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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 07:33:12 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 07:33:12 +0000
commit36082a2fe36ecd800d784ae44c14f1f18c66a7e9 (patch)
tree6c68e0c0097987aff85a01dabddd34b862309a7c /lib/dh-session.c
parentInitial commit. (diff)
downloadgnutls28-upstream.tar.xz
gnutls28-upstream.zip
Adding upstream version 3.7.9.upstream/3.7.9upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'lib/dh-session.c')
-rw-r--r--lib/dh-session.c393
1 files changed, 393 insertions, 0 deletions
diff --git a/lib/dh-session.c b/lib/dh-session.c
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+/*
+ * Copyright (C) 2001-2015 Free Software Foundation, Inc.
+ * Copyright (C) 2015 Nikos Mavrogiannopoulos
+ *
+ * Author: Nikos Mavrogiannopoulos
+ *
+ * This file is part of GnuTLS.
+ *
+ * The GnuTLS 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.
+ *
+ * This library 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/>
+ *
+ */
+
+/* This file contains certificate authentication functions to be exported in the
+ * API which did not fit elsewhere.
+ */
+
+#include "gnutls_int.h"
+#include <auth/srp_kx.h>
+#include <auth/anon.h>
+#include <auth/cert.h>
+#include <auth/psk.h>
+#include "errors.h"
+#include <auth.h>
+#include <state.h>
+#include <datum.h>
+#include <algorithms.h>
+
+/* ANON & DHE */
+
+#if defined(ENABLE_DHE) || defined(ENABLE_ANON)
+/**
+ * gnutls_dh_set_prime_bits:
+ * @session: is a #gnutls_session_t type.
+ * @bits: is the number of bits
+ *
+ * This function sets the number of bits, for use in a Diffie-Hellman
+ * key exchange. This is used both in DH ephemeral and DH anonymous
+ * cipher suites. This will set the minimum size of the prime that
+ * will be used for the handshake.
+ *
+ * In the client side it sets the minimum accepted number of bits. If
+ * a server sends a prime with less bits than that
+ * %GNUTLS_E_DH_PRIME_UNACCEPTABLE will be returned by the handshake.
+ *
+ * Note that this function will warn via the audit log for value that
+ * are believed to be weak.
+ *
+ * The function has no effect in server side.
+ *
+ * Note that since 3.1.7 this function is deprecated. The minimum
+ * number of bits is set by the priority string level.
+ * Also this function must be called after gnutls_priority_set_direct()
+ * or the set value may be overridden by the selected priority options.
+ *
+ *
+ **/
+void gnutls_dh_set_prime_bits(gnutls_session_t session, unsigned int bits)
+{
+ if (bits < gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, GNUTLS_SEC_PARAM_WEAK)
+ && bits != 0)
+ _gnutls_audit_log(session,
+ "Note that the security level of the Diffie-Hellman key exchange has been lowered to %u bits and this may allow decryption of the session data\n",
+ bits);
+ session->internals.dh_prime_bits = bits;
+}
+
+
+/**
+ * gnutls_dh_get_group:
+ * @session: is a gnutls session
+ * @raw_gen: will hold the generator.
+ * @raw_prime: will hold the prime.
+ *
+ * This function will return the group parameters used in the last
+ * Diffie-Hellman key exchange with the peer. These are the prime and
+ * the generator used. This function should be used for both
+ * anonymous and ephemeral Diffie-Hellman. The output parameters must
+ * be freed with gnutls_free().
+ *
+ * Note, that the prime and generator are exported as non-negative
+ * integers and may include a leading zero byte.
+ *
+ * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise
+ * an error code is returned.
