drivers/crypto/omap-aes-gcm.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Cryptographic API.
   4  *
   5  * Support for OMAP AES GCM HW acceleration.
   6  *
   7  * Copyright (c) 2016 Texas Instruments Incorporated
   8  */
   9
  10 #include <linux/errno.h>
  11 #include <linux/scatterlist.h>
  12 #include <linux/dma-mapping.h>
  13 #include <linux/dmaengine.h>
  14 #include <linux/omap-dma.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/pm_runtime.h>
  17 #include <crypto/aes.h>
  18 #include <crypto/gcm.h>
  19 #include <crypto/scatterwalk.h>
  20 #include <crypto/skcipher.h>
  21 #include <crypto/internal/aead.h>
  22
  23 #include "omap-crypto.h"
  24 #include "omap-aes.h"
  25
  26 static int omap_aes_gcm_handle_queue(struct omap_aes_dev *dd,
  27                                      struct aead_request *req);
  28
  29 static void omap_aes_gcm_finish_req(struct omap_aes_dev *dd, int ret)
  30 {
  31         struct aead_request *req = dd->aead_req;
  32
  33         dd->in_sg = NULL;
  34         dd->out_sg = NULL;
  35
  36         crypto_finalize_aead_request(dd->engine, req, ret);
  37
  38         pm_runtime_mark_last_busy(dd->dev);
  39         pm_runtime_put_autosuspend(dd->dev);
  40 }
  41
  42 static void omap_aes_gcm_done_task(struct omap_aes_dev *dd)
  43 {
  44         u8 *tag;
  45         int alen, clen, i, ret = 0, nsg;
  46         struct omap_aes_reqctx *rctx;
  47
  48         alen = ALIGN(dd->assoc_len, AES_BLOCK_SIZE);
  49         clen = ALIGN(dd->total, AES_BLOCK_SIZE);
  50         rctx = aead_request_ctx(dd->aead_req);
  51
  52         nsg = !!(dd->assoc_len && dd->total);
  53
  54         dma_sync_sg_for_device(dd->dev, dd->out_sg, dd->out_sg_len,
  55                                DMA_FROM_DEVICE);
  56         dma_unmap_sg(dd->dev, dd->in_sg, dd->in_sg_len, DMA_TO_DEVICE);
  57         dma_unmap_sg(dd->dev, dd->out_sg, dd->out_sg_len, DMA_FROM_DEVICE);
  58         omap_aes_crypt_dma_stop(dd);
  59
  60         omap_crypto_cleanup(dd->out_sg, dd->orig_out,
  61                             dd->aead_req->assoclen, dd->total,
  62                             FLAGS_OUT_DATA_ST_SHIFT, dd->flags);
  63
  64         if (dd->flags & FLAGS_ENCRYPT)
  65                 scatterwalk_map_and_copy(rctx->auth_tag,
  66                                          dd->aead_req->dst,
  67                                          dd->total + dd->aead_req->assoclen,
  68                                          dd->authsize, 1);
  69
  70         omap_crypto_cleanup(&dd->in_sgl[0], NULL, 0, alen,
  71                             FLAGS_ASSOC_DATA_ST_SHIFT, dd->flags);
  72
  73         omap_crypto_cleanup(&dd->in_sgl[nsg], NULL, 0, clen,
  74                             FLAGS_IN_DATA_ST_SHIFT, dd->flags);
  75
  76         if (!(dd->flags & FLAGS_ENCRYPT)) {
  77                 tag = (u8 *)rctx->auth_tag;
  78                 for (i = 0; i < dd->authsize; i++) {
  79                         if (tag[i]) {
  80                                 dev_err(dd->dev, "GCM decryption: Tag Message is wrong\n");
  81                                 ret = -EBADMSG;
  82                         }
  83                 }
  84         }
  85
  86         omap_aes_gcm_finish_req(dd, ret);
  87 }
  88
  89 static int omap_aes_gcm_copy_buffers(struct omap_aes_dev *dd,
  90                                      struct aead_request *req)
  91 {
  92         int alen, clen, cryptlen, assoclen, ret;
  93         struct crypto_aead *aead = crypto_aead_reqtfm(req);
  94         unsigned int authlen = crypto_aead_authsize(aead);
