drivers/crypto/ccp/ccp-crypto-aes-galois.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * AMD Cryptographic Coprocessor (CCP) AES GCM crypto API support
   4  *
   5  * Copyright (C) 2016,2017 Advanced Micro Devices, Inc.
   6  *
   7  * Author: Gary R Hook <gary.hook@amd.com>
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/sched.h>
  12 #include <linux/delay.h>
  13 #include <linux/scatterlist.h>
  14 #include <linux/crypto.h>
  15 #include <crypto/internal/aead.h>
  16 #include <crypto/algapi.h>
  17 #include <crypto/aes.h>
  18 #include <crypto/ctr.h>
  19 #include <crypto/gcm.h>
  20 #include <crypto/scatterwalk.h>
  21
  22 #include "ccp-crypto.h"
  23
  24 static int ccp_aes_gcm_complete(struct crypto_async_request *async_req, int ret)
  25 {
  26         return ret;
  27 }
  28
  29 static int ccp_aes_gcm_setkey(struct crypto_aead *tfm, const u8 *key,
  30                               unsigned int key_len)
  31 {
  32         struct ccp_ctx *ctx = crypto_aead_ctx_dma(tfm);
  33
  34         switch (key_len) {
  35         case AES_KEYSIZE_128:
  36                 ctx->u.aes.type = CCP_AES_TYPE_128;
  37                 break;
  38         case AES_KEYSIZE_192:
  39                 ctx->u.aes.type = CCP_AES_TYPE_192;
  40                 break;
  41         case AES_KEYSIZE_256:
  42                 ctx->u.aes.type = CCP_AES_TYPE_256;
  43                 break;
  44         default:
  45                 return -EINVAL;
  46         }
  47
  48         ctx->u.aes.mode = CCP_AES_MODE_GCM;
  49         ctx->u.aes.key_len = key_len;
  50
  51         memcpy(ctx->u.aes.key, key, key_len);
  52         sg_init_one(&ctx->u.aes.key_sg, ctx->u.aes.key, key_len);
  53
  54         return 0;
  55 }
  56
  57 static int ccp_aes_gcm_setauthsize(struct crypto_aead *tfm,
  58                                    unsigned int authsize)
  59 {
  60         switch (authsize) {
  61         case 16:
  62         case 15:
  63         case 14:
  64         case 13:
  65         case 12:
  66         case 8:
  67         case 4:
  68                 break;
  69         default:
  70                 return -EINVAL;
  71         }
  72
  73         return 0;
  74 }
  75
  76 static int ccp_aes_gcm_crypt(struct aead_request *req, bool encrypt)
  77 {
  78         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
  79         struct ccp_ctx *ctx = crypto_aead_ctx_dma(tfm);
  80         struct ccp_aes_req_ctx *rctx = aead_request_ctx_dma(req);
  81         struct scatterlist *iv_sg = NULL;
  82         unsigned int iv_len = 0;
  83         int i;
  84         int ret = 0;
  85
  86         if (!ctx->u.aes.key_len)
  87                 return -EINVAL;
  88
  89         if (ctx->u.aes.mode != CCP_AES_MODE_GCM)
  90                 return -EINVAL;
  91
  92         if (!req->iv)
  93                 return -EINVAL;
  94
  95         /*
  96          * 5 parts:
  97          *   plaintext/ciphertext input
  98          *   AAD
  99          *   key
 100          *   IV
 101          *   Destination+tag buffer
 102          */
 103
 104         /* Prepare the IV: 12 bytes + an integer (counter) */
 105         memcpy(rctx->iv, req->iv, GCM_AES_IV_SIZE);
 106         for (i = 0; i < 3; i++)
 107                 rctx->iv[i + GCM_AES_IV_SIZE] = 0;
 108         rctx->iv[AES_BLOCK_SIZE - 1] = 1;
 109
 110         /* Set up a scatterlist for the IV */
 111         iv_sg = &rctx->iv_sg;
 112         iv_len = AES_BLOCK_SIZE;
 113         sg_init_one(iv_sg, rctx->iv, iv_len);
 114
 115         /* The AAD + plaintext are concatenated in the src buffer */
 116         memset(&rctx->cmd, 0, sizeof(rctx->cmd));
 117         INIT_LIST_HEAD(&rctx->cmd.entry);
 118         rctx->cmd.engine = CCP_ENGINE_AES;
 119         rctx->cmd.u.aes.authsize = crypto_aead_authsize(tfm);
 120         rctx->cmd.u.aes.type = ctx->u.aes.type;
 121         rctx->cmd.u.aes.mode = ctx->u.aes.mode;
 122         rctx->cmd.u.aes.action = encrypt;
 123         rctx->cmd.u.aes.key = &ctx->u.aes.key_sg;
 124         rctx->cmd.u.aes.key_len = ctx->u.aes.key_len;
 125         rctx->cmd.u.aes.iv = iv_sg;
 126         rctx->cmd.u.aes.iv_len = iv_len;
 127         rctx->cmd.u.aes.src = req->src;
 128         rctx->cmd.u.aes.src_len = req->cryptlen;
 129         rctx->cmd.u.aes.aad_len = req->assoclen;
 130
 131         /* The cipher text + the tag are in the dst buffer */
 132         rctx->cmd.u.aes.dst = req->dst;
