crypto/akcipher.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Public Key Encryption
   4  *
   5  * Copyright (c) 2015, Intel Corporation
   6  * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
   7  */
   8 #include <crypto/internal/akcipher.h>
   9 #include <linux/cryptouser.h>
  10 #include <linux/errno.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/scatterlist.h>
  14 #include <linux/seq_file.h>
  15 #include <linux/slab.h>
  16 #include <linux/string.h>
  17 #include <net/netlink.h>
  18
  19 #include "internal.h"
  20
  21 #define CRYPTO_ALG_TYPE_AHASH_MASK      0x0000000e
  22
  23 static int __maybe_unused crypto_akcipher_report(
  24         struct sk_buff *skb, struct crypto_alg *alg)
  25 {
  26         struct crypto_report_akcipher rakcipher;
  27
  28         memset(&rakcipher, 0, sizeof(rakcipher));
  29
  30         strscpy(rakcipher.type, "akcipher", sizeof(rakcipher.type));
  31
  32         return nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER,
  33                        sizeof(rakcipher), &rakcipher);
  34 }
  35
  36 static void crypto_akcipher_show(struct seq_file *m, struct crypto_alg *alg)
  37         __maybe_unused;
  38
  39 static void crypto_akcipher_show(struct seq_file *m, struct crypto_alg *alg)
  40 {
  41         seq_puts(m, "type         : akcipher\n");
  42 }
  43
  44 static void crypto_akcipher_exit_tfm(struct crypto_tfm *tfm)
  45 {
  46         struct crypto_akcipher *akcipher = __crypto_akcipher_tfm(tfm);
  47         struct akcipher_alg *alg = crypto_akcipher_alg(akcipher);
  48
  49         alg->exit(akcipher);
  50 }
  51
  52 static int crypto_akcipher_init_tfm(struct crypto_tfm *tfm)
  53 {
  54         struct crypto_akcipher *akcipher = __crypto_akcipher_tfm(tfm);
  55         struct akcipher_alg *alg = crypto_akcipher_alg(akcipher);
  56
  57         if (alg->exit)
  58                 akcipher->base.exit = crypto_akcipher_exit_tfm;
  59
  60         if (alg->init)
  61                 return alg->init(akcipher);
  62
  63         return 0;
  64 }
  65
  66 static void crypto_akcipher_free_instance(struct crypto_instance *inst)
  67 {
  68         struct akcipher_instance *akcipher = akcipher_instance(inst);
  69
  70         akcipher->free(akcipher);
  71 }
  72
  73 static const struct crypto_type crypto_akcipher_type = {
  74         .extsize = crypto_alg_extsize,
  75         .init_tfm = crypto_akcipher_init_tfm,
  76         .free = crypto_akcipher_free_instance,
  77 #ifdef CONFIG_PROC_FS
  78         .show = crypto_akcipher_show,
  79 #endif
  80 #if IS_ENABLED(CONFIG_CRYPTO_USER)
  81         .report = crypto_akcipher_report,
  82 #endif
  83         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
  84         .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
  85         .type = CRYPTO_ALG_TYPE_AKCIPHER,
  86         .tfmsize = offsetof(struct crypto_akcipher, base),
  87 };
  88
  89 int crypto_grab_akcipher(struct crypto_akcipher_spawn *spawn,
  90                          struct crypto_instance *inst,
  91                          const char *name, u32 type, u32 mask)
  92 {
  93         spawn->base.frontend = &crypto_akcipher_type;
  94         return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
  95 }
  96 EXPORT_SYMBOL_GPL(crypto_grab_akcipher);
  97
  98 struct crypto_akcipher *crypto_alloc_akcipher(const char *alg_name, u32 type,
  99                                               u32 mask)
 100 {
 101         return crypto_alloc_tfm(alg_name, &crypto_akcipher_type, type, mask);
 102 }
 103 EXPORT_SYMBOL_GPL(crypto_alloc_akcipher);
 104
 105 static void akcipher_prepare_alg(struct akcipher_alg *alg)
 106 {
 107         struct crypto_alg *base = &alg->base;
 108
 109         base->cra_type = &crypto_akcipher_type;
 110         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 111         base->cra_flags |= CRYPTO_ALG_TYPE_AKCIPHER;
 112 }
 113
 114 static int akcipher_default_op(struct akcipher_request *req)
 115 {
 116         return -ENOSYS;
 117 }
 118
 119 static int akcipher_default_set_key(struct crypto_akcipher *tfm,
 120                                      const void *key, unsigned int keylen)
 121 {
 122         return -ENOSYS;
 123 }
 124
 125 int crypto_register_akcipher(struct akcipher_alg *alg)
 126 {
 127         struct crypto_alg *base = &alg->base;
 128
 129         if (!alg->sign)
 130                 alg->sign = akcipher_default_op;
 131         if (!alg->verify)
 132                 alg->verify = akcipher_default_op;
 133         if (!alg->encrypt)
 134                 alg->encrypt = akcipher_default_op;
 135         if (!alg->decrypt)
 136                 alg->decrypt = akcipher_default_op;
 137         if (!alg->set_priv_key)
 138                 alg->set_priv_key = akcipher_default_set_key;
 139
 140         akcipher_prepare_alg(alg);
 141         return crypto_register_alg(base);
 142 }
 143 EXPORT_SYMBOL_GPL(crypto_register_akcipher);
