1 /* 2 * AMD Cryptographic Coprocessor (CCP) SHA crypto API support 3 * 4 * Copyright (C) 2013 Advanced Micro Devices, Inc. 5 * 6 * Author: Tom Lendacky <thomas.lendacky@amd.com> 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 version 2 as 10 * published by the Free Software Foundation. 11 */ 12 13 #include <linux/module.h> 14 #include <linux/sched.h> 15 #include <linux/delay.h> 16 #include <linux/scatterlist.h> 17 #include <linux/crypto.h> 18 #include <crypto/algapi.h> 19 #include <crypto/hash.h> 20 #include <crypto/internal/hash.h> 21 #include <crypto/sha.h> 22 #include <crypto/scatterwalk.h> 23 24 #include "ccp-crypto.h" 25 26 static int ccp_sha_complete(struct crypto_async_request *async_req, int ret) 27 { 28 struct ahash_request *req = ahash_request_cast(async_req); 29 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 30 struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req); 31 unsigned int digest_size = crypto_ahash_digestsize(tfm); 32 33 if (ret) 34 goto e_free; 35 36 if (rctx->hash_rem) { 37 /* Save remaining data to buffer */ 38 unsigned int offset = rctx->nbytes - rctx->hash_rem; 39 40 scatterwalk_map_and_copy(rctx->buf, rctx->src, 41 offset, rctx->hash_rem, 0); 42 rctx->buf_count = rctx->hash_rem; 43 } else { 44 rctx->buf_count = 0; 45 } 46 47 /* Update result area if supplied */ 48 if (req->result) 49 memcpy(req->result, rctx->ctx, digest_size); 50 51 e_free: 52 sg_free_table(&rctx->data_sg); 53 54 return ret; 55 } 56 57 static int ccp_do_sha_update(struct ahash_request *req, unsigned int nbytes, 58 unsigned int final) 59 { 60 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 61 struct ccp_ctx *ctx = crypto_ahash_ctx(tfm); 62 struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req); 63 struct scatterlist *sg; 64 unsigned int block_size = 65 crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm)); 66 unsigned int sg_count; 67 gfp_t gfp; 68 u64 len; 69 int ret; 70 71 len = (u64)rctx->buf_count + (u64)nbytes; 72 73 if (!final && (len <= block_size)) { 74 scatterwalk_map_and_copy(rctx->buf + rctx->buf_count, req->src, 75 0, nbytes, 0); 76 rctx->buf_count += nbytes; 77 78 return 0; 79 } 80 81 rctx->src = req->src; 82 rctx->nbytes = nbytes; 83 84 rctx->final = final; 85 rctx->hash_rem = final ? 0 : len & (block_size - 1); 86 rctx->hash_cnt = len - rctx->hash_rem; 87 if (!final && !rctx->hash_rem) { 88 /* CCP can't do zero length final, so keep some data around */ 89 rctx->hash_cnt -= block_size; 90 rctx->hash_rem = block_size; 91 } 92 93 /* Initialize the context scatterlist */ 94 sg_init_one(&rctx->ctx_sg, rctx->ctx, sizeof(rctx->ctx)); 95 96 sg = NULL; 97 if (rctx->buf_count && nbytes) { 98 /* Build the data scatterlist table - allocate enough entries 99 * for both data pieces (buffer and input data) 100 */ 101 gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? 102 GFP_KERNEL : GFP_ATOMIC; 103 sg_count = sg_nents(req->src) + 1; 104 ret = sg_alloc_table(&rctx->data_sg, sg_count, gfp); 105 if (ret) 106 return ret; 107 108 sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count); 109 sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->buf_sg); 110 sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src); 111 sg_mark_end(sg); 112 113 sg = rctx->data_sg.sgl; 114 } else if (rctx->buf_count) { 115 sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count); 116 117 sg = &rctx->buf_sg; 118 } else if (nbytes) { 119 sg = req->src; 120 } 121 122 rctx->msg_bits += (rctx->hash_cnt << 3); /* Total in bits */ 123 124 memset(&rctx->cmd, 0, sizeof(rctx->cmd)); 125 INIT_LIST_HEAD(&rctx->cmd.entry); 126 rctx->cmd.engine = CCP_ENGINE_SHA; 127 rctx->cmd.u.sha.type = rctx->type; 128 rctx->cmd.u.sha.ctx = &rctx->ctx_sg; 129 rctx->cmd.u.sha.ctx_len = sizeof(rctx->ctx); 130 rctx->cmd.u.sha.src = sg; 131 rctx->cmd.u.sha.src_len = rctx->hash_cnt; 132 rctx->cmd.u.sha.opad = ctx->u.sha.key_len ? 133 &ctx->u.sha.opad_sg : NULL; 134 rctx->cmd.u.sha.opad_len = ctx->u.sha.key_len ? 