[mirror_ubuntu-jammy-kernel.git] / crypto / rsa.c

/* RSA asymmetric public-key algorithm [RFC3447]
 *
 * Copyright (c) 2015, Intel Corporation
 * Authors: Tadeusz Struk <tadeusz.struk@intel.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */

#include <linux/module.h>
#include <linux/mpi.h>
#include <crypto/internal/rsa.h>
#include <crypto/internal/akcipher.h>
#include <crypto/akcipher.h>
#include <crypto/algapi.h>

struct rsa_mpi_key {
	MPI n;
	MPI e;
	MPI d;
};

/*
 * RSAEP function [RFC3447 sec 5.1.1]
 * c = m^e mod n;
 */
static int _rsa_enc(const struct rsa_mpi_key *key, MPI c, MPI m)
{
	/* (1) Validate 0 <= m < n */
	if (mpi_cmp_ui(m, 0) < 0 || mpi_cmp(m, key->n) >= 0)
		return -EINVAL;

	/* (2) c = m^e mod n */
	return mpi_powm(c, m, key->e, key->n);
}

/*
 * RSADP function [RFC3447 sec 5.1.2]
 * m = c^d mod n;
 */
static int _rsa_dec(const struct rsa_mpi_key *key, MPI m, MPI c)
{
	/* (1) Validate 0 <= c < n */
	if (mpi_cmp_ui(c, 0) < 0 || mpi_cmp(c, key->n) >= 0)
		return -EINVAL;

	/* (2) m = c^d mod n */
	return mpi_powm(m, c, key->d, key->n);
}

static inline struct rsa_mpi_key *rsa_get_key(struct crypto_akcipher *tfm)
{
	return akcipher_tfm_ctx(tfm);
}

static int rsa_enc(struct akcipher_request *req)
{
	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
	const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
	MPI m, c = mpi_alloc(0);
	int ret = 0;
	int sign;

	if (!c)
		return -ENOMEM;

	if (unlikely(!pkey->n || !pkey->e)) {
		ret = -EINVAL;
		goto err_free_c;
	}

	ret = -ENOMEM;
	m = mpi_read_raw_from_sgl(req->src, req->src_len);
	if (!m)
		goto err_free_c;

	ret = _rsa_enc(pkey, c, m);
	if (ret)
		goto err_free_m;

	ret = mpi_write_to_sgl(c, req->dst, req->dst_len, &sign);
	if (ret)
		goto err_free_m;

	if (sign < 0)
		ret = -EBADMSG;

err_free_m:
	mpi_free(m);
err_free_c:
	mpi_free(c);
	return ret;
}

static int rsa_dec(struct akcipher_request *req)
{
	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
	const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
	MPI c, m = mpi_alloc(0);
	int ret = 0;
	int sign;

	if (!m)
		return -ENOMEM;

	if (unlikely(!pkey->n || !pkey->d)) {
		ret = -EINVAL;
		goto err_free_m;
	}

	ret = -ENOMEM;
	c = mpi_read_raw_from_sgl(req->src, req->src_len);
	if (!c)
		goto err_free_m;

	ret = _rsa_dec(pkey, m, c);
	if (ret)
		goto err_free_c;

	ret = mpi_write_to_sgl(m, req->dst, req->dst_len, &sign);
	if (ret)
		goto err_free_c;

	if (sign < 0)
		ret = -EBADMSG;
err_free_c:
	mpi_free(c);
err_free_m:
	mpi_free(m);
	return ret;
}

static void rsa_free_mpi_key(struct rsa_mpi_key *key)
{
	mpi_free(key->d);
	mpi_free(key->e);
	mpi_free(key->n);
	key->d = NULL;
	key->e = NULL;
	key->n = NULL;
}

static int rsa_check_key_length(unsigned int len)
{
	switch (len) {
	case 512:
	case 1024:
	case 1536:
	case 2048:
	case 3072:
	case 4096:
		return 0;
	}

	return -EINVAL;
}

static int rsa_set_pub_key(struct crypto_akcipher *tfm, const void *key,
			   unsigned int keylen)
{
	struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm);
	struct rsa_key raw_key = {0};
	int ret;

