc_weak_srand32(s) +#if defined(RAND_MAX) +#undef RAND_MAX +#endif +#define RAND_MAX 0x7fffffff /* Hopefully this is correct */ + + +static int32_t glibc_weak_rand32_state = 1; + + +void +glibc_weak_srand32 (int32_t s) +{ + glibc_weak_rand32_state = s; +} + + +int32_t +glibc_weak_rand32 () +{ + int32_t val = glibc_weak_rand32_state; + + val = ((glibc_weak_rand32_state * 1103515245) + 12345) & 0x7fffffff; + glibc_weak_rand32_state = val; + return val; +} +#endif + /** * Create a cryptographically weak pseudo-random number in the interval of 0 to 1. * * @return number between 0 and 1. */ static double -weak_random () +get_weak_random () { return ((double) RANDOM () / RAND_MAX); } +/** + * Seed a weak random generator. Only GNUNET_CRYPTO_QUALITY_WEAK-mode generator + * can be seeded. + * + * @param seed the seed to use + */ +void +GNUNET_CRYPTO_seed_weak_random (int32_t seed) +{ + SRANDOM (seed); +} + + /** * Produce a random value. * @@ -89,7 +148,7 @@ GNUNET_CRYPTO_random_u32 (enum GNUNET_CRYPTO_Quality mode, uint32_t i) while (ret >= ul); return ret % i; case GNUNET_CRYPTO_QUALITY_WEAK: - ret = i * weak_random (); + ret = i * get_weak_random (); if (ret >= i) ret = i - 1; return ret; @@ -166,7 +225,7 @@ GNUNET_CRYPTO_random_u64 (enum GNUNET_CRYPTO_Quality mode, uint64_t max) return ret % max; case GNUNET_CRYPTO_QUALITY_WEAK: - ret = max * weak_random (); + ret = max * get_weak_random (); if (ret >= max) ret = max - 1; return ret; @@ -176,6 +235,19 @@ GNUNET_CRYPTO_random_u64 (enum GNUNET_CRYPTO_Quality mode, uint64_t max) return 0; } + +/** + * Check if we are using weak random number generation. + * + * @return GNUNET_YES if weak number generation is on + */ +int +GNUNET_CRYPTO_random_is_weak () +{ + return weak_random; +} + + /** * This function should only be called in testcases * where strong entropy gathering is not desired @@ -184,6 +256,7 @@ GNUNET_CRYPTO_random_u64 (enum GNUNET_CRYPTO_Quality mode, uint64_t max) void GNUNET_CRYPTO_random_disable_entropy_gathering () { + weak_random = GNUNET_YES; gcry_control (GCRYCTL_ENABLE_QUICK_RANDOM, 0); } @@ -194,6 +267,7 @@ GNUNET_CRYPTO_random_disable_entropy_gathering () */ static struct GNUNET_OS_Process *genproc; + /** * Function called by libgcrypt whenever we are * blocked gathering entropy. @@ -215,7 +289,7 @@ entropy_generator (void *cls, const char *what, int printchar, int current, if (0 != GNUNET_OS_process_kill (genproc, SIGTERM)) LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR, "kill"); GNUNET_break (GNUNET_OK == GNUNET_OS_process_wait (genproc)); - GNUNET_OS_process_close (genproc); + GNUNET_OS_process_destroy (genproc); genproc = NULL; } return; @@ -233,15 +307,16 @@ entropy_generator (void *cls, const char *what, int printchar, int current, if (0 != GNUNET_OS_process_kill (genproc, SIGTERM)) LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR, "kill"); GNUNET_break (GNUNET_OK == GNUNET_OS_process_wait (genproc)); - GNUNET_OS_process_close (genproc); + GNUNET_OS_process_destroy (genproc); genproc = NULL; } LOG (GNUNET_ERROR_TYPE_INFO, _("Starting `%s' process to generate entropy\n"), "find"); genproc = - GNUNET_OS_start_process (NULL, NULL, "sh", "sh", "-c", - "exec find / -mount -type f -exec cp {} /dev/null \\; 2>/dev/null", - NULL); + GNUNET_OS_start_process (GNUNET_NO, 0, + NULL, NULL, "sh", "sh", "-c", + "exec find / -mount -type f -exec cp {} /dev/null \\; 2>/dev/null", + NULL); } @@ -251,7 +326,7 @@ killfind () if (genproc != NULL) { GNUNET_OS_process_kill (genproc, SIGKILL); - GNUNET_OS_process_close (genproc); + GNUNET_OS_process_destroy (genproc); genproc = NULL; } } @@ -260,21 +335,25 @@ killfind () void __attribute__ ((constructor)) GNUNET_CRYPTO_random_init () { gcry_control (GCRYCTL_DISABLE_SECMEM, 0); - if (!gcry_check_version (GCRYPT_VERSION)) + if (!gcry_check_version (NEED_LIBGCRYPT_VERSION)) { - fprintf (stderr, + FPRINTF (stderr, _ ("libgcrypt has not the expected version (version %s is required).\n"), - GCRYPT_VERSION); + NEED_LIBGCRYPT_VERSION); GNUNET_abort (); } +#ifdef GCRYCTL_INITIALIZATION_FINISHED + gcry_control (GCRYCTL_INITIALIZATION_FINISHED, 0); +#endif #ifdef gcry_fast_random_poll gcry_fast_random_poll (); #endif gcry_set_progress_handler (&entropy_generator, NULL); atexit (&killfind); - SRANDOM (time (NULL) ^ - GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX)); + GNUNET_CRYPTO_seed_weak_random (time (NULL) ^ + GNUNET_CRYPTO_random_u32 + (GNUNET_CRYPTO_QUALITY_NONCE, UINT32_MAX)); }