linux/drivers/crypto/ccp/ccp-crypto-aes-galois.c
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   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
  27static int ccp_aes_gcm_complete(struct crypto_async_request *async_req, int ret)
  28{
  29        return ret;
  30}
  31
  32static 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
  61static int ccp_aes_gcm_setauthsize(struct crypto_aead *tfm,
  62                                   unsigned int authsize)
  63{
  64        return 0;
  65}
  66
  67static 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
 129static int ccp_aes_gcm_encrypt(struct aead_request *req)
 130{
 131        return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_ENCRYPT);
 132}
 133
 134static int ccp_aes_gcm_decrypt(struct aead_request *req)
 135{
 136        return ccp_aes_gcm_crypt(req, CCP_AES_ACTION_DECRYPT);
 137}
 138
 139static 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
 151static void ccp_aes_gcm_cra_exit(struct crypto_tfm *tfm)
 152{
 153}
 154
 155static 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
 177struct 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
 187static 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
 199static 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
 236int 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}
 251