1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AMD Cryptographic Coprocessor (CCP) AES CMAC crypto API support 4 * 5 * Copyright (C) 2013,2018 Advanced Micro Devices, Inc. 6 * 7 * Author: Tom Lendacky <thomas.lendacky@amd.com> 8 */ 9 10 #include <linux/module.h> 11 #include <linux/sched.h> 12 #include <linux/delay.h> 13 #include <linux/scatterlist.h> 14 #include <linux/crypto.h> 15 #include <crypto/algapi.h> 16 #include <crypto/aes.h> 17 #include <crypto/hash.h> 18 #include <crypto/internal/hash.h> 19 #include <crypto/scatterwalk.h> 20 21 #include "ccp-crypto.h" 22 23 static int ccp_aes_cmac_complete(struct crypto_async_request *async_req, 24 int ret) 25 { 26 struct ahash_request *req = ahash_request_cast(async_req); 27 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 28 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx_dma(req); 29 unsigned int digest_size = crypto_ahash_digestsize(tfm); 30 31 if (ret) 32 goto e_free; 33 34 if (rctx->hash_rem) { 35 /* Save remaining data to buffer */ 36 unsigned int offset = rctx->nbytes - rctx->hash_rem; 37 38 scatterwalk_map_and_copy(rctx->buf, rctx->src, 39 offset, rctx->hash_rem, 0); 40 rctx->buf_count = rctx->hash_rem; 41 } else { 42 rctx->buf_count = 0; 43 } 44 45 /* Update result area if supplied */ 46 if (req->result && rctx->final) 47 memcpy(req->result, rctx->iv, digest_size); 48 49 e_free: 50 sg_free_table(&rctx->data_sg); 51 52 return ret; 53 } 54 55 static int ccp_do_cmac_update(struct ahash_request *req, unsigned int nbytes, 56 unsigned int final) 57 { 58 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req); 59 struct ccp_ctx *ctx = crypto_ahash_ctx_dma(tfm); 60 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx_dma(req); 61 struct scatterlist *sg, *cmac_key_sg = NULL; 62 unsigned int block_size = 63 crypto_tfm_alg_blocksize(crypto_ahash_tfm(tfm)); 64 unsigned int need_pad, sg_count; 65 gfp_t gfp; 66 u64 len; 67 int ret; 68 69 if (!ctx->u.aes.key_len) 70 return -EINVAL; 71 72 if (nbytes) 73 rctx->null_msg = 0; 74 75 len = (u64)rctx->buf_count + (u64)nbytes; 76 77 if (!final && (len <= block_size)) { 78 scatterwalk_map_and_copy(rctx->buf + rctx->buf_count, req->src, 79 0, nbytes, 0); 80 rctx->buf_count += nbytes; 81 82 return 0; 83 } 84 85 rctx->src = req->src; 86 rctx->nbytes = nbytes; 87 88 rctx->final = final; 89 rctx->hash_rem = final ? 0 : len & (block_size - 1); 90 rctx->hash_cnt = len - rctx->hash_rem; 91 if (!final && !rctx->hash_rem) { 92 /* CCP can't do zero length final, so keep some data around */ 93 rctx->hash_cnt -= block_size; 94 rctx->hash_rem = block_size; 95 } 96 97 if (final && (rctx->null_msg || (len & (block_size - 1)))) 98 need_pad = 1; 99 else 100 need_pad = 0; 101 102 sg_init_one(&rctx->iv_sg, rctx->iv, sizeof(rctx->iv)); 103 104 /* Build the data scatterlist table - allocate enough entries for all 105 * possible data pieces (buffer, input data, padding) 106 */ 107 sg_count = (nbytes) ? sg_nents(req->src) + 2 : 2; 108 gfp = req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP ? 109 GFP_KERNEL : GFP_ATOMIC; 110 ret = sg_alloc_table(&rctx->data_sg, sg_count, gfp); 111 if (ret) 112 return ret; 113 114 sg = NULL; 115 if (rctx->buf_count) { 116 sg_init_one(&rctx->buf_sg, rctx->buf, rctx->buf_count); 117 sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->buf_sg); 118 if (!sg) { 119 ret = -EINVAL; 120 goto e_free; 121 } 122 } 123 124 if (nbytes) { 125 sg = ccp_crypto_sg_table_add(&rctx->data_sg, req->src); 126 if (!sg) { 127 ret = -EINVAL; 128 goto e_free; 129 } 130 } 131 132 if (need_pad) { 133 int pad_length = block_size - (len & (block_size - 1)); 134 135 rctx->hash_cnt += pad_length; 136 137 memset(rctx->pad, 0, sizeof(rctx->pad)); 138 rctx->pad[0] = 0x80; 139 sg_init_one(&rctx->pad_sg, rctx->pad, pad_length); 140 sg = ccp_crypto_sg_table_add(&rctx->data_sg, &rctx->pad_sg); 141 if (!sg) { 142 ret = -EINVAL; 143 goto e_free; 144 } 145 } 146 if (sg) { 147 sg_mark_end(sg); 148 sg = rctx->data_sg.sgl; 149 } 150 151 /* Initialize the K1/K2 scatterlist */ 152 if (final) 153 cmac_key_sg = (need_pad) ? &ctx->u.aes.k2_sg 154 : &ctx->u.aes.k1_sg; 155 156 memset(&rctx->cmd, 0, sizeof(rctx->cmd)); 157 INIT_LIST_HEAD(&rctx->cmd.entry); 158 rctx->cmd.engine = CCP_ENGINE_AES; 159 rctx->cmd.u.aes.type = ctx->u.aes.type; 160 rctx->cmd.u.aes.mode = ctx->u.aes.mode; 161 rctx->cmd.u.aes.action = CCP_AES_ACTION_ENCRYPT; 162 rctx->cmd.u.aes.key = &ctx->u.aes.key_sg; 163 rctx->cmd.u.aes.key_len = ctx->u.aes.key_len; 164 rctx->cmd.u.aes.iv = &rctx->iv_sg; 165 rctx->cmd.u.aes.iv_len = AES_BLOCK_SIZE; 166 rctx->cmd.u.aes.src = sg; 167 rctx->cmd.u.aes.src_len = rctx->hash_cnt; 168 rctx->cmd.u.aes.dst = NULL; 169 rctx->cmd.u.aes.cmac_key = cmac_key_sg; 170 rctx->cmd.u.aes.cmac_key_len = ctx->u.aes.kn_len; 171 rctx->cmd.u.aes.cmac_final = final; 172 173 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd); 174 175 return ret; 176 177 e_free: 178 sg_free_table(&rctx->data_sg); 179 180 return ret; 181 } 182 183 static int ccp_aes_cmac_init(struct ahash_request *req) 184 { 185 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx_dma(req); 186 187 memset(rctx, 0, sizeof(*rctx)); 188 189 rctx->null_msg = 1; 190 191 return 0; 192 } 193 194 static int ccp_aes_cmac_update(struct ahash_request *req) 195 { 196 return ccp_do_cmac_update(req, req->nbytes, 0); 197 } 198 199 static int ccp_aes_cmac_final(struct ahash_request *req) 200 { 201 return ccp_do_cmac_update(req, 0, 1); 202 } 203 204 static int ccp_aes_cmac_finup(struct ahash_request *req) 205 { 206 return ccp_do_cmac_update(req, req->nbytes, 1); 207 } 208 209 static int ccp_aes_cmac_digest(struct ahash_request *req) 210 { 211 int ret; 212 213 ret = ccp_aes_cmac_init(req); 214 if (ret) 215 return ret; 216 217 return ccp_aes_cmac_finup(req); 218 } 219 220 static int ccp_aes_cmac_export(struct ahash_request *req, void *out) 221 { 222 struct ccp_aes_cmac_req_ctx *rctx = ahash_request_ctx_dma(req); 223 struct ccp_aes_cmac_exp_ctx state; 224 225 /* Don't let anything leak to 'out' */ 226 memset(&state, 0, sizeof(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_dma(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_ahash_ctx_dma(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 struct crypto_aes_ctx aes; 265 __be64 *gk; 266 int ret; 267 268 switch (key_len) { 269 case AES_KEYSIZE_128: 270 ctx->u.aes.type = CCP_AES_TYPE_128; 271 break; 272 case AES_KEYSIZE_192: 273 ctx->u.aes.type = CCP_AES_TYPE_192; 274 break; 275 case AES_KEYSIZE_256: 276 ctx->u.aes.type = CCP_AES_TYPE_256; 277 break; 278 default: 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 = aes_expandkey(&aes, 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 aes_encrypt(&aes, ctx->u.aes.key, ctx->u.aes.key); 294 memzero_explicit(&aes, sizeof(aes)); 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_dma(tfm); 338 struct crypto_ahash *ahash = __crypto_ahash_cast(tfm); 339 340 ctx->complete = ccp_aes_cmac_complete; 341 ctx->u.aes.key_len = 0; 342 343 crypto_ahash_set_reqsize_dma(ahash, 344 sizeof(struct ccp_aes_cmac_req_ctx)); 345 346 return 0; 347 } 348 349 int ccp_register_aes_cmac_algs(struct list_head *head) 350 { 351 struct ccp_crypto_ahash_alg *ccp_alg; 352 struct ahash_alg *alg; 353 struct hash_alg_common *halg; 354 struct crypto_alg *base; 355 int ret; 356 357 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL); 358 if (!ccp_alg) 359 return -ENOMEM; 360 361 INIT_LIST_HEAD(&ccp_alg->entry); 362 ccp_alg->mode = CCP_AES_MODE_CMAC; 363 364 alg = &ccp_alg->alg; 365 alg->init = ccp_aes_cmac_init; 366 alg->update = ccp_aes_cmac_update; 367 alg->final = ccp_aes_cmac_final; 368 alg->finup = ccp_aes_cmac_finup; 369 alg->digest = ccp_aes_cmac_digest; 370 alg->export = ccp_aes_cmac_export; 371 alg->import = ccp_aes_cmac_import; 372 alg->setkey = ccp_aes_cmac_setkey; 373 374 halg = &alg->halg; 375 halg->digestsize = AES_BLOCK_SIZE; 376 halg->statesize = sizeof(struct ccp_aes_cmac_exp_ctx); 377 378 base = &halg->base; 379 snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "cmac(aes)"); 380 snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "cmac-aes-ccp"); 381 base->cra_flags = CRYPTO_ALG_ASYNC | 382 CRYPTO_ALG_ALLOCATES_MEMORY | 383 CRYPTO_ALG_KERN_DRIVER_ONLY | 384 CRYPTO_ALG_NEED_FALLBACK; 385 base->cra_blocksize = AES_BLOCK_SIZE; 386 base->cra_ctxsize = sizeof(struct ccp_ctx) + crypto_dma_padding(); 387 base->cra_priority = CCP_CRA_PRIORITY; 388 base->cra_init = ccp_aes_cmac_cra_init; 389 base->cra_module = THIS_MODULE; 390 391 ret = crypto_register_ahash(alg); 392 if (ret) { 393 pr_err("%s ahash algorithm registration error (%d)\n", 394 base->cra_name, ret); 395 kfree(ccp_alg); 396 return ret; 397 } 398 399 list_add(&ccp_alg->entry, head); 400 401 return 0; 402 } 403