	/* Free the old MPI key if any */
	rsa_free_mpi_key(mpi_key);

	ret = rsa_parse_pub_key(&raw_key, key, keylen);
	if (ret)
		return ret;

	mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz);
	if (!mpi_key->e)
		goto err;

	mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz);
	if (!mpi_key->n)
		goto err;

	if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
		rsa_free_mpi_key(mpi_key);
		return -EINVAL;
	}

	return 0;

err:
	rsa_free_mpi_key(mpi_key);
	return -ENOMEM;
}

static int rsa_set_priv_key(struct crypto_akcipher *tfm, const void *key,
			    unsigned int keylen)
{
	struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm);
	struct rsa_key raw_key = {0};
	int ret;

	/* Free the old MPI key if any */
	rsa_free_mpi_key(mpi_key);

	ret = rsa_parse_priv_key(&raw_key, key, keylen);
	if (ret)
		return ret;

	mpi_key->d = mpi_read_raw_data(raw_key.d, raw_key.d_sz);
	if (!mpi_key->d)
		goto err;

	mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz);
	if (!mpi_key->e)
		goto err;

	mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz);
	if (!mpi_key->n)
		goto err;

	if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
		rsa_free_mpi_key(mpi_key);
		return -EINVAL;
	}

	return 0;

err:
	rsa_free_mpi_key(mpi_key);
	return -ENOMEM;
}

static unsigned int rsa_max_size(struct crypto_akcipher *tfm)
{
	struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm);

	return mpi_get_size(pkey->n);
}

static void rsa_exit_tfm(struct crypto_akcipher *tfm)
{
	struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm);

	rsa_free_mpi_key(pkey);
}

static struct akcipher_alg rsa = {
	.encrypt = rsa_enc,
	.decrypt = rsa_dec,
	.set_priv_key = rsa_set_priv_key,
	.set_pub_key = rsa_set_pub_key,
	.max_size = rsa_max_size,
	.exit = rsa_exit_tfm,
	.base = {
		.cra_name = "rsa",
		.cra_driver_name = "rsa-generic",
		.cra_priority = 100,
		.cra_module = THIS_MODULE,
		.cra_ctxsize = sizeof(struct rsa_mpi_key),
	},
};

static int rsa_init(void)
{
	int err;

	err = crypto_register_akcipher(&rsa);
	if (err)
		return err;

	err = crypto_register_template(&rsa_pkcs1pad_tmpl);
	if (err) {
		crypto_unregister_akcipher(&rsa);
		return err;
	}

	return 0;
}

static void rsa_exit(void)
{
	crypto_unregister_template(&rsa_pkcs1pad_tmpl);
	crypto_unregister_akcipher(&rsa);
}

