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Diffstat (limited to 'src/lib/libc/crypt/arc4random.c')
-rw-r--r--src/lib/libc/crypt/arc4random.c204
1 files changed, 0 insertions, 204 deletions
diff --git a/src/lib/libc/crypt/arc4random.c b/src/lib/libc/crypt/arc4random.c
deleted file mode 100644
index 2da8e010ad..0000000000
--- a/src/lib/libc/crypt/arc4random.c
+++ /dev/null
@@ -1,204 +0,0 @@
1/* $OpenBSD: arc4random.c,v 1.58 2022/07/31 13:41:45 tb Exp $ */
2
3/*
4 * Copyright (c) 1996, David Mazieres <dm@uun.org>
5 * Copyright (c) 2008, Damien Miller <djm@openbsd.org>
6 * Copyright (c) 2013, Markus Friedl <markus@openbsd.org>
7 * Copyright (c) 2014, Theo de Raadt <deraadt@openbsd.org>
8 *
9 * Permission to use, copy, modify, and distribute this software for any
10 * purpose with or without fee is hereby granted, provided that the above
11 * copyright notice and this permission notice appear in all copies.
12 *
13 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
14 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
15 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
16 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
17 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
18 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
19 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
20 */
21
22/*
23 * ChaCha based random number generator for OpenBSD.
24 */
25
26#include <fcntl.h>
27#include <limits.h>
28#include <signal.h>
29#include <stdint.h>
30#include <stdlib.h>
31#include <string.h>
32#include <unistd.h>
33#include <sys/types.h>
34#include <sys/time.h>
35
36#define KEYSTREAM_ONLY
37#include "chacha_private.h"
38
39#define minimum(a, b) ((a) < (b) ? (a) : (b))
40
41#if defined(__GNUC__) || defined(_MSC_VER)
42#define inline __inline
43#else /* __GNUC__ || _MSC_VER */
44#define inline
45#endif /* !__GNUC__ && !_MSC_VER */
46
47#define KEYSZ 32
48#define IVSZ 8
49#define BLOCKSZ 64
50#define RSBUFSZ (16*BLOCKSZ)
51
52#define REKEY_BASE (1024*1024) /* NB. should be a power of 2 */
53
54/* Marked MAP_INHERIT_ZERO, so zero'd out in fork children. */
55static struct _rs {
56 size_t rs_have; /* valid bytes at end of rs_buf */
57 size_t rs_count; /* bytes till reseed */
58} *rs;
59
60/* Maybe be preserved in fork children, if _rs_allocate() decides. */
61static struct _rsx {
62 chacha_ctx rs_chacha; /* chacha context for random keystream */
63 u_char rs_buf[RSBUFSZ]; /* keystream blocks */
64} *rsx;
65
66static inline int _rs_allocate(struct _rs **, struct _rsx **);
67static inline void _rs_forkdetect(void);
68#include "arc4random.h"
69
70static inline void _rs_rekey(u_char *dat, size_t datlen);
71
72static inline void
73_rs_init(u_char *buf, size_t n)
74{
75 if (n < KEYSZ + IVSZ)
76 return;
77
78 if (rs == NULL) {
79 if (_rs_allocate(&rs, &rsx) == -1)
80 _exit(1);
81 }
82
83 chacha_keysetup(&rsx->rs_chacha, buf, KEYSZ * 8);
84 chacha_ivsetup(&rsx->rs_chacha, buf + KEYSZ);
85}
86
87static void
88_rs_stir(void)
89{
90 u_char rnd[KEYSZ + IVSZ];
91 uint32_t rekey_fuzz = 0;
92
93 if (getentropy(rnd, sizeof rnd) == -1)
94 _getentropy_fail();
95
96 if (!rs)
97 _rs_init(rnd, sizeof(rnd));
98 else
99 _rs_rekey(rnd, sizeof(rnd));
100 explicit_bzero(rnd, sizeof(rnd)); /* discard source seed */
101
102 /* invalidate rs_buf */
103 rs->rs_have = 0;
104 memset(rsx->rs_buf, 0, sizeof(rsx->rs_buf));
105
106 /* rekey interval should not be predictable */
107 chacha_encrypt_bytes(&rsx->rs_chacha, (uint8_t *)&rekey_fuzz,
108 (uint8_t *)&rekey_fuzz, sizeof(rekey_fuzz));
109 rs->rs_count = REKEY_BASE + (rekey_fuzz % REKEY_BASE);
110}
111
112static inline void
113_rs_stir_if_needed(size_t len)
114{
115 _rs_forkdetect();
116 if (!rs || rs->rs_count <= len)
117 _rs_stir();
118 if (rs->rs_count <= len)
119 rs->rs_count = 0;
120 else
121 rs->rs_count -= len;
122}
123
124static inline void
125_rs_rekey(u_char *dat, size_t datlen)
126{
127#ifndef KEYSTREAM_ONLY
128 memset(rsx->rs_buf, 0, sizeof(rsx->rs_buf));
129#endif
130 /* fill rs_buf with the keystream */
131 chacha_encrypt_bytes(&rsx->rs_chacha, rsx->rs_buf,
132 rsx->rs_buf, sizeof(rsx->rs_buf));
133 /* mix in optional user provided data */
134 if (dat) {
135 size_t i, m;
136
137 m = minimum(datlen, KEYSZ + IVSZ);
138 for (i = 0; i < m; i++)
139 rsx->rs_buf[i] ^= dat[i];
140 }
141 /* immediately reinit for backtracking resistance */
142 _rs_init(rsx->rs_buf, KEYSZ + IVSZ);
143 memset(rsx->rs_buf, 0, KEYSZ + IVSZ);
144 rs->rs_have = sizeof(rsx->rs_buf) - KEYSZ - IVSZ;
145}
146
147static inline void
148_rs_random_buf(void *_buf, size_t n)
149{
150 u_char *buf = (u_char *)_buf;
151 u_char *keystream;
152 size_t m;
153
154 _rs_stir_if_needed(n);
155 while (n > 0) {
156 if (rs->rs_have > 0) {
157 m = minimum(n, rs->rs_have);
158 keystream = rsx->rs_buf + sizeof(rsx->rs_buf)
159 - rs->rs_have;
160 memcpy(buf, keystream, m);
161 memset(keystream, 0, m);
162 buf += m;
163 n -= m;
164 rs->rs_have -= m;
165 }
166 if (rs->rs_have == 0)
167 _rs_rekey(NULL, 0);
168 }
169}
170
171static inline void
172_rs_random_u32(uint32_t *val)
173{
174 u_char *keystream;
175
176 _rs_stir_if_needed(sizeof(*val));
177 if (rs->rs_have < sizeof(*val))
178 _rs_rekey(NULL, 0);
179 keystream = rsx->rs_buf + sizeof(rsx->rs_buf) - rs->rs_have;
180 memcpy(val, keystream, sizeof(*val));
181 memset(keystream, 0, sizeof(*val));
182 rs->rs_have -= sizeof(*val);
183}
184
185uint32_t
186arc4random(void)
187{
188 uint32_t val;
189
190 _ARC4_LOCK();
191 _rs_random_u32(&val);
192 _ARC4_UNLOCK();
193 return val;
194}
195DEF_WEAK(arc4random);
196
197void
198arc4random_buf(void *buf, size_t n)
199{
200 _ARC4_LOCK();
201 _rs_random_buf(buf, n);
202 _ARC4_UNLOCK();
203}
204DEF_WEAK(arc4random_buf);
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