diff --git a/src/random.c b/src/random.c index cedbf18c3..d25b51a06 100644 --- a/src/random.c +++ b/src/random.c @@ -1,6 +1,6 @@ /************************************************************************ * IRC - Internet Relay Chat, random.c - * (C) 2004-2010 Bram Matthys (Syzop) and the UnrealIRCd Team + * (C) 2004-2019 Bram Matthys (Syzop) and the UnrealIRCd Team * * See file AUTHORS in IRC package for additional names of * the programmers. @@ -22,114 +22,412 @@ */ #include "unrealircd.h" - -/* - * Based on Arc4 random number generator for FreeBSD/OpenBSD. - * Copyright 1996 David Mazieres . - * - * Modification and redistribution in source and binary forms is - * permitted provided that due credit is given to the author and the - * OpenBSD project (for instance by leaving this copyright notice - * intact). - * - * This code is derived from section 17.1 of Applied Cryptography, second edition. - * - * *BSD code modified by Syzop to suit our needs (unreal'ized, windows, etc) - */ - -struct arc4_stream { - u_char i; - u_char j; - u_char s[256]; -}; - -static struct arc4_stream rs; - -static void arc4_init(void) -{ -int n; - - for (n = 0; n < 256; n++) - rs.s[n] = n; - rs.i = 0; - rs.j = 0; -} - -static inline void arc4_doaddrandom(u_char *dat, int datlen) -{ -int n; -u_char si; -#ifdef DEBUGMODE -int i; -char outbuf[512], *p = outbuf; - *p = '\0'; - for (i=0; i < datlen; i++) - { - sprintf(p, "%.2X/", dat[i]); - p += 3; - if (p > outbuf + 500) - { - strcpy(p, "...."); - break; - } - } - if (strlen(outbuf) > 0) - outbuf[strlen(outbuf)-1] = '\0'; - Debug((DEBUG_DEBUG, "arc4_addrandom() called, datlen=%d, data dump: %s", datlen, outbuf)); +// FIXME: move this to unrealircd.h and add the config test +#ifdef HAVE_SYS_RANDOM_H +# include #endif - rs.i--; - for (n = 0; n < 256; n++) { - rs.i = (rs.i + 1); - si = rs.s[rs.i]; - rs.j = (rs.j + si + dat[n % datlen]); - rs.s[rs.i] = rs.s[rs.j]; - rs.s[rs.j] = si; + +#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 pid_t rs_stir_pid; +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)); + explicit_bzero(rnd, sizeof(rnd)); + + /* invalidate rs_buf */ + rs_have = 0; + memset(rs_buf, 0, RSBUFSZ); + + rs_count = 1600000; +} + +static inline void _rs_stir_if_needed(size_t len) +{ + pid_t pid = getpid(); + + if (rs_count <= len || !rs_initialized || rs_stir_pid != pid) { + rs_stir_pid = pid; + _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 arc4_addrandom(void *dat, int datlen) +static inline void _rs_random_u32(u_int32_t *val) { - arc4_doaddrandom((unsigned char *)dat, datlen); + _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; } - -u_char getrandom8() +void arc4random_stir(void) { -u_char si, sj; - - rs.i = (rs.i + 1); - si = rs.s[rs.i]; - rs.j = (rs.j + si); - sj = rs.s[rs.j]; - rs.s[rs.i] = sj; - rs.s[rs.j] = si; - return (rs.s[(si + sj) & 0xff]); + _rs_stir(); } -u_int16_t getrandom16() +void arc4random_doaddrandom(u_char *dat, int datlen) { -u_int16_t val; - val = getrandom8() << 8; - val |= getrandom8(); - return val; + int m; + + if (!rs_initialized) + _rs_stir(); + while (datlen > 0) { + m = MIN(datlen, KEYSZ + IVSZ); + _rs_rekey(dat, m); + dat += m; + datlen -= m; + } } -u_int32_t getrandom32() -{ -u_int32_t val; +#endif /* !HAVE_ARC4RANDOM */ - val = getrandom8() << 24; - val |= getrandom8() << 16; - val |= getrandom8() << 8; - val |= getrandom8(); - return val; +/* 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]; + unsigned char mdbuf[16]; arc4_addrandom(&st->st_size, sizeof(st->st_size)); arc4_addrandom(&st->st_mtime, sizeof(st->st_mtime)); @@ -137,29 +435,52 @@ unsigned char mdbuf[16]; arc4_addrandom(&mdbuf, sizeof(mdbuf)); } +u_int32_t arc4random(void) +{ + u_int32_t val; + + _rs_random_u32(&val); + return val; +} + +u_char getrandom8() +{ + return arc4random() & 0xff; +} + +u_int16_t getrandom16() +{ + return arc4random() & 0xffff; +} + +u_int32_t getrandom32() +{ + return arc4random(); +} + /* * init_random, written by Syzop. * This function tries to initialize the arc4 random number generator securely. */ void init_random() { -struct { + struct { #ifndef _WIN32 - struct timeval nowt; /* time */ - char rnd[32]; /* /dev/urandom */ + struct timeval nowt; /* time */ + char rnd[32]; /* /dev/urandom */ #else - MEMORYSTATUS mstat; /* memory status */ - struct _timeb nowt; /* time */ + MEMORYSTATUS mstat; /* memory status */ + struct _timeb nowt; /* time */ #endif -} rdat; + } rdat; #ifndef _WIN32 -int fd; + int fd; #else -MEMORYSTATUS mstat; + MEMORYSTATUS mstat; #endif - arc4_init(); + _rs_stir(); /* Grab OS specific "random" data */ #ifndef _WIN32