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 int __maybe_unused crypto_sig_report_stat(struct sk_buff *skb,
  49                                                  struct crypto_alg *alg)
  50 {
  51         struct crypto_stat_akcipher rsig = {};
  52
  53         strscpy(rsig.type, "sig", sizeof(rsig.type));
  54
  55         return nla_put(skb, CRYPTOCFGA_STAT_AKCIPHER, sizeof(rsig), &rsig);
  56 }
  57
  58 static const struct crypto_type crypto_sig_type = {
  59         .extsize = crypto_alg_extsize,
  60         .init_tfm = crypto_sig_init_tfm,
  61 #ifdef CONFIG_PROC_FS
  62         .show = crypto_sig_show,
  63 #endif
  64 #if IS_ENABLED(CONFIG_CRYPTO_USER)
  65         .report = crypto_sig_report,
  66 #endif
  67 #ifdef CONFIG_CRYPTO_STATS
  68         .report_stat = crypto_sig_report_stat,
  69 #endif
  70         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
  71         .maskset = CRYPTO_ALG_TYPE_SIG_MASK,
  72         .type = CRYPTO_ALG_TYPE_SIG,
  73         .tfmsize = offsetof(struct crypto_sig, base),
  74 };
  75
  76 struct crypto_sig *crypto_alloc_sig(const char *alg_name, u32 type, u32 mask)
  77 {
  78         return crypto_alloc_tfm(alg_name, &crypto_sig_type, type, mask);
  79 }
  80 EXPORT_SYMBOL_GPL(crypto_alloc_sig);
  81
  82 int crypto_sig_maxsize(struct crypto_sig *tfm)
  83 {
  84         struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
  85
  86         return crypto_akcipher_maxsize(*ctx);
  87 }
  88 EXPORT_SYMBOL_GPL(crypto_sig_maxsize);
  89
  90 int crypto_sig_sign(struct crypto_sig *tfm,
  91                     const void *src, unsigned int slen,
  92                     void *dst, unsigned int dlen)
  93 {
  94         struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
  95         struct crypto_akcipher_sync_data data = {
  96                 .tfm = *ctx,
  97                 .src = src,
  98                 .dst = dst,
  99                 .slen = slen,
 100                 .dlen = dlen,
 101         };
 102
 103         return crypto_akcipher_sync_prep(&data) ?:
 104                crypto_akcipher_sync_post(&data,
 105                                          crypto_akcipher_sign(data.req));
 106 }
 107 EXPORT_SYMBOL_GPL(crypto_sig_sign);
 108
 109 int crypto_sig_verify(struct crypto_sig *tfm,
 110                       const void *src, unsigned int slen,
 111                       const void *digest, unsigned int dlen)
 112 {
 113         struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
 114         struct crypto_akcipher_sync_data data = {
 115                 .tfm = *ctx,
 116                 .src = src,
 117                 .slen = slen,
 118                 .dlen = dlen,
 119         };
 120         int err;
 121
 122         err = crypto_akcipher_sync_prep(&data);
 123         if (err)
 124                 return err;
 125
 126         memcpy(data.buf + slen, digest, dlen);
 127
 128         return crypto_akcipher_sync_post(&data,
 129                                          crypto_akcipher_verify(data.req));
 130 }
 131 EXPORT_SYMBOL_GPL(crypto_sig_verify);
 132
 133 int crypto_sig_set_pubkey(struct crypto_sig *tfm,
 134                           const void *key, unsigned int keylen)
 135 {
 136         struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
 137
 138         return crypto_akcipher_set_pub_key(*ctx, key, keylen);
 139 }
 140 EXPORT_SYMBOL_GPL(crypto_sig_set_pubkey);
 141
 142 int crypto_sig_set_privkey(struct crypto_sig *tfm,
 143                           const void *key, unsigned int keylen)
 144 {
 145         struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
 146
 147         return crypto_akcipher_set_priv_key(*ctx, key, keylen);
 148 }
 149 EXPORT_SYMBOL_GPL(crypto_sig_set_privkey);
 150
 151 MODULE_LICENSE("GPL");
 152 MODULE_DESCRIPTION("Public Key Signature Algorithms");