1 /** 2 * AES CCM 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 ccm_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 default: 52 return -EINVAL; 53 } 54 55 csbcpb->cpb.hdr.mode = NX_MODE_AES_CCM; 56 memcpy(csbcpb->cpb.aes_ccm.key, in_key, key_len); 57 58 csbcpb_aead->cpb.hdr.mode = NX_MODE_AES_CCA; 59 memcpy(csbcpb_aead->cpb.aes_cca.key, in_key, key_len); 60 61 return 0; 62 63 } 64 65 static int ccm4309_aes_nx_set_key(struct crypto_aead *tfm, 66 const u8 *in_key, 67 unsigned int key_len) 68 { 69 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(&tfm->base); 70 71 if (key_len < 3) 72 return -EINVAL; 73 74 key_len -= 3; 75 76 memcpy(nx_ctx->priv.ccm.nonce, in_key + key_len, 3); 77 78 return ccm_aes_nx_set_key(tfm, in_key, key_len); 79 } 80 81 static int ccm_aes_nx_setauthsize(struct crypto_aead *tfm, 82 unsigned int authsize) 83 { 84 switch (authsize) { 85 case 4: 86 case 6: 87 case 8: 88 case 10: 89 case 12: 90 case 14: 91 case 16: 92 break; 93 default: 94 return -EINVAL; 95 } 96 97 crypto_aead_crt(tfm)->authsize = authsize; 98 99 return 0; 100 } 101 102 static int ccm4309_aes_nx_setauthsize(struct crypto_aead *tfm, 103 unsigned int authsize) 104 { 105 switch (authsize) { 106 case 8: 107 case 12: 108 case 16: 109 break; 110 default: 111 return -EINVAL; 112 } 113 114 crypto_aead_crt(tfm)->authsize = authsize; 115 116 return 0; 117 } 118 119 /* taken from crypto/ccm.c */ 120 static int set_msg_len(u8 *block, unsigned int msglen, int csize) 121 { 122 __be32 data; 123 124 memset(block, 0, csize); 125 block += csize; 126 127 if (csize >= 4) 128 csize = 4; 129 else if (msglen > (unsigned int)(1 << (8 * csize))) 130 return -EOVERFLOW; 131 132 data = cpu_to_be32(msglen); 133 memcpy(block - csize, (u8 *)&data + 4 - csize, csize); 134 135 return 0; 136 } 137 138 /* taken from crypto/ccm.c */ 139 static inline int crypto_ccm_check_iv(const u8 *iv) 140 { 141 /* 2 <= L <= 8, so 1 <= L' <= 7. */ 142 if (1 > iv[0] || iv[0] > 7) 143 return -EINVAL; 144 145 return 0; 146 } 147 148 /* based on code from crypto/ccm.c */ 149 static int generate_b0(u8 *iv, unsigned int assoclen, unsigned int authsize, 150 unsigned int cryptlen, u8 *b0) 151 { 152 unsigned int l, lp, m = authsize; 153 int rc; 154 155 memcpy(b0, iv, 16); 156 157 lp = b0[0]; 158 l = lp + 1; 159 160 /* set m, bits 3-5 */ 161 *b0 |= (8 * ((m - 2) / 2)); 162 163 /* set adata, bit 6, if associated data is used */ 164 if (assoclen) 165 *b0 |= 64; 166 167 rc = set_msg_len(b0 + 16 - l, cryptlen, l); 168 169 return rc; 170 } 171 172 static int generate_pat(u8 *iv, 173 struct aead_request *req, 174 struct nx_crypto_ctx *nx_ctx, 175 unsigned int authsize, 176 unsigned int nbytes, 177 u8 *out) 178 { 179 struct nx_sg *nx_insg = nx_ctx->in_sg; 180 struct nx_sg *nx_outsg = nx_ctx->out_sg; 181 unsigned int iauth_len = 0; 182 u8 tmp[16], *b1 = NULL, *b0 = NULL, *result = NULL; 183 int rc; 184 unsigned int max_sg_len; 185 186 /* zero the ctr value */ 187 memset(iv + 15 - iv[0], 0, iv[0] + 1); 188 189 /* page 78 of nx_wb.pdf has, 190 * Note: RFC3610 allows the AAD data to be up to 2^64 -1 bytes 191 * in length. If a full message is used, the AES CCA implementation 192 * restricts the maximum AAD length to 2^32 -1 bytes. 