 144
 145 void crypto_unregister_akcipher(struct akcipher_alg *alg)
 146 {
 147         crypto_unregister_alg(&alg->base);
 148 }
 149 EXPORT_SYMBOL_GPL(crypto_unregister_akcipher);
 150
 151 int akcipher_register_instance(struct crypto_template *tmpl,
 152                                struct akcipher_instance *inst)
 153 {
 154         if (WARN_ON(!inst->free))
 155                 return -EINVAL;
 156         akcipher_prepare_alg(&inst->alg);
 157         return crypto_register_instance(tmpl, akcipher_crypto_instance(inst));
 158 }
 159 EXPORT_SYMBOL_GPL(akcipher_register_instance);
 160
 161 int crypto_akcipher_sync_prep(struct crypto_akcipher_sync_data *data)
 162 {
 163         unsigned int reqsize = crypto_akcipher_reqsize(data->tfm);
 164         struct akcipher_request *req;
 165         struct scatterlist *sg;
 166         unsigned int mlen;
 167         unsigned int len;
 168         u8 *buf;
 169
 170         if (data->dst)
 171                 mlen = max(data->slen, data->dlen);
 172         else
 173                 mlen = data->slen + data->dlen;
 174
 175         len = sizeof(*req) + reqsize + mlen;
 176         if (len < mlen)
 177                 return -EOVERFLOW;
 178
 179         req = kzalloc(len, GFP_KERNEL);
 180         if (!req)
 181                 return -ENOMEM;
 182
 183         data->req = req;
 184         akcipher_request_set_tfm(req, data->tfm);
 185
 186         buf = (u8 *)(req + 1) + reqsize;
 187         data->buf = buf;
 188         memcpy(buf, data->src, data->slen);
 189
 190         sg = &data->sg;
 191         sg_init_one(sg, buf, mlen);
 192         akcipher_request_set_crypt(req, sg, data->dst ? sg : NULL,
 193                                    data->slen, data->dlen);
 194
 195         crypto_init_wait(&data->cwait);
 196         akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP,
 197                                       crypto_req_done, &data->cwait);
 198
 199         return 0;
 200 }
 201 EXPORT_SYMBOL_GPL(crypto_akcipher_sync_prep);
 202
 203 int crypto_akcipher_sync_post(struct crypto_akcipher_sync_data *data, int err)
 204 {
 205         err = crypto_wait_req(err, &data->cwait);
 206         if (data->dst)
 207                 memcpy(data->dst, data->buf, data->dlen);
 208         data->dlen = data->req->dst_len;
 209         kfree_sensitive(data->req);
 210         return err;
 211 }
 212 EXPORT_SYMBOL_GPL(crypto_akcipher_sync_post);
 213
 214 int crypto_akcipher_sync_encrypt(struct crypto_akcipher *tfm,
 215                                  const void *src, unsigned int slen,
 216                                  void *dst, unsigned int dlen)
 217 {
 218         struct crypto_akcipher_sync_data data = {
 219                 .tfm = tfm,
 220                 .src = src,
 221                 .dst = dst,
 222                 .slen = slen,
 223                 .dlen = dlen,
 224         };
 225
 226         return crypto_akcipher_sync_prep(&data) ?:
 227                crypto_akcipher_sync_post(&data,
 228                                          crypto_akcipher_encrypt(data.req));
 229 }
 230 EXPORT_SYMBOL_GPL(crypto_akcipher_sync_encrypt);
 231
 232 int crypto_akcipher_sync_decrypt(struct crypto_akcipher *tfm,
 233                                  const void *src, unsigned int slen,
 234                                  void *dst, unsigned int dlen)
 235 {
 236         struct crypto_akcipher_sync_data data = {
 237                 .tfm = tfm,
 238                 .src = src,
 239                 .dst = dst,
 240                 .slen = slen,
 241                 .dlen = dlen,
 242         };
 243
 244         return crypto_akcipher_sync_prep(&data) ?:
 245                crypto_akcipher_sync_post(&data,
 246                                          crypto_akcipher_decrypt(data.req)) ?:
 247                data.dlen;
 248 }
 249 EXPORT_SYMBOL_GPL(crypto_akcipher_sync_decrypt);
 250
 251 static void crypto_exit_akcipher_ops_sig(struct crypto_tfm *tfm)
 252 {
 253         struct crypto_akcipher **ctx = crypto_tfm_ctx(tfm);
 254
 255         crypto_free_akcipher(*ctx);
 256 }
 257
 258 int crypto_init_akcipher_ops_sig(struct crypto_tfm *tfm)
 259 {
 260         struct crypto_akcipher **ctx = crypto_tfm_ctx(tfm);
 261         struct crypto_alg *calg = tfm->__crt_alg;
 262         struct crypto_akcipher *akcipher;
 263
 264         if (!crypto_mod_get(calg))
 265                 return -EAGAIN;
 266
 267         akcipher = crypto_create_tfm(calg, &crypto_akcipher_type);
 268         if (IS_ERR(akcipher)) {
 269                 crypto_mod_put(calg);
 270                 return PTR_ERR(akcipher);
 271         }
 272
 273         *ctx = akcipher;
 274         tfm->exit = crypto_exit_akcipher_ops_sig;
 275
 276         return 0;
 277 }
 278 EXPORT_SYMBOL_GPL(crypto_init_akcipher_ops_sig);
 279
 280 MODULE_LICENSE("GPL");
 281 MODULE_DESCRIPTION("Generic public key cipher type");