1 /** 2 * AES GCM routines supporting the Power 7+ Nest Accelerators driver 3 * 4 * Copyright (C) 2012 International Business Machines Inc. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; version 2 only. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. 18 * 19 * Author: Kent Yoder <yoder1@us.ibm.com> 20 */ 21 22 #include <crypto/internal/aead.h> 23 #include <crypto/aes.h> 24 #include <crypto/algapi.h> 25 #include <crypto/scatterwalk.h> 26 #include <linux/module.h> 27 #include <linux/types.h> 28 #include <linux/crypto.h> 29 #include <asm/vio.h> 30 31 #include "nx_csbcpb.h" 32 #include "nx.h" 33 34 35 static int gcm_aes_nx_set_key(struct crypto_aead *tfm, 36 const u8 *in_key, 37 unsigned int key_len) 38 { 39 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base); 40 struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; 41 struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead; 42 43 nx_ctx_init(nx_ctx, HCOP_FC_AES); 44 45 switch (key_len) { 46 case AES_KEYSIZE_128: 47 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_128); 48 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_128); 49 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_128]; 50 break; 51 case AES_KEYSIZE_192: 52 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_192); 53 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_192); 54 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_192]; 55 break; 56 case AES_KEYSIZE_256: 57 NX_CPB_SET_KEY_SIZE(csbcpb, NX_KS_AES_256); 58 NX_CPB_SET_KEY_SIZE(csbcpb_aead, NX_KS_AES_256); 59 nx_ctx->ap = &nx_ctx->props[NX_PROPS_AES_256]; 60 break; 61 default: 62 return -EINVAL; 63 } 64 65 csbcpb->cpb.hdr.mode = NX_MODE_AES_GCM; 66 memcpy(csbcpb->cpb.aes_gcm.key, in_key, key_len); 67 68 csbcpb_aead->cpb.hdr.mode = NX_MODE_AES_GCA; 69 memcpy(csbcpb_aead->cpb.aes_gca.key, in_key, key_len); 70 71 return 0; 72 } 73 74 static int gcm4106_aes_nx_set_key(struct crypto_aead *tfm, 75 const u8 *in_key, 76 unsigned int key_len) 77 { 78 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base); 79 char *nonce = nx_ctx->priv.gcm.nonce; 80 int rc; 81 82 if (key_len < 4) 83 return -EINVAL; 84 85 key_len -= 4; 86 87 rc = gcm_aes_nx_set_key(tfm, in_key, key_len); 88 if (rc) 89 goto out; 90 91 memcpy(nonce, in_key + key_len, 4); 92 out: 93 return rc; 94 } 95 96 static int gcm_aes_nx_setauthsize(struct crypto_aead *tfm, 97 unsigned int authsize) 98 { 99 if (authsize > crypto_aead_alg(tfm)->maxauthsize) 100 return -EINVAL; 101 102 crypto_aead_crt(tfm)->authsize = authsize; 103 104 return 0; 105 } 106 107 static int gcm4106_aes_nx_setauthsize(struct crypto_aead *tfm, 108 unsigned int authsize) 109 { 110 switch (authsize) { 111 case 8: 112 case 12: 113 case 16: 114 break; 115 default: 116 return -EINVAL; 117 } 118 119 crypto_aead_crt(tfm)->authsize = authsize; 120 121 return 0; 122 } 123 124 static int nx_gca(struct nx_crypto_ctx *nx_ctx, 125 struct aead_request *req, 126 u8 *out) 127 { 128 int rc; 129 struct nx_csbcpb *csbcpb_aead = nx_ctx->csbcpb_aead; 130 struct scatter_walk walk; 131 struct nx_sg *nx_sg = nx_ctx->in_sg; 132 unsigned int nbytes = req->assoclen; 133 unsigned int processed = 0, to_process; 134 u32 max_sg_len; 135 136 if (nbytes <= AES_BLOCK_SIZE) { 137 scatterwalk_start(&walk, req->assoc); 138 scatterwalk_copychunks(out, &walk, nbytes, SCATTERWALK_FROM_SG); 139 scatterwalk_done(&walk, SCATTERWALK_FROM_SG, 0); 140 return 0; 141 } 142 143 NX_CPB_FDM(csbcpb_aead) &= ~NX_FDM_CONTINUATION; 144 145 /* page_limit: number of sg entries that fit on one page */ 146 max_sg_len = min_t(u32, nx_driver.of.max_sg_len/sizeof(struct nx_sg), 147 nx_ctx->ap->sglen); 148 149 do { 150 /* 151 * to_process: the data chunk to process in this update. 152 * This value is bound by sg list limits. 153 */ 154 to_process = min_t(u64, nbytes - processed, 155 nx_ctx->ap->databytelen); 156 to_process = min_t(u64, to_process, 157 NX_PAGE_SIZE * (max_sg_len - 1)); 158 159 if ((to_process + processed) < nbytes) 160 NX_CPB_FDM(csbcpb_aead) |= NX_FDM_INTERMEDIATE; 161 else 162 NX_CPB_FDM(csbcpb_aead) &= ~NX_FDM_INTERMEDIATE; 163 164 nx_sg = nx_walk_and_build(nx_ctx->in_sg, nx_ctx->ap->sglen, 165 req->assoc, processed, to_process); 166 nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_sg) 167 * sizeof(struct nx_sg); 168 169 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op_aead, 170 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); 171 if (rc) 172 return rc; 173 174 memcpy(csbcpb_aead->cpb.aes_gca.in_pat, 175 csbcpb_aead->cpb.aes_gca.out_pat, 176 AES_BLOCK_SIZE); 177 NX_CPB_FDM(csbcpb_aead) |= NX_FDM_CONTINUATION; 178 179 atomic_inc(&(nx_ctx->stats->aes_ops)); 180 atomic64_add(req->assoclen, &(nx_ctx->stats->aes_bytes)); 181 182 processed += to_process; 183 } while (processed < nbytes); 184 185 memcpy(out, csbcpb_aead->cpb.aes_gca.out_pat, AES_BLOCK_SIZE); 186 187 return rc; 188 } 189 190 static int gcm_empty(struct aead_request *req, struct blkcipher_desc *desc, 191 int enc) 192 { 193 int rc; 194 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 195 struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; 196 197 /* For scenarios where the input message is zero length, AES CTR mode 198 * may be used. Set the source data to be a single block (16B) of all 199 * zeros, and set the input IV value to be the same as the GMAC IV 200 * value. - nx_wb 4.8.1.3 */ 201 char src[AES_BLOCK_SIZE] = {}; 202 struct scatterlist sg; 203 204 desc->tfm = crypto_alloc_blkcipher("ctr(aes)", 0, 0); 205 if (IS_ERR(desc->tfm)) { 206 rc = -ENOMEM; 207 goto out; 208 } 209 210 crypto_blkcipher_setkey(desc->tfm, csbcpb->cpb.aes_gcm.key, 211 NX_CPB_KEY_SIZE(csbcpb) == NX_KS_AES_128 ? 16 : 212 NX_CPB_KEY_SIZE(csbcpb) == NX_KS_AES_192 ? 