1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * AMD Cryptographic Coprocessor (CCP) AES XTS crypto API support 4 * 5 * Copyright (C) 2013,2017 Advanced Micro Devices, Inc. 6 * 7 * Author: Gary R Hook <gary.hook@amd.com> 8 * Author: Tom Lendacky <thomas.lendacky@amd.com> 9 */ 10 11 #include <linux/module.h> 12 #include <linux/sched.h> 13 #include <linux/delay.h> 14 #include <linux/scatterlist.h> 15 #include <crypto/aes.h> 16 #include <crypto/xts.h> 17 #include <crypto/internal/skcipher.h> 18 #include <crypto/scatterwalk.h> 19 20 #include "ccp-crypto.h" 21 22 struct ccp_aes_xts_def { 23 const char *name; 24 const char *drv_name; 25 }; 26 27 static struct ccp_aes_xts_def aes_xts_algs[] = { 28 { 29 .name = "xts(aes)", 30 .drv_name = "xts-aes-ccp", 31 }, 32 }; 33 34 struct ccp_unit_size_map { 35 unsigned int size; 36 u32 value; 37 }; 38 39 static struct ccp_unit_size_map xts_unit_sizes[] = { 40 { 41 .size = 16, 42 .value = CCP_XTS_AES_UNIT_SIZE_16, 43 }, 44 { 45 .size = 512, 46 .value = CCP_XTS_AES_UNIT_SIZE_512, 47 }, 48 { 49 .size = 1024, 50 .value = CCP_XTS_AES_UNIT_SIZE_1024, 51 }, 52 { 53 .size = 2048, 54 .value = CCP_XTS_AES_UNIT_SIZE_2048, 55 }, 56 { 57 .size = 4096, 58 .value = CCP_XTS_AES_UNIT_SIZE_4096, 59 }, 60 }; 61 62 static int ccp_aes_xts_complete(struct crypto_async_request *async_req, int ret) 63 { 64 struct ablkcipher_request *req = ablkcipher_request_cast(async_req); 65 struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req); 66 67 if (ret) 68 return ret; 69 70 memcpy(req->info, rctx->iv, AES_BLOCK_SIZE); 71 72 return 0; 73 } 74 75 static int ccp_aes_xts_setkey(struct crypto_ablkcipher *tfm, const u8 *key, 76 unsigned int key_len) 77 { 78 struct crypto_tfm *xfm = crypto_ablkcipher_tfm(tfm); 79 struct ccp_ctx *ctx = crypto_tfm_ctx(xfm); 80 unsigned int ccpversion = ccp_version(); 81 int ret; 82 83 ret = xts_check_key(xfm, key, key_len); 84 if (ret) 85 return ret; 86 87 /* Version 3 devices support 128-bit keys; version 5 devices can 88 * accommodate 128- and 256-bit keys. 89 */ 90 switch (key_len) { 91 case AES_KEYSIZE_128 * 2: 92 memcpy(ctx->u.aes.key, key, key_len); 93 break; 94 case AES_KEYSIZE_256 * 2: 95 if (ccpversion > CCP_VERSION(3, 0)) 96 memcpy(ctx->u.aes.key, key, key_len); 97 break; 98 } 99 ctx->u.aes.key_len = key_len / 2; 100 sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len); 101 102 return crypto_sync_skcipher_setkey(ctx->u.aes.tfm_skcipher, key, key_len); 103 } 104 105 static int ccp_aes_xts_crypt(struct ablkcipher_request *req, 106 unsigned int encrypt) 107 { 108 struct ccp_ctx *ctx = crypto_tfm_ctx(req->base.tfm); 109 struct ccp_aes_req_ctx *rctx = ablkcipher_request_ctx(req); 110 unsigned int ccpversion = ccp_version(); 111 unsigned int fallback = 0; 112 unsigned int unit; 113 u32 unit_size; 114 int ret; 115 116 if (!ctx->u.aes.key_len) 117 return -EINVAL; 118 119 if (req->nbytes & (AES_BLOCK_SIZE - 1)) 120 return -EINVAL; 121 122 if (!req->info) 123 return -EINVAL; 124 125 /* Check conditions under which the CCP can fulfill a request. The 126 * device can handle input plaintext of a length that is a multiple 127 * of the unit_size, bug the crypto implementation only supports 128 * the unit_size being equal to the input length. This limits the 129 * number of scenarios we can handle. 130 */ 131 unit_size = CCP_XTS_AES_UNIT_SIZE__LAST; 132 for (unit = 0; unit < ARRAY_SIZE(xts_unit_sizes); unit++) { 133 if (req->nbytes == xts_unit_sizes[unit].size) { 134 unit_size = unit; 135 break; 136 } 137 } 138 /* The CCP has restrictions on block sizes. Also, a version 3 device 139 * only supports AES-128 operations; version 5 CCPs support both 140 * AES-128 and -256 operations. 