135 ctx->u.sha.opad_count : 0; 136 rctx->cmd.u.sha.first = rctx->first; 137 rctx->cmd.u.sha.final = rctx->final; 138 rctx->cmd.u.sha.msg_bits = rctx->msg_bits; 139 140 rctx->first = 0; 141 142 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd); 143 144 return ret; 145 } 146 147 static int ccp_sha_init(struct ahash_request *req) 148 { 149 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 150 struct ccp_ctx *ctx = crypto_ahash_ctx(tfm); 151 struct ccp_sha_req_ctx *rctx = ahash_request_ctx(req); 152 struct ccp_crypto_ahash_alg *alg = 153 ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm)); 154 unsigned int block_size = 155 crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm)); 156 157 memset(rctx, 0, sizeof(*rctx)); 158 159 rctx->type = alg->type; 160 rctx->first = 1; 161 162 if (ctx->u.sha.key_len) { 163 /* Buffer the HMAC key for first update */ 164 memcpy(rctx->buf, ctx->u.sha.ipad, block_size); 165 rctx->buf_count = block_size; 166 } 167 168 return 0; 169 } 170 171 static int ccp_sha_update(struct ahash_request *req) 172 { 173 return ccp_do_sha_update(req, req->nbytes, 0); 174 } 175 176 static int ccp_sha_final(struct ahash_request *req) 177 { 178 return ccp_do_sha_update(req, 0, 1); 179 } 180 181 static int ccp_sha_finup(struct ahash_request *req) 182 { 183 return ccp_do_sha_update(req, req->nbytes, 1); 184 } 185 186 static int ccp_sha_digest(struct ahash_request *req) 187 { 188 int ret; 189 190 ret = ccp_sha_init(req); 191 if (ret) 192 return ret; 193 194 return ccp_sha_finup(req); 195 } 196 197 static int ccp_sha_setkey(struct crypto_ahash *tfm, const u8 *key, 198 unsigned int key_len) 199 { 200 struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm)); 201 struct crypto_shash *shash = ctx->u.sha.hmac_tfm; 202 203 SHASH_DESC_ON_STACK(sdesc, shash); 204 205 unsigned int block_size = crypto_shash_blocksize(shash); 206 unsigned int digest_size = crypto_shash_digestsize(shash); 207 int i, ret; 208 209 /* Set to zero until complete */ 210 ctx->u.sha.key_len = 0; 211 212 /* Clear key area to provide zero padding for keys smaller 213 * than the block size 214 */ 215 memset(ctx->u.sha.key, 0, sizeof(ctx->u.sha.key)); 216 217 if (key_len > block_size) { 218 /* Must hash the input key */ 219 sdesc->tfm = shash; 220 sdesc->flags = crypto_ahash_get_flags(tfm) & 221 CRYPTO_TFM_REQ_MAY_SLEEP; 222 223 ret = crypto_shash_digest(sdesc, key, key_len, 224 ctx->u.sha.key); 225 if (ret) { 226 crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 227 return -EINVAL; 228 } 229 230 key_len = digest_size; 231 } else { 232 memcpy(ctx->u.sha.key, key, key_len); 233 } 234 235 for (i = 0; i < block_size; i++) { 236 ctx->u.sha.ipad[i] = ctx->u.sha.key[i] ^ 0x36; 237 ctx->u.sha.opad[i] = ctx->u.sha.key[i] ^ 0x5c; 238 } 239 240 sg_init_one(&ctx->u.sha.opad_sg, ctx->u.sha.opad, block_size); 241 ctx->u.sha.opad_count = block_size; 242 243 ctx->u.sha.key_len = key_len; 244 245 return 0; 246 } 247 248 static int ccp_sha_cra_init(struct crypto_tfm *tfm) 249 { 250 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); 251 struct crypto_ahash *ahash = __crypto_ahash_cast(tfm); 252 253 ctx->complete = ccp_sha_complete; 254 ctx->u.sha.key_len = 0; 255 256 crypto_ahash_set_reqsize(ahash, sizeof(struct ccp_sha_req_ctx)); 257 258 return 0; 259 } 260 261 static void ccp_sha_cra_exit(struct crypto_tfm *tfm) 262 { 263 } 264 265 static int ccp_hmac_sha_cra_init(struct crypto_tfm *tfm) 266 { 267 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); 268 struct ccp_crypto_ahash_alg *alg = ccp_crypto_ahash_alg(tfm); 269 struct crypto_shash *hmac_tfm; 270 271 hmac_tfm = crypto_alloc_shash(alg->child_alg, 0, 0); 272 if (IS_ERR(hmac_tfm)) { 273 pr_warn("could not load driver %s need for HMAC support\n", 274 alg->child_alg); 275 return PTR_ERR(hmac_tfm); 276 } 277 278 ctx->u.sha.hmac_tfm = hmac_tfm; 279 280 return ccp_sha_cra_init(tfm); 281 } 282 283 static void ccp_hmac_sha_cra_exit(struct crypto_tfm *tfm) 