1 /* 2 * Cryptographic API. 3 * 4 * Support for VIA PadLock hardware crypto engine. 5 * 6 * Copyright (c) 2006 Michal Ludvig <michal@logix.cz> 7 * 8 * This program is free software; you can redistribute it and/or modify 9 * it under the terms of the GNU General Public License as published by 10 * the Free Software Foundation; either version 2 of the License, or 11 * (at your option) any later version. 12 * 13 */ 14 15 #include <crypto/algapi.h> 16 #include <linux/err.h> 17 #include <linux/module.h> 18 #include <linux/init.h> 19 #include <linux/errno.h> 20 #include <linux/cryptohash.h> 21 #include <linux/interrupt.h> 22 #include <linux/kernel.h> 23 #include <linux/scatterlist.h> 24 #include "padlock.h" 25 26 #define SHA1_DEFAULT_FALLBACK "sha1-generic" 27 #define SHA1_DIGEST_SIZE 20 28 #define SHA1_HMAC_BLOCK_SIZE 64 29 30 #define SHA256_DEFAULT_FALLBACK "sha256-generic" 31 #define SHA256_DIGEST_SIZE 32 32 #define SHA256_HMAC_BLOCK_SIZE 64 33 34 struct padlock_sha_ctx { 35 char *data; 36 size_t used; 37 int bypass; 38 void (*f_sha_padlock)(const char *in, char *out, int count); 39 struct hash_desc fallback; 40 }; 41 42 static inline struct padlock_sha_ctx *ctx(struct crypto_tfm *tfm) 43 { 44 return crypto_tfm_ctx(tfm); 45 } 46 47 /* We'll need aligned address on the stack */ 48 #define NEAREST_ALIGNED(ptr) \ 49 ((void *)ALIGN((size_t)(ptr), PADLOCK_ALIGNMENT)) 50 51 static struct crypto_alg sha1_alg, sha256_alg; 52 53 static void padlock_sha_bypass(struct crypto_tfm *tfm) 54 { 55 if (ctx(tfm)->bypass) 56 return; 57 58 crypto_hash_init(&ctx(tfm)->fallback); 59 if (ctx(tfm)->data && ctx(tfm)->used) { 60 struct scatterlist sg; 61 62 sg_set_buf(&sg, ctx(tfm)->data, ctx(tfm)->used); 63 crypto_hash_update(&ctx(tfm)->fallback, &sg, sg.length); 64 } 65 66 ctx(tfm)->used = 0; 67 ctx(tfm)->bypass = 1; 68 } 69 70 static void padlock_sha_init(struct crypto_tfm *tfm) 71 { 72 ctx(tfm)->used = 0; 73 ctx(tfm)->bypass = 0; 74 } 75 76 static void padlock_sha_update(struct crypto_tfm *tfm, 77 const uint8_t *data, unsigned int length) 78 { 79 /* Our buffer is always one page. */ 80 if (unlikely(!ctx(tfm)->bypass && 81 (ctx(tfm)->used + length > PAGE_SIZE))) 82 padlock_sha_bypass(tfm); 83 84 if (unlikely(ctx(tfm)->bypass)) { 85 struct scatterlist sg; 86 sg_set_buf(&sg, (uint8_t *)data, length); 87 crypto_hash_update(&ctx(tfm)->fallback, &sg, length); 88 return; 89 } 90 91 memcpy(ctx(tfm)->data + ctx(tfm)->used, data, length); 92 ctx(tfm)->used += length; 93 } 94 95 static inline void padlock_output_block(uint32_t *src, 96 uint32_t *dst, size_t count) 97 { 98 while (count--) 99 *dst++ = swab32(*src++); 100 } 101 102 static void padlock_do_sha1(const char *in, char *out, int count) 103 { 104 /* We can't store directly to *out as it may be unaligned. */ 105 /* BTW Don't reduce the buffer size below 128 Bytes! 