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

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