1 /* 2 * AMD Cryptographic Coprocessor (CCP) AES CMAC 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/aes.h> 20 #include <crypto/hash.h> 21 #include <crypto/internal/hash.h> 22 #include <crypto/scatterwalk.h> 23 24 #include "ccp-crypto.h" 25 26 static int ccp_aes_cmac_complete(struct crypto_async_request *async_req, 27 int ret) 28 { 29 struct ahash_request *req = ahash_request_cast(async_req); 30 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 31 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req); 32 unsigned int digest_size = crypto_ahash_digestsize(tfm); 33 34 if (ret) 35 goto e_free; 36 37 if (rctx->hash_rem) { 38 /* Save remaining data to buffer */ 39 unsigned int offset = rctx->nbytes - rctx->hash_rem; 40 41 scatterwalk_map_and_copy(rctx->buf, rctx->src, 42 offset, rctx->hash_rem, 0); 43 rctx->buf_count = rctx->hash_rem; 44 } else { 45 rctx->buf_count = 0; 46 } 47 48 /* Update result area if supplied */ 49 if (req->result) 50 memcpy(req->result, rctx->iv, digest_size); 51 52 e_free: 53 sg_free_table(&rctx->data_sg); 54 55 return ret; 56 } 57 58 static int ccp_do_cmac_update(struct ahash_request *req, unsigned int nbytes, 59 unsigned int final) 60 { 61 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 62 struct ccp_ctx *ctx = crypto_ahash_ctx(tfm); 63 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req); 64 struct scatterlist *sg, *cmac_key_sg = NULL; 65 unsigned int block_size = 66 crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm)); 67 unsigned int need_pad, sg_count; 68 gfp_t gfp; 69 u64 len; 70 int ret; 71 72 if (!ctx->u.aes.key_len) 73 return -EINVAL; 74 75 if (nbytes) 76 rctx->null_msg = 0; 77 78 len = (u64)rctx->buf_count + (u64)nbytes; 79 80 if (!final && (len <= block_size)) { 81 scatterwalk_map_and_copy(rctx->buf + rctx->buf_count, req->src, 82 0, nbytes, 0); 83 rctx->buf_count += nbytes; 84 85 return 0; 86 } 87 88 rctx->src = req->src; 89 rctx->nbytes = nbytes; 90 91 rctx->final = final; 92 rctx->hash_rem = final ? 0 : len & (block_size - 1); 93 rctx->hash_cnt = len - rctx->hash_rem; 94 if (!final && !rctx->hash_rem) { 95 /* CCP can't do zero length final, so keep some data around */ 96 rctx->hash_cnt -= block_size; 97 rctx->hash_rem = block_size; 98 } 99 100 if (final && (rctx->null_msg || (len & (block_size - 1)))) 101 need_pad = 1; 102 else 103 need_pad = 0; 104 105 sg_init_one(&rctx->iv_sg, rctx->iv, sizeof(rctx->iv)); 106 107 /* Build the data scatterlist table - allocate enough entries for all 108 * possible data pieces (buffer, input data, padding) 109 */ 110 sg_count = (nbytes) ? sg_nents(req->src) + 2 : 2; 111 gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? 112 GFP_KERNEL : GFP_ATOMIC; 113 ret = sg_alloc_table(&rctx->data_sg, sg_count, gfp); 114 if (ret) 115 return ret; 116 117 sg = NULL; 118 if (rctx->buf_count) { 119 sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count); 120 sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->buf_sg); 121 if (!sg) { 122 ret = -EINVAL; 123 goto e_free; 124 } 125 } 126 127 if (nbytes) { 128 sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src); 129 if (!sg) { 130 ret = -EINVAL; 131 goto e_free; 132 } 133 } 134 135 if (need_pad) { 136 int pad_length = block_size - (len & (block_size - 1)); 137 138 rctx->hash_cnt += pad_length; 139 140 memset(rctx->pad, 0, sizeof(rctx->pad)); 141 rctx->pad[0] = 0x80; 142 sg_init_one(&rctx->pad_sg, rctx->pad, pad_length); 143 sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->pad_sg); 144 if (!sg) { 145 ret = -EINVAL; 146 goto e_free; 147 } 148 } 149 if (sg) { 150 sg_mark_end(sg); 151 sg = rctx->data_sg.sgl; 152 } 153 154 /* Initialize the K1/K2 scatterlist */ 155 if (final) 156 cmac_key_sg = (need_pad) ? &ctx->u.aes.k2_sg 157 : &ctx->u.aes.k1_sg; 158 159 memset(&rctx->cmd, 0, sizeof(rctx->cmd)); 