subsys_initcall(rsa_init);
module_exit(rsa_exit);
MODULE_ALIAS_CRYPTO("rsa");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("RSA generic algorithm");
Commit	Line	Data
cfc2bb32 TS	1	/* RSA asymmetric public-key algorithm [RFC3447]
	2	*
	3	* Copyright (c) 2015, Intel Corporation
	4	* Authors: Tadeusz Struk <tadeusz.struk@intel.com>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public Licence
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the Licence, or (at your option) any later version.
	10	*/
	11
	12	#include <linux/module.h>
5a7de973	13	#include <linux/mpi.h>
cfc2bb32 TS	14	#include <crypto/internal/rsa.h>
	15	#include <crypto/internal/akcipher.h>
	16	#include <crypto/akcipher.h>
3d5b1ecd	17	#include <crypto/algapi.h>
cfc2bb32	18
5a7de973 TA	19	struct rsa_mpi_key {
	20	MPI n;
	21	MPI e;
	22	MPI d;
	23	};
	24
cfc2bb32 TS	25	/*
	26	* RSAEP function [RFC3447 sec 5.1.1]
	27	* c = m^e mod n;
	28	*/
5a7de973	29	static int _rsa_enc(const struct rsa_mpi_key *key, MPI c, MPI m)
cfc2bb32 TS	30	{
	31	/* (1) Validate 0 <= m < n */
	32	if (mpi_cmp_ui(m, 0) < 0 \|\| mpi_cmp(m, key->n) >= 0)
	33	return -EINVAL;
	34
	35	/* (2) c = m^e mod n */
	36	return mpi_powm(c, m, key->e, key->n);
	37	}
	38
	39	/*
	40	* RSADP function [RFC3447 sec 5.1.2]
	41	* m = c^d mod n;
	42	*/
5a7de973	43	static int _rsa_dec(const struct rsa_mpi_key *key, MPI m, MPI c)
cfc2bb32 TS	44	{
	45	/* (1) Validate 0 <= c < n */
	46	if (mpi_cmp_ui(c, 0) < 0 \|\| mpi_cmp(c, key->n) >= 0)
	47	return -EINVAL;
	48
	49	/* (2) m = c^d mod n */
	50	return mpi_powm(m, c, key->d, key->n);
	51	}
	52
5a7de973	53	static inline struct rsa_mpi_key rsa_get_key(struct crypto_akcipher tfm)
cfc2bb32 TS	54	{
	55	return akcipher_tfm_ctx(tfm);
	56	}
	57
	58	static int rsa_enc(struct akcipher_request *req)
	59	{
	60	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
5a7de973	61	const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
cfc2bb32 TS	62	MPI m, c = mpi_alloc(0);
	63	int ret = 0;
	64	int sign;
	65
	66	if (!c)
	67	return -ENOMEM;
	68
	69	if (unlikely(!pkey->n \|\| !pkey->e)) {
	70	ret = -EINVAL;
	71	goto err_free_c;
	72	}
	73
22287b0b TS	74	ret = -ENOMEM;
	75	m = mpi_read_raw_from_sgl(req->src, req->src_len);
	76	if (!m)
cfc2bb32	77	goto err_free_c;
cfc2bb32 TS	78
	79	ret = _rsa_enc(pkey, c, m);
	80	if (ret)
	81	goto err_free_m;
	82
9b45b7bb	83	ret = mpi_write_to_sgl(c, req->dst, req->dst_len, &sign);
cfc2bb32 TS	84	if (ret)
	85	goto err_free_m;
	86
22287b0b	87	if (sign < 0)
cfc2bb32	88	ret = -EBADMSG;
cfc2bb32 TS	89
	90	err_free_m:
	91	mpi_free(m);
	92	err_free_c:
	93	mpi_free(c);
	94	return ret;
	95	}
	96
	97	static int rsa_dec(struct akcipher_request *req)
	98	{
	99	struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req);
5a7de973	100	const struct rsa_mpi_key *pkey = rsa_get_key(tfm);
cfc2bb32 TS	101	MPI c, m = mpi_alloc(0);
	102	int ret = 0;
	103	int sign;
	104
	105	if (!m)
	106	return -ENOMEM;
	107
	108	if (unlikely(!pkey->n \|\| !pkey->d)) {
	109	ret = -EINVAL;
	110	goto err_free_m;
	111	}
	112
22287b0b TS	113	ret = -ENOMEM;
	114	c = mpi_read_raw_from_sgl(req->src, req->src_len);
	115	if (!c)
cfc2bb32	116	goto err_free_m;
cfc2bb32 TS	117
	118	ret = _rsa_dec(pkey, m, c);
	119	if (ret)
	120	goto err_free_c;
	121
9b45b7bb	122	ret = mpi_write_to_sgl(m, req->dst, req->dst_len, &sign);
cfc2bb32 TS	123	if (ret)
	124	goto err_free_c;
	125
22287b0b	126	if (sign < 0)
cfc2bb32	127	ret = -EBADMSG;
cfc2bb32 TS	128	err_free_c:
	129	mpi_free(c);
	130	err_free_m:
	131	mpi_free(m);
	132	return ret;
	133	}
	134
5a7de973 TA	135	static void rsa_free_mpi_key(struct rsa_mpi_key *key)
	136	{
	137	mpi_free(key->d);
	138	mpi_free(key->e);
	139	mpi_free(key->n);
	140	key->d = NULL;
	141	key->e = NULL;
	142	key->n = NULL;
	143	}
	144
6e8ec66c TS	145	static int rsa_check_key_length(unsigned int len)
	146	{
