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 struct vio_pfo_op *op = NULL; 183 u8 tmp[16], *b1 = NULL, *b0 = NULL, *result = NULL; 184 int rc; 185 186 /* zero the ctr value */ 187 memset(iv + 15 - iv[0], 0, iv[0] + 1); 188 189 if (!req->assoclen) { 190 b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0; 191 } else if (req->assoclen <= 14) { 192 /* if associated data is 14 bytes or less, we do 1 GCM 193 * operation on 2 AES blocks, B0 (stored in the csbcpb) and B1, 194 * which is fed in through the source buffers here */ 195 b0 = nx_ctx->csbcpb->cpb.aes_ccm.in_pat_or_b0; 196 b1 = nx_ctx->priv.ccm.iauth_tag; 197 iauth_len = req->assoclen; 198 199 nx_insg = nx_build_sg_list(nx_insg, b1, 16, nx_ctx->ap->sglen); 200 nx_outsg = nx_build_sg_list(nx_outsg, tmp, 16, 201 nx_ctx->ap->sglen); 202 203 /* inlen should be negative, indicating to phyp that its a 204 * pointer to an sg list */ 205 nx_ctx->op.inlen = (nx_ctx->in_sg - nx_insg) * 206 sizeof(struct nx_sg); 207 nx_ctx->op.outlen = (nx_ctx->out_sg - nx_outsg) * 208 sizeof(struct nx_sg); 209 210 NX_CPB_FDM(nx_ctx->csbcpb) |= NX_FDM_ENDE_ENCRYPT; 211 NX_CPB_FDM(nx_ctx->csbcpb) |= NX_FDM_INTERMEDIATE; 212 213 op = &nx_ctx->op; 214 result = nx_ctx->csbcpb->cpb.aes_ccm.out_pat_or_mac; 215 } else if (req->assoclen <= 65280) { 216 /* if associated data is less than (2^16 - 2^8), we construct 217 * B1 differently and feed in the associated data to a CCA 218 * operation */ 219 b0 = nx_ctx->csbcpb_aead->cpb.aes_cca.b0; 220 b1 = nx_ctx->csbcpb_aead->cpb.aes_cca.b1; 221 iauth_len = 14; 222 223 /* remaining assoc data must have scatterlist built for it */ 224 nx_insg = nx_walk_and_build(nx_insg, nx_ctx->ap->sglen, 225 req->assoc, iauth_len, 226 req->assoclen - iauth_len); 227 nx_ctx->op_aead.inlen = (nx_ctx->in_sg - nx_insg) * 228 sizeof(struct nx_sg); 229 230 op = &nx_ctx->op_aead; 231 result = nx_ctx->csbcpb_aead->cpb.aes_cca.out_pat_or_b0; 232 } else { 233 /* if associated data is less than (2^32), we construct B1 234 * differently yet again and feed in the associated data to a 235 * CCA operation */ 236 pr_err("associated data len is %u bytes (returning -EINVAL)\n", 237 req->assoclen); 238 rc = -EINVAL; 239 } 240 241 rc = generate_b0(iv, req->assoclen, authsize, nbytes, b0); 242 if (rc) 243 goto done; 244 245 if (b1) { 246 memset(b1, 0, 16); 247 *(u16 *)b1 = (u16)req->assoclen; 248 249 scatterwalk_map_and_copy(b1 + 2, req->assoc, 0, 250 iauth_len, SCATTERWALK_FROM_SG); 251 252 rc = nx_hcall_sync(nx_ctx, op, 253 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); 254 if (rc) 255 goto done; 256 257 atomic_inc(&(nx_ctx->stats->aes_ops)); 258 atomic64_add(req->assoclen, &(nx_ctx->stats->aes_bytes)); 259 260 memcpy(out, result, AES_BLOCK_SIZE); 261 } 262 done: 263 return rc; 264 } 265 266 static int ccm_nx_decrypt(struct aead_request *req, 267 struct blkcipher_desc *desc) 268 { 269 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 270 struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; 271 unsigned int nbytes = req->cryptlen; 272 unsigned int authsize = crypto_aead_authsize(crypto_aead_reqtfm(req)); 273 struct nx_ccm_priv *priv = &nx_ctx->priv.ccm; 274 int rc = -1; 275 276 if (nbytes > nx_ctx->ap->databytelen) 277 return -EINVAL; 278 279 nbytes -= authsize; 280 281 /* copy out the auth tag to compare with later */ 282 scatterwalk_map_and_copy(priv->oauth_tag, 283 req->src, nbytes, authsize, 284 SCATTERWALK_FROM_SG); 285 286 rc = generate_pat(desc->info, req, nx_ctx, authsize, nbytes, 287 csbcpb->cpb.aes_ccm.in_pat_or_b0); 288 if (rc) 289 goto out; 290 291 rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src, nbytes, 292 csbcpb->cpb.aes_ccm.iv_or_ctr); 293 if (rc) 294 goto out; 295 296 NX_CPB_FDM(nx_ctx->csbcpb) &= ~NX_FDM_ENDE_ENCRYPT; 297 NX_CPB_FDM(nx_ctx->csbcpb) &= ~NX_FDM_INTERMEDIATE; 298 299 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 300 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); 301 if (rc) 302 goto out; 303 304 atomic_inc(&(nx_ctx->stats->aes_ops)); 305 atomic64_add(csbcpb->csb.processed_byte_count, 306 &(nx_ctx->stats->aes_bytes)); 307 308 rc = memcmp(csbcpb->cpb.aes_ccm.out_pat_or_mac, priv->oauth_tag, 309 authsize) ? -EBADMSG : 0; 310 out: 311 return rc; 312 } 313 314 static int ccm_nx_encrypt(struct aead_request *req, 315 struct blkcipher_desc *desc) 316 { 317 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 318 struct nx_csbcpb *csbcpb = nx_ctx->csbcpb; 319 unsigned int nbytes = req->cryptlen; 320 unsigned int authsize = crypto_aead_authsize(crypto_aead_reqtfm(req)); 321 int rc = -1; 322 323 if (nbytes > nx_ctx->ap->databytelen) 324 return -EINVAL; 325 326 rc = generate_pat(desc->info, req, nx_ctx, authsize, nbytes, 327 csbcpb->cpb.aes_ccm.in_pat_or_b0); 328 if (rc) 329 goto out; 330 331 rc = nx_build_sg_lists(nx_ctx, desc, req->dst, req->src, nbytes, 332 csbcpb->cpb.aes_ccm.iv_or_ctr); 333 if (rc) 334 goto out; 335 336 NX_CPB_FDM(csbcpb) |= NX_FDM_ENDE_ENCRYPT; 337 NX_CPB_FDM(csbcpb) &= ~NX_FDM_INTERMEDIATE; 338 339 rc = nx_hcall_sync(nx_ctx, &nx_ctx->op, 340 req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP); 341 if (rc) 342 goto out; 343 344 atomic_inc(&(nx_ctx->stats->aes_ops)); 345 atomic64_add(csbcpb->csb.processed_byte_count, 346 &(nx_ctx->stats->aes_bytes)); 347 348 /* copy out the auth tag */ 349 scatterwalk_map_and_copy(csbcpb->cpb.aes_ccm.out_pat_or_mac, 350 req->dst, nbytes, authsize, 351 SCATTERWALK_TO_SG); 352 out: 353 return rc; 354 } 355 356 static int ccm4309_aes_nx_encrypt(struct aead_request *req) 357 { 358 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 359 struct blkcipher_desc desc; 360 u8 *iv = nx_ctx->priv.ccm.iv; 361 362 iv[0] = 3; 363 memcpy(iv + 1, nx_ctx->priv.ccm.nonce, 3); 364 memcpy(iv + 4, req->iv, 8); 365 366 desc.info = iv; 367 desc.tfm = (struct crypto_blkcipher *)req->base.tfm; 368 369 return ccm_nx_encrypt(req, &desc); 