24 : 32); 213 214 sg_init_one(&sg, src, AES_BLOCK_SIZE); 215 if (enc) 216 rc = crypto_blkcipher_encrypt_iv(desc, req->dst, &sg, 217 AES_BLOCK_SIZE); 218 else 219 rc = crypto_blkcipher_decrypt_iv(desc, req->dst, &sg, 220 AES_BLOCK_SIZE); 221 crypto_free_blkcipher(desc->tfm); 222 223 out: 224 return rc; 225 } 226 227 static int gcm_aes_nx_crypt(struct aead_request *req, int enc) 228 { 229 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 230 struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; 231 struct blkcipher_desc desc; 232 unsigned int nbytes = req->cryptlen; 233 unsigned int processed = 0, to_process; 234 unsigned long irq_flags; 235 u32 max_sg_len; 236 int rc = -EINVAL; 237 238 spin_lock_irqsave(&nx_ctx->lock, irq_flags); 239 240 desc.info = nx_ctx->priv.gcm.iv; 241 /* initialize the counter */ 242 *(u32 *)(desc.info + NX_GCM_CTR_OFFSET) = 1; 243 244 if (nbytes == 0) { 245 rc = gcm_empty(req, &desc, enc); 246 goto out; 247 } 248 249 /* Process associated data */ 250 csbcpb->cpb.aes_gcm.bit_length_aad = req->assoclen * 8; 251 if (req->assoclen) { 252 rc = nx_gca(nx_ctx, req, csbcpb->cpb.aes_gcm.in_pat_or_aad); 253 if (rc) 254 goto out; 255 } 256 257 /* Set flags for encryption */ 258 NX_CPB_FDM(csbcpb) &= ~NX_FDM_CONTINUATION; 259 if (enc) { 260 NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT; 261 } else { 262 NX_CPB_FDM(csbcpb) &= ~NX_FDM_ENDE_ENCRYPT; 263 nbytes -= crypto_aead_authsize(crypto_aead_reqtfm(req)); 264 } 265 266 /* page_limit: number of sg entries that fit on one page */ 267 max_sg_len = min_t(u32, nx_driver.of.max_sg_len/sizeof(struct nx_sg), 268 nx_ctx->ap->sglen); 269 270 do { 271 /* 272 * to_process: the data chunk to process in this update. 273 * This value is bound by sg list limits. 274 */ 275 to_process = min_t(u64, nbytes - processed, 276 nx_ctx->ap->databytelen); 277 to_process = min_t(u64, to_process, 278 NX_PAGE_SIZE * (max_sg_len - 1)); 279 280 if ((to_process + processed) < nbytes) 281 NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE; 282 else 283 NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE; 284 285 csbcpb->cpb.aes_gcm.bit_length_data = nbytes * 8; 286 desc.tfm = (struct crypto_blkcipher *) req->base.tfm; 287 rc = nx_build_sg_lists(nx_ctx, &desc, req->dst, 288 req->src, to_process, processed, 289 csbcpb->cpb.aes_gcm.iv_or_cnt); 290 if (rc) 291 goto out; 292 293 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 294 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); 295 if (rc) 296 goto out; 297 298 memcpy(desc.info, csbcpb->cpb.aes_gcm.out_cnt, AES_BLOCK_SIZE); 299 memcpy(csbcpb->cpb.aes_gcm.in_pat_or_aad, 300 csbcpb->cpb.aes_gcm.out_pat_or_mac, AES_BLOCK_SIZE); 301 memcpy(csbcpb->cpb.aes_gcm.in_s0, 302 csbcpb->cpb.aes_gcm.out_s0, AES_BLOCK_SIZE); 303 304 NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION; 305 306 atomic_inc(&(nx_ctx->stats->aes_ops)); 307 atomic64_add(csbcpb->csb.processed_byte_count, 308 &(nx_ctx->stats->aes_bytes)); 309 310 processed += to_process; 311 } while (processed < nbytes); 312 313 if (enc) { 314 /* copy out the auth tag */ 315 scatterwalk_map_and_copy(csbcpb->cpb.aes_gcm.out_pat_or_mac, 316 req->dst, nbytes, 317 crypto_aead_authsize(crypto_aead_reqtfm(req)), 318 SCATTERWALK_TO_SG); 319 } else { 320 u8 *itag = nx_ctx->priv.gcm.iauth_tag; 321 u8 *otag = csbcpb->cpb.aes_gcm.out_pat_or_mac; 322 323 scatterwalk_map_and_copy(itag, req->src, nbytes, 324 crypto_aead_authsize(crypto_aead_reqtfm(req)), 325 SCATTERWALK_FROM_SG); 326 rc = memcmp(itag, otag, 327 crypto_aead_authsize(crypto_aead_reqtfm(req))) ? 