drivers/crypto/nx/nx-aes-gcm.c

   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 };