Hi, On Sun, Feb 16, 2020 at 11:00 AM Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx> wrote: > > The digital certificate format based on SM2 crypto algorithm as > specified in GM/T 0015-2012. It was published by State Encryption > Management Bureau, China. > > The method of generating Other User Information is defined as > ZA=H256(ENTLA || IDA || a || b || xG || yG || xA || yA), it also > specified in https://tools.ietf.org/html/draft-shen-sm2-ecdsa-02. > > The x509 certificate supports sm2-with-sm3 type certificate > verification. Because certificate verification requires ZA > in addition to tbs data, ZA also depends on elliptic curve > parameters and public key data, so you need to access tbs in sig > and calculate ZA. Finally calculate the digest of the > signature and complete the verification work. The calculation > process of ZA is declared in specifications GM/T 0009-2012 > and GM/T 0003.2-2012. > > Signed-off-by: Tianjia Zhang <tianjia.zhang@xxxxxxxxxxxxxxxxx> > --- > crypto/asymmetric_keys/public_key.c | 61 ++++++++++++++++++++++++ > crypto/asymmetric_keys/x509_public_key.c | 2 + > include/crypto/public_key.h | 1 + > 3 files changed, 64 insertions(+) > > diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c > index d7f43d4ea925..a51b09ee484d 100644 > --- a/crypto/asymmetric_keys/public_key.c > +++ b/crypto/asymmetric_keys/public_key.c > @@ -17,6 +17,11 @@ > #include <keys/asymmetric-subtype.h> > #include <crypto/public_key.h> > #include <crypto/akcipher.h> hmmm... ifdefs like these are kind of ugly. > +#ifdef CONFIG_CRYPTO_SM2 > +#include <crypto/sm3_base.h> > +#include <crypto/sm2.h> > +#include "x509_parser.h" > +#endif > > MODULE_DESCRIPTION("In-software asymmetric public-key subtype"); > MODULE_AUTHOR("Red Hat, Inc."); > @@ -245,6 +250,54 @@ static int software_key_eds_op(struct kernel_pkey_params *params, > return ret; > } > > +#ifdef CONFIG_CRYPTO_SM2 > +static int cert_sig_digest_update(const struct public_key_signature *sig, > + struct crypto_akcipher *tfm_pkey) > +{ > + struct x509_certificate *cert = sig->cert; > + struct crypto_shash *tfm; > + struct shash_desc *desc; > + size_t desc_size; > + unsigned char dgst[SM3_DIGEST_SIZE]; > + int ret; > + > + if (!cert) > + return -EINVAL; > + > + ret = sm2_compute_z_digest(tfm_pkey, SM2_DEFAULT_USERID, > + SM2_DEFAULT_USERID_LEN, dgst); > + if (ret) > + return ret; > + > + tfm = crypto_alloc_shash(sig->hash_algo, 0, 0); > + if (IS_ERR(tfm)) > + return PTR_ERR(tfm); > + > + desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); > + desc = kzalloc(desc_size, GFP_KERNEL); > + if (!desc) > + goto error_free_tfm; > + > + desc->tfm = tfm; > + > + ret = crypto_shash_init(desc); > + if (ret < 0) > + goto error_free_desc; > + > + ret = crypto_shash_update(desc, dgst, SM3_DIGEST_SIZE); > + if (ret < 0) > + goto error_free_desc; > + > + ret = crypto_shash_finup(desc, cert->tbs, cert->tbs_size, sig->digest); > + > +error_free_desc: > + kfree(desc); > +error_free_tfm: > + crypto_free_shash(tfm); > + return ret; > +} > +#endif > + > /* > * Verify a signature using a public key. > */ > @@ -298,6 +351,14 @@ int public_key_verify_signature(const struct public_key *pkey, > if (ret) > goto error_free_key; > OK, how about you put cert_sig_digest_update() in a separate file that only gets compiled with CONFIG_CRYPTO_SM2 and have a static inline version that returns -ENOTSUPP otherwise? or at least something in this spirit. Done right it will allow you to drop the ifdefs and make for a much cleaner code. > +#ifdef CONFIG_CRYPTO_SM2 > + if (strcmp(sig->pkey_algo, "sm2") == 0) { > + ret = cert_sig_digest_update(sig, tfm); > + if (ret) > + goto error_free_key; > + } > +#endif > + > sg_init_table(src_sg, 2); > sg_set_buf(&src_sg[0], sig->s, sig->s_size); > sg_set_buf(&src_sg[1], sig->digest, sig->digest_size); > diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c > index d964cc82b69c..feccec08b244 100644 > --- a/crypto/asymmetric_keys/x509_public_key.c > +++ b/crypto/asymmetric_keys/x509_public_key.c > @@ -30,6 +30,8 @@ int x509_get_sig_params(struct x509_certificate *cert) > > pr_devel("==>%s()\n", __func__); > > + sig->cert = cert; > + > if (!cert->pub->pkey_algo) > cert->unsupported_key = true; > > diff --git a/include/crypto/public_key.h b/include/crypto/public_key.h > index 0588ef3bc6ff..27775e617e38 100644 > --- a/include/crypto/public_key.h > +++ b/include/crypto/public_key.h > @@ -44,6 +44,7 @@ struct public_key_signature { > const char *pkey_algo; > const char *hash_algo; > const char *encoding; > + void *cert; /* For certificate */ > }; > > extern void public_key_signature_free(struct public_key_signature *sig); > -- > 2.17.1 > -- Gilad Ben-Yossef Chief Coffee Drinker values of β will give rise to dom!