	147	switch (len) {
	148	case 512:
	149	case 1024:
	150	case 1536:
	151	case 2048:
	152	case 3072:
	153	case 4096:
	154	return 0;
	155	}
	156
	157	return -EINVAL;
	158	}
	159
22287b0b TS	160	static int rsa_set_pub_key(struct crypto_akcipher tfm, const void key,
22287b0b TS	161	unsigned int keylen)
cfc2bb32	162	{
5a7de973 TA	163	struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm);
5a7de973 TA	164	struct rsa_key raw_key = {0};
6e8ec66c	165	int ret;
cfc2bb32	166
5a7de973 TA	167	/* Free the old MPI key if any */
	168	rsa_free_mpi_key(mpi_key);
	169
	170	ret = rsa_parse_pub_key(&raw_key, key, keylen);
6e8ec66c TS	171	if (ret)
	172	return ret;
	173
5a7de973 TA	174	mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz);
	175	if (!mpi_key->e)
	176	goto err;
	177
	178	mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz);
	179	if (!mpi_key->n)
	180	goto err;
	181
	182	if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
	183	rsa_free_mpi_key(mpi_key);
	184	return -EINVAL;
6e8ec66c	185	}
5a7de973 TA	186
	187	return 0;
	188
	189	err:
	190	rsa_free_mpi_key(mpi_key);
	191	return -ENOMEM;
cfc2bb32 TS	192	}
cfc2bb32 TS	193
22287b0b TS	194	static int rsa_set_priv_key(struct crypto_akcipher tfm, const void key,
	195	unsigned int keylen)
	196	{
5a7de973 TA	197	struct rsa_mpi_key *mpi_key = akcipher_tfm_ctx(tfm);
5a7de973 TA	198	struct rsa_key raw_key = {0};
22287b0b TS	199	int ret;
22287b0b TS	200
5a7de973 TA	201	/* Free the old MPI key if any */
	202	rsa_free_mpi_key(mpi_key);
	203
	204	ret = rsa_parse_priv_key(&raw_key, key, keylen);
22287b0b TS	205	if (ret)
	206	return ret;
	207
5a7de973 TA	208	mpi_key->d = mpi_read_raw_data(raw_key.d, raw_key.d_sz);
	209	if (!mpi_key->d)
	210	goto err;
	211
	212	mpi_key->e = mpi_read_raw_data(raw_key.e, raw_key.e_sz);
	213	if (!mpi_key->e)
	214	goto err;
	215
	216	mpi_key->n = mpi_read_raw_data(raw_key.n, raw_key.n_sz);
	217	if (!mpi_key->n)
	218	goto err;
	219
	220	if (rsa_check_key_length(mpi_get_size(mpi_key->n) << 3)) {
	221	rsa_free_mpi_key(mpi_key);
	222	return -EINVAL;
22287b0b	223	}
5a7de973 TA	224
	225	return 0;
	226
	227	err:
	228	rsa_free_mpi_key(mpi_key);
	229	return -ENOMEM;
22287b0b TS	230	}
22287b0b TS	231
1c23b466	232	static unsigned int rsa_max_size(struct crypto_akcipher *tfm)
22287b0b	233	{
5a7de973	234	struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm);
22287b0b	235
1c23b466	236	return mpi_get_size(pkey->n);
22287b0b TS	237	}
22287b0b TS	238
cfc2bb32 TS	239	static void rsa_exit_tfm(struct crypto_akcipher *tfm)
cfc2bb32 TS	240	{
5a7de973	241	struct rsa_mpi_key *pkey = akcipher_tfm_ctx(tfm);
cfc2bb32	242
5a7de973	243	rsa_free_mpi_key(pkey);
cfc2bb32 TS	244	}
	245
	246	static struct akcipher_alg rsa = {
	247	.encrypt = rsa_enc,
	248	.decrypt = rsa_dec,
22287b0b TS	249	.set_priv_key = rsa_set_priv_key,
	250	.set_pub_key = rsa_set_pub_key,
	251	.max_size = rsa_max_size,
cfc2bb32 TS	252	.exit = rsa_exit_tfm,
	253	.base = {
	254	.cra_name = "rsa",
	255	.cra_driver_name = "rsa-generic",
	256	.cra_priority = 100,
	257	.cra_module = THIS_MODULE,
5a7de973	258	.cra_ctxsize = sizeof(struct rsa_mpi_key),
cfc2bb32 TS	259	},
	260	};
	261
	262	static int rsa_init(void)
	263	{
3d5b1ecd AZ	264	int err;
	265
	266	err = crypto_register_akcipher(&rsa);
	267	if (err)
	268	return err;
	269
	270	err = crypto_register_template(&rsa_pkcs1pad_tmpl);
	271	if (err) {
	272	crypto_unregister_akcipher(&rsa);
	273	return err;
	274	}
	275
	276	return 0;
cfc2bb32 TS	277	}
	278
	279	static void rsa_exit(void)
	280	{
3d5b1ecd	281	crypto_unregister_template(&rsa_pkcs1pad_tmpl);
cfc2bb32 TS	282	crypto_unregister_akcipher(&rsa);
	283	}
	284
c4741b23	285	subsys_initcall(rsa_init);
cfc2bb32 TS	286	module_exit(rsa_exit);
	287	MODULE_ALIAS_CRYPTO("rsa");
	288	MODULE_LICENSE("GPL");
	289	MODULE_DESCRIPTION("RSA generic algorithm");