328 -EBADMSG : 0; 329 } 330 out: 331 spin_unlock_irqrestore(&nx_ctx->lock, irq_flags); 332 return rc; 333 } 334 335 static int gcm_aes_nx_encrypt(struct aead_request *req) 336 { 337 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 338 char *iv = nx_ctx->priv.gcm.iv; 339 340 memcpy(iv, req->iv, 12); 341 342 return gcm_aes_nx_crypt(req, 1); 343 } 344 345 static int gcm_aes_nx_decrypt(struct aead_request *req) 346 { 347 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 348 char *iv = nx_ctx->priv.gcm.iv; 349 350 memcpy(iv, req->iv, 12); 351 352 return gcm_aes_nx_crypt(req, 0); 353 } 354 355 static int gcm4106_aes_nx_encrypt(struct aead_request *req) 356 { 357 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 358 char *iv = nx_ctx->priv.gcm.iv; 359 char *nonce = nx_ctx->priv.gcm.nonce; 360 361 memcpy(iv, nonce, NX_GCM4106_NONCE_LEN); 362 memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8); 363 364 return gcm_aes_nx_crypt(req, 1); 365 } 366 367 static int gcm4106_aes_nx_decrypt(struct aead_request *req) 368 { 369 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 370 char *iv = nx_ctx->priv.gcm.iv; 371 char *nonce = nx_ctx->priv.gcm.nonce; 372 373 memcpy(iv, nonce, NX_GCM4106_NONCE_LEN); 374 memcpy(iv + NX_GCM4106_NONCE_LEN, req->iv, 8); 375 376 return gcm_aes_nx_crypt(req, 0); 377 } 378 379 /* tell the block cipher walk routines that this is a stream cipher by 380 * setting cra_blocksize to 1. Even using blkcipher_walk_virt_block 381 * during encrypt/decrypt doesn't solve this problem, because it calls 382 * blkcipher_walk_done under the covers, which doesn't use walk->blocksize, 383 * but instead uses this tfm->blocksize. */ 384 struct crypto_alg nx_gcm_aes_alg = { 385 .cra_name = "gcm(aes)", 386 .cra_driver_name = "gcm-aes-nx", 387 .cra_priority = 300, 388 .cra_flags = CRYPTO_ALG_TYPE_AEAD, 389 .cra_blocksize = 1, 390 .cra_ctxsize = sizeof(struct nx_crypto_ctx), 391 .cra_type = &crypto_aead_type, 392 .cra_module = THIS_MODULE, 393 .cra_init = nx_crypto_ctx_aes_gcm_init, 394 .cra_exit = nx_crypto_ctx_exit, 395 .cra_aead = { 396 .ivsize = AES_BLOCK_SIZE, 397 .maxauthsize = AES_BLOCK_SIZE, 398 .setkey = gcm_aes_nx_set_key, 399 .setauthsize = gcm_aes_nx_setauthsize, 400 .encrypt = gcm_aes_nx_encrypt, 401 .decrypt = gcm_aes_nx_decrypt, 402 } 403 }; 404 405 struct crypto_alg nx_gcm4106_aes_alg = { 406 .cra_name = "rfc4106(gcm(aes))", 407 .cra_driver_name = "rfc4106-gcm-aes-nx", 408 .cra_priority = 300, 409 .cra_flags = CRYPTO_ALG_TYPE_AEAD, 410 .cra_blocksize = 1, 411 .cra_ctxsize = sizeof(struct nx_crypto_ctx), 412 .cra_type = &crypto_nivaead_type, 413 .cra_module = THIS_MODULE, 414 .cra_init = nx_crypto_ctx_aes_gcm_init, 415 .cra_exit = nx_crypto_ctx_exit, 416 .cra_aead = { 417 .ivsize = 8, 418 .maxauthsize = AES_BLOCK_SIZE, 419 .geniv = "seqiv", 420 .setkey = gcm4106_aes_nx_set_key, 421 .setauthsize = gcm4106_aes_nx_setauthsize, 422 .encrypt = gcm4106_aes_nx_encrypt, 423 .decrypt = gcm4106_aes_nx_decrypt, 424 } 425 }; 426