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
 22static const struct crypto_type crypto_sig_type;
 23
 24static 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
 32static 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
 38static 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
 48static 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
 58static 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
 76struct 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}
 80EXPORT_SYMBOL_GPL(crypto_alloc_sig);
 81
 82int 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}
 88EXPORT_SYMBOL_GPL(crypto_sig_maxsize);
 89
 90int 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}
107EXPORT_SYMBOL_GPL(crypto_sig_sign);
108
109int 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}
131EXPORT_SYMBOL_GPL(crypto_sig_verify);
132
133int 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}
140EXPORT_SYMBOL_GPL(crypto_sig_set_pubkey);
141
142int 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}
149EXPORT_SYMBOL_GPL(crypto_sig_set_privkey);
150
151MODULE_LICENSE("GPL");
152MODULE_DESCRIPTION("Public Key Signature Algorithms");