From 5dd39ae86c106d789db1865576c5c335bb3369b3 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 15 Jun 2023 18:28:53 +0800 Subject: KEYS: asymmetric: Move sm2 code into x509_public_key The sm2 certificate requires a modified digest. Move the code for the hashing from the signature verification path into the code where we generate the digest. Signed-off-by: Herbert Xu --- crypto/sm2.c | 106 +++++++++++++++++++++++++++++++++++++++-------------------- 1 file changed, 70 insertions(+), 36 deletions(-) (limited to 'crypto/sm2.c') diff --git a/crypto/sm2.c b/crypto/sm2.c index ed9307da..285b3cb7 100644 --- a/crypto/sm2.c +++ b/crypto/sm2.c @@ -13,11 +13,14 @@ #include #include #include -#include #include #include #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 { @@ -60,6 +63,9 @@ static const struct ecc_domain_parms sm2_ecp = { .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; @@ -213,12 +219,13 @@ int sm2_get_signature_s(void *context, size_t hdrlen, unsigned char tag, return 0; } -static int sm2_z_digest_update(struct sm3_state *sctx, - MPI m, unsigned int pbytes) +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) @@ -226,21 +233,22 @@ static int sm2_z_digest_update(struct sm3_state *sctx, if (inlen < pbytes) { /* padding with zero */ - sm3_update(sctx, zero, pbytes - inlen); - sm3_update(sctx, in, inlen); + err = crypto_shash_update(desc, zero, pbytes - inlen) ?: + crypto_shash_update(desc, in, inlen); } else if (inlen > pbytes) { /* skip the starting zero */ - sm3_update(sctx, in + inlen - pbytes, pbytes); + err = crypto_shash_update(desc, in + inlen - pbytes, pbytes); } else { - sm3_update(sctx, in, inlen); + err = crypto_shash_update(desc, in, inlen); } kfree(in); - return 0; + return err; } -static int sm2_z_digest_update_point(struct sm3_state *sctx, - MPI_POINT point, struct mpi_ec_ctx *ec, unsigned int pbytes) +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; @@ -248,50 +256,68 @@ static int sm2_z_digest_update_point(struct sm3_state *sctx, x = mpi_new(0); y = mpi_new(0); - if (!mpi_ec_get_affine(x, y, point, ec) && - !sm2_z_digest_update(sctx, x, pbytes) && - !sm2_z_digest_update(sctx, y, pbytes)) - ret = 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 crypto_akcipher *tfm, - const unsigned char *id, size_t id_len, - unsigned char dgst[SM3_DIGEST_SIZE]) +int sm2_compute_z_digest(struct shash_desc *desc, + const void *key, unsigned int keylen, void *dgst) { - struct mpi_ec_ctx *ec = akcipher_tfm_ctx(tfm); - uint16_t bits_len; - unsigned char entl[2]; - struct sm3_state sctx; + struct mpi_ec_ctx *ec; + unsigned int bits_len; unsigned int pbytes; + u8 entl[2]; + int err; - if (id_len > (USHRT_MAX / 8) || !ec->Q) - return -EINVAL; + ec = kmalloc(sizeof(*ec), GFP_KERNEL); + if (!ec) + return -ENOMEM; + + err = __sm2_set_pub_key(ec, key, keylen); + if (err) + goto out_free_ec; - bits_len = (uint16_t)(id_len * 8); + 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) */ - sm3_init(&sctx); - sm3_update(&sctx, entl, 2); - sm3_update(&sctx, id, id_len); - - if (sm2_z_digest_update(&sctx, ec->a, pbytes) || - sm2_z_digest_update(&sctx, ec->b, pbytes) || - sm2_z_digest_update_point(&sctx, ec->G, ec, pbytes) || - sm2_z_digest_update_point(&sctx, ec->Q, ec, pbytes)) - return -EINVAL; + err = crypto_shash_init(desc); + if (err) + goto out_deinit_ec; - sm3_final(&sctx, dgst); - return 0; + 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(sm2_compute_z_digest); +EXPORT_SYMBOL_GPL(sm2_compute_z_digest); static int _sm2_verify(struct mpi_ec_ctx *ec, MPI hash, MPI sig_r, MPI sig_s) { @@ -391,6 +417,14 @@ 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; -- cgit v1.2.3