160 INIT_LIST_HEAD(&rctx->cmd.entry); 161 rctx->cmd.engine = CCP_ENGINE_AES; 162 rctx->cmd.u.aes.type = ctx->u.aes.type; 163 rctx->cmd.u.aes.mode = ctx->u.aes.mode; 164 rctx->cmd.u.aes.action = CCP_AES_ACTION_ENCRYPT; 165 rctx->cmd.u.aes.key = &ctx->u.aes.key_sg; 166 rctx->cmd.u.aes.key_len = ctx->u.aes.key_len; 167 rctx->cmd.u.aes.iv = &rctx->iv_sg; 168 rctx->cmd.u.aes.iv_len = AES_BLOCK_SIZE; 169 rctx->cmd.u.aes.src = sg; 170 rctx->cmd.u.aes.src_len = rctx->hash_cnt; 171 rctx->cmd.u.aes.dst = NULL; 172 rctx->cmd.u.aes.cmac_key = cmac_key_sg; 173 rctx->cmd.u.aes.cmac_key_len = ctx->u.aes.kn_len; 174 rctx->cmd.u.aes.cmac_final = final; 175 176 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd); 177 178 return ret; 179 180 e_free: 181 sg_free_table(&rctx->data_sg); 182 183 return ret; 184 } 185 186 static int ccp_aes_cmac_init(struct ahash_request *req) 187 { 188 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req); 189 190 memset(rctx, 0, sizeof(*rctx)); 191 192 rctx->null_msg = 1; 193 194 return 0; 195 } 196 197 static int ccp_aes_cmac_update(struct ahash_request *req) 198 { 199 return ccp_do_cmac_update(req, req->nbytes, 0); 200 } 201 202 static int ccp_aes_cmac_final(struct ahash_request *req) 203 { 204 return ccp_do_cmac_update(req, 0, 1); 205 } 206 207 static int ccp_aes_cmac_finup(struct ahash_request *req) 208 { 209 return ccp_do_cmac_update(req, req->nbytes, 1); 210 } 211 212 static int ccp_aes_cmac_digest(struct ahash_request *req) 213 { 214 int ret; 215 216 ret = ccp_aes_cmac_init(req); 217 if (ret) 218 return ret; 219 220 return ccp_aes_cmac_finup(req); 221 } 222 223 static int ccp_aes_cmac_export(struct ahash_request *req, void *out) 224 { 225 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req); 226 struct ccp_aes_cmac_exp_ctx state; 227 228 state.null_msg = rctx->null_msg; 229 memcpy(state.iv, rctx->iv, sizeof(state.iv)); 230 state.buf_count = rctx->buf_count; 231 memcpy(state.buf, rctx->buf, sizeof(state.buf)); 232 233 /* 'out' may not be aligned so memcpy from local variable */ 234 memcpy(out, &state, sizeof(state)); 235 236 return 0; 237 } 238 239 static int ccp_aes_cmac_import(struct ahash_request *req, const void *in) 240 { 241 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req); 242 struct ccp_aes_cmac_exp_ctx state; 243 244 /* 'in' may not be aligned so memcpy to local variable */ 245 memcpy(&state, in, sizeof(state)); 246 247 memset(rctx, 0, sizeof(*rctx)); 248 rctx->null_msg = state.null_msg; 249 memcpy(rctx->iv, state.iv, sizeof(rctx->iv)); 250 rctx->buf_count = state.buf_count; 251 memcpy(rctx->buf, state.buf, sizeof(rctx->buf)); 252 253 return 0; 254 } 255 256 static int ccp_aes_cmac_setkey(struct crypto_ahash *tfm, const u8 *key, 257 unsigned int key_len) 258 { 259 struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm)); 260 struct ccp_crypto_ahash_alg *alg = 261 ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm)); 262 u64 k0_hi, k0_lo, k1_hi, k1_lo, k2_hi, k2_lo; 263 u64 rb_hi = 0x00, rb_lo = 0x87; 264 __be64 *gk; 265 int ret; 266 267 switch (key_len) { 268 case AES_KEYSIZE_128: 269 ctx->u.aes.type = CCP_AES_TYPE_128; 270 break; 271 case AES_KEYSIZE_192: 272 ctx->u.aes.type = CCP_AES_TYPE_192; 273 break; 274 case AES_KEYSIZE_256: 275 ctx->u.aes.type = CCP_AES_TYPE_256; 276 break; 277 default: 278 crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 279 return -EINVAL; 280 } 281 ctx->u.aes.mode = alg->mode; 282 283 /* Set to zero until complete */ 284 ctx->u.aes.key_len = 0; 285 286 /* Set the key for the AES cipher used to generate the keys */ 287 ret = crypto_cipher_setkey(ctx->u.aes.tfm_cipher, key, key_len); 288 if (ret) 289 return ret; 290 291 /* Encrypt a block of zeroes - use key area in context */ 292 memset(ctx->u.aes.key, 0, sizeof(ctx->u.aes.key)); 293 