193 * If partial messages are used, the implementation supports 194 * 2^64 -1 bytes maximum AAD length. 195 * 196 * However, in the cryptoapi's aead_request structure, 197 * assoclen is an unsigned int, thus it cannot hold a length 198 * value greater than 2^32 - 1. 199 * Thus the AAD is further constrained by this and is never 200 * greater than 2^32. 201 */ 202 203 if (!req->assoclen) { 204 b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0; 205 } else if (req->assoclen <= 14) { 206 /* if associated data is 14 bytes or less, we do 1 GCM 207 * operation on 2 AES blocks, B0 (stored in the csbcpb) and B1, 208 * which is fed in through the source buffers here */ 209 b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0; 210 b1 = nx_ctx->priv.ccm.iauth_tag; 211 iauth_len = req->assoclen; 212 } else if (req->assoclen <= 65280) { 213 /* if associated data is less than (2^16 - 2^8), we construct 214 * B1 differently and feed in the associated data to a CCA 215 * operation */ 216 b0 = nx_ctx->csbcpb_aead->cpb.aes_cca.b0; 217 b1 = nx_ctx->csbcpb_aead->cpb.aes_cca.b1; 218 iauth_len = 14; 219 } else { 220 b0 = nx_ctx->csbcpb_aead->cpb.aes_cca.b0; 221 b1 = nx_ctx->csbcpb_aead->cpb.aes_cca.b1; 222 iauth_len = 10; 223 } 224 225 /* generate B0 */ 226 rc = generate_b0(iv, req->assoclen, authsize, nbytes, b0); 227 if (rc) 228 return rc; 229 230 /* generate B1: 231 * add control info for associated data 232 * RFC 3610 and NIST Special Publication 800-38C 233 */ 234 if (b1) { 235 memset(b1, 0, 16); 236 if (req->assoclen <= 65280) { 237 *(u16 *)b1 = (u16)req->assoclen; 238 scatterwalk_map_and_copy(b1 + 2, req->assoc, 0, 239 iauth_len, SCATTERWALK_FROM_SG); 240 } else { 241 *(u16 *)b1 = (u16)(0xfffe); 242 *(u32 *)&b1[2] = (u32)req->assoclen; 243 scatterwalk_map_and_copy(b1 + 6, req->assoc, 0, 244 iauth_len, SCATTERWALK_FROM_SG); 245 } 246 } 247 248 /* now copy any remaining AAD to scatterlist and call nx... */ 249 if (!req->assoclen) { 250 return rc; 251 } else if (req->assoclen <= 14) { 252 unsigned int len = 16; 253 254 nx_insg = nx_build_sg_list(nx_insg, b1, &len, nx_ctx->ap->sglen); 255 256 if (len != 16) 257 return -EINVAL; 258 259 nx_outsg = nx_build_sg_list(nx_outsg, tmp, &len, 260 nx_ctx->ap->sglen); 261 262 if (len != 16) 263 return -EINVAL; 264 265 /* inlen should be negative, indicating to phyp that its a 266 * pointer to an sg list */ 267 nx_ctx->op.inlen = (nx_ctx->in_sg - nx_insg) * 268 sizeof(struct nx_sg); 269 nx_ctx->op.outlen = (nx_ctx->out_sg - nx_outsg) * 270 sizeof(struct nx_sg); 271 272 NX_CPB_FDM(nx_ctx->csbcpb) |= NX_FDM_ENDE_ENCRYPT; 273 NX_CPB_FDM(nx_ctx->csbcpb) |= NX_FDM_INTERMEDIATE; 274 275 result = nx_ctx->csbcpb->cpb.aes_ccm.out_pat_or_mac; 276 277 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 278 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); 279 if (rc) 280 return rc; 281 282 atomic_inc(&(nx_ctx->stats->aes_ops)); 283 atomic64_add(req->assoclen, &(nx_ctx->stats->aes_bytes)); 284 285 } else { 286 unsigned int processed = 0, to_process; 287 288 