  95         struct scatterlist *tmp, sg_arr[2];
  96         int nsg;
  97         u16 flags;
  98
  99         assoclen = req->assoclen;
 100         cryptlen = req->cryptlen;
 101
 102         if (dd->flags & FLAGS_RFC4106_GCM)
 103                 assoclen -= 8;
 104
 105         if (!(dd->flags & FLAGS_ENCRYPT))
 106                 cryptlen -= authlen;
 107
 108         alen = ALIGN(assoclen, AES_BLOCK_SIZE);
 109         clen = ALIGN(cryptlen, AES_BLOCK_SIZE);
 110
 111         nsg = !!(assoclen && cryptlen);
 112
 113         omap_aes_clear_copy_flags(dd);
 114
 115         sg_init_table(dd->in_sgl, nsg + 1);
 116         if (assoclen) {
 117                 tmp = req->src;
 118                 ret = omap_crypto_align_sg(&tmp, assoclen,
 119                                            AES_BLOCK_SIZE, dd->in_sgl,
 120                                            OMAP_CRYPTO_COPY_DATA |
 121                                            OMAP_CRYPTO_ZERO_BUF |
 122                                            OMAP_CRYPTO_FORCE_SINGLE_ENTRY,
 123                                            FLAGS_ASSOC_DATA_ST_SHIFT,
 124                                            &dd->flags);
 125                 if (ret)
 126                         return ret;
 127         }
 128
 129         if (cryptlen) {
 130                 tmp = scatterwalk_ffwd(sg_arr, req->src, req->assoclen);
 131
 132                 if (nsg)
 133                         sg_unmark_end(dd->in_sgl);
 134
 135                 ret = omap_crypto_align_sg(&tmp, cryptlen,
 136                                            AES_BLOCK_SIZE, &dd->in_sgl[nsg],
 137                                            OMAP_CRYPTO_COPY_DATA |
 138                                            OMAP_CRYPTO_ZERO_BUF |
 139                                            OMAP_CRYPTO_FORCE_SINGLE_ENTRY,
 140                                            FLAGS_IN_DATA_ST_SHIFT,
 141                                            &dd->flags);
 142                 if (ret)
 143                         return ret;
 144         }
 145
 146         dd->in_sg = dd->in_sgl;
 147         dd->total = cryptlen;
 148         dd->assoc_len = assoclen;
 149         dd->authsize = authlen;
 150
 151         dd->out_sg = req->dst;
 152         dd->orig_out = req->dst;
 153
 154         dd->out_sg = scatterwalk_ffwd(sg_arr, req->dst, req->assoclen);
 155
 156         flags = 0;
 157         if (req->src == req->dst || dd->out_sg == sg_arr)
 158                 flags |= OMAP_CRYPTO_FORCE_COPY;
 159
 160         if (cryptlen) {
 161                 ret = omap_crypto_align_sg(&dd->out_sg, cryptlen,
 162                                            AES_BLOCK_SIZE, &dd->out_sgl,
 163                                            flags,
 164                                            FLAGS_OUT_DATA_ST_SHIFT, &dd->flags);
 165                 if (ret)
 166                         return ret;
 167         }
 168
 169         dd->in_sg_len = sg_nents_for_len(dd->in_sg, alen + clen);
 170         dd->out_sg_len = sg_nents_for_len(dd->out_sg, clen);
 171
 172         return 0;
 173 }
 174
 175 static int do_encrypt_iv(struct aead_request *req, u32 *tag, u32 *iv)
 176 {
 177         struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 178
 179         aes_encrypt(&ctx->actx, (u8 *)tag, (u8 *)iv);
 180         return 0;
 181 }
 182
 183 void omap_aes_gcm_dma_out_callback(void *data)
 184 {
 185         struct omap_aes_dev *dd = data;
 186         struct omap_aes_reqctx *rctx;
 187         int i, val;
 188         u32 *auth_tag, tag[4];
