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 26static 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 52e_free: 53 sg_free_table(&rctx->data_sg); 54 55 return ret; 56} 57 58static 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 } 122 123 if (nbytes) 124 sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src); 125 126 if (need_pad) { 127 int pad_length = block_size - (len & (block_size - 1)); 128 129 rctx->hash_cnt += pad_length; 130 131 memset(rctx->pad, 0, sizeof(rctx->pad)); 132 rctx->pad[0] = 0x80; 133 sg_init_one(&rctx->pad_sg, rctx->pad, pad_length); 134 sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->pad_sg); 135 } 136 if (sg) { 137 sg_mark_end(sg); 138 sg = rctx->data_sg.sgl; 139 } 140 141 /* Initialize the K1/K2 scatterlist */ 142 if (final) 143 cmac_key_sg = (need_pad) ? &ctx->u.aes.k2_sg 144 : &ctx->u.aes.k1_sg; 145 146 memset(&rctx->cmd, 0, sizeof(rctx->cmd)); 147 INIT_LIST_HEAD(&rctx->cmd.entry); 148 rctx->cmd.engine = CCP_ENGINE_AES; 149 rctx->cmd.u.aes.type = ctx->u.aes.type; 150 rctx->cmd.u.aes.mode = ctx->u.aes.mode; 151 rctx->cmd.u.aes.action = CCP_AES_ACTION_ENCRYPT; 152 rctx->cmd.u.aes.key = &ctx->u.aes.key_sg; 153 rctx->cmd.u.aes.key_len = ctx->u.aes.key_len; 154 rctx->cmd.u.aes.iv = &rctx->iv_sg; 155 rctx->cmd.u.aes.iv_len = AES_BLOCK_SIZE; 156 rctx->cmd.u.aes.src = sg; 157 rctx->cmd.u.aes.src_len = rctx->hash_cnt; 158 rctx->cmd.u.aes.dst = NULL; 159 rctx->cmd.u.aes.cmac_key = cmac_key_sg; 160 rctx->cmd.u.aes.cmac_key_len = ctx->u.aes.kn_len; 161 rctx->cmd.u.aes.cmac_final = final; 162 163 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd); 164 165 return ret; 166} 167 168static int ccp_aes_cmac_init(struct ahash_request *req) 169{ 170 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req); 171 172 memset(rctx, 0, sizeof(*rctx)); 173 174 rctx->null_msg = 1; 175 176 return 0; 177} 178 179static int ccp_aes_cmac_update(struct ahash_request *req) 180{ 181 return ccp_do_cmac_update(req, req->nbytes, 0); 182} 183 184static int ccp_aes_cmac_final(struct ahash_request *req) 185{ 186 return ccp_do_cmac_update(req, 0, 1); 187} 188 189static int ccp_aes_cmac_finup(struct ahash_request *req) 190{ 191 return ccp_do_cmac_update(req, req->nbytes, 1); 192} 193 194static int ccp_aes_cmac_digest(struct ahash_request *req) 195{ 196 int ret; 197 198 ret = ccp_aes_cmac_init(req); 199 if (ret) 200 return ret; 201 202 return ccp_aes_cmac_finup(req); 203} 204 205static int ccp_aes_cmac_export(struct ahash_request *req, void *out) 206{ 207 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req); 208 struct ccp_aes_cmac_exp_ctx state; 209 210 /* Don't let anything leak to 'out' */ 211 memset(&state, 0, sizeof(state)); 212 213 state.null_msg = rctx->null_msg; 214 memcpy(state.iv, rctx->iv, sizeof(state.iv)); 215 state.buf_count = rctx->buf_count; 216 memcpy(state.buf, rctx->buf, sizeof(state.buf)); 217 218 /* 'out' may not be aligned so memcpy from local variable */ 219 memcpy(out, &state, sizeof(state)); 220 221 return 0; 222} 223 224static int ccp_aes_cmac_import(struct ahash_request *req, const void *in) 225{ 226 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx(req); 227 struct ccp_aes_cmac_exp_ctx state; 228 229 /* 'in' may not be aligned so memcpy to local variable */ 230 memcpy(&state, in, sizeof(state)); 231 232 memset(rctx, 0, sizeof(*rctx)); 233 rctx->null_msg = state.null_msg; 234 memcpy(rctx->iv, state.iv, sizeof(rctx->iv)); 235 rctx->buf_count = state.buf_count; 236 memcpy(rctx->buf, state.buf, sizeof(rctx->buf)); 237 238 return 0; 239} 240 241static int ccp_aes_cmac_setkey(struct crypto_ahash *tfm, const u8 *key, 242 unsigned int key_len) 243{ 244 struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm)); 245 struct ccp_crypto_ahash_alg *alg = 246 ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm)); 247 u64 k0_hi, k0_lo, k1_hi, k1_lo, k2_hi, k2_lo; 248 u64 rb_hi = 0x00, rb_lo = 0x87; 249 __be64 *gk; 250 int ret; 251 252 switch (key_len) { 253 case AES_KEYSIZE_128: 254 ctx->u.aes.type = CCP_AES_TYPE_128; 255 break; 256 case AES_KEYSIZE_192: 257 ctx->u.aes.type = CCP_AES_TYPE_192; 258 break; 259 case AES_KEYSIZE_256: 260 ctx->u.aes.type = CCP_AES_TYPE_256; 261 break; 262 default: 263 crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 