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Diffstat (limited to 'src/lib/libc/crypt/arc4random.c')
-rw-r--r--src/lib/libc/crypt/arc4random.c198
1 files changed, 0 insertions, 198 deletions
diff --git a/src/lib/libc/crypt/arc4random.c b/src/lib/libc/crypt/arc4random.c
deleted file mode 100644
index 1a16bd3940..0000000000
--- a/src/lib/libc/crypt/arc4random.c
+++ /dev/null
@@ -1,198 +0,0 @@
1/* $OpenBSD: arc4random.c,v 1.55 2019/03/24 17:56:54 deraadt 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/* Marked MAP_INHERIT_ZERO, so zero'd out in fork children. */
53static struct _rs {
54 size_t rs_have; /* valid bytes at end of rs_buf */
55 size_t rs_count; /* bytes till reseed */
56} *rs;
57
58/* Maybe be preserved in fork children, if _rs_allocate() decides. */
59static struct _rsx {
60 chacha_ctx rs_chacha; /* chacha context for random keystream */
61 u_char rs_buf[RSBUFSZ]; /* keystream blocks */
62} *rsx;
63
64static inline int _rs_allocate(struct _rs **, struct _rsx **);
65static inline void _rs_forkdetect(void);
66#include "arc4random.h"
67
68static inline void _rs_rekey(u_char *dat, size_t datlen);
69
70static inline void
71_rs_init(u_char *buf, size_t n)
72{
73 if (n < KEYSZ + IVSZ)
74 return;
75
76 if (rs == NULL) {
77 if (_rs_allocate(&rs, &rsx) == -1)
78 _exit(1);
79 }
80
81 chacha_keysetup(&rsx->rs_chacha, buf, KEYSZ * 8, 0);
82 chacha_ivsetup(&rsx->rs_chacha, buf + KEYSZ);
83}
84
85static void
86_rs_stir(void)
87{
88 u_char rnd[KEYSZ + IVSZ];
89
90 if (getentropy(rnd, sizeof rnd) == -1)
91 _getentropy_fail();
92
93 if (!rs)
94 _rs_init(rnd, sizeof(rnd));
95 else
96 _rs_rekey(rnd, sizeof(rnd));
97 explicit_bzero(rnd, sizeof(rnd)); /* discard source seed */
98
99 /* invalidate rs_buf */
100 rs->rs_have = 0;
101 memset(rsx->rs_buf, 0, sizeof(rsx->rs_buf));
102
103 rs->rs_count = 1600000;
104}
105
106static inline void
107_rs_stir_if_needed(size_t len)
108{
109 _rs_forkdetect();
110 if (!rs || rs->rs_count <= len)
111 _rs_stir();
112 if (rs->rs_count <= len)
113 rs->rs_count = 0;
114 else
115 rs->rs_count -= len;
116}
117
118static inline void
119_rs_rekey(u_char *dat, size_t datlen)
120{
121#ifndef KEYSTREAM_ONLY
122 memset(rsx->rs_buf, 0, sizeof(rsx->rs_buf));
123#endif
124 /* fill rs_buf with the keystream */
125 chacha_encrypt_bytes(&rsx->rs_chacha, rsx->rs_buf,
126 rsx->rs_buf, sizeof(rsx->rs_buf));
127 /* mix in optional user provided data */
128 if (dat) {
129 size_t i, m;
130
131 m = minimum(datlen, KEYSZ + IVSZ);
132 for (i = 0; i < m; i++)
133 rsx->rs_buf[i] ^= dat[i];
134 }
135 /* immediately reinit for backtracking resistance */
136 _rs_init(rsx->rs_buf, KEYSZ + IVSZ);
137 memset(rsx->rs_buf, 0, KEYSZ + IVSZ);
138 rs->rs_have = sizeof(rsx->rs_buf) - KEYSZ - IVSZ;
139}
140
141static inline void
142_rs_random_buf(void *_buf, size_t n)
143{
144 u_char *buf = (u_char *)_buf;
145 u_char *keystream;
146 size_t m;
147
148 _rs_stir_if_needed(n);
149 while (n > 0) {
150 if (rs->rs_have > 0) {
151 m = minimum(n, rs->rs_have);
152 keystream = rsx->rs_buf + sizeof(rsx->rs_buf)
153 - rs->rs_have;
154 memcpy(buf, keystream, m);
155 memset(keystream, 0, m);
156 buf += m;
157 n -= m;
158 rs->rs_have -= m;
159 }
160 if (rs->rs_have == 0)
161 _rs_rekey(NULL, 0);
162 }
163}
164
165static inline void
166_rs_random_u32(uint32_t *val)
167{
168 u_char *keystream;
169
170 _rs_stir_if_needed(sizeof(*val));
171 if (rs->rs_have < sizeof(*val))
172 _rs_rekey(NULL, 0);
173 keystream = rsx->rs_buf + sizeof(rsx->rs_buf) - rs->rs_have;
174 memcpy(val, keystream, sizeof(*val));
175 memset(keystream, 0, sizeof(*val));
176 rs->rs_have -= sizeof(*val);
177}
178
179uint32_t
180arc4random(void)
181{
182 uint32_t val;
183
184 _ARC4_LOCK();
185 _rs_random_u32(&val);
186 _ARC4_UNLOCK();
187 return val;
188}
189DEF_WEAK(arc4random);
190
191void
192arc4random_buf(void *buf, size_t n)
193{
194 _ARC4_LOCK();
195 _rs_random_buf(buf, n);
196 _ARC4_UNLOCK();
197}
198DEF_WEAK(arc4random_buf);
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