processed += iauth_len; 289 290 /* page_limit: number of sg entries that fit on one page */ 291 max_sg_len = min_t(u64, nx_ctx->ap->sglen, 292 nx_driver.of.max_sg_len/sizeof(struct nx_sg)); 293 max_sg_len = min_t(u64, max_sg_len, 294 nx_ctx->ap->databytelen/NX_PAGE_SIZE); 295 296 do { 297 to_process = min_t(u32, req->assoclen - processed, 298 nx_ctx->ap->databytelen); 299 300 nx_insg = nx_walk_and_build(nx_ctx->in_sg, 301 nx_ctx->ap->sglen, 302 req->assoc, processed, 303 &to_process); 304 305 if ((to_process + processed) < req->assoclen) { 306 NX_CPB_FDM(nx_ctx->csbcpb_aead) |= 307 NX_FDM_INTERMEDIATE; 308 } else { 309 NX_CPB_FDM(nx_ctx->csbcpb_aead) &= 310 ~NX_FDM_INTERMEDIATE; 311 } 312 313 314 nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_insg) * 315 sizeof(struct nx_sg); 316 317 result = nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0; 318 319 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op_aead, 320 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); 321 if (rc) 322 return rc; 323 324 memcpy(nx_ctx->csbcpb_aead->cpb.aes_cca.b0, 325 nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0, 326 AES_BLOCK_SIZE); 327 328 NX_CPB_FDM(nx_ctx->csbcpb_aead) |= NX_FDM_CONTINUATION; 329 330 atomic_inc(&(nx_ctx->stats->aes_ops)); 331 atomic64_add(req->assoclen, 332 &(nx_ctx->stats->aes_bytes)); 333 334 processed += to_process; 335 } while (processed < req->assoclen); 336 337 result = nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0; 338 } 339 340 memcpy(out, result, AES_BLOCK_SIZE); 341 342 return rc; 343 } 344 345 static int ccm_nx_decrypt(struct aead_request *req, 346 struct blkcipher_desc *desc) 347 { 348 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 349 struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; 350 unsigned int nbytes = req->cryptlen; 351 unsigned int authsize = crypto_aead_authsize(crypto_aead_reqtfm(req)); 352 struct nx_ccm_priv *priv = &nx_ctx->priv.ccm; 353 unsigned long irq_flags; 354 unsigned int processed = 0, to_process; 355 int rc = -1; 356 357 spin_lock_irqsave(&nx_ctx->lock, irq_flags); 358 359 nbytes -= authsize; 360 361 /* copy out the auth tag to compare with later */ 362 scatterwalk_map_and_copy(priv->oauth_tag, 363 req->src, nbytes, authsize, 364 SCATTERWALK_FROM_SG); 365 366 rc = generate_pat(desc->info, req, nx_ctx, authsize, nbytes, 367 csbcpb->cpb.aes_ccm.in_pat_or_b0); 368 if (rc) 369 goto out; 370 371 do { 372 373 /* to_process: the AES_BLOCK_SIZE data chunk to process in this 374 * update. This value is bound by sg list limits. 375 */ 376 to_process = nbytes - processed; 377 378 if ((to_process + processed) < nbytes) 379 NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE; 380 else 381 NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE; 382 383 NX_CPB_FDM(nx_ctx->csbcpb) &= ~NX_FDM_ENDE_ENCRYPT; 384 385 rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src, 386 &to_process, processed, 387 csbcpb->cpb.aes_ccm.iv_or_ctr); 388 if (rc) 389 goto out; 390 391 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 392 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); 393 if (rc) 394 