264 return -EINVAL; 265 } 266 ctx->u.aes.mode = alg->mode; 267 268 /* Set to zero until complete */ 269 ctx->u.aes.key_len = 0; 270 271 /* Set the key for the AES cipher used to generate the keys */ 272 ret = crypto_cipher_setkey(ctx->u.aes.tfm_cipher, key, key_len); 273 if (ret) 274 return ret; 275 276 /* Encrypt a block of zeroes - use key area in context */ 277 memset(ctx->u.aes.key, 0, sizeof(ctx->u.aes.key)); 278 crypto_cipher_encrypt_one(ctx->u.aes.tfm_cipher, ctx->u.aes.key, 279 ctx->u.aes.key); 280 281 /* Generate K1 and K2 */ 282 k0_hi = be64_to_cpu(*((__be64 *)ctx->u.aes.key)); 283 k0_lo = be64_to_cpu(*((__be64 *)ctx->u.aes.key + 1)); 284 285 k1_hi = (k0_hi << 1) | (k0_lo >> 63); 286 k1_lo = k0_lo << 1; 287 if (ctx->u.aes.key[0] & 0x80) { 288 k1_hi ^= rb_hi; 289 k1_lo ^= rb_lo; 290 } 291 gk = (__be64 *)ctx->u.aes.k1; 292 *gk = cpu_to_be64(k1_hi); 293 gk++; 294 *gk = cpu_to_be64(k1_lo); 295 296 k2_hi = (k1_hi << 1) | (k1_lo >> 63); 297 k2_lo = k1_lo << 1; 298 if (ctx->u.aes.k1[0] & 0x80) { 299 k2_hi ^= rb_hi; 300 k2_lo ^= rb_lo; 301 } 302 gk = (__be64 *)ctx->u.aes.k2; 303 *gk = cpu_to_be64(k2_hi); 304 gk++; 305 *gk = cpu_to_be64(k2_lo); 306 307 ctx->u.aes.kn_len = sizeof(ctx->u.aes.k1); 308 sg_init_one(&ctx->u.aes.k1_sg, ctx->u.aes.k1, sizeof(ctx->u.aes.k1)); 309 sg_init_one(&ctx->u.aes.k2_sg, ctx->u.aes.k2, sizeof(ctx->u.aes.k2)); 310 311 /* Save the supplied key */ 312 memset(ctx->u.aes.key, 0, sizeof(ctx->u.aes.key)); 313 memcpy(ctx->u.aes.key, key, key_len); 314 ctx->u.aes.key_len = key_len; 315 sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len); 316 317 return ret; 318} 319 320static int ccp_aes_cmac_cra_init(struct crypto_tfm *tfm) 321{ 322 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); 323 struct crypto_ahash *ahash = __crypto_ahash_cast(tfm); 324 struct crypto_cipher *cipher_tfm; 325 326 ctx->complete = ccp_aes_cmac_complete; 327 ctx->u.aes.key_len = 0; 328 329 crypto_ahash_set_reqsize(ahash, sizeof(struct ccp_aes_cmac_req_ctx)); 330 331 cipher_tfm = crypto_alloc_cipher("aes", 0, 332 CRYPTO_ALG_ASYNC | 333 CRYPTO_ALG_NEED_FALLBACK); 334 if (IS_ERR(cipher_tfm)) { 335 pr_warn("could not load aes cipher driver\n"); 336 return PTR_ERR(cipher_tfm); 337 } 338 ctx->u.aes.tfm_cipher = cipher_tfm; 339 340 return 0; 341} 342 343static void ccp_aes_cmac_cra_exit(struct crypto_tfm *tfm) 344{ 345 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); 346 347 if (ctx->u.aes.tfm_cipher) 348 crypto_free_cipher(ctx->u.aes.tfm_cipher); 349 ctx->u.aes.tfm_cipher = NULL; 350} 351 352int ccp_register_aes_cmac_algs(struct list_head *head) 353{ 354 struct ccp_crypto_ahash_alg *ccp_alg; 355 struct ahash_alg *alg; 356 struct hash_alg_common *halg; 357 struct crypto_alg *base; 358 int ret; 359 360 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL); 361 if (!ccp_alg) 362 return -ENOMEM; 363 364 INIT_LIST_HEAD(&ccp_alg->entry); 365 ccp_alg->mode = CCP_AES_MODE_CMAC; 366 367 alg = &ccp_alg->alg; 368 alg->init = ccp_aes_cmac_init; 369 alg->update = ccp_aes_cmac_update; 370 alg->final = ccp_aes_cmac_final; 371 alg->finup = ccp_aes_cmac_finup; 372 alg->digest = ccp_aes_cmac_digest; 373 alg->export = ccp_aes_cmac_export; 374 alg->import = ccp_aes_cmac_import; 375 alg->setkey = ccp_aes_cmac_setkey; 376 377 halg = &alg->halg; 378 halg->digestsize = AES_BLOCK_SIZE; 379 halg->statesize = sizeof(struct ccp_aes_cmac_exp_ctx); 380 381 base = &halg->base; 382 snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "cmac(aes)"); 383 snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "cmac-aes-ccp"); 384 base->cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC | 385 CRYPTO_ALG_KERN_DRIVER_ONLY | 386 CRYPTO_ALG_NEED_FALLBACK; 387 base->cra_blocksize = AES_BLOCK_SIZE; 388 base->cra_ctxsize = sizeof(struct ccp_ctx); 389 base->cra_priority = CCP_CRA_PRIORITY; 390 base->cra_type = &crypto_ahash_type; 391 base->cra_init = ccp_aes_cmac_cra_init; 392 base->cra_exit = ccp_aes_cmac_cra_exit; 393 base->cra_module = THIS_MODULE; 394 395 ret = crypto_register_ahash(alg); 396 if (ret) { 397 pr_err("%s ahash algorithm registration error (%d)\n", 398 base->cra_name, ret); 399 kfree(ccp_alg); 400 return ret; 401 } 402 403 list_add(&ccp_alg->entry, head); 404 405 return 0; 406} 407