crypto/sig.c

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * Public Key Signature Algorithm
   4  *
   5  * Copyright (c) 2023 Herbert Xu <herbert@gondor.apana.org.au>
   6  */
   7
   8 #include <crypto/akcipher.h>
   9 #include <crypto/internal/sig.h>
  10 #include <linux/cryptouser.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/string.h>
  16 #include <net/netlink.h>
  17
  18 #include "internal.h"
  19
  20 #define CRYPTO_ALG_TYPE_SIG_MASK        0x0000000e
  21
  22 static const struct crypto_type crypto_sig_type;
  23
  24 static int crypto_sig_init_tfm(struct crypto_tfm *tfm)
  25 {
  26         if (tfm->__crt_alg->cra_type != &crypto_sig_type)
  27                 return crypto_init_akcipher_ops_sig(tfm);
  28
  29         return 0;
  30 }
  31
  32 static void __maybe_unused crypto_sig_show(struct seq_file *m,
  33                                            struct crypto_alg *alg)
  34 {
  35         seq_puts(m, "type         : sig\n");
  36 }
  37
  38 static int __maybe_unused crypto_sig_report(struct sk_buff *skb,
  39                                             struct crypto_alg *alg)
  40 {
  41         struct crypto_report_akcipher rsig = {};
  42
  43         strscpy(rsig.type, "sig", sizeof(rsig.type));
  44
  45         return nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER, sizeof(rsig), &rsig);
  46 }
  47
  48 static const struct crypto_type crypto_sig_type = {
  49         .extsize = crypto_alg_extsize,
  50         .init_tfm = crypto_sig_init_tfm,
  51 #ifdef CONFIG_PROC_FS
  52         .show = crypto_sig_show,
  53 #endif
  54 #if IS_ENABLED(CONFIG_CRYPTO_USER)
  55         .report = crypto_sig_report,
  56 #endif
  57         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
  58         .maskset = CRYPTO_ALG_TYPE_SIG_MASK,
  59         .type = CRYPTO_ALG_TYPE_SIG,
  60         .tfmsize = offsetof(struct crypto_sig, base),
  61 };
  62
  63 struct crypto_sig *crypto_alloc_sig(const char *alg_name, u32 type, u32 mask)
  64 {
  65         return crypto_alloc_tfm(alg_name, &crypto_sig_type, type, mask);
  66 }
  67 EXPORT_SYMBOL_GPL(crypto_alloc_sig);
  68
  69 int crypto_sig_maxsize(struct crypto_sig *tfm)
  70 {
  71         struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
  72
  73         return crypto_akcipher_maxsize(*ctx);
  74 }
  75 EXPORT_SYMBOL_GPL(crypto_sig_maxsize);
  76
  77 int crypto_sig_sign(struct crypto_sig *tfm,
  78                     const void *src, unsigned int slen,
  79                     void *dst, unsigned int dlen)
  80 {
  81         struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
  82         struct crypto_akcipher_sync_data data = {
  83                 .tfm = *ctx,
  84                 .src = src,
  85                 .dst = dst,
  86                 .slen = slen,
  87                 .dlen = dlen,
  88         };
  89
  90         return crypto_akcipher_sync_prep(&data) ?:
  91                crypto_akcipher_sync_post(&data,
  92                                          crypto_akcipher_sign(data.req));
  93 }
  94 EXPORT_SYMBOL_GPL(crypto_sig_sign);
  95
  96 int crypto_sig_verify(struct crypto_sig *tfm,
  97                       const void *src, unsigned int slen,
  98                       const void *digest, unsigned int dlen)
  99 {
 100         struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
 101         struct crypto_akcipher_sync_data data = {
 102                 .tfm = *ctx,
 103                 .src = src,
 104                 .slen = slen,
 105                 .dlen = dlen,
 106         };
 107         int err;
 108
 109         err = crypto_akcipher_sync_prep(&data);
 110         if (err)
 111                 return err;
 112
 113         memcpy(data.buf + slen, digest, dlen);
 114
 115         return crypto_akcipher_sync_post(&data,
 116                                          crypto_akcipher_verify(data.req));
 117 }
 118 EXPORT_SYMBOL_GPL(crypto_sig_verify);
 119
 120 int crypto_sig_set_pubkey(struct crypto_sig *tfm,
 121                           const void *key, unsigned int keylen)
 122 {
 123         struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
 124
 125         return crypto_akcipher_set_pub_key(*ctx, key, keylen);
 126 }
 127 EXPORT_SYMBOL_GPL(crypto_sig_set_pubkey);
 128
 129 int crypto_sig_set_privkey(struct crypto_sig *tfm,
 130                           const void *key, unsigned int keylen)
 131 {
 132         struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
 133
 134         return crypto_akcipher_set_priv_key(*ctx, key, keylen);
 135 }
 136 EXPORT_SYMBOL_GPL(crypto_sig_set_privkey);
 137
 138 MODULE_LICENSE("GPL");
 139 MODULE_DESCRIPTION("Public Key Signature Algorithms");