141 */ 142 if (unit_size == CCP_XTS_AES_UNIT_SIZE__LAST) 143 fallback = 1; 144 if ((ccpversion < CCP_VERSION(5, 0)) && 145 (ctx->u.aes.key_len != AES_KEYSIZE_128)) 146 fallback = 1; 147 if ((ctx->u.aes.key_len != AES_KEYSIZE_128) && 148 (ctx->u.aes.key_len != AES_KEYSIZE_256)) 149 fallback = 1; 150 if (fallback) { 151 SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, 152 ctx->u.aes.tfm_skcipher); 153 154 /* Use the fallback to process the request for any 155 * unsupported unit sizes or key sizes 156 */ 157 skcipher_request_set_sync_tfm(subreq, ctx->u.aes.tfm_skcipher); 158 skcipher_request_set_callback(subreq, req->base.flags, 159 NULL, NULL); 160 skcipher_request_set_crypt(subreq, req->src, req->dst, 161 req->nbytes, req->info); 162 ret = encrypt ? crypto_skcipher_encrypt(subreq) : 163 crypto_skcipher_decrypt(subreq); 164 skcipher_request_zero(subreq); 165 return ret; 166 } 167 168 memcpy(rctx->iv, req->info, AES_BLOCK_SIZE); 169 sg_init_one(&rctx->iv_sg, rctx->iv, AES_BLOCK_SIZE); 170 171 memset(&rctx->cmd, 0, sizeof(rctx->cmd)); 172 INIT_LIST_HEAD(&rctx->cmd.entry); 173 rctx->cmd.engine = CCP_ENGINE_XTS_AES_128; 174 rctx->cmd.u.xts.type = CCP_AES_TYPE_128; 175 rctx->cmd.u.xts.action = (encrypt) ? CCP_AES_ACTION_ENCRYPT 176 : CCP_AES_ACTION_DECRYPT; 177 rctx->cmd.u.xts.unit_size = unit_size; 178 rctx->cmd.u.xts.key = &ctx->u.aes.key_sg; 179 rctx->cmd.u.xts.key_len = ctx->u.aes.key_len; 180 rctx->cmd.u.xts.iv = &rctx->iv_sg; 181 rctx->cmd.u.xts.iv_len = AES_BLOCK_SIZE; 182 rctx->cmd.u.xts.src = req->src; 183 rctx->cmd.u.xts.src_len = req->nbytes; 184 rctx->cmd.u.xts.dst = req->dst; 185 186 ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd); 187 188 return ret; 189 } 190 191 static int ccp_aes_xts_encrypt(struct ablkcipher_request *req) 192 { 193 return ccp_aes_xts_crypt(req, 1); 194 } 195 196 static int ccp_aes_xts_decrypt(struct ablkcipher_request *req) 197 { 198 return ccp_aes_xts_crypt(req, 0); 199 } 200 201 static int ccp_aes_xts_cra_init(struct crypto_tfm *tfm) 202 { 203 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); 204 struct crypto_sync_skcipher *fallback_tfm; 205 206 ctx->complete = ccp_aes_xts_complete; 207 ctx->u.aes.key_len = 0; 208 209 fallback_tfm = crypto_alloc_sync_skcipher("xts(aes)", 0, 210 CRYPTO_ALG_ASYNC | 211 CRYPTO_ALG_NEED_FALLBACK); 212 if (IS_ERR(fallback_tfm)) { 213 pr_warn("could not load fallback driver xts(aes)\n"); 214 return PTR_ERR(fallback_tfm); 215 } 216 ctx->u.aes.tfm_skcipher = fallback_tfm; 217 218 tfm->crt_ablkcipher.reqsize = sizeof(struct ccp_aes_req_ctx); 219 220 return 0; 221 } 222 223 static void ccp_aes_xts_cra_exit(struct crypto_tfm *tfm) 224 { 225 struct ccp_ctx *ctx = crypto_tfm_ctx(tfm); 226 227 crypto_free_sync_skcipher(ctx->u.aes.tfm_skcipher); 228 } 229 230 static int ccp_register_aes_xts_alg(struct list_head *head, 231 const struct ccp_aes_xts_def *def) 232 { 233 struct ccp_crypto_ablkcipher_alg *ccp_alg; 234 struct crypto_alg *alg; 235 int ret; 236 237 ccp_alg = kzalloc(sizeof(*ccp_alg), GFP_KERNEL); 238 if (!ccp_alg) 239 return -ENOMEM; 240 241 INIT_LIST_HEAD(&ccp_alg->entry); 242 243 alg = &ccp_alg->alg; 244 245 snprintf(alg->cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name); 246 snprintf(alg->cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s", 247 def->drv_name); 248 alg->cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC | 249 CRYPTO_ALG_KERN_DRIVER_ONLY | 250 CRYPTO_ALG_NEED_FALLBACK; 251 alg->cra_blocksize = AES_BLOCK_SIZE; 252 alg->cra_ctxsize = sizeof(struct ccp_ctx); 253 alg->cra_priority = CCP_CRA_PRIORITY; 254 alg->cra_type = &crypto_ablkcipher_type; 255 alg->cra_ablkcipher.setkey = ccp_aes_xts_setkey; 256 alg->cra_ablkcipher.encrypt = ccp_aes_xts_encrypt; 257 alg->cra_ablkcipher.decrypt = ccp_aes_xts_decrypt; 258 alg->cra_ablkcipher.min_keysize = AES_MIN_KEY_SIZE * 2; 259 alg->cra_ablkcipher.max_keysize = AES_MAX_KEY_SIZE * 2; 260 alg->cra_ablkcipher.ivsize = AES_BLOCK_SIZE; 261 alg->cra_init = ccp_aes_xts_cra_init; 262 alg->cra_exit = ccp_aes_xts_cra_exit; 263 alg->cra_module = THIS_MODULE; 264 265 ret = crypto_register_alg(alg); 266 if (ret) { 267 pr_err("%s ablkcipher algorithm registration error (%d)\n", 268 alg->cra_name, ret); 269 kfree(ccp_alg); 270 return ret; 271 } 272 273 list_add(&ccp_alg->entry, head); 274 275 return 0; 276 } 277 278 int ccp_register_aes_xts_algs(struct list_head *head) 279 { 280 int i, ret; 281 282 for (i = 0; i < ARRAY_SIZE(aes_xts_algs); i++) { 283 ret = ccp_register_aes_xts_alg(head, &aes_xts_algs[i]); 284 if (ret) 285 return ret; 286 } 287 288 return 0; 289 } 290