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