284 { 285 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); 286 287 if (ctx->u.sha.hmac_tfm) 288 crypto_free_shash(ctx->u.sha.hmac_tfm); 289 290 ccp_sha_cra_exit(tfm); 291 } 292 293 struct ccp_sha_def { 294 const char *name; 295 const char *drv_name; 296 enum ccp_sha_type type; 297 u32 digest_size; 298 u32 block_size; 299 }; 300 301 static struct ccp_sha_def sha_algs[] = { 302 { 303 .name = "sha1", 304 .drv_name = "sha1-ccp", 305 .type = CCP_SHA_TYPE_1, 306 .digest_size = SHA1_DIGEST_SIZE, 307 .block_size = SHA1_BLOCK_SIZE, 308 }, 309 { 310 .name = "sha224", 311 .drv_name = "sha224-ccp", 312 .type = CCP_SHA_TYPE_224, 313 .digest_size = SHA224_DIGEST_SIZE, 314 .block_size = SHA224_BLOCK_SIZE, 315 }, 316 { 317 .name = "sha256", 318 .drv_name = "sha256-ccp", 319 .type = CCP_SHA_TYPE_256, 320 .digest_size = SHA256_DIGEST_SIZE, 321 .block_size = SHA256_BLOCK_SIZE, 322 }, 323 }; 324 325 static int ccp_register_hmac_alg(struct list_head *head, 326 const struct ccp_sha_def *def, 327 const struct ccp_crypto_ahash_alg *base_alg) 328 { 329 struct ccp_crypto_ahash_alg *ccp_alg; 330 struct ahash_alg *alg; 331 struct hash_alg_common *halg; 332 struct crypto_alg *base; 333 int ret; 334 335 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL); 336 if (!ccp_alg) 337 return -ENOMEM; 338 339 /* Copy the base algorithm and only change what's necessary */ 340 *ccp_alg = *base_alg; 341 INIT_LIST_HEAD(&ccp_alg->entry); 342 343 strncpy(ccp_alg->child_alg, def->name, CRYPTO_MAX_ALG_NAME); 344 345 alg = &ccp_alg->alg; 346 alg->setkey = ccp_sha_setkey; 347 348 halg = &alg->halg; 349 350 base = &halg->base; 351 snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "hmac(%s)", def->name); 352 snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "hmac-%s", 353 def->drv_name); 354 base->cra_init = ccp_hmac_sha_cra_init; 355 base->cra_exit = ccp_hmac_sha_cra_exit; 356 357 ret = crypto_register_ahash(alg); 358 if (ret) { 359 pr_err("%s ahash algorithm registration error (%d)\n", 360 base->cra_name, ret); 361 kfree(ccp_alg); 362 return ret; 363 } 364 365 list_add(&ccp_alg->entry, head); 366 367 return ret; 368 } 369 370 static int ccp_register_sha_alg(struct list_head *head, 371 const struct ccp_sha_def *def) 372 { 373 struct ccp_crypto_ahash_alg *ccp_alg; 374 struct ahash_alg *alg; 375 struct hash_alg_common *halg; 376 struct crypto_alg *base; 377 int ret; 378 379 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL); 380 if (!ccp_alg) 381 return -ENOMEM; 382 383 INIT_LIST_HEAD(&ccp_alg->entry); 384 385 ccp_alg->type = def->type; 386 387 alg = &ccp_alg->alg; 388 alg->init = ccp_sha_init; 389 alg->update = ccp_sha_update; 390 alg->final = ccp_sha_final; 391 alg->finup = ccp_sha_finup; 392 alg->digest = ccp_sha_digest; 393 394 halg = &alg->halg; 395 halg->digestsize = def->digest_size; 396 397 base = &halg->base; 398 snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name); 399 snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s", 400 def->drv_name); 401 base->cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC | 402 CRYPTO_ALG_KERN_DRIVER_ONLY | 403 CRYPTO_ALG_NEED_FALLBACK; 404 base->cra_blocksize = def->block_size; 405 base->cra_ctxsize = sizeof(struct ccp_ctx); 406 base->cra_priority = CCP_CRA_PRIORITY; 407 base->cra_type = &crypto_ahash_type; 408 base->cra_init = ccp_sha_cra_init; 409 base->cra_exit = ccp_sha_cra_exit; 410 base->cra_module = THIS_MODULE; 411 412 ret = crypto_register_ahash(alg); 413 if (ret) { 414 pr_err("%s ahash algorithm registration error (%d)\n", 415 base->cra_name, ret); 416 kfree(ccp_alg); 417 return ret; 418 } 419 420 list_add(&ccp_alg->entry, head); 421 422 ret = ccp_register_hmac_alg(head, def, ccp_alg); 423 424 return ret; 425 } 426 427 int ccp_register_sha_algs(struct list_head *head) 428 { 429 int i, ret; 430 431 for (i = 0; i < ARRAY_SIZE(sha_algs); i++) { 432 ret = ccp_register_sha_alg(head, &sha_algs[i]); 433 if (ret) 434 return ret; 435 } 436 437 return 0; 438 } 439