Mercurial > dropbear
view libtomcrypt/src/prngs/rng_get_bytes.c @ 1156:a8f4dade70e5
avoid getpass when not used
some systems (like android's bionic) do not provide getpass. you can
disable ENABLE_CLI_PASSWORD_AUTH & ENABLE_CLI_INTERACT_AUTH to avoid
its use (and rely on pubkey auth), but the link still fails because
the support file calls getpass. do not define this func if both of
those auth methods are not used.
author | Mike Frysinger <vapier@gentoo.org> |
---|---|
date | Wed, 21 Oct 2015 22:39:55 +0800 |
parents | 0cbe8f6dbf9e |
children | f849a5ca2efc |
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/* LibTomCrypt, modular cryptographic library -- Tom St Denis * * LibTomCrypt is a library that provides various cryptographic * algorithms in a highly modular and flexible manner. * * The library is free for all purposes without any express * guarantee it works. * * Tom St Denis, [email protected], http://libtomcrypt.com */ #include "tomcrypt.h" /** @file rng_get_bytes.c portable way to get secure random bits to feed a PRNG (Tom St Denis) */ #ifdef DEVRANDOM /* on *NIX read /dev/random */ static unsigned long rng_nix(unsigned char *buf, unsigned long len, void (*callback)(void)) { #ifdef LTC_NO_FILE return 0; #else FILE *f; unsigned long x; #ifdef TRY_URANDOM_FIRST f = fopen("/dev/urandom", "rb"); if (f == NULL) #endif /* TRY_URANDOM_FIRST */ f = fopen("/dev/random", "rb"); if (f == NULL) { return 0; } /* disable buffering */ if (setvbuf(f, NULL, _IONBF, 0) != 0) { fclose(f); return 0; } x = (unsigned long)fread(buf, 1, (size_t)len, f); fclose(f); return x; #endif /* LTC_NO_FILE */ } #endif /* DEVRANDOM */ /* on ANSI C platforms with 100 < CLOCKS_PER_SEC < 10000 */ #if defined(CLOCKS_PER_SEC) && !defined(WINCE) #define ANSI_RNG static unsigned long rng_ansic(unsigned char *buf, unsigned long len, void (*callback)(void)) { clock_t t1; int l, acc, bits, a, b; if (XCLOCKS_PER_SEC < 100 || XCLOCKS_PER_SEC > 10000) { return 0; } l = len; bits = 8; acc = a = b = 0; while (len--) { if (callback != NULL) callback(); while (bits--) { do { t1 = XCLOCK(); while (t1 == XCLOCK()) a ^= 1; t1 = XCLOCK(); while (t1 == XCLOCK()) b ^= 1; } while (a == b); acc = (acc << 1) | a; } *buf++ = acc; acc = 0; bits = 8; } acc = bits = a = b = 0; return l; } #endif /* Try the Microsoft CSP */ #if defined(WIN32) || defined(WINCE) #define _WIN32_WINNT 0x0400 #ifdef WINCE #define UNDER_CE #define ARM #endif #include <windows.h> #include <wincrypt.h> static unsigned long rng_win32(unsigned char *buf, unsigned long len, void (*callback)(void)) { HCRYPTPROV hProv = 0; if (!CryptAcquireContext(&hProv, NULL, MS_DEF_PROV, PROV_RSA_FULL, (CRYPT_VERIFYCONTEXT | CRYPT_MACHINE_KEYSET)) && !CryptAcquireContext (&hProv, NULL, MS_DEF_PROV, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT | CRYPT_MACHINE_KEYSET | CRYPT_NEWKEYSET)) return 0; if (CryptGenRandom(hProv, len, buf) == TRUE) { CryptReleaseContext(hProv, 0); return len; } else { CryptReleaseContext(hProv, 0); return 0; } } #endif /* WIN32 */ /** Read the system RNG @param out Destination @param outlen Length desired (octets) @param callback Pointer to void function to act as "callback" when RNG is slow. This can be NULL @return Number of octets read */ unsigned long rng_get_bytes(unsigned char *out, unsigned long outlen, void (*callback)(void)) { unsigned long x; LTC_ARGCHK(out != NULL); #if defined(DEVRANDOM) x = rng_nix(out, outlen, callback); if (x != 0) { return x; } #endif #ifdef WIN32 x = rng_win32(out, outlen, callback); if (x != 0) { return x; } #endif #ifdef ANSI_RNG x = rng_ansic(out, outlen, callback); if (x != 0) { return x; } #endif return 0; } /* $Source: /cvs/libtom/libtomcrypt/src/prngs/rng_get_bytes.c,v $ */ /* $Revision: 1.5 $ */ /* $Date: 2006/12/06 02:01:29 $ */