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