diff options
Diffstat (limited to 'libtommath/bn_s_mp_rand_platform.c')
| -rw-r--r-- | libtommath/bn_s_mp_rand_platform.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/libtommath/bn_s_mp_rand_platform.c b/libtommath/bn_s_mp_rand_platform.c new file mode 100644 index 0000000..27339bf --- /dev/null +++ b/libtommath/bn_s_mp_rand_platform.c @@ -0,0 +1,148 @@ +#include "tommath_private.h" +#ifdef BN_S_MP_RAND_PLATFORM_C +/* LibTomMath, multiple-precision integer library -- Tom St Denis */ +/* SPDX-License-Identifier: Unlicense */ + +/* First the OS-specific special cases + * - *BSD + * - Windows + */ +#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) || defined(__DragonFly__) +#define BN_S_READ_ARC4RANDOM_C +static mp_err s_read_arc4random(void *p, size_t n) +{ + arc4random_buf(p, n); + return MP_OKAY; +} +#endif + +#if defined(_WIN32) || defined(_WIN32_WCE) +#define BN_S_READ_WINCSP_C + +#ifndef _WIN32_WINNT +#define _WIN32_WINNT 0x0400 +#endif +#ifdef _WIN32_WCE +#define UNDER_CE +#define ARM +#endif + +#define WIN32_LEAN_AND_MEAN +#include <windows.h> +#include <wincrypt.h> + +static mp_err s_read_wincsp(void *p, size_t n) +{ + static HCRYPTPROV hProv = 0; + if (hProv == 0) { + HCRYPTPROV h = 0; + if (!CryptAcquireContext(&h, NULL, MS_DEF_PROV, PROV_RSA_FULL, + (CRYPT_VERIFYCONTEXT | CRYPT_MACHINE_KEYSET)) && + !CryptAcquireContext(&h, NULL, MS_DEF_PROV, PROV_RSA_FULL, + CRYPT_VERIFYCONTEXT | CRYPT_MACHINE_KEYSET | CRYPT_NEWKEYSET)) { + return MP_ERR; + } + hProv = h; + } + return CryptGenRandom(hProv, (DWORD)n, (BYTE *)p) == TRUE ? MP_OKAY : MP_ERR; +} +#endif /* WIN32 */ + +#if !defined(BN_S_READ_WINCSP_C) && defined(__linux__) && defined(__GLIBC_PREREQ) +#if __GLIBC_PREREQ(2, 25) +#define BN_S_READ_GETRANDOM_C +#include <sys/random.h> +#include <errno.h> + +static mp_err s_read_getrandom(void *p, size_t n) +{ + char *q = (char *)p; + while (n > 0u) { + ssize_t ret = getrandom(q, n, 0); + if (ret < 0) { + if (errno == EINTR) { + continue; + } + return MP_ERR; + } + q += ret; + n -= (size_t)ret; + } + return MP_OKAY; +} +#endif +#endif + +/* We assume all platforms besides windows provide "/dev/urandom". + * In case yours doesn't, define MP_NO_DEV_URANDOM at compile-time. + */ +#if !defined(BN_S_READ_WINCSP_C) && !defined(MP_NO_DEV_URANDOM) +#define BN_S_READ_URANDOM_C +#ifndef MP_DEV_URANDOM +#define MP_DEV_URANDOM "/dev/urandom" +#endif +#include <fcntl.h> +#include <errno.h> +#include <unistd.h> + +static mp_err s_read_urandom(void *p, size_t n) +{ + int fd; + char *q = (char *)p; + + do { + fd = open(MP_DEV_URANDOM, O_RDONLY); + } while ((fd == -1) && (errno == EINTR)); + if (fd == -1) return MP_ERR; + + while (n > 0u) { + ssize_t ret = read(fd, p, n); + if (ret < 0) { + if (errno == EINTR) { + continue; + } + close(fd); + return MP_ERR; + } + q += ret; + n -= (size_t)ret; + } + + close(fd); + return MP_OKAY; +} +#endif + +#if defined(MP_PRNG_ENABLE_LTM_RNG) +#define BN_S_READ_LTM_RNG +unsigned long (*ltm_rng)(unsigned char *out, unsigned long outlen, void (*callback)(void)); +void (*ltm_rng_callback)(void); + +static mp_err s_read_ltm_rng(void *p, size_t n) +{ + unsigned long res; + if (ltm_rng == NULL) return MP_ERR; + res = ltm_rng(p, n, ltm_rng_callback); + if (res != n) return MP_ERR; + return MP_OKAY; +} +#endif + +mp_err s_read_arc4random(void *p, size_t n); +mp_err s_read_wincsp(void *p, size_t n); +mp_err s_read_getrandom(void *p, size_t n); +mp_err s_read_urandom(void *p, size_t n); +mp_err s_read_ltm_rng(void *p, size_t n); + +mp_err s_mp_rand_platform(void *p, size_t n) +{ + mp_err err = MP_ERR; + if ((err != MP_OKAY) && MP_HAS(S_READ_ARC4RANDOM)) err = s_read_arc4random(p, n); + if ((err != MP_OKAY) && MP_HAS(S_READ_WINCSP)) err = s_read_wincsp(p, n); + if ((err != MP_OKAY) && MP_HAS(S_READ_GETRANDOM)) err = s_read_getrandom(p, n); + if ((err != MP_OKAY) && MP_HAS(S_READ_URANDOM)) err = s_read_urandom(p, n); + if ((err != MP_OKAY) && MP_HAS(S_READ_LTM_RNG)) err = s_read_ltm_rng(p, n); + return err; +} + +#endif |