diff options
Diffstat (limited to 'crypto/sm2.c')
| -rw-r--r-- | crypto/sm2.c | 498 |
1 files changed, 0 insertions, 498 deletions
diff --git a/crypto/sm2.c b/crypto/sm2.c deleted file mode 100644 index 5ab120d74c59..000000000000 --- a/crypto/sm2.c +++ /dev/null @@ -1,498 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* - * SM2 asymmetric public-key algorithm - * as specified by OSCCA GM/T 0003.1-2012 -- 0003.5-2012 SM2 and - * described at https://tools.ietf.org/html/draft-shen-sm2-ecdsa-02 - * - * Copyright (c) 2020, Alibaba Group. - * Authors: Tianjia Zhang <tianjia.zhang@linux.alibaba.com> - */ - -#include <linux/module.h> -#include <linux/mpi.h> -#include <crypto/internal/akcipher.h> -#include <crypto/akcipher.h> -#include <crypto/hash.h> -#include <crypto/rng.h> -#include <crypto/sm2.h> -#include "sm2signature.asn1.h" - -/* The default user id as specified in GM/T 0009-2012 */ -#define SM2_DEFAULT_USERID "1234567812345678" -#define SM2_DEFAULT_USERID_LEN 16 - -#define MPI_NBYTES(m) ((mpi_get_nbits(m) + 7) / 8) - -struct ecc_domain_parms { - const char *desc; /* Description of the curve. */ - unsigned int nbits; /* Number of bits. */ - unsigned int fips:1; /* True if this is a FIPS140-2 approved curve */ - - /* The model describing this curve. This is mainly used to select - * the group equation. - */ - enum gcry_mpi_ec_models model; - - /* The actual ECC dialect used. This is used for curve specific - * optimizations and to select encodings etc. - */ - enum ecc_dialects dialect; - - const char *p; /* The prime defining the field. */ - const char *a, *b; /* The coefficients. For Twisted Edwards - * Curves b is used for d. For Montgomery - * Curves (a,b) has ((A-2)/4,B^-1). - */ - const char *n; /* The order of the base point. */ - const char *g_x, *g_y; /* Base point. */ - unsigned int h; /* Cofactor. */ -}; - -static const struct ecc_domain_parms sm2_ecp = { - .desc = "sm2p256v1", - .nbits = 256, - .fips = 0, - .model = MPI_EC_WEIERSTRASS, - .dialect = ECC_DIALECT_STANDARD, - .p = "0xfffffffeffffffffffffffffffffffffffffffff00000000ffffffffffffffff", - .a = "0xfffffffeffffffffffffffffffffffffffffffff00000000fffffffffffffffc", - .b = "0x28e9fa9e9d9f5e344d5a9e4bcf6509a7f39789f515ab8f92ddbcbd414d940e93", - .n = "0xfffffffeffffffffffffffffffffffff7203df6b21c6052b53bbf40939d54123", - .g_x = "0x32c4ae2c1f1981195f9904466a39c9948fe30bbff2660be1715a4589334c74c7", - .g_y = "0xbc3736a2f4f6779c59bdcee36b692153d0a9877cc62a474002df32e52139f0a0", - .h = 1 -}; - -static int __sm2_set_pub_key(struct mpi_ec_ctx *ec, - const void *key, unsigned int keylen); - -static int sm2_ec_ctx_init(struct mpi_ec_ctx *ec) -{ - const struct ecc_domain_parms *ecp = &sm2_ecp; - MPI p, a, b; - MPI x, y; - int rc = -EINVAL; - - p = mpi_scanval(ecp->p); - a = mpi_scanval(ecp->a); - b = mpi_scanval(ecp->b); - if (!p || !a || !b) - goto free_p; - - x = mpi_scanval(ecp->g_x); - y = mpi_scanval(ecp->g_y); - if (!x || !y) - goto free; - - rc = -ENOMEM; - - ec->Q = mpi_point_new(0); - if (!ec->Q) - goto free; - - /* mpi_ec_setup_elliptic_curve */ - ec->G = mpi_point_new(0); - if (!ec->G) { - mpi_point_release(ec->Q); - goto free; - } - - mpi_set(ec->G->x, x); - mpi_set(ec->G->y, y); - mpi_set_ui(ec->G->z, 1); - - rc = -EINVAL; - ec->n = mpi_scanval(ecp->n); - if (!ec->n) { - mpi_point_release(ec->Q); - mpi_point_release(ec->G); - goto free; - } - - ec->h = ecp->h; - ec->name = ecp->desc; - mpi_ec_init(ec, ecp->model, ecp->dialect, 0, p, a, b); - - rc = 0; - -free: - mpi_free(x); - mpi_free(y); -free_p: - mpi_free(p); - mpi_free(a); - mpi_free(b); - - return rc; -} - -static void sm2_ec_ctx_deinit(struct mpi_ec_ctx *ec) -{ - mpi_ec_deinit(ec); - - memset(ec, 0, sizeof(*ec)); -} - -/* RESULT must have been initialized and is set on