 133
 134         ret = ccp_crypto_enqueue_request(&req->base, &rctx->cmd);
 135
 136         return ret;
 137 }
 138
 139 static int ccp_aes_gcm_encrypt(struct aead_request *req)
 140 {
 141         return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_ENCRYPT);
 142 }
 143
 144 static int ccp_aes_gcm_decrypt(struct aead_request *req)
 145 {
 146         return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_DECRYPT);
 147 }
 148
 149 static int ccp_aes_gcm_cra_init(struct crypto_aead *tfm)
 150 {
 151         struct ccp_ctx *ctx = crypto_aead_ctx_dma(tfm);
 152
 153         ctx->complete = ccp_aes_gcm_complete;
 154         ctx->u.aes.key_len = 0;
 155
 156         crypto_aead_set_reqsize_dma(tfm, sizeof(struct ccp_aes_req_ctx));
 157
 158         return 0;
 159 }
 160
 161 static void ccp_aes_gcm_cra_exit(struct crypto_tfm *tfm)
 162 {
 163 }
 164
 165 static struct aead_alg ccp_aes_gcm_defaults = {
 166         .setkey = ccp_aes_gcm_setkey,
 167         .setauthsize = ccp_aes_gcm_setauthsize,
 168         .encrypt = ccp_aes_gcm_encrypt,
 169         .decrypt = ccp_aes_gcm_decrypt,
 170         .init = ccp_aes_gcm_cra_init,
 171         .ivsize = GCM_AES_IV_SIZE,
 172         .maxauthsize = AES_BLOCK_SIZE,
 173         .base = {
 174                 .cra_flags      = CRYPTO_ALG_ASYNC |
 175                                   CRYPTO_ALG_ALLOCATES_MEMORY |
 176                                   CRYPTO_ALG_KERN_DRIVER_ONLY |
 177                                   CRYPTO_ALG_NEED_FALLBACK,
 178                 .cra_blocksize  = AES_BLOCK_SIZE,
 179                 .cra_ctxsize    = sizeof(struct ccp_ctx) + CRYPTO_DMA_PADDING,
 180                 .cra_priority   = CCP_CRA_PRIORITY,
 181                 .cra_exit       = ccp_aes_gcm_cra_exit,
 182                 .cra_module     = THIS_MODULE,
 183         },
 184 };
 185
 186 struct ccp_aes_aead_def {
 187         enum ccp_aes_mode mode;
 188         unsigned int version;
 189         const char *name;
 190         const char *driver_name;
 191         unsigned int blocksize;
 192         unsigned int ivsize;
 193         struct aead_alg *alg_defaults;
 194 };
 195
 196 static struct ccp_aes_aead_def aes_aead_algs[] = {
 197         {
 198                 .mode           = CCP_AES_MODE_GHASH,
 199                 .version        = CCP_VERSION(5, 0),
 200                 .name           = "gcm(aes)",
 201                 .driver_name    = "gcm-aes-ccp",
 202                 .blocksize      = 1,
 203                 .ivsize         = AES_BLOCK_SIZE,
 204                 .alg_defaults   = &ccp_aes_gcm_defaults,
 205         },
 206 };
 207
 208 static int ccp_register_aes_aead(struct list_head *head,
 209                                  const struct ccp_aes_aead_def *def)
 210 {
 211         struct ccp_crypto_aead *ccp_aead;
 212         struct aead_alg *alg;
 213         int ret;
 214
 215         ccp_aead = kzalloc(sizeof(*ccp_aead), GFP_KERNEL);
 216         if (!ccp_aead)
 217                 return -ENOMEM;
 218
 219         INIT_LIST_HEAD(&ccp_aead->entry);
 220
 221         ccp_aead->mode = def->mode;
 222
 223         /* Copy the defaults and override as necessary */
 224         alg = &ccp_aead->alg;
 225         *alg = *def->alg_defaults;
 226         snprintf(alg->base.cra_name, CRYPTO_MAX_ALG_NAME, "%s", def->name);
 227         snprintf(alg->base.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s",
 228                  def->driver_name);
 229         alg->base.cra_blocksize = def->blocksize;
 230
 231         ret = crypto_register_aead(alg);
 232         if (ret) {
 233                 pr_err("%s aead algorithm registration error (%d)\n",
 234                        alg->base.cra_name, ret);
 235                 kfree(ccp_aead);
 236                 return ret;
 237         }
 238
 239         list_add(&ccp_aead->entry, head);
 240
 241         return 0;
 242 }
 243
 244 int ccp_register_aes_aeads(struct list_head *head)
 245 {
 246         int i, ret;
 247         unsigned int ccpversion = ccp_version();
 248
 249         for (i = 0; i < ARRAY_SIZE(aes_aead_algs); i++) {
 250                 if (aes_aead_algs[i].version > ccpversion)
 251                         continue;
 252                 ret = ccp_register_aes_aead(head, &aes_aead_algs[i]);
 253                 if (ret)
 254                         return ret;
 255         }
 256
 257         return 0;
 258 }