diff options
Diffstat (limited to 'common/kem.c')
| -rw-r--r-- | common/kem.c | 60 |
1 files changed, 43 insertions, 17 deletions
diff --git a/common/kem.c b/common/kem.c index bbb450e1b..fc5575f4f 100644 --- a/common/kem.c +++ b/common/kem.c @@ -150,24 +150,50 @@ gpg_error_t gnupg_ecc_kem_kdf (void *kek, size_t kek_len, int hashalgo, const void *ecdh, size_t ecdh_len, const void *ecc_ct, size_t ecc_ct_len, - const void *ecc_pk, size_t ecc_pk_len) + const void *ecc_pk, size_t ecc_pk_len, + gcry_buffer_t *fixed_info) { - gcry_buffer_t iov[3]; - unsigned int dlen; - - dlen = gcry_md_get_algo_dlen (hashalgo); - if (kek_len != dlen) - return gpg_error (GPG_ERR_INV_LENGTH); - - memset (iov, 0, sizeof (iov)); - - iov[0].data = (unsigned char *)ecdh; - iov[0].len = ecdh_len; - iov[1].data = (unsigned char *)ecc_ct; - iov[1].len = ecc_ct_len; - iov[2].data = (unsigned char *)ecc_pk; - iov[2].len = ecc_pk_len; - gcry_md_hash_buffers (hashalgo, 0, kek, iov, 3); + if (fixed_info) + { + /* Traditional ECC */ + gpg_error_t err; + gcry_kdf_hd_t hd; + unsigned long param[1]; + + param[0] = kek_len; + err = gcry_kdf_open (&hd, GCRY_KDF_ONESTEP_KDF, hashalgo, param, 1, + ecdh, ecdh_len, NULL, 0, NULL, 0, + (char *)fixed_info->data+fixed_info->off, + fixed_info->len); + if (!err) + { + gcry_kdf_compute (hd, NULL); + gcry_kdf_final (hd, kek_len, kek); + gcry_kdf_close (hd); + } + + return err; + } + else + { + /* ECC in composite KEM */ + gcry_buffer_t iov[3]; + unsigned int dlen; + + dlen = gcry_md_get_algo_dlen (hashalgo); + if (kek_len != dlen) + return gpg_error (GPG_ERR_INV_LENGTH); + + memset (iov, 0, sizeof (iov)); + + iov[0].data = (unsigned char *)ecdh; + iov[0].len = ecdh_len; + iov[1].data = (unsigned char *)ecc_ct; + iov[1].len = ecc_ct_len; + iov[2].data = (unsigned char *)ecc_pk; + iov[2].len = ecc_pk_len; + gcry_md_hash_buffers (hashalgo, 0, kek, iov, 3); + } return 0; } |