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util-src/crand.c @ 10419:3b9d17c234df
Back out c8aa66595072: Extra changes accidentally included
author | Kim Alvefur <zash@zash.se> |
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date | Sun, 17 Nov 2019 23:45:44 +0100 |
parent | 8451:770f79a9635c |
child | 12470:80f3123053e2 |
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/* Prosody IM -- Copyright (C) 2008-2017 Matthew Wild -- Copyright (C) 2008-2017 Waqas Hussain -- Copyright (C) 2016-2017 Kim Alvefur -- -- This project is MIT/X11 licensed. Please see the -- COPYING file in the source package for more information. -- */ /* * crand.c * C PRNG interface * * The purpose of this module is to provide access to a PRNG in * environments without /dev/urandom * * Caution! This has not been extensively tested. * */ #define _DEFAULT_SOURCE #include <stdlib.h> #include <string.h> #include <errno.h> #include "lualib.h" #include "lauxlib.h" #if defined(WITH_GETRANDOM) #ifndef __GLIBC_PREREQ /* Not compiled with glibc at all */ #define __GLIBC_PREREQ(a,b) 0 #endif #if ! __GLIBC_PREREQ(2,25) /* Not compiled with a glibc that provides getrandom() */ #include <unistd.h> #include <sys/syscall.h> #ifndef SYS_getrandom #error getrandom() requires Linux 3.17 or later #endif /* This wasn't present before glibc 2.25 */ int getrandom(void *buf, size_t buflen, unsigned int flags) { return syscall(SYS_getrandom, buf, buflen, flags); } #else #include <sys/random.h> #endif #elif defined(WITH_OPENSSL) #include <openssl/rand.h> #elif defined(WITH_ARC4RANDOM) #ifdef __linux__ #include <bsd/stdlib.h> #endif #else #error util.crand compiled without a random source #endif #ifndef SMALLBUFSIZ #define SMALLBUFSIZ 32 #endif int Lrandom(lua_State *L) { char smallbuf[SMALLBUFSIZ]; char *buf = &smallbuf[0]; const lua_Integer l = luaL_checkinteger(L, 1); const size_t len = l; luaL_argcheck(L, l >= 0, 1, "must be > 0"); if(len == 0) { lua_pushliteral(L, ""); return 1; } if(len > SMALLBUFSIZ) { buf = lua_newuserdata(L, len); } #if defined(WITH_GETRANDOM) /* * This acts like a read from /dev/urandom with the exception that it * *does* block if the entropy pool is not yet initialized. */ int left = len; char *p = buf; do { int ret = getrandom(p, left, 0); if(ret < 0) { lua_pushstring(L, strerror(errno)); return lua_error(L); } p += ret; left -= ret; } while(left > 0); #elif defined(WITH_ARC4RANDOM) arc4random_buf(buf, len); #elif defined(WITH_OPENSSL) if(!RAND_status()) { lua_pushliteral(L, "OpenSSL PRNG not seeded"); return lua_error(L); } if(RAND_bytes((unsigned char *)buf, len) != 1) { /* TODO ERR_get_error() */ lua_pushstring(L, "RAND_bytes() failed"); return lua_error(L); } #endif lua_pushlstring(L, buf, len); return 1; } int luaopen_util_crand(lua_State *L) { #if (LUA_VERSION_NUM > 501) luaL_checkversion(L); #endif lua_createtable(L, 0, 2); lua_pushcfunction(L, Lrandom); lua_setfield(L, -2, "bytes"); #if defined(WITH_GETRANDOM) lua_pushstring(L, "Linux"); #elif defined(WITH_ARC4RANDOM) lua_pushstring(L, "arc4random()"); #elif defined(WITH_OPENSSL) lua_pushstring(L, "OpenSSL"); #endif lua_setfield(L, -2, "_source"); return 1; }