 189
 190         if (!(dd->flags & FLAGS_ENCRYPT))
 191                 scatterwalk_map_and_copy(tag, dd->aead_req->src,
 192                                          dd->total + dd->aead_req->assoclen,
 193                                          dd->authsize, 0);
 194
 195         rctx = aead_request_ctx(dd->aead_req);
 196         auth_tag = (u32 *)rctx->auth_tag;
 197         for (i = 0; i < 4; i++) {
 198                 val = omap_aes_read(dd, AES_REG_TAG_N(dd, i));
 199                 auth_tag[i] = val ^ auth_tag[i];
 200                 if (!(dd->flags & FLAGS_ENCRYPT))
 201                         auth_tag[i] = auth_tag[i] ^ tag[i];
 202         }
 203
 204         omap_aes_gcm_done_task(dd);
 205 }
 206
 207 static int omap_aes_gcm_handle_queue(struct omap_aes_dev *dd,
 208                                      struct aead_request *req)
 209 {
 210         if (req)
 211                 return crypto_transfer_aead_request_to_engine(dd->engine, req);
 212
 213         return 0;
 214 }
 215
 216 static int omap_aes_gcm_prepare_req(struct crypto_engine *engine, void *areq)
 217 {
 218         struct aead_request *req = container_of(areq, struct aead_request,
 219                                                 base);
 220         struct omap_aes_reqctx *rctx = aead_request_ctx(req);
 221         struct omap_aes_dev *dd = rctx->dd;
 222         struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 223         int err;
 224
 225         dd->aead_req = req;
 226
 227         rctx->mode &= FLAGS_MODE_MASK;
 228         dd->flags = (dd->flags & ~FLAGS_MODE_MASK) | rctx->mode;
 229
 230         err = omap_aes_gcm_copy_buffers(dd, req);
 231         if (err)
 232                 return err;
 233
 234         dd->ctx = &ctx->octx;
 235
 236         return omap_aes_write_ctrl(dd);
 237 }
 238
 239 static int omap_aes_gcm_crypt(struct aead_request *req, unsigned long mode)
 240 {
 241         struct omap_aes_reqctx *rctx = aead_request_ctx(req);
 242         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 243         unsigned int authlen = crypto_aead_authsize(aead);
 244         struct omap_aes_dev *dd;
 245         __be32 counter = cpu_to_be32(1);
 246         int err, assoclen;
 247
 248         memset(rctx->auth_tag, 0, sizeof(rctx->auth_tag));
 249         memcpy(rctx->iv + GCM_AES_IV_SIZE, &counter, 4);
 250
 251         err = do_encrypt_iv(req, (u32 *)rctx->auth_tag, (u32 *)rctx->iv);
 252         if (err)
 253                 return err;
 254
 255         if (mode & FLAGS_RFC4106_GCM)
 256                 assoclen = req->assoclen - 8;
 257         else
 258                 assoclen = req->assoclen;
 259         if (assoclen + req->cryptlen == 0) {
 260                 scatterwalk_map_and_copy(rctx->auth_tag, req->dst, 0, authlen,
 261                                          1);
 262                 return 0;
 263         }
 264
 265         dd = omap_aes_find_dev(rctx);
 266         if (!dd)
 267                 return -ENODEV;
 268         rctx->mode = mode;
 269
 270         return omap_aes_gcm_handle_queue(dd, req);
 271 }
 272
 273 int omap_aes_gcm_encrypt(struct aead_request *req)
 274 {
 275         struct omap_aes_reqctx *rctx = aead_request_ctx(req);
 276
 277         memcpy(rctx->iv, req->iv, GCM_AES_IV_SIZE);
 278         return omap_aes_gcm_crypt(req, FLAGS_ENCRYPT | FLAGS_GCM);
 279 }
 280
 281 int omap_aes_gcm_decrypt(struct aead_request *req)
 282 {
 283         struct omap_aes_reqctx *rctx = aead_request_ctx(req);
 284
 285         memcpy(rctx->iv, req->iv, GCM_AES_IV_SIZE);