106 * PadLock microcode needs it that big. */ 107 char buf[128+16]; 108 char *result = NEAREST_ALIGNED(buf); 109 110 ((uint32_t *)result)[0] = 0x67452301; 111 ((uint32_t *)result)[1] = 0xEFCDAB89; 112 ((uint32_t *)result)[2] = 0x98BADCFE; 113 ((uint32_t *)result)[3] = 0x10325476; 114 ((uint32_t *)result)[4] = 0xC3D2E1F0; 115 116 asm volatile (".byte 0xf3,0x0f,0xa6,0xc8" /* rep xsha1 */ 117 : "+S"(in), "+D"(result) 118 : "c"(count), "a"(0)); 119 120 padlock_output_block((uint32_t *)result, (uint32_t *)out, 5); 121 } 122 123 static void padlock_do_sha256(const char *in, char *out, int count) 124 { 125 /* We can't store directly to *out as it may be unaligned. */ 126 /* BTW Don't reduce the buffer size below 128 Bytes! 127 * PadLock microcode needs it that big. */ 128 char buf[128+16]; 129 char *result = NEAREST_ALIGNED(buf); 130 131 ((uint32_t *)result)[0] = 0x6A09E667; 132 ((uint32_t *)result)[1] = 0xBB67AE85; 133 ((uint32_t *)result)[2] = 0x3C6EF372; 134 ((uint32_t *)result)[3] = 0xA54FF53A; 135 ((uint32_t *)result)[4] = 0x510E527F; 136 ((uint32_t *)result)[5] = 0x9B05688C; 137 ((uint32_t *)result)[6] = 0x1F83D9AB; 138 ((uint32_t *)result)[7] = 0x5BE0CD19; 139 140 asm volatile (".byte 0xf3,0x0f,0xa6,0xd0" /* rep xsha256 */ 141 : "+S"(in), "+D"(result) 142 : "c"(count), "a"(0)); 143 144 padlock_output_block((uint32_t *)result, (uint32_t *)out, 8); 145 } 146 147 static void padlock_sha_final(struct crypto_tfm *tfm, uint8_t *out) 148 { 149 if (unlikely(ctx(tfm)->bypass)) { 150 crypto_hash_final(&ctx(tfm)->fallback, out); 151 ctx(tfm)->bypass = 0; 152 return; 153 } 154 155 /* Pass the input buffer to PadLock microcode... */ 156 ctx(tfm)->f_sha_padlock(ctx(tfm)->data, out, ctx(tfm)->used); 157 158 ctx(tfm)->used = 0; 159 } 160 161 static int padlock_cra_init(struct crypto_tfm *tfm) 162 { 163 const char *fallback_driver_name = tfm->__crt_alg->cra_name; 164 struct crypto_hash *fallback_tfm; 165 166 /* For now we'll allocate one page. This 167 * could eventually be configurable one day. */ 168 ctx(tfm)->data = (char *)__get_free_page(GFP_KERNEL); 169 if (!ctx(tfm)->data) 170 return -ENOMEM; 171 172 /* Allocate a fallback and abort if it failed. */ 173 fallback_tfm = crypto_alloc_hash(fallback_driver_name, 0, 174 CRYPTO_ALG_ASYNC | 175 CRYPTO_ALG_NEED_FALLBACK); 176 if (IS_ERR(fallback_tfm)) { 177 printk(KERN_WARNING PFX "Fallback driver '%s' could not be loaded!\n", 178 fallback_driver_name); 179 free_page((unsigned long)(ctx(tfm)->data)); 180 return PTR_ERR(fallback_tfm); 181 } 182 183 ctx(tfm)->fallback.tfm = fallback_tfm; 184 return 0; 185 } 186 187 static int padlock_sha1_cra_init(struct crypto_tfm *tfm) 188 { 189 ctx(tfm)->f_sha_padlock = padlock_do_sha1; 190 191 return padlock_cra_init(tfm); 192 } 193 194 static int padlock_sha256_cra_init(struct crypto_tfm *tfm) 195 { 196 ctx(tfm)->f_sha_padlock = padlock_do_sha256; 197 198 return padlock_cra_init(tfm); 199 } 200 201 static void padlock_cra_exit(struct crypto_tfm *tfm) 202 { 203 if (ctx(tfm)->data) { 204 free_page((unsigned long)(ctx(tfm)->data)); 205 ctx(tfm)->data = NULL; 206 } 207 208 crypto_free_hash(ctx(tfm)->fallback.tfm); 209 ctx(tfm)->fallback.tfm = NULL; 210 } 211 212 static struct crypto_alg sha1_alg = { 213 .cra_name = "sha1", 214 .cra_driver_name = "sha1-padlock", 215 .cra_priority = PADLOCK_CRA_PRIORITY, 216 .cra_flags = CRYPTO_ALG_TYPE_DIGEST | 217 CRYPTO_ALG_NEED_FALLBACK, 218 .cra_blocksize = SHA1_HMAC_BLOCK_SIZE, 219 .cra_ctxsize = sizeof(struct padlock_sha_ctx), 220 .cra_module = THIS_MODULE, 221 .cra_list = LIST_HEAD_INIT(sha1_alg.cra_list), 222 .cra_init = padlock_sha1_cra_init, 223 .cra_exit = padlock_cra_exit, 224 .cra_u = { 225 .digest = { 226 .dia_digestsize = SHA1_DIGEST_SIZE, 227 .dia_init = padlock_sha_init, 228 .dia_update = padlock_sha_update, 229 .dia_final = padlock_sha_final, 230 } 231 } 232 }; 233 234 static struct crypto_alg sha256_alg = { 235 .cra_name = "sha256", 236 .cra_driver_name = "sha256-padlock", 237 .cra_priority = PADLOCK_CRA_PRIORITY, 238 .cra_flags = CRYPTO_ALG_TYPE_DIGEST | 239 CRYPTO_ALG_NEED_FALLBACK, 240 .cra_blocksize = SHA256_HMAC_BLOCK_SIZE, 241 .cra_ctxsize = sizeof(struct padlock_sha_ctx), 242 .cra_module = THIS_MODULE, 243 .cra_list = LIST_HEAD_INIT(sha256_alg.cra_list), 244 .cra_init = padlock_sha256_cra_init, 245 .cra_exit = padlock_cra_exit, 246 .cra_u = { 247 .digest = { 248 .dia_digestsize = SHA256_DIGEST_SIZE, 249 .dia_init = padlock_sha_init, 250 .dia_update = padlock_sha_update, 251 .dia_final = padlock_sha_final, 252 } 253 } 254 }; 255 256 static void __init padlock_sha_check_fallbacks(void) 257 { 258 if (!crypto_has_hash("sha1", 0, CRYPTO_ALG_ASYNC | 259 CRYPTO_ALG_NEED_FALLBACK)) 260 printk(KERN_WARNING PFX 261 "Couldn't load fallback module for sha1.\n"); 262 263 if (!crypto_has_hash("sha256", 0, CRYPTO_ALG_ASYNC | 264 CRYPTO_ALG_NEED_FALLBACK)) 265 printk(KERN_WARNING PFX 266 "Couldn't load fallback module for sha256.\n"); 267 } 268 269 static int __init padlock_init(void) 270 { 271 int rc = -ENODEV; 272 273 if (!cpu_has_phe) { 274 printk(KERN_ERR PFX "VIA PadLock Hash Engine not detected.\n"); 275 return -ENODEV; 276 } 277 278 if (!cpu_has_phe_enabled) { 279 printk(KERN_ERR PFX "VIA PadLock detected, but not enabled. Hmm, strange...\n"); 280 return -ENODEV; 281 } 282 283 padlock_sha_check_fallbacks(); 284 285 rc = crypto_register_alg(&sha1_alg); 286 if (rc) 287 goto out; 288 289 rc = crypto_register_alg(&sha256_alg); 290 if (rc) 291 goto out_unreg1; 292 293 printk(KERN_NOTICE PFX "Using VIA PadLock ACE for SHA1/SHA256 algorithms.\n"); 294 295 return 0; 296 297 out_unreg1: 298 crypto_unregister_alg(&sha1_alg); 299 out: 300 printk(KERN_ERR PFX "VIA PadLock SHA1/SHA256 initialization failed.\n"); 301 return rc; 302 } 303 304 static void __exit padlock_fini(void) 305 { 306 crypto_unregister_alg(&sha1_alg); 307 crypto_unregister_alg(&sha256_alg); 308 } 309 310 module_init(padlock_init); 311 module_exit(padlock_fini); 312 313 MODULE_DESCRIPTION("VIA PadLock SHA1/SHA256 algorithms support."); 314 MODULE_LICENSE("GPL"); 315 MODULE_AUTHOR("Michal Ludvig"); 316 317 MODULE_ALIAS("sha1-padlock"); 318 MODULE_ALIAS("sha256-padlock"); 319