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/internal/sig.h>
  9#include <linux/cryptouser.h>
 10#include <linux/kernel.h>
 11#include <linux/module.h>
 12#include <linux/seq_file.h>
 13#include <linux/string.h>
 14#include <net/netlink.h>
 15
 16#include "internal.h"
 17
 18#define CRYPTO_ALG_TYPE_SIG_MASK	0x0000000e
 19
 20static void crypto_sig_exit_tfm(struct crypto_tfm *tfm)
 21{
 22	struct crypto_sig *sig = __crypto_sig_tfm(tfm);
 23	struct sig_alg *alg = crypto_sig_alg(sig);
 24
 25	alg->exit(sig);
 26}
 27
 28static int crypto_sig_init_tfm(struct crypto_tfm *tfm)
 29{
 30	struct crypto_sig *sig = __crypto_sig_tfm(tfm);
 31	struct sig_alg *alg = crypto_sig_alg(sig);
 32
 33	if (alg->exit)
 34		sig->base.exit = crypto_sig_exit_tfm;
 35
 36	if (alg->init)
 37		return alg->init(sig);
 38
 39	return 0;
 40}
 41
 42static void crypto_sig_free_instance(struct crypto_instance *inst)
 43{
 44	struct sig_instance *sig = sig_instance(inst);
 45
 46	sig->free(sig);
 47}
 48
 49static void __maybe_unused crypto_sig_show(struct seq_file *m,
 50					   struct crypto_alg *alg)
 51{
 52	seq_puts(m, "type         : sig\n");
 53}
 54
 55static int __maybe_unused crypto_sig_report(struct sk_buff *skb,
 56					    struct crypto_alg *alg)
 57{
 58	struct crypto_report_sig rsig = {};
 59
 60	strscpy(rsig.type, "sig", sizeof(rsig.type));
 61
 62	return nla_put(skb, CRYPTOCFGA_REPORT_SIG, sizeof(rsig), &rsig);
 63}
 64
 65static const struct crypto_type crypto_sig_type = {
 66	.extsize = crypto_alg_extsize,
 67	.init_tfm = crypto_sig_init_tfm,
 68	.free = crypto_sig_free_instance,
 69#ifdef CONFIG_PROC_FS
 70	.show = crypto_sig_show,
 71#endif
 72#if IS_ENABLED(CONFIG_CRYPTO_USER)
 73	.report = crypto_sig_report,
 74#endif
 75	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
 76	.maskset = CRYPTO_ALG_TYPE_SIG_MASK,
 77	.type = CRYPTO_ALG_TYPE_SIG,
 78	.tfmsize = offsetof(struct crypto_sig, base),
 79};
 80
 81struct crypto_sig *crypto_alloc_sig(const char *alg_name, u32 type, u32 mask)
 82{
 83	return crypto_alloc_tfm(alg_name, &crypto_sig_type, type, mask);
 84}
 85EXPORT_SYMBOL_GPL(crypto_alloc_sig);
 86
 87static int sig_default_sign(struct crypto_sig *tfm,
 88			    const void *src, unsigned int slen,
 89			    void *dst, unsigned int dlen)
 90{
 91	return -ENOSYS;
 92}
 93
 94static int sig_default_verify(struct crypto_sig *tfm,
 95			      const void *src, unsigned int slen,
 96			      const void *dst, unsigned int dlen)
 97{
 98	return -ENOSYS;
 99}
100
101static int sig_default_set_key(struct crypto_sig *tfm,
102			       const void *key, unsigned int keylen)
103{
104	return -ENOSYS;
105}
106
107static int sig_prepare_alg(struct sig_alg *alg)
108{
109	struct crypto_alg *base = &alg->base;
110
111	if (!alg->sign)
112		alg->sign = sig_default_sign;
113	if (!alg->verify)
114		alg->verify = sig_default_verify;
115	if (!alg->set_priv_key)
116		alg->set_priv_key = sig_default_set_key;
117	if (!alg->set_pub_key)
118		return -EINVAL;
119	if (!alg->key_size)
120		return -EINVAL;
121	if (!alg->max_size)
122		alg->max_size = alg->key_size;
123	if (!alg->digest_size)
124		alg->digest_size = alg->key_size;
125
126	base->cra_type = &crypto_sig_type;
127	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
128	base->cra_flags |= CRYPTO_ALG_TYPE_SIG;
129
130	return 0;
131}
132
133int crypto_register_sig(struct sig_alg *alg)
134{
135	struct crypto_alg *base = &alg->base;
136	int err;
137
138	err = sig_prepare_alg(alg);
139	if (err)
140		return err;
141
142	return crypto_register_alg(base);
143}
144EXPORT_SYMBOL_GPL(crypto_register_sig);
145
146void crypto_unregister_sig(struct sig_alg *alg)
147{
148	crypto_unregister_alg(&alg->base);
149}
150EXPORT_SYMBOL_GPL(crypto_unregister_sig);
151
152int sig_register_instance(struct crypto_template *tmpl,
153			  struct sig_instance *inst)
154{
155	int err;
156
157	if (WARN_ON(!inst->free))
158		return -EINVAL;
159
160	err = sig_prepare_alg(&inst->alg);
161	if (err)
162		return err;
163
164	return crypto_register_instance(tmpl, sig_crypto_instance(inst));
165}
166EXPORT_SYMBOL_GPL(sig_register_instance);
167
168int crypto_grab_sig(struct crypto_sig_spawn *spawn,
169		    struct crypto_instance *inst,
170		    const char *name, u32 type, u32 mask)
171{
172	spawn->base.frontend = &crypto_sig_type;
173	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
174}
175EXPORT_SYMBOL_GPL(crypto_grab_sig);
176
177MODULE_LICENSE("GPL");
178MODULE_DESCRIPTION("Public Key Signature Algorithms");