1 /*- 2 * Copyright (c) 2004 Mark R V Murray 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 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. 14 * 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. 25 * 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 #include "opt_cpu.h" 32 33 #ifdef PADLOCK_RNG 34 35 #include <sys/param.h> 36 #include <sys/time.h> 37 #include <sys/lock.h> 38 #include <sys/mutex.h> 39 #include <sys/selinfo.h> 40 #include <sys/systm.h> 41 42 #include <machine/pcb.h> 43 44 #include <dev/random/randomdev.h> 45 46 #define RANDOM_BLOCK_SIZE 256 47 #define CIPHER_BLOCK_SIZE 16 48 49 static void random_nehemiah_init(void); 50 static void random_nehemiah_deinit(void); 51 static int random_nehemiah_read(void *, int); 52 53 struct random_systat random_nehemiah = { 54 .ident = "Hardware, VIA Nehemiah", 55 .init = random_nehemiah_init, 56 .deinit = random_nehemiah_deinit, 57 .read = random_nehemiah_read, 58 .write = (random_write_func_t *)random_null_func, 59 .reseed = (random_reseed_func_t *)random_null_func, 60 .seeded = 1, 61 }; 62 63 union VIA_ACE_CW { 64 uint64_t raw; 65 struct { 66 u_int round_count : 4; 67 u_int algorithm_type : 3; 68 u_int key_generation_type : 1; 69 u_int intermediate : 1; 70 u_int decrypt : 1; 71 u_int key_size : 2; 72 u_int filler0 : 20; 73 u_int filler1 : 32; 74 u_int filler2 : 32; 75 u_int filler3 : 32; 76 } field; 77 }; 78 79 /* The extra 7 is to allow an 8-byte write on the last byte of the 80 * arrays. The ACE wants the AES data 16-byte/128-bit aligned, and 81 * it _always_ writes n*64 bits. The RNG does not care about alignment, 82 * and it always writes n*32 bits or n*64 bits. 83 */ 84 static uint8_t key[CIPHER_BLOCK_SIZE+7] __aligned(16); 85 static uint8_t iv[CIPHER_BLOCK_SIZE+7] __aligned(16); 86 static uint8_t in[RANDOM_BLOCK_SIZE+7] __aligned(16); 87 static uint8_t out[RANDOM_BLOCK_SIZE+7] __aligned(16); 88 89 static union VIA_ACE_CW acw __aligned(16); 90 91 static struct fpu_kern_ctx *fpu_ctx_save; 92 93 static struct mtx random_nehemiah_mtx; 94 95 /* ARGSUSED */ 96 static __inline size_t 97 VIA_RNG_store(void *buf) 98 { 99 #ifdef __GNUCLIKE_ASM 100 uint32_t retval = 0; 101 uint32_t rate = 0; 102 103 /* The .byte line is really VIA C3 "xstore" instruction */ 104 __asm __volatile( 105 "movl $0,%%edx \n\t" 106 ".byte 0x0f, 0xa7, 0xc0" 107 : "=a" (retval), "+d" (rate), "+D" (buf) 108 : 109 : "memory" 110 ); 111 if (rate == 0) 112 return (retval&0x1f); 113 #endif 114 return (0); 115 } 116 117 /* ARGSUSED */ 118 static __inline void 119 VIA_ACE_cbc(void *in, void *out, size_t count, void *key, union VIA_ACE_CW *cw, void *iv) 120 { 121 #ifdef __GNUCLIKE_ASM 122 /* The .byte line is really VIA C3 "xcrypt-cbc" instruction */ 123 __asm __volatile( 124 "pushf \n\t" 125 "popf \n\t" 126 "rep \n\t" 127 ".byte 0x0f, 0xa7, 0xc8" 128 : "+a" (iv), "+c" (count), "+D" (out), "+S" (in) 129 : "b" (key), "d" (cw) 130 : "cc", "memory" 131 ); 132 #endif 133 } 134 135 static void 136 random_nehemiah_init(void) 137 { 138 acw.raw = 0ULL; 139 acw.field.round_count = 12; 140 141 mtx_init(&random_nehemiah_mtx, "random nehemiah", NULL, MTX_DEF); 142 fpu_ctx_save = fpu_kern_alloc_ctx(FPU_KERN_NORMAL); 143 } 144 145 void 146 random_nehemiah_deinit(void) 147 { 148 149 fpu_kern_free_ctx(fpu_ctx_save); 150 mtx_destroy(&random_nehemiah_mtx); 151 } 152 153 static int 154 random_nehemiah_read(void *buf, int c) 155 { 156 int i, error; 157 size_t count, ret; 158 uint8_t *p; 159 160 mtx_lock(&random_nehemiah_mtx); 161 error = fpu_kern_enter(curthread, fpu_ctx_save, FPU_KERN_NORMAL); 162 if (error != 0) { 163 mtx_unlock(&random_nehemiah_mtx); 164 return (0); 165 } 166 167 /* Get a random AES key */ 168 count = 0; 169 p = key; 170 do { 171 ret = VIA_RNG_store(p); 172 p += ret; 173 count += ret; 174 } while (count < CIPHER_BLOCK_SIZE); 175 176 /* Get a random AES IV */ 177 count = 0; 178 p = iv; 179 do { 180 ret = VIA_RNG_store(p); 181 p += ret; 182 count += ret; 183 } while (count < CIPHER_BLOCK_SIZE); 184 185 /* Get a block of random bytes */ 186 count = 0; 187 p = in; 188 do { 189 ret = VIA_RNG_store(p); 190 p += ret; 191 count += ret; 192 } while (count < RANDOM_BLOCK_SIZE); 193 194 /* This is a Davies-Meyer hash of the most paranoid variety; the 195 * key, IV and the data are all read directly from the hardware RNG. 196 * All of these are used precisely once. 197 */ 198 VIA_ACE_cbc(in, out, RANDOM_BLOCK_SIZE/CIPHER_BLOCK_SIZE, 199 key, &acw, iv); 200 for (i = 0; i < RANDOM_BLOCK_SIZE; i++) 201 out[i] ^= in[i]; 202 203 c = MIN(RANDOM_BLOCK_SIZE, c); 204 memcpy(buf, out, (size_t)c); 205 206 fpu_kern_leave(curthread, fpu_ctx_save); 207 mtx_unlock(&random_nehemiah_mtx); 208 return (c); 209 } 210 211 #endif 212