diff options
Diffstat (limited to 'cipher/pkey-ecc-nist.c')
| -rw-r--r-- | cipher/pkey-ecc-nist.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/cipher/pkey-ecc-nist.c b/cipher/pkey-ecc-nist.c new file mode 100644 index 00000000..9011a15e --- /dev/null +++ b/cipher/pkey-ecc-nist.c @@ -0,0 +1,220 @@ +/* pkey-ecc-nist.c - PKEY API implementation for NIST Curves + * Copyright (C) 2021 g10 Code GmbH + * + * This file is part of Libgcrypt. + * + * Libgcrypt is free software; you can redistribute it and/or modify + * it under the terms of the GNU Lesser general Public License as + * published by the Free Software Foundation; either version 2.1 of + * the License, or (at your option) any later version. + * + * Libgcrypt is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this program; if not, see <https://www.gnu.org/licenses/>. + * SPDX-License-Identifier: LGPL-2.1+ + */ + +#include <config.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <stdarg.h> +#include <errno.h> + +#include "g10lib.h" +#include "gcrypt-int.h" +#include "pkey-internal.h" + +static const char * +get_curve_name (int curve) +{ + switch (curve) + { + case GCRY_PKEY_CURVE_NIST_P224: + return "nistp224"; + case GCRY_PKEY_CURVE_NIST_P256: + return "nistp256"; + case GCRY_PKEY_CURVE_NIST_P384: + return "nistp384"; + case GCRY_PKEY_CURVE_NIST_P521: + return "nistp521"; + default: + return "unknown"; + } +} + +gcry_error_t +_gcry_pkey_nist_sign (gcry_pkey_hd_t h, + int num_in, const unsigned char *const in[], + const size_t in_len[], + int num_out, unsigned char *out[], size_t out_len[]) +{ + gcry_error_t err = 0; + gcry_sexp_t s_sk = NULL; + gcry_sexp_t s_msg= NULL; + gcry_sexp_t s_sig= NULL; + gcry_sexp_t s_tmp, s_tmp2; + const char *curve; + const char *md_name; + + if (num_in != 2) /* For now, k should be specified by the caller. */ + return gpg_error (GPG_ERR_INV_ARG); + + if (num_out != 2) + return gpg_error (GPG_ERR_INV_ARG); + + curve = get_curve_name (h->ecc.curve); + if (h->ecc.pk) + err = sexp_build (&s_sk, NULL, + "(private-key" + " (ecc" + " (curve %s)" + " (q %b)" + " (d %b)))", curve, + (int)h->ecc.pk_len, h->ecc.pk, + (int)h->ecc.sk_len, h->ecc.sk); + else + err = sexp_build (&s_sk, NULL, + "(private-key" + " (ecc" + " (curve %s)" + " (d %b)))", curve, + (int)h->ecc.sk_len, h->ecc.sk); + if (err) + return err; + + md_name = _gcry_md_algo_name (h->ecc.md_algo); + + if ((h->flags & GCRY_PKEY_FLAG_PREHASH)) + err = sexp_build (&s_msg, NULL, + "(data" + " (flags prehash)" + " (label %b)" + " (hash-algo %s)" + " (value %b))", + (int)in_len[1], in[1], + md_name, (int)in_len[0], in[0]); + else + err = sexp_build (&s_msg, NULL, + "(data " + " (label %b)" + " (value %b))", (int)in_len[1], in[1], + (int)in_len[0], in[0]); + if (err) + { + sexp_release (s_sk); + return err; + } + + err = _gcry_pk_sign (&s_sig, s_msg, s_sk); + sexp_release (s_sk); + sexp_release (s_msg); + if (err) + return err; + + out[0] = out[1] = NULL; + s_tmp2 = NULL; + s_tmp = sexp_find_token (s_sig, "sig-val", 0); + if (s_tmp) + { + s_tmp2 = s_tmp; + s_tmp = sexp_find_token (s_tmp2, "ecdsa", 0); + if (s_tmp) + { + sexp_release (s_tmp2); + s_tmp2 = s_tmp; + s_tmp = sexp_find_token (s_tmp2, "r", 0); + if (s_tmp) + { + out[0] = sexp_nth_buffer (s_tmp, 1, &out_len[0]); + sexp_release (s_tmp); + } + s_tmp = sexp_find_token (s_tmp2, "s", 0); + if (s_tmp) + { + out[1] = sexp_nth_buffer (s_tmp, 1, &out_len[1]); + sexp_release (s_tmp); + } + } + } + sexp_release (s_tmp2); + + if (out[0] == NULL || out[1] == NULL) + err = gpg_error (GPG_ERR_BAD_SIGNATURE); + + sexp_release (s_sig); + + return err; +} + +gcry_error_t +_gcry_pkey_nist_verify (gcry_pkey_hd_t h, + int num_in, const unsigned char *const in[], + const size_t in_len[]) +{ + gcry_error_t err = 0; + gcry_sexp_t s_pk = NULL; + gcry_sexp_t s_msg= NULL; + gcry_sexp_t s_sig= NULL; + const char *curve; + const char *md_name; + + if (num_in != 4) /* For now, k should be specified by the caller. */ + return gpg_error (GPG_ERR_INV_ARG); + + curve = get_curve_name (h->ecc.curve); + err = sexp_build (&s_pk, NULL, + "(public-key" + " (ecc" + " (curve %s)" + " (q %b)))", curve, + (int)h->ecc.pk_len, h->ecc.pk); + if (err) + return err; + + md_name = _gcry_md_algo_name (h->ecc.md_algo); + + if ((h->flags & GCRY_PKEY_FLAG_PREHASH)) + err = sexp_build (&s_msg, NULL, + "(data" + " (flags prehash)" + " (label %b)" + " (hash-algo %s)" + " (value %b))", + (int)in_len[1], in[1], + md_name, (int)in_len[0], in[0]); + else + err = sexp_build (&s_msg, NULL, + "(data " + " (label %b)" + " (value %b))", (int)in_len[1], in[1], + (int)in_len[0], in[0]); + if (err) + { + sexp_release (s_pk); + return err; + } + + err = sexp_build (&s_sig, NULL, + "(sig-val(ecdsa(r %b)(s %b)))", + (int)in_len[2], in[2], + (int)in_len[3], in[3]); + if (err) + { + sexp_release (s_msg); + sexp_release (s_pk); + return err; + } + + err = _gcry_pk_verify (s_sig, s_msg, s_pk); + + sexp_release (s_sig); + sexp_release (s_msg); + sexp_release (s_pk); + + return err; +} |