crypto_cipher_encrypt_one(ctx->u.aes.tfm_cipher, ctx->u.aes.key, 294 ctx->u.aes.key); 295 296 /* Generate K1 and K2 */ 297 k0_hi = be64_to_cpu(*((__be64 *)ctx->u.aes.key)); 298 k0_lo = be64_to_cpu(*((__be64 *)ctx->u.aes.key + 1)); 299 300 k1_hi = (k0_hi << 1) | (k0_lo >> 63); 301 k1_lo = k0_lo << 1; 302 if (ctx->u.aes.key[0] & 0x80) { 303 k1_hi ^= rb_hi; 304 k1_lo ^= rb_lo; 305 } 306 gk = (__be64 *)ctx->u.aes.k1; 307 *gk = cpu_to_be64(k1_hi); 308 gk++; 309 *gk = cpu_to_be64(k1_lo); 310 311 k2_hi = (k1_hi << 1) | (k1_lo >> 63); 312 k2_lo = k1_lo << 1; 313 if (ctx->u.aes.k1[0] & 0x80) { 314 k2_hi ^= rb_hi; 315 k2_lo ^= rb_lo; 316 } 317 gk = (__be64 *)ctx->u.aes.k2; 318 *gk = cpu_to_be64(k2_hi); 319 gk++; 320 *gk = cpu_to_be64(k2_lo); 321 322 ctx->u.aes.kn_len = sizeof(ctx->u.aes.k1); 323 sg_init_one(&ctx->u.aes.k1_sg, ctx->u.aes.k1, sizeof(ctx->u.aes.k1)); 324 sg_init_one(&ctx->u.aes.k2_sg, ctx->u.aes.k2, sizeof(ctx->u.aes.k2)); 325 326 /* Save the supplied key */ 327 memset(ctx->u.aes.key, 0, sizeof(ctx->u.aes.key)); 328 memcpy(ctx->u.aes.key, key, key_len); 329 ctx->u.aes.key_len = key_len; 330 sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len); 331 332 return ret; 333 } 334 335 static int ccp_aes_cmac_cra_init(struct crypto_tfm *tfm) 336 { 337 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); 338 struct crypto_ahash *ahash = __crypto_ahash_cast(tfm); 339 struct crypto_cipher *cipher_tfm; 340 341 ctx->complete = ccp_aes_cmac_complete; 342 ctx->u.aes.key_len = 0; 343 344 crypto_ahash_set_reqsize(ahash, sizeof(struct ccp_aes_cmac_req_ctx)); 345 346 cipher_tfm = crypto_alloc_cipher("aes", 0, 347 CRYPTO_ALG_ASYNC | 348 CRYPTO_ALG_NEED_FALLBACK); 349 if (IS_ERR(cipher_tfm)) { 350 pr_warn("could not load aes cipher driver\n"); 351 return PTR_ERR(cipher_tfm); 352 } 353 ctx->u.aes.tfm_cipher = cipher_tfm; 354 355 return 0; 356 } 357 358 static void ccp_aes_cmac_cra_exit(struct crypto_tfm *tfm) 359 { 360 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); 361 362 if (ctx->u.aes.tfm_cipher) 363 crypto_free_cipher(ctx->u.aes.tfm_cipher); 364 ctx->u.aes.tfm_cipher = NULL; 365 } 366 367 int ccp_register_aes_cmac_algs(struct list_head *head) 368 { 369 struct ccp_crypto_ahash_alg *ccp_alg; 370 struct ahash_alg *alg; 371 struct hash_alg_common *halg; 372 struct crypto_alg *base; 373 int ret; 374 375 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL); 376 if (!ccp_alg) 377 return -ENOMEM; 378 379 INIT_LIST_HEAD(&ccp_alg->entry); 380 ccp_alg->mode = CCP_AES_MODE_CMAC; 381 382 alg = &ccp_alg->alg; 383 alg->init = ccp_aes_cmac_init; 384 alg->update = ccp_aes_cmac_update; 385 alg->final = ccp_aes_cmac_final; 386 alg->finup = ccp_aes_cmac_finup; 387 alg->digest = ccp_aes_cmac_digest; 388 alg->export = ccp_aes_cmac_export; 389 alg->import = ccp_aes_cmac_import; 390 alg->setkey = ccp_aes_cmac_setkey; 391 392 halg = &alg->halg; 393 halg->digestsize = AES_BLOCK_SIZE; 394 halg->statesize = sizeof(struct ccp_aes_cmac_exp_ctx); 395 396 base = &halg->base; 397 snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "cmac(aes)"); 398 snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "cmac-aes-ccp"); 399 base->cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC | 400 CRYPTO_ALG_KERN_DRIVER_ONLY | 401 CRYPTO_ALG_NEED_FALLBACK; 402 base->cra_blocksize = AES_BLOCK_SIZE; 403 base->cra_ctxsize = sizeof(struct ccp_ctx); 404 base->cra_priority = CCP_CRA_PRIORITY; 405 base->cra_type = &crypto_ahash_type; 406 base->cra_init = ccp_aes_cmac_cra_init; 407 base->cra_exit = ccp_aes_cmac_cra_exit; 408 base->cra_module = THIS_MODULE; 409 410 ret = crypto_register_ahash(alg); 411 if (ret) { 412 pr_err("%s ahash algorithm registration error (%d)\n", 413 base->cra_name, ret); 414 kfree(ccp_alg); 415 return ret; 416 } 417 418 list_add(&ccp_alg->entry, head); 419 420 return 0; 421 } 422