370 } 371 372 static int ccm_aes_nx_encrypt(struct aead_request *req) 373 { 374 struct blkcipher_desc desc; 375 int rc; 376 377 desc.info = req->iv; 378 desc.tfm = (struct crypto_blkcipher *)req->base.tfm; 379 380 rc = crypto_ccm_check_iv(desc.info); 381 if (rc) 382 return rc; 383 384 return ccm_nx_encrypt(req, &desc); 385 } 386 387 static int ccm4309_aes_nx_decrypt(struct aead_request *req) 388 { 389 struct nx_crypto_ctx *nx_ctx = crypto_tfm_ctx(req->base.tfm); 390 struct blkcipher_desc desc; 391 u8 *iv = nx_ctx->priv.ccm.iv; 392 393 iv[0] = 3; 394 memcpy(iv + 1, nx_ctx->priv.ccm.nonce, 3); 395 memcpy(iv + 4, req->iv, 8); 396 397 desc.info = iv; 398 desc.tfm = (struct crypto_blkcipher *)req->base.tfm; 399 400 return ccm_nx_decrypt(req, &desc); 401 } 402 403 static int ccm_aes_nx_decrypt(struct aead_request *req) 404 { 405 struct blkcipher_desc desc; 406 int rc; 407 408 desc.info = req->iv; 409 desc.tfm = (struct crypto_blkcipher *)req->base.tfm; 410 411 rc = crypto_ccm_check_iv(desc.info); 412 if (rc) 413 return rc; 414 415 return ccm_nx_decrypt(req, &desc); 416 } 417 418 /* tell the block cipher walk routines that this is a stream cipher by 419 * setting cra_blocksize to 1. Even using blkcipher_walk_virt_block 420 * during encrypt/decrypt doesn't solve this problem, because it calls 421 * blkcipher_walk_done under the covers, which doesn't use walk->blocksize, 422 * but instead uses this tfm->blocksize. */ 423 struct crypto_alg nx_ccm_aes_alg = { 424 .cra_name = "ccm(aes)", 425 .cra_driver_name = "ccm-aes-nx", 426 .cra_priority = 300, 427 .cra_flags = CRYPTO_ALG_TYPE_AEAD | 428 CRYPTO_ALG_NEED_FALLBACK, 429 .cra_blocksize = 1, 430 .cra_ctxsize = sizeof(struct nx_crypto_ctx), 431 .cra_type = &crypto_aead_type, 432 .cra_module = THIS_MODULE, 433 .cra_list = LIST_HEAD_INIT(nx_ccm_aes_alg.cra_list), 434 .cra_init = nx_crypto_ctx_aes_ccm_init, 435 .cra_exit = nx_crypto_ctx_exit, 436 .cra_aead = { 437 .ivsize = AES_BLOCK_SIZE, 438 .maxauthsize = AES_BLOCK_SIZE, 439 .setkey = ccm_aes_nx_set_key, 440 .setauthsize = ccm_aes_nx_setauthsize, 441 .encrypt = ccm_aes_nx_encrypt, 442 .decrypt = ccm_aes_nx_decrypt, 443 } 444 }; 445 446 struct crypto_alg nx_ccm4309_aes_alg = { 447 .cra_name = "rfc4309(ccm(aes))", 448 .cra_driver_name = "rfc4309-ccm-aes-nx", 449 .cra_priority = 300, 450 .cra_flags = CRYPTO_ALG_TYPE_AEAD | 451 CRYPTO_ALG_NEED_FALLBACK, 452 .cra_blocksize = 1, 453 .cra_ctxsize = sizeof(struct nx_crypto_ctx), 454 .cra_type = &crypto_nivaead_type, 455 .cra_module = THIS_MODULE, 456 .cra_list = LIST_HEAD_INIT(nx_ccm4309_aes_alg.cra_list), 457 .cra_init = nx_crypto_ctx_aes_ccm_init, 458 .cra_exit = nx_crypto_ctx_exit, 459 .cra_aead = { 460 .ivsize = 8, 461 .maxauthsize = AES_BLOCK_SIZE, 462 .setkey = ccm4309_aes_nx_set_key, 463 .setauthsize = ccm4309_aes_nx_setauthsize, 464 .encrypt = ccm4309_aes_nx_encrypt, 465 .decrypt = ccm4309_aes_nx_decrypt, 466 .geniv = "seqiv", 467 } 468 }; 469