2 * Copyright (c) 2004 Mark R V Murray
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
31 #include <sys/param.h>
34 #include <sys/mutex.h>
35 #include <sys/selinfo.h>
36 #include <sys/systm.h>
38 #include <machine/pcb.h>
40 #include <dev/random/randomdev.h>
42 #define RANDOM_BLOCK_SIZE 256
43 #define CIPHER_BLOCK_SIZE 16
45 static void random_nehemiah_init(void);
46 static void random_nehemiah_deinit(void);
47 static int random_nehemiah_read(void *, int);
49 struct random_systat random_nehemiah = {
50 .ident = "Hardware, VIA Nehemiah",
51 .init = random_nehemiah_init,
52 .deinit = random_nehemiah_deinit,
53 .read = random_nehemiah_read,
54 .write = (random_write_func_t *)random_null_func,
55 .reseed = (random_reseed_func_t *)random_null_func,
62 u_int round_count : 4;
63 u_int algorithm_type : 3;
64 u_int key_generation_type : 1;
65 u_int intermediate : 1;
75 /* The extra 7 is to allow an 8-byte write on the last byte of the
76 * arrays. The ACE wants the AES data 16-byte/128-bit aligned, and
77 * it _always_ writes n*64 bits. The RNG does not care about alignment,
78 * and it always writes n*32 bits or n*64 bits.
80 static uint8_t key[CIPHER_BLOCK_SIZE+7] __aligned(16);
81 static uint8_t iv[CIPHER_BLOCK_SIZE+7] __aligned(16);
82 static uint8_t in[RANDOM_BLOCK_SIZE+7] __aligned(16);
83 static uint8_t out[RANDOM_BLOCK_SIZE+7] __aligned(16);
85 static union VIA_ACE_CW acw __aligned(16);
87 static struct fpu_kern_ctx fpu_ctx_save;
89 static struct mtx random_nehemiah_mtx;
92 static __inline size_t
93 VIA_RNG_store(void *buf)
99 /* The .byte line is really VIA C3 "xstore" instruction */
102 ".byte 0x0f, 0xa7, 0xc0"
103 : "=a" (retval), "+d" (rate), "+D" (buf)
108 return (retval&0x1f);
115 VIA_ACE_cbc(void *in, void *out, size_t count, void *key, union VIA_ACE_CW *cw, void *iv)
117 #ifdef __GNUCLIKE_ASM
118 /* The .byte line is really VIA C3 "xcrypt-cbc" instruction */
123 ".byte 0x0f, 0xa7, 0xc8"
124 : "+a" (iv), "+c" (count), "+D" (out), "+S" (in)
125 : "b" (key), "d" (cw)
132 random_nehemiah_init(void)
135 acw.field.round_count = 12;
137 mtx_init(&random_nehemiah_mtx, "random nehemiah", NULL, MTX_DEF);
141 random_nehemiah_deinit(void)
143 mtx_destroy(&random_nehemiah_mtx);
147 random_nehemiah_read(void *buf, int c)
153 mtx_lock(&random_nehemiah_mtx);
154 error = fpu_kern_enter(curthread, &fpu_ctx_save, FPU_KERN_NORMAL);
156 mtx_unlock(&random_nehemiah_mtx);
160 /* Get a random AES key */
164 ret = VIA_RNG_store(p);
167 } while (count < CIPHER_BLOCK_SIZE);
169 /* Get a random AES IV */
173 ret = VIA_RNG_store(p);
176 } while (count < CIPHER_BLOCK_SIZE);
178 /* Get a block of random bytes */
182 ret = VIA_RNG_store(p);
185 } while (count < RANDOM_BLOCK_SIZE);
187 /* This is a Davies-Meyer hash of the most paranoid variety; the
188 * key, IV and the data are all read directly from the hardware RNG.
189 * All of these are used precisely once.
191 VIA_ACE_cbc(in, out, RANDOM_BLOCK_SIZE/CIPHER_BLOCK_SIZE,
193 for (i = 0; i < RANDOM_BLOCK_SIZE; i++)
196 c = MIN(RANDOM_BLOCK_SIZE, c);
197 memcpy(buf, out, (size_t)c);
199 fpu_kern_leave(curthread, &fpu_ctx_save);
200 mtx_unlock(&random_nehemiah_mtx);