+ **/
+int
+gnutls_dh_get_group(gnutls_session_t session,
+ gnutls_datum_t * raw_gen, gnutls_datum_t * raw_prime)
+{
+ dh_info_st *dh;
+ int ret;
+ anon_auth_info_t anon_info;
+ cert_auth_info_t cert_info;
+ psk_auth_info_t psk_info;
+
+ switch (gnutls_auth_get_type(session)) {
+ case GNUTLS_CRD_ANON:
+ anon_info = _gnutls_get_auth_info(session, GNUTLS_CRD_ANON);
+ if (anon_info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+ dh = &anon_info->dh;
+ break;
+ case GNUTLS_CRD_PSK:
+ psk_info = _gnutls_get_auth_info(session, GNUTLS_CRD_PSK);
+ if (psk_info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+ dh = &psk_info->dh;
+ break;
+ case GNUTLS_CRD_CERTIFICATE:
+ cert_info = _gnutls_get_auth_info(session, GNUTLS_CRD_CERTIFICATE);
+ if (cert_info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+ dh = &cert_info->dh;
+ break;
+ default:
+ gnutls_assert();
+ return GNUTLS_E_INVALID_REQUEST;
+ }
+
+ ret = _gnutls_set_datum(raw_prime, dh->prime.data, dh->prime.size);
+ if (ret < 0) {
+ gnutls_assert();
+ return ret;
+ }
+
+ ret =
+ _gnutls_set_datum(raw_gen, dh->generator.data,
+ dh->generator.size);
+ if (ret < 0) {
+ gnutls_assert();
+ _gnutls_free_datum(raw_prime);
+ return ret;
+ }
+
+ return 0;
+}
+
+/**
+ * gnutls_dh_get_pubkey:
+ * @session: is a gnutls session
+ * @raw_key: will hold the public key.
+ *
+ * This function will return the peer's public key used in the last
+ * Diffie-Hellman key exchange. This function should be used for both
+ * anonymous and ephemeral Diffie-Hellman. The output parameters must
+ * be freed with gnutls_free().
+ *
+ * Note, that public key is exported as non-negative
+ * integer and may include a leading zero byte.
+ *
+ * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise
+ * an error code is returned.
+ **/
+int
+gnutls_dh_get_pubkey(gnutls_session_t session, gnutls_datum_t * raw_key)
+{
+ dh_info_st *dh;
+ anon_auth_info_t anon_info;
+ cert_auth_info_t cert_info;
+ psk_auth_info_t psk_info;
+
+ switch (gnutls_auth_get_type(session)) {
+ case GNUTLS_CRD_ANON:
+ {
+ anon_info = _gnutls_get_auth_info(session, GNUTLS_CRD_ANON);
+ if (anon_info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+ dh = &anon_info->dh;
+ break;
+ }
+ case GNUTLS_CRD_PSK:
+ {
+ psk_info = _gnutls_get_auth_info(session, GNUTLS_CRD_PSK);
+ if (psk_info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+ dh = &psk_info->dh;
+ break;
+ }
+ case GNUTLS_CRD_CERTIFICATE:
+ {
+
+ cert_info = _gnutls_get_auth_info(session, GNUTLS_CRD_CERTIFICATE);
+ if (cert_info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+ dh = &cert_info->dh;
+ break;
+ }
+ default:
+ gnutls_assert();
+ return GNUTLS_E_INVALID_REQUEST;
+ }
+
+ return _gnutls_set_datum(raw_key, dh->public_key.data,
+ dh->public_key.size);
+}
+
+/**
+ * gnutls_dh_get_secret_bits:
+ * @session: is a gnutls session
+ *
+ * This function will return the bits used in the last Diffie-Hellman
+ * key exchange with the peer. Should be used for both anonymous and
+ * ephemeral Diffie-Hellman.
+ *
+ * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise
+ * an error code is returned.
