/************************************************************************ * IRC - Internet Relay Chat, random.c * (C) 2004-2019 Bram Matthys (Syzop) and the UnrealIRCd Team * * See file AUTHORS in IRC package for additional names of * the programmers. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 1, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. * */ #include "unrealircd.h" #ifndef HAVE_ARC4RANDOM #define KEYSTREAM_ONLY /* chacha_private.h from openssh/openssh-portable * "chacha-merged.c version 20080118 * D. J. Bernstein * Public domain." */ /* $OpenBSD: chacha_private.h,v 1.2 2013/10/04 07:02:27 djm Exp $ */ typedef unsigned char u8; typedef unsigned int u32; typedef struct { u32 input[16]; /* could be compressed */ } chacha_ctx; #define U8C(v) (v##U) #define U32C(v) (v##U) #define U8V(v) ((u8)(v) & U8C(0xFF)) #define U32V(v) ((u32)(v) & U32C(0xFFFFFFFF)) #define ROTL32(v, n) \ (U32V((v) << (n)) | ((v) >> (32 - (n)))) #define U8TO32_LITTLE(p) \ (((u32)((p)[0]) ) | \ ((u32)((p)[1]) << 8) | \ ((u32)((p)[2]) << 16) | \ ((u32)((p)[3]) << 24)) #define U32TO8_LITTLE(p, v) \ do { \ (p)[0] = U8V((v) ); \ (p)[1] = U8V((v) >> 8); \ (p)[2] = U8V((v) >> 16); \ (p)[3] = U8V((v) >> 24); \ } while (0) #define ROTATE(v,c) (ROTL32(v,c)) #define XOR(v,w) ((v) ^ (w)) #define PLUS(v,w) (U32V((v) + (w))) #define PLUSONE(v) (PLUS((v),1)) #define QUARTERROUND(a,b,c,d) \ a = PLUS(a,b); d = ROTATE(XOR(d,a),16); \ c = PLUS(c,d); b = ROTATE(XOR(b,c),12); \ a = PLUS(a,b); d = ROTATE(XOR(d,a), 8); \ c = PLUS(c,d); b = ROTATE(XOR(b,c), 7); static const char sigma[16] = "expand 32-byte k"; static const char tau[16] = "expand 16-byte k"; static void chacha_keysetup(chacha_ctx *x,const u8 *k,u32 kbits,u32 ivbits) { const char *constants; x->input[4] = U8TO32_LITTLE(k + 0); x->input[5] = U8TO32_LITTLE(k + 4); x->input[6] = U8TO32_LITTLE(k + 8); x->input[7] = U8TO32_LITTLE(k + 12); if (kbits == 256) { /* recommended */ k += 16; constants = sigma; } else { /* kbits == 128 */ constants = tau; } x->input[8] = U8TO32_LITTLE(k + 0); x->input[9] = U8TO32_LITTLE(k + 4); x->input[10] = U8TO32_LITTLE(k + 8); x->input[11] = U8TO32_LITTLE(k + 12); x->input[0] = U8TO32_LITTLE(constants + 0); x->input[1] = U8TO32_LITTLE(constants + 4); x->input[2] = U8TO32_LITTLE(constants + 8); x->input[3] = U8TO32_LITTLE(constants + 12); } static void chacha_ivsetup(chacha_ctx *x,const u8 *iv) { x->input[12] = 0; x->input[13] = 0; x->input[14] = U8TO32_LITTLE(iv + 0); x->input[15] = U8TO32_LITTLE(iv + 4); } static void chacha_encrypt_bytes(chacha_ctx *x,const u8 *m,u8 *c,u32 bytes) { u32 x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11, x12, x13, x14, x15; u32 j0, j1, j2, j3, j4, j5, j6, j7, j8, j9, j10, j11, j12, j13, j14, j15; u8 *ctarget = NULL; u8 tmp[64]; u_int i; if (!bytes) return; j0 = x->input[0]; j1 = x->input[1]; j2 = x->input[2]; j3 = x->input[3]; j4 = x->input[4]; j5 = x->input[5]; j6 = x->input[6]; j7 = x->input[7]; j8 = x->input[8]; j9 = x->input[9]; j10 = x->input[10]; j11 = x->input[11]; j12 = x->input[12]; j13 = x->input[13]; j14 = x->input[14]; j15 = x->input[15]; for (;;) { if (bytes < 64) { for (i = 0;i < bytes;++i) tmp[i] = m[i]; m = tmp; ctarget = c; c = tmp; } x0 = j0; x1 = j1; x2 = j2; x3 = j3; x4 = j4; x5 = j5; x6 = j6; x7 = j7; x8 = j8; x9 = j9; x10 = j10; x11 = j11; x12 = j12; x13 = j13; x14 = j14; x15 = j15; for (i = 20;i > 0;i -= 2) { QUARTERROUND( x0, x4, x8,x12) QUARTERROUND( x1, x5, x9,x13) QUARTERROUND( x2, x6,x10,x14) QUARTERROUND( x3, x7,x11,x15) QUARTERROUND( x0, x5,x10,x15) QUARTERROUND( x1, x6,x11,x12) QUARTERROUND( x2, x7, x8,x13) QUARTERROUND( x3, x4, x9,x14) } x0 = PLUS(x0,j0); x1 = PLUS(x1,j1); x2 = PLUS(x2,j2); x3 = PLUS(x3,j3); x4 = PLUS(x4,j4); x5 = PLUS(x5,j5); x6 = PLUS(x6,j6); x7 = PLUS(x7,j7); x8 = PLUS(x8,j8); x9 = PLUS(x9,j9); x10 = PLUS(x10,j10); x11 = PLUS(x11,j11); x12 = PLUS(x12,j12); x13 = PLUS(x13,j13); x14 = PLUS(x14,j14); x15 = PLUS(x15,j15); #ifndef KEYSTREAM_ONLY x0 = XOR(x0,U8TO32_LITTLE(m + 0)); x1 = XOR(x1,U8TO32_LITTLE(m + 4)); x2 = XOR(x2,U8TO32_LITTLE(m + 8)); x3 = XOR(x3,U8TO32_LITTLE(m + 12)); x4 = XOR(x4,U8TO32_LITTLE(m + 16)); x5 = XOR(x5,U8TO32_LITTLE(m + 20)); x6 = XOR(x6,U8TO32_LITTLE(m + 24)); x7 = XOR(x7,U8TO32_LITTLE(m + 28)); x8 = XOR(x8,U8TO32_LITTLE(m + 32)); x9 = XOR(x9,U8TO32_LITTLE(m + 36)); x10 = XOR(x10,U8TO32_LITTLE(m + 40)); x11 = XOR(x11,U8TO32_LITTLE(m + 44)); x12 = XOR(x12,U8TO32_LITTLE(m + 48)); x13 = XOR(x13,U8TO32_LITTLE(m + 52)); x14 = XOR(x14,U8TO32_LITTLE(m + 56)); x15 = XOR(x15,U8TO32_LITTLE(m + 60)); #endif j12 = PLUSONE(j12); if (!j12) { j13 = PLUSONE(j13); /* stopping at 2^70 bytes per nonce is user's responsibility */ } U32TO8_LITTLE(c + 0,x0); U32TO8_LITTLE(c + 4,x1); U32TO8_LITTLE(c + 8,x2); U32TO8_LITTLE(c + 12,x3); U32TO8_LITTLE(c + 16,x4); U32TO8_LITTLE(c + 20,x5); U32TO8_LITTLE(c + 24,x6); U32TO8_LITTLE(c + 28,x7); U32TO8_LITTLE(c + 32,x8); U32TO8_LITTLE(c + 36,x9); U32TO8_LITTLE(c + 40,x10); U32TO8_LITTLE(c + 44,x11); U32TO8_LITTLE(c + 48,x12); U32TO8_LITTLE(c + 52,x13); U32TO8_LITTLE(c + 56,x14); U32TO8_LITTLE(c + 60,x15); if (bytes <= 64) { if (bytes < 64) { for (i = 0;i < bytes;++i) ctarget[i] = c[i]; } x->input[12] = j12; x->input[13] = j13; return; } bytes -= 64; c += 64; #ifndef KEYSTREAM_ONLY m += 64; #endif } } /* The following is taken from arc4random.c * from openssh/openssh-portable/, which has an ISC license, * which is GPL compatible. */ /* OPENBSD ORIGINAL: lib/libc/crypto/arc4random.c */ /* $OpenBSD: arc4random.c,v 1.25 2013/10/01 18:34:57 markus Exp $ */ /* * Copyright (c) 1996, David Mazieres * Copyright (c) 2008, Damien Miller * Copyright (c) 2013, Markus Friedl * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* Modified for UnrealIRCd by Bram Matthys ("Syzop") in 2019. * Things like taking out #if(n)def's for openssl (which we always * compile with), re-indenting, removing various stuff, etc. */ #define KEYSZ 32 #define IVSZ 8 #define BLOCKSZ 64 #define RSBUFSZ (16*BLOCKSZ) static int rs_initialized; static chacha_ctx rs; /* chacha context for random keystream */ static u_char rs_buf[RSBUFSZ]; /* keystream blocks */ static size_t rs_have; /* valid bytes at end of rs_buf */ static size_t rs_count; /* bytes till reseed */ static inline void _rs_rekey(u_char *dat, size_t datlen); static inline void _rs_init(u_char *buf, size_t n) { if (n < KEYSZ + IVSZ) return; chacha_keysetup(&rs, buf, KEYSZ * 8, 0); chacha_ivsetup(&rs, buf + KEYSZ); } static void _rs_stir(void) { u_char rnd[KEYSZ + IVSZ]; if (RAND_bytes(rnd, sizeof(rnd)) <= 0) { ircd_log(LOG_ERROR, "Couldn't obtain random bytes (error 0x%lx)", (unsigned long)ERR_get_error()); abort(); } if (!rs_initialized) { rs_initialized = 1; _rs_init(rnd, sizeof(rnd)); } else _rs_rekey(rnd, sizeof(rnd)); #ifdef HAVE_EXPLICIT_BZERO explicit_bzero(rnd, sizeof(rnd)); #else /* Not terribly important in this case */ memset(rnd, 0, sizeof(rnd)); #endif /* invalidate rs_buf */ rs_have = 0; memset(rs_buf, 0, RSBUFSZ); rs_count = 1600000; } static inline void _rs_stir_if_needed(size_t len) { if (rs_count <= len || !rs_initialized) { _rs_stir(); } else rs_count -= len; } static inline void _rs_rekey(u_char *dat, size_t datlen) { #ifndef KEYSTREAM_ONLY memset(rs_buf, 0,RSBUFSZ); #endif /* fill rs_buf with the keystream */ chacha_encrypt_bytes(&rs, rs_buf, rs_buf, RSBUFSZ); /* mix in optional user provided data */ if (dat) { size_t i, m; m = MIN(datlen, KEYSZ + IVSZ); for (i = 0; i < m; i++) rs_buf[i] ^= dat[i]; } /* immediately reinit for backtracking resistance */ _rs_init(rs_buf, KEYSZ + IVSZ); memset(rs_buf, 0, KEYSZ + IVSZ); rs_have = RSBUFSZ - KEYSZ - IVSZ; } static inline void _rs_random_buf(void *_buf, size_t n) { u_char *buf = (u_char *)_buf; size_t m; _rs_stir_if_needed(n); while (n > 0) { if (rs_have > 0) { m = MIN(n, rs_have); memcpy(buf, rs_buf + RSBUFSZ - rs_have, m); memset(rs_buf + RSBUFSZ - rs_have, 0, m); buf += m; n -= m; rs_have -= m; } if (rs_have == 0) _rs_rekey(NULL, 0); } } static inline void _rs_random_u32(uint32_t *val) { _rs_stir_if_needed(sizeof(*val)); if (rs_have < sizeof(*val)) _rs_rekey(NULL, 0); memcpy(val, rs_buf + RSBUFSZ - rs_have, sizeof(*val)); memset(rs_buf + RSBUFSZ - rs_have, 0, sizeof(*val)); rs_have -= sizeof(*val); return; } void arc4random_stir(void) { _rs_stir(); } void arc4random_doaddrandom(u_char *dat, int datlen) { int m; if (!rs_initialized) _rs_stir(); while (datlen > 0) { m = MIN(datlen, KEYSZ + IVSZ); _rs_rekey(dat, m); dat += m; datlen -= m; } } #endif /* !HAVE_ARC4RANDOM */ /* UnrealIRCd-specific functions follow */ static void arc4_addrandom(void *dat, int datlen) { arc4random_doaddrandom((unsigned char *)dat, datlen); return; } void add_entropy_configfile(struct stat *st, char *buf) { unsigned char mdbuf[16]; arc4_addrandom(&st->st_size, sizeof(st->st_size)); arc4_addrandom(&st->st_mtime, sizeof(st->st_mtime)); DoMD5(mdbuf, buf, strlen(buf)); arc4_addrandom(&mdbuf, sizeof(mdbuf)); } /* * init_random, written by Syzop. * This function tries to initialize the arc4 random number generator securely. */ void init_random() { struct { #ifndef _WIN32 struct timeval nowt; /* time */ char rnd[32]; /* /dev/urandom */ #else MEMORYSTATUS mstat; /* memory status */ struct _timeb nowt; /* time */ #endif } rdat; #ifndef _WIN32 int fd; #else MEMORYSTATUS mstat; #endif _rs_stir(); /* Grab OS specific "random" data */ #ifndef _WIN32 gettimeofday(&rdat.nowt, NULL); fd = open("/dev/urandom", O_RDONLY); if (fd >= 0) { int n = read(fd, &rdat.rnd, sizeof(rdat.rnd)); Debug((DEBUG_INFO, "init_random: read from /dev/urandom returned %d", n)); close(fd); } #else _ftime(&rdat.nowt); GlobalMemoryStatus (&rdat.mstat); #endif arc4_addrandom(&rdat, sizeof(rdat)); /* NOTE: addtional entropy is added by add_entropy_* function(s) */ } uint32_t arc4random(void) { uint32_t val; _rs_random_u32(&val); return val; } /** Get 8 bits (1 byte) of randomness */ u_char getrandom8() { return arc4random() & 0xff; } /** Get 16 bits (2 bytes) of randomness */ uint16_t getrandom16() { return arc4random() & 0xffff; } /** Get 32 bits (4 bytes) of randomness */ uint32_t getrandom32() { return arc4random(); } /** Generate an alphanumeric string (eg: XzHe5G). * @param buf The buffer * @param numbytes The number of random bytes. * @note Note that numbytes+1 bytes are written to buf. * In other words, numbytes does NOT include the NUL byte. */ void gen_random_alnum(char *buf, int numbytes) { for (; numbytes > 0; numbytes--) { unsigned char v = getrandom8() % (26+26+10); if (v < 26) *buf++ = 'a'+v; else if (v < 52) *buf++ = 'A'+(v-26); else *buf++ = '0'+(v-52); } *buf = '\0'; }