goto out; 395 396 /* for partial completion, copy following for next 397 * entry into loop... 398 */ 399 memcpy(desc->info, csbcpb->cpb.aes_ccm.out_ctr, AES_BLOCK_SIZE); 400 memcpy(csbcpb->cpb.aes_ccm.in_pat_or_b0, 401 csbcpb->cpb.aes_ccm.out_pat_or_mac, AES_BLOCK_SIZE); 402 memcpy(csbcpb->cpb.aes_ccm.in_s0, 403 csbcpb->cpb.aes_ccm.out_s0, AES_BLOCK_SIZE); 404 405 NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION; 406 407 /* update stats */ 408 atomic_inc(&(nx_ctx->stats->aes_ops)); 409 atomic64_add(csbcpb->csb.processed_byte_count, 410 &(nx_ctx->stats->aes_bytes)); 411 412 processed += to_process; 413 } while (processed < nbytes); 414 415 rc = memcmp(csbcpb->cpb.aes_ccm.out_pat_or_mac, priv->oauth_tag, 416 authsize) ? -EBADMSG : 0; 417 out: 418 spin_unlock_irqrestore(&nx_ctx->lock, irq_flags); 419 return rc; 420 } 421 422 static int ccm_nx_encrypt(struct aead_request *req, 423 struct blkcipher_desc *desc) 424 { 425 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 426 struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; 427 unsigned int nbytes = req->cryptlen; 428 unsigned int authsize = crypto_aead_authsize(crypto_aead_reqtfm(req)); 429 unsigned long irq_flags; 430 unsigned int processed = 0, to_process; 431 int rc = -1; 432 433 spin_lock_irqsave(&nx_ctx->lock, irq_flags); 434 435 rc = generate_pat(desc->info, req, nx_ctx, authsize, nbytes, 436 csbcpb->cpb.aes_ccm.in_pat_or_b0); 437 if (rc) 438 goto out; 439 440 do { 441 /* to process: the AES_BLOCK_SIZE data chunk to process in this 442 * update. This value is bound by sg list limits. 443 */ 444 to_process = nbytes - processed; 445 446 if ((to_process + processed) < nbytes) 447 NX_CPB_FDM(csbcpb) |= NX_FDM_INTERMEDIATE; 448 else 449 NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE; 450 451 NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT; 452 453 rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src, 454 &to_process, processed, 455 csbcpb->cpb.aes_ccm.iv_or_ctr); 456 if (rc) 457 goto out; 458 459 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 460 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); 461 if (rc) 462 goto out; 463 464 /* for partial completion, copy following for next 465 * entry into loop... 466 */ 467 memcpy(desc->info, csbcpb->cpb.aes_ccm.out_ctr, AES_BLOCK_SIZE); 468 memcpy(csbcpb->cpb.aes_ccm.in_pat_or_b0, 469 csbcpb->cpb.aes_ccm.out_pat_or_mac, AES_BLOCK_SIZE); 470 memcpy(csbcpb->cpb.aes_ccm.in_s0, 471 csbcpb->cpb.aes_ccm.out_s0, AES_BLOCK_SIZE); 472 473 NX_CPB_FDM(csbcpb) |= NX_FDM_CONTINUATION; 474 475 /* update stats */ 476 atomic_inc(&(nx_ctx->stats->aes_ops)); 477 atomic64_add(csbcpb->csb.processed_byte_count, 478 &(nx_ctx->stats->aes_bytes)); 479 480 processed += to_process; 481 482 } while (processed < nbytes); 483 484 /* copy out the auth tag */ 485 scatterwalk_map_and_copy(csbcpb->cpb.aes_ccm.out_pat_or_mac, 486 req->dst, nbytes, authsize, 487 SCATTERWALK_TO_SG); 488 489 out: 490 spin_unlock_irqrestore(&nx_ctx->lock, irq_flags); 491 return rc; 492 } 493 494 static int ccm4309_aes_nx_encrypt(struct aead_request *req) 495 { 496 