linux/crypto/sig.c
Herbert Xu 6cb8815f41 crypto: sig - Add interface for sign/verify
Split out the sign/verify functionality from the existing akcipher
interface.  Most algorithms in akcipher either support encryption
and decryption, or signing and verify.  Only one supports both.

As a signature algorithm may not support encryption at all, these
two should be spearated.

For now sig is simply a wrapper around akcipher as all algorithms
remain unchanged.  This is a first step and allows users to start
allocating sig instead of akcipher.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2023-06-23 16:15:36 +08:00

160 lines
3.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Public Key Signature Algorithm
*
* Copyright (c) 2023 Herbert Xu <herbert@gondor.apana.org.au>
*/
#include <crypto/akcipher.h>
#include <crypto/internal/sig.h>
#include <linux/cryptouser.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/seq_file.h>
#include <linux/string.h>
#include <net/netlink.h>
#include "internal.h"
#define CRYPTO_ALG_TYPE_SIG_MASK 0x0000000e
static const struct crypto_type crypto_sig_type;
static inline struct crypto_sig *__crypto_sig_tfm(struct crypto_tfm *tfm)
{
return container_of(tfm, struct crypto_sig, base);
}
static int crypto_sig_init_tfm(struct crypto_tfm *tfm)
{
if (tfm->__crt_alg->cra_type != &crypto_sig_type)
return crypto_init_akcipher_ops_sig(tfm);
return 0;
}
static void __maybe_unused crypto_sig_show(struct seq_file *m,
struct crypto_alg *alg)
{
seq_puts(m, "type : sig\n");
}
static int __maybe_unused crypto_sig_report(struct sk_buff *skb,
struct crypto_alg *alg)
{
struct crypto_report_akcipher rsig = {};
strscpy(rsig.type, "sig", sizeof(rsig.type));
return nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER, sizeof(rsig), &rsig);
}
static int __maybe_unused crypto_sig_report_stat(struct sk_buff *skb,
struct crypto_alg *alg)
{
struct crypto_stat_akcipher rsig = {};
strscpy(rsig.type, "sig", sizeof(rsig.type));
return nla_put(skb, CRYPTOCFGA_STAT_AKCIPHER, sizeof(rsig), &rsig);
}
static const struct crypto_type crypto_sig_type = {
.extsize = crypto_alg_extsize,
.init_tfm = crypto_sig_init_tfm,
#ifdef CONFIG_PROC_FS
.show = crypto_sig_show,
#endif
#if IS_ENABLED(CONFIG_CRYPTO_USER)
.report = crypto_sig_report,
#endif
#ifdef CONFIG_CRYPTO_STATS
.report_stat = crypto_sig_report_stat,
#endif
.maskclear = ~CRYPTO_ALG_TYPE_MASK,
.maskset = CRYPTO_ALG_TYPE_SIG_MASK,
.type = CRYPTO_ALG_TYPE_SIG,
.tfmsize = offsetof(struct crypto_sig, base),
};
struct crypto_sig *crypto_alloc_sig(const char *alg_name, u32 type, u32 mask)
{
return crypto_alloc_tfm(alg_name, &crypto_sig_type, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_alloc_sig);
int crypto_sig_maxsize(struct crypto_sig *tfm)
{
struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
return crypto_akcipher_maxsize(*ctx);
}
EXPORT_SYMBOL_GPL(crypto_sig_maxsize);
int crypto_sig_sign(struct crypto_sig *tfm,
const void *src, unsigned int slen,
void *dst, unsigned int dlen)
{
struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
struct crypto_akcipher_sync_data data = {
.tfm = *ctx,
.src = src,
.dst = dst,
.slen = slen,
.dlen = dlen,
};
return crypto_akcipher_sync_prep(&data) ?:
crypto_akcipher_sync_post(&data,
crypto_akcipher_sign(data.req));
}
EXPORT_SYMBOL_GPL(crypto_sig_sign);
int crypto_sig_verify(struct crypto_sig *tfm,
const void *src, unsigned int slen,
const void *digest, unsigned int dlen)
{
struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
struct crypto_akcipher_sync_data data = {
.tfm = *ctx,
.src = src,
.slen = slen,
.dlen = dlen,
};
int err;
err = crypto_akcipher_sync_prep(&data);
if (err)
return err;
sg_init_table(data.sg, 2);
sg_set_buf(&data.sg[0], src, slen);
sg_set_buf(&data.sg[1], digest, dlen);
return crypto_akcipher_sync_post(&data,
crypto_akcipher_verify(data.req));
}
EXPORT_SYMBOL_GPL(crypto_sig_verify);
int crypto_sig_set_pubkey(struct crypto_sig *tfm,
const void *key, unsigned int keylen)
{
struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
return crypto_akcipher_set_pub_key(*ctx, key, keylen);
}
EXPORT_SYMBOL_GPL(crypto_sig_set_pubkey);
int crypto_sig_set_privkey(struct crypto_sig *tfm,
const void *key, unsigned int keylen)
{
struct crypto_akcipher **ctx = crypto_sig_ctx(tfm);
return crypto_akcipher_set_priv_key(*ctx, key, keylen);
}
EXPORT_SYMBOL_GPL(crypto_sig_set_privkey);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Public Key Signature Algorithms");