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 } 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 } 167 168 static 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 } 178 179 static int ccp_aes_cmac_update(struct ahash_request *req) 180 { 181 return ccp_do_cmac_update(req, req->nbytes, 0); 182 } 183 184 static int ccp_aes_cmac_final(struct ahash_request *req) 185 { 186 return ccp_do_cmac_update(req, 0, 1); 187 } 188 189 static int ccp_aes_cmac_finup(struct ahash_request *req) 190 { 191 return ccp_do_cmac_update(req, req->nbytes, 1); 192 } 193 194 static 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 } 204 205 static int ccp_aes_cmac_setkey(struct crypto_ahash *tfm, const u8 *key, 206 unsigned int key_len) 207 { 208 struct ccp_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm)); 209 struct ccp_crypto_ahash_alg *alg = 210 ccp_crypto_ahash_alg(crypto_ahash_tfm(tfm)); 211 u64 k0_hi, k0_lo, k1_hi, k1_lo, k2_hi, k2_lo; 212 u64 rb_hi = 0x00, rb_lo = 0x87; 213 __be64 *gk; 214 int ret; 215 216 switch (key_len) { 217 case AES_KEYSIZE_128: 218 ctx->u.aes.type = CCP_AES_TYPE_128; 219 break; 220 case AES_KEYSIZE_192: 221 ctx->u.aes.type = CCP_AES_TYPE_192; 222 break; 223 case AES_KEYSIZE_256: 224 ctx->u.aes.type = CCP_AES_TYPE_256; 225 break; 226 default: 227 crypto_ahash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN); 228 return -EINVAL; 229 } 230 ctx->u.aes.mode = alg->mode; 231 232 /* Set to zero until complete */ 233 ctx->u.aes.key_len = 0; 234 235 /* Set the key for the AES cipher used to generate the keys */ 236 ret = crypto_cipher_setkey(ctx->u.aes.tfm_cipher, key, key_len); 237 if (ret) 238 return ret; 239 240 /* Encrypt a block of zeroes - use key area in context */ 241 memset(ctx->u.aes.key, 0, sizeof(ctx->u.aes.key)); 242 crypto_cipher_encrypt_one(ctx->u.aes.tfm_cipher, ctx->u.aes.key, 243 ctx->u.aes.key); 244 245 /* Generate K1 and K2 */ 246 k0_hi = be64_to_cpu(*((__be64 *)ctx->u.aes.key)); 247 k0_lo = be64_to_cpu(*((__be64 *)ctx->u.aes.key + 1)); 248 249 k1_hi = (k0_hi << 1) | (k0_lo >> 63); 250 k1_lo = k0_lo << 1; 251 if (ctx->u.aes.key[0] & 0x80) { 252 k1_hi ^= rb_hi; 253 k1_lo ^= rb_lo; 254 } 255 gk = (__be64 *)ctx->u.aes.k1; 256 *gk = cpu_to_be64(k1_hi); 257 gk++; 258 *gk = cpu_to_be64(k1_lo); 259 260 k2_hi = (k1_hi << 1) | (k1_lo >> 63); 261 k2_lo = k1_lo << 1; 262 if (ctx->u.aes.k1[0] & 0x80) { 263 k2_hi ^= rb_hi; 264 k2_lo ^= rb_lo; 265 } 266 gk = (__be64 *)ctx->u.aes.k2; 267 *gk = cpu_to_be64(k2_hi); 268 gk++; 269 *gk = cpu_to_be64(k2_lo); 270 271 ctx->u.aes.kn_len = sizeof(ctx->u.aes.k1); 272 sg_init_one(&ctx->u.aes.k1_sg, ctx->u.aes.k1, sizeof(ctx->u.aes.k1)); 273 sg_init_one(&ctx->u.aes.k2_sg, ctx->u.aes.k2, sizeof(ctx->u.aes.k2)); 274 275 /* Save the supplied key */ 276 memset(ctx->u.aes.key, 0, sizeof(ctx->u.aes.key)); 277 memcpy(ctx->u.aes.key, key, key_len); 278 ctx->u.aes.key_len = key_len; 279 sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len); 280 281 return ret; 282 } 283 284 static int ccp_aes_cmac_cra_init(struct crypto_tfm *tfm) 285 { 286 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); 287 struct crypto_ahash *ahash = __crypto_ahash_cast(tfm); 288 struct crypto_cipher *cipher_tfm; 289 290 ctx->complete = ccp_aes_cmac_complete; 291 ctx->u.aes.key_len = 0; 292 293 crypto_ahash_set_reqsize(ahash, sizeof(struct ccp_aes_cmac_req_ctx)); 294 295 cipher_tfm = crypto_alloc_cipher("aes", 0, 296 CRYPTO_ALG_ASYNC | 297 CRYPTO_ALG_NEED_FALLBACK); 298 if (IS_ERR(cipher_tfm)) { 299 pr_warn("could not load aes cipher driver\n"); 300 return PTR_ERR(cipher_tfm); 301 } 302 ctx->u.aes.tfm_cipher = cipher_tfm; 303 304 return 0; 305 } 306 307 static void ccp_aes_cmac_cra_exit(struct crypto_tfm *tfm) 308 { 309 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); 310 311 if (ctx->u.aes.tfm_cipher) 312 crypto_free_cipher(ctx->u.aes.tfm_cipher); 313 ctx->u.aes.tfm_cipher = NULL; 314 } 315 316 int ccp_register_aes_cmac_algs(struct list_head *head) 317 { 318 struct ccp_crypto_ahash_alg *ccp_alg; 319 struct ahash_alg *alg; 320 struct hash_alg_common *halg; 321 struct crypto_alg *base; 322 int ret; 323 324 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL); 325 if (!ccp_alg) 326 return -ENOMEM; 327 328 INIT_LIST_HEAD(&ccp_alg->entry); 329 ccp_alg->mode = CCP_AES_MODE_CMAC; 330 331 alg = &ccp_alg->alg; 332 alg->init = ccp_aes_cmac_init; 333 alg->update = ccp_aes_cmac_update; 334 alg->final = ccp_aes_cmac_final; 335 alg->finup = ccp_aes_cmac_finup; 336 alg->digest = ccp_aes_cmac_digest; 337 alg->setkey = ccp_aes_cmac_setkey; 338 339 halg = &alg->halg; 340 halg->digestsize = AES_BLOCK_SIZE; 341 342 base = &halg->base; 343 snprintf(base->cra_name, CRYPTO_MAX_ALG_NAME, "cmac(aes)"); 344 snprintf(base->cra_driver_name, CRYPTO_MAX_ALG_NAME, "cmac-aes-ccp"); 345 base->cra_flags = CRYPTO_ALG_TYPE_AHASH | CRYPTO_ALG_ASYNC | 346 CRYPTO_ALG_KERN_DRIVER_ONLY | 347 CRYPTO_ALG_NEED_FALLBACK; 348 base->cra_blocksize = AES_BLOCK_SIZE; 349 base->cra_ctxsize = sizeof(struct ccp_ctx); 350 base->cra_priority = CCP_CRA_PRIORITY; 351 base->cra_type = &crypto_ahash_type; 352 base->cra_init = ccp_aes_cmac_cra_init; 353 base->cra_exit = ccp_aes_cmac_cra_exit; 354 base->cra_module = THIS_MODULE; 355 356 ret = crypto_register_ahash(alg); 357 if (ret) { 358 pr_err("%s ahash algorithm registration error (%d)\n", 359 base->cra_name, ret); 360 kfree(ccp_alg); 361 return ret; 362 } 363 364 list_add(&ccp_alg->entry, head); 365 366 return 0; 367 } 368