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 497 struct blkcipher_desc desc; 498 u8 *iv = nx_ctx->priv.ccm.iv; 499 500 iv[0] = 3; 501 memcpy(iv + 1, nx_ctx->priv.ccm.nonce, 3); 502 memcpy(iv + 4, req->iv, 8); 503 504 desc.info = iv; 505 desc.tfm = (struct crypto_blkcipher *)req->base.tfm; 506 507 return ccm_nx_encrypt(req, &desc); 508 } 509 510 static int ccm_aes_nx_encrypt(struct aead_request *req) 511 { 512 struct blkcipher_desc desc; 513 int rc; 514 515 desc.info = req->iv; 516 desc.tfm = (struct crypto_blkcipher *)req->base.tfm; 517 518 rc = crypto_ccm_check_iv(desc.info); 519 if (rc) 520 return rc; 521 522 return ccm_nx_encrypt(req, &desc); 523 } 524 525 static int ccm4309_aes_nx_decrypt(struct aead_request *req) 526 { 527 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 528 struct blkcipher_desc desc; 529 u8 *iv = nx_ctx->priv.ccm.iv; 530 531 iv[0] = 3; 532 memcpy(iv + 1, nx_ctx->priv.ccm.nonce, 3); 533 memcpy(iv + 4, req->iv, 8); 534 535 desc.info = iv; 536 desc.tfm = (struct crypto_blkcipher *)req->base.tfm; 537 538 return ccm_nx_decrypt(req, &desc); 539 } 540 541 static int ccm_aes_nx_decrypt(struct aead_request *req) 542 { 543 struct blkcipher_desc desc; 544 int rc; 545 546 desc.info = req->iv; 547 desc.tfm = (struct crypto_blkcipher *)req->base.tfm; 548 549 rc = crypto_ccm_check_iv(desc.info); 550 if (rc) 551 return rc; 552 553 return ccm_nx_decrypt(req, &desc); 554 } 555 556 /* tell the block cipher walk routines that this is a stream cipher by 557 * setting cra_blocksize to 1. Even using blkcipher_walk_virt_block 558 * during encrypt/decrypt doesn't solve this problem, because it calls 559 * blkcipher_walk_done under the covers, which doesn't use walk->blocksize, 560 * but instead uses this tfm->blocksize. */ 561 struct crypto_alg nx_ccm_aes_alg = { 562 .cra_name = "ccm(aes)", 563 .cra_driver_name = "ccm-aes-nx", 564 .cra_priority = 300, 565 .cra_flags = CRYPTO_ALG_TYPE_AEAD | 566 CRYPTO_ALG_NEED_FALLBACK, 567 .cra_blocksize = 1, 568 .cra_ctxsize = sizeof(struct nx_crypto_ctx), 569 .cra_type = &crypto_aead_type, 570 .cra_module = THIS_MODULE, 571 .cra_init = nx_crypto_ctx_aes_ccm_init, 572 .cra_exit = nx_crypto_ctx_exit, 573 .cra_aead = { 574 .ivsize = AES_BLOCK_SIZE, 575 .maxauthsize = AES_BLOCK_SIZE, 576 .setkey = ccm_aes_nx_set_key, 577 .setauthsize = ccm_aes_nx_setauthsize, 578 .encrypt = ccm_aes_nx_encrypt, 579 .decrypt = ccm_aes_nx_decrypt, 580 } 581 }; 582 583 struct crypto_alg nx_ccm4309_aes_alg = { 584 .cra_name = "rfc4309(ccm(aes))", 585 .cra_driver_name = "rfc4309-ccm-aes-nx", 586 .cra_priority = 300, 587 .cra_flags = CRYPTO_ALG_TYPE_AEAD | 588 CRYPTO_ALG_NEED_FALLBACK, 589 .cra_blocksize = 1, 590 .cra_ctxsize = sizeof(struct nx_crypto_ctx), 591 .cra_type = &crypto_nivaead_type, 592 .cra_module = THIS_MODULE, 593 .cra_init = nx_crypto_ctx_aes_ccm_init, 594 .cra_exit = nx_crypto_ctx_exit, 595 .cra_aead = { 596 .ivsize = 8, 597 .maxauthsize = AES_BLOCK_SIZE, 598 .setkey = ccm4309_aes_nx_set_key, 599 .setauthsize = ccm4309_aes_nx_setauthsize, 600 .encrypt = ccm4309_aes_nx_encrypt, 601 .decrypt = ccm4309_aes_nx_decrypt, 602 .geniv = "seqiv", 603 } 604 }; 605