+ **/
+int gnutls_dh_get_secret_bits(gnutls_session_t session)
+{
+ switch (gnutls_auth_get_type(session)) {
+ case GNUTLS_CRD_ANON:
+ {
+ anon_auth_info_t info;
+
+ info = _gnutls_get_auth_info(session, GNUTLS_CRD_ANON);
+ if (info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+ return info->dh.secret_bits;
+ }
+ case GNUTLS_CRD_PSK:
+ {
+ psk_auth_info_t info;
+
+ info = _gnutls_get_auth_info(session, GNUTLS_CRD_PSK);
+ if (info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+ return info->dh.secret_bits;
+ }
+ case GNUTLS_CRD_CERTIFICATE:
+ {
+ cert_auth_info_t info;
+
+ info = _gnutls_get_auth_info(session, GNUTLS_CRD_CERTIFICATE);
+ if (info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+
+ return info->dh.secret_bits;
+ }
+ default:
+ gnutls_assert();
+ return GNUTLS_E_INVALID_REQUEST;
+ }
+}
+
+
+static int mpi_buf2bits(gnutls_datum_t * mpi_buf)
+{
+ bigint_t mpi;
+ int rc;
+
+ rc = _gnutls_mpi_init_scan_nz(&mpi, mpi_buf->data, mpi_buf->size);
+ if (rc) {
+ gnutls_assert();
+ return rc;
+ }
+
+ rc = _gnutls_mpi_get_nbits(mpi);
+ _gnutls_mpi_release(&mpi);
+
+ return rc;
+}
+
+/**
+ * gnutls_dh_get_prime_bits:
+ * @session: is a gnutls session
+ *
+ * This function will return the bits of the prime used in the last
+ * Diffie-Hellman key exchange with the peer. Should be used for both
+ * anonymous and ephemeral Diffie-Hellman. Note that some ciphers,
+ * like RSA and DSA without DHE, do not use a Diffie-Hellman key
+ * exchange, and then this function will return 0.
+ *
+ * Returns: The Diffie-Hellman bit strength is returned, or 0 if no
+ * Diffie-Hellman key exchange was done, or a negative error code on
+ * failure.
+ **/
+int gnutls_dh_get_prime_bits(gnutls_session_t session)
+{
+ dh_info_st *dh;
+
+ switch (gnutls_auth_get_type(session)) {
+ case GNUTLS_CRD_ANON:
+ {
+ anon_auth_info_t info;
+
+ info = _gnutls_get_auth_info(session, GNUTLS_CRD_ANON);
+ if (info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+ dh = &info->dh;
+ break;
+ }
+ case GNUTLS_CRD_PSK:
+ {
+ psk_auth_info_t info;
+
+ info = _gnutls_get_auth_info(session, GNUTLS_CRD_PSK);
+ if (info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+ dh = &info->dh;
+ break;
+ }
+ case GNUTLS_CRD_CERTIFICATE:
+ {
+ cert_auth_info_t info;
+
+ info = _gnutls_get_auth_info(session, GNUTLS_CRD_CERTIFICATE);
+ if (info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+
+ dh = &info->dh;
+ break;
+ }
+ default:
+ gnutls_assert();
+ return GNUTLS_E_INVALID_REQUEST;
+ }
+
+ if(dh->prime.size == 0)
+ return 0;
+
+ return mpi_buf2bits(&dh->prime);
+}
+
+
+/**
+ * gnutls_dh_get_peers_public_bits:
+ * @session: is a gnutls session
+ *
+ * Get the Diffie-Hellman public key bit size. Can be used for both
+ * anonymous and ephemeral Diffie-Hellman.
+ *
+ * Returns: The public key bit size used in the last Diffie-Hellman
+ * key exchange with the peer, or a negative error code in case of error.
+ **/
+int gnutls_dh_get_peers_public_bits(gnutls_session_t session)
+{
+ dh_info_st *dh;
+
+ switch (gnutls_auth_get_type(session)) {
+ case GNUTLS_CRD_ANON:
+ {
+ anon_auth_info_t info;
+
+ info = _gnutls_get_auth_info(session, GNUTLS_CRD_ANON);
+ if (info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+
+ dh = &info->dh;
+ break;
+ }
+ case GNUTLS_CRD_PSK:
+ {
+ psk_auth_info_t info;
+
+ info = _gnutls_get_auth_info(session, GNUTLS_CRD_PSK);
+ if (info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+
+ dh = &info->dh;
+ break;
+ }
+ case GNUTLS_CRD_CERTIFICATE:
+ {
+ cert_auth_info_t info;
+
+ info = _gnutls_get_auth_info(session, GNUTLS_CRD_CERTIFICATE);
+ if (info == NULL)
+ return gnutls_assert_val(GNUTLS_E_INTERNAL_ERROR);
+
+ dh = &info->dh;
+ break;
+ }
+ default:
+ gnutls_assert();
+ return GNUTLS_E_INVALID_REQUEST;
+ }
+
+ return mpi_buf2bits(&dh->public_key);
+}
+
+#endif /* DH */
+