 286         return omap_aes_gcm_crypt(req, FLAGS_GCM);
 287 }
 288
 289 int omap_aes_4106gcm_encrypt(struct aead_request *req)
 290 {
 291         struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 292         struct omap_aes_reqctx *rctx = aead_request_ctx(req);
 293
 294         memcpy(rctx->iv, ctx->octx.nonce, 4);
 295         memcpy(rctx->iv + 4, req->iv, 8);
 296         return crypto_ipsec_check_assoclen(req->assoclen) ?:
 297                omap_aes_gcm_crypt(req, FLAGS_ENCRYPT | FLAGS_GCM |
 298                                   FLAGS_RFC4106_GCM);
 299 }
 300
 301 int omap_aes_4106gcm_decrypt(struct aead_request *req)
 302 {
 303         struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req));
 304         struct omap_aes_reqctx *rctx = aead_request_ctx(req);
 305
 306         memcpy(rctx->iv, ctx->octx.nonce, 4);
 307         memcpy(rctx->iv + 4, req->iv, 8);
 308         return crypto_ipsec_check_assoclen(req->assoclen) ?:
 309                omap_aes_gcm_crypt(req, FLAGS_GCM | FLAGS_RFC4106_GCM);
 310 }
 311
 312 int omap_aes_gcm_setkey(struct crypto_aead *tfm, const u8 *key,
 313                         unsigned int keylen)
 314 {
 315         struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(tfm);
 316         int ret;
 317
 318         ret = aes_expandkey(&ctx->actx, key, keylen);
 319         if (ret)
 320                 return ret;
 321
 322         memcpy(ctx->octx.key, key, keylen);
 323         ctx->octx.keylen = keylen;
 324
 325         return 0;
 326 }
 327
 328 int omap_aes_4106gcm_setkey(struct crypto_aead *tfm, const u8 *key,
 329                             unsigned int keylen)
 330 {
 331         struct omap_aes_gcm_ctx *ctx = crypto_aead_ctx(tfm);
 332         int ret;
 333
 334         if (keylen < 4)
 335                 return -EINVAL;
 336         keylen -= 4;
 337
 338         ret = aes_expandkey(&ctx->actx, key, keylen);
 339         if (ret)
 340                 return ret;
 341
 342         memcpy(ctx->octx.key, key, keylen);
 343         memcpy(ctx->octx.nonce, key + keylen, 4);
 344         ctx->octx.keylen = keylen;
 345
 346         return 0;
 347 }
 348
 349 int omap_aes_gcm_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
 350 {
 351         return crypto_gcm_check_authsize(authsize);
 352 }
 353
 354 int omap_aes_4106gcm_setauthsize(struct crypto_aead *parent,
 355                                  unsigned int authsize)
 356 {
 357         return crypto_rfc4106_check_authsize(authsize);
 358 }
 359
 360 static int omap_aes_gcm_crypt_req(struct crypto_engine *engine, void *areq)
 361 {
 362         struct aead_request *req = container_of(areq, struct aead_request,
 363                                                 base);
 364         struct omap_aes_reqctx *rctx = aead_request_ctx(req);
 365         struct omap_aes_dev *dd = rctx->dd;
 366         int ret = 0;
 367
 368         if (!dd)
 369                 return -ENODEV;
 370
 371         if (dd->in_sg_len)
 372                 ret = omap_aes_crypt_dma_start(dd);
 373         else
 374                 omap_aes_gcm_dma_out_callback(dd);
 375
 376         return ret;
 377 }
 378
 379 int omap_aes_gcm_cra_init(struct crypto_aead *tfm)
 380 {
 381         struct omap_aes_ctx *ctx = crypto_aead_ctx(tfm);
 382
 383         ctx->enginectx.op.prepare_request = omap_aes_gcm_prepare_req;
 384         ctx->enginectx.op.unprepare_request = NULL;
 385         ctx->enginectx.op.do_one_request = omap_aes_gcm_crypt_req;
 386
 387         crypto_aead_set_reqsize(tfm, sizeof(struct omap_aes_reqctx));
 388
 389         return 0;
 390 }