success to the - * point given by VALUE. - */ -static int sm2_ecc_os2ec(MPI_POINT result, MPI value) -{ - int rc; - size_t n; - unsigned char *buf; - MPI x, y; - - n = MPI_NBYTES(value); - buf = kmalloc(n, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - rc = mpi_print(GCRYMPI_FMT_USG, buf, n, &n, value); - if (rc) - goto err_freebuf; - - rc = -EINVAL; - if (n < 1 || ((n - 1) % 2)) - goto err_freebuf; - /* No support for point compression */ - if (*buf != 0x4) - goto err_freebuf; - - rc = -ENOMEM; - n = (n - 1) / 2; - x = mpi_read_raw_data(buf + 1, n); - if (!x) - goto err_freebuf; - y = mpi_read_raw_data(buf + 1 + n, n); - if (!y) - goto err_freex; - - mpi_normalize(x); - mpi_normalize(y); - mpi_set(result->x, x); - mpi_set(result->y, y); - mpi_set_ui(result->z, 1); - - rc = 0; - - mpi_free(y); -err_freex: - mpi_free(x); -err_freebuf: - kfree(buf); - return rc; -} - -struct sm2_signature_ctx { - MPI sig_r; - MPI sig_s; -}; - -int sm2_get_signature_r(void *context, size_t hdrlen, unsigned char tag, - const void *value, size_t vlen) -{ - struct sm2_signature_ctx *sig = context; - - if (!value || !vlen) - return -EINVAL; - - sig->sig_r = mpi_read_raw_data(value, vlen); - if (!sig->sig_r) - return -ENOMEM; - - return 0; -} - -int sm2_get_signature_s(void *context, size_t hdrlen, unsigned char tag, - const void *value, size_t vlen) -{ - struct sm2_signature_ctx *sig = context; - - if (!value || !vlen) - return -EINVAL; - - sig->sig_s = mpi_read_raw_data(value, vlen); - if (!sig->sig_s) - return -ENOMEM; - - return 0; -} - -static int sm2_z_digest_update(struct shash_desc *desc, - MPI m, unsigned int pbytes) -{ - static const unsigned char zero[32]; - unsigned char *in; - unsigned int inlen; - int err; - - in = mpi_get_buffer(m, &inlen, NULL); - if (!in) - return -EINVAL; - - if (inlen < pbytes) { - /* padding with zero */ - err = crypto_shash_update(desc, zero, pbytes - inlen) ?: - crypto_shash_update(desc, in, inlen); - } else if (inlen > pbytes) { - /* skip the starting zero */ - err = crypto_shash_update(desc, in + inlen - pbytes, pbytes); - } else { - err = crypto_shash_update(desc, in, inlen); - } - - kfree(in); - return err; -} - -static int sm2_z_digest_update_point(struct shash_desc *desc, - MPI_POINT point, struct mpi_ec_ctx *ec, - unsigned int pbytes) -{ - MPI x, y; - int ret = -EINVAL; - - x = mpi_new(0); - y = mpi_new(0); - - ret = mpi_ec_get_affine(x, y, point, ec) ? -EINVAL : - sm2_z_digest_update(desc, x, pbytes) ?: - sm2_z_digest_update(desc, y, pbytes); - - mpi_free(x); - mpi_free(y); - return ret; -} - -int sm2_compute_z_digest(struct shash_desc *desc, - const void *key, unsigned int keylen, void *dgst) -{ - struct mpi_ec_ctx *ec; - unsigned int bits_len; - unsigned int pbytes; - u8 entl[2]; - int err; - - ec = kmalloc(sizeof(*ec), GFP_KERNEL); - if (!ec) - return -ENOMEM; - - err = sm2_ec_ctx_init(ec); - if (err) - goto out_free_ec; - - err = __sm2_set_pub_key(ec, key, keylen); - if (err) - goto out_deinit_ec; - - bits_len = SM2_DEFAULT_USERID_LEN * 8; - entl[0] = bits_len >> 8; - entl[1] = bits_len & 0xff; - - pbytes = MPI_NBYTES(ec->p); - - /* ZA = H256(ENTLA | IDA | a | b | xG | yG | xA | yA) */ - err = crypto_shash_init(desc); - if (err) - goto out_deinit_ec; - - err = crypto_shash_update(desc, entl, 2); - if (err) - goto out_deinit_ec; - - err = crypto_shash_update(desc, SM2_DEFAULT_USERID, - SM2_DEFAULT_USERID_LEN); - if (err) - goto out_deinit_ec; - - err = sm2_z_digest_update(desc, ec->a, pbytes) ?: - sm2_z_digest_update(desc, ec->b, pbytes) ?: - sm2_z_digest_update_point(desc, ec->G, ec, pbytes) ?: - sm2_z_digest_update_point(desc, ec->Q, ec, pbytes); - if (err) - goto out_deinit_ec; - - err = crypto_shash_final(desc, dgst); - -out_deinit_ec: - sm2_ec_ctx_deinit(ec); -out_free_ec: - kfree(ec); - return err; -} -EXPORT_SYMBOL_GPL(sm2_compute_z_digest); - -static int _sm2_verify(struct mpi_ec_ctx *ec, MPI hash, MPI sig_r, MPI sig_s) -{ - int rc = -EINVAL; - struct gcry_mpi_point sG, tP; - MPI t = NULL; - MPI x1 = NULL, y1 = NULL; - - mpi_point_init(&sG); - mpi_point_init(&tP); - x1 = mpi_new(0); - y1 = mpi_new(0); - t = mpi_new(0); - - /* r, s in [1, n-1] */ - if (mpi_cmp_ui(sig_r, 1) < 0 || mpi_cmp(sig_r, ec->n) > 0 || - mpi_cmp_ui(sig_s, 1) < 0 || mpi_cmp(sig_s, ec->n) > 0) { - goto leave; - } - - /* t = (r + s) % n, t == 0 */ - mpi_addm(t, sig_r, sig_s, ec->n); - if (mpi_cmp_ui(t, 0) == 0) - goto leave; - - /* sG + tP = (x1, y1) */ - rc = -EBADMSG; - mpi_ec_mul_point(&sG, sig_s, ec->G, ec); - mpi_ec_mul_point(&tP, t, ec->Q, ec); - mpi_ec_add_points(&sG, &sG, &tP, ec); - if (mpi_ec_get_affine(x1, y1, &sG, ec)) - goto leave; - - /* R = (e + x1) % n */ - mpi_addm(t, hash, x1, ec->n); - - /* check R == r */ - rc = -EKEYREJECTED; - if (mpi_cmp(t, sig_r)) - goto leave; - - rc = 0; - -leave: - mpi_point_free_parts(&sG); - mpi_point_free_parts(&tP); - mpi_free(x1); - mpi_free(y1); - mpi_free(t); - - return rc; -} - -static int sm2_verify(struct akcipher_request *req) -{ - struct crypto_akcipher *tfm = crypto_akcipher_reqtfm(req); - struct mpi_ec_ctx *ec = akcipher_tfm_ctx(tfm); - unsigned char *buffer; - struct sm2_signature_ctx sig; - MPI hash; - int ret; - - if (unlikely(!ec->Q)) - return -EINVAL; - - buffer = kmalloc(req->src_len + req->dst_len, GFP_KERNEL); - if (!buffer) - return -ENOMEM; - - sg_pcopy_to_buffer(req->src, - sg_nents_for_len(req->src, req->src_len + req->dst_len), - buffer, req->src_len + req->dst_len, 0); - - sig.sig_r = NULL; - sig.sig_s = NULL; - ret = asn1_ber_decoder(&sm2signature_decoder, &sig, - buffer, req->src_len); - if (ret) - goto error; - - ret = -ENOMEM; - hash = mpi_read_raw_data(buffer + req->src_len, req->dst_len); - if (!hash) - goto error; - - ret = _sm2_verify(ec, hash, sig.sig_r, sig.sig_s); - - mpi_free(hash); -error: - mpi_free(sig.sig_r); - mpi_free(sig.sig_s); - kfree(buffer); - return ret; -} - -static int sm2_set_pub_key(struct crypto_akcipher *tfm, - const void *key, unsigned int keylen) -{ - struct mpi_ec_ctx *ec = akcipher_tfm_ctx(tfm); - - return __sm2_set_pub_key(ec, key, keylen); - -} - -static int __sm2_set_pub_key(struct mpi_ec_ctx *ec, - const void *key, unsigned int keylen) -{ - MPI a; - int rc; - - /* include the uncompressed flag '0x04' */ - a = mpi_read_raw_data(key, keylen); - if (!a) - return -ENOMEM; - - mpi_normalize(a); - rc = sm2_ecc_os2ec(ec->Q, a); - mpi_free(a); - - return rc; -} - -static unsigned int sm2_max_size(struct crypto_akcipher *tfm) -{ - /* Unlimited max size */ - return PAGE_SIZE; -} - -static int sm2_init_tfm(struct crypto_akcipher *tfm) -{ - struct mpi_ec_ctx *ec = akcipher_tfm_ctx(tfm); - - return sm2_ec_ctx_init(ec); -} - -static void sm2_exit_tfm(struct crypto_akcipher *tfm) -{ - struct mpi_ec_ctx *ec = akcipher_tfm_ctx(tfm); - - sm2_ec_ctx_deinit(ec); -} - -static struct akcipher_alg sm2 = { - .verify = sm2_verify, - .set_pub_key = sm2_set_pub_key, - .max_size = sm2_max_size, - .init = sm2_init_tfm, - .exit = sm2_exit_tfm, - .base = { - .cra_name = "sm2", - .cra_driver_name = "sm2-generic", - .cra_priority = 100, - .cra_module = THIS_MODULE, - .cra_ctxsize = sizeof(struct mpi_ec_ctx), - }, -}; - -static int __init sm2_init(void) -{ - return crypto_register_akcipher(&sm2); -} - -static void __exit sm2_exit(void) -{ - crypto_unregister_akcipher(&sm2); -} - -subsys_initcall(sm2_init); -module_exit(sm2_exit); - -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Tianjia Zhang <tianjia.zhang@linux.alibaba.com>"); -MODULE_DESCRIPTION("SM2 generic algorithm"); -MODULE_ALIAS_CRYPTO("sm2-generic"); |