90fd660803
Also add support older (< 3.5.0) GnuTLS versions
317 lines
8.2 KiB
C
317 lines
8.2 KiB
C
/* -*- c-basic-offset: 8 -*-
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rdesktop: A Remote Desktop Protocol client.
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ASN.1 utility functions
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Copyright 2012-2017 Henrik Andersson <hean01@cendio.se> for Cendio AB
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Copyright 2017 Alexander Zakharov <uglym8@gmail.com>
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <gnutls/gnutls.h>
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#include <libtasn1.h>
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#include <stdlib.h>
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#include "rdesktop.h"
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#include "asn.h"
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// Generated by asn1Parser
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#include "pkix_asn1_tab.c"
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static asn1_node *asn_defs = NULL;
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#define MAX_ERROR_DESCRIPTION_SIZE 1024
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char errstr[MAX_ERROR_DESCRIPTION_SIZE];
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/* Parse an ASN.1 BER header */
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RD_BOOL
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ber_parse_header(STREAM s, int tagval, uint32 *length)
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{
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int tag, len;
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if (tagval > 0xff)
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{
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in_uint16_be(s, tag);
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}
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else
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{
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in_uint8(s, tag);
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}
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if (tag != tagval)
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{
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logger(Core, Error, "ber_parse_header(), expected tag %d, got %d", tagval, tag);
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return False;
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}
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in_uint8(s, len);
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if (len & 0x80)
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{
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len &= ~0x80;
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*length = 0;
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while (len--)
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next_be(s, *length);
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}
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else
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*length = len;
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return s_check(s);
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}
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void
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ber_out_sequence(STREAM out, STREAM content)
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{
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size_t length;
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length = (content ? s_length(content) : 0);
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ber_out_header(out, BER_TAG_SEQUENCE | BER_TAG_CONSTRUCTED, length);
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if (content)
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out_stream(out, content);
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}
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/* Output an ASN.1 BER header */
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void
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ber_out_header(STREAM s, int tagval, int length)
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{
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if (tagval > 0xff)
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{
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out_uint16_be(s, tagval);
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}
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else
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{
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out_uint8(s, tagval);
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}
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if (length >= 0x80)
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{
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out_uint8(s, 0x82);
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out_uint16_be(s, length);
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}
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else
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out_uint8(s, length);
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}
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/* Output an ASN.1 BER integer */
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void
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ber_out_integer(STREAM s, int value)
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{
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ber_out_header(s, BER_TAG_INTEGER, 2);
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out_uint16_be(s, value);
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}
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RD_BOOL
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ber_in_header(STREAM s, int *tagval, int *decoded_len)
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{
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in_uint8(s, *tagval);
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in_uint8(s, *decoded_len);
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if (*decoded_len < 0x80)
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return True;
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else if (*decoded_len == 0x81)
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{
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in_uint8(s, *decoded_len);
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return True;
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}
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else if (*decoded_len == 0x82)
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{
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in_uint16_be(s, *decoded_len);
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return True;
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}
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return False;
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}
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int init_asn1_lib(void)
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{
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int asn1_rv;
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if (asn_defs) {
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return 0;
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}
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asn_defs = malloc(sizeof(*asn_defs));
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if (!asn_defs) {
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logger(Core, Error, "%s:%s:%d Failed to allocate memory for ASN.1 parser\n",
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__FILE__, __func__, __LINE__);
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return 1;
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}
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*asn_defs = NULL;
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if (ASN1_SUCCESS != (asn1_rv = asn1_array2tree(pkix_asn1_tab, asn_defs, errstr))) {
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logger(Core, Error, "%s:%s:%d Failed to init ASN.1 parser. Error = 0x%x (%s)\n",
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__FILE__, __func__, __LINE__, asn1_rv, asn1_strerror(asn1_rv));
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return 1;
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}
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return 0;
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}
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/* Encode RSA public key into DER PKCS#1 */
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/* Returns; 0 - success, 1 - fatal error, 2 - insufficient space in buffer */
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int write_pkcs1_der_pubkey(const gnutls_datum_t *m, const gnutls_datum_t *e, uint8_t *out, int *out_len)
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{
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int asn1_rv;
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asn1_node asn_cert;
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if (!asn_defs) {
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if (init_asn1_lib() != 0) {
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return 1;
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}
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}
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if (ASN1_SUCCESS != (asn1_rv = asn1_create_element(*asn_defs, "PKIX1Implicit88.RSAPublicKey", &asn_cert))) {
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logger(Core, Error, "%s:%s:%d Failed to create ASN.1 parser element for RSAPublicKey. Error = 0x%x (%s)\n",
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__FILE__, __func__, __LINE__, asn1_rv, asn1_strerror(asn1_rv));
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return 1;
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}
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if (ASN1_SUCCESS != (asn1_rv = asn1_write_value(asn_cert, "modulus", m->data, m->size))) {
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logger(Core, Error, "%s:%s:%d Failed to write modulus. Error = 0x%x (%s)\n",
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__FILE__, __func__, __LINE__, asn1_rv, asn1_strerror(asn1_rv));
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return 1;
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}
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if (ASN1_SUCCESS != (asn1_rv = asn1_write_value(asn_cert, "publicExponent", e->data, e->size))) {
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logger(Core, Error, "%s:%s:%d Failed to write publicExponent. Error = 0x%x (%s)\n",
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__FILE__, __func__, __LINE__, asn1_rv, asn1_strerror(asn1_rv));
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return 1;
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}
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if (ASN1_SUCCESS != (asn1_rv = asn1_der_coding(asn_cert, "", out, out_len, errstr))) {
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logger(Core, Error, "%s:%s:%d Failed to encode PKIX1Implicit88.RSAPublicKey. Error = 0x%x (%s)\n",
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__FILE__, __func__, __LINE__, asn1_rv, asn1_strerror(asn1_rv));
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if (asn1_rv == ASN1_MEM_ERROR) {
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return 2;
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}
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return 1;
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}
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return 0;
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}
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int libtasn_read_cert_pk_parameters(uint8_t *data, size_t len, gnutls_datum_t *m, gnutls_datum_t *e, int check_pk_algo)
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{
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int asn1_rv;
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asn1_node asn_cert;
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int buflen;
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uint8_t buf[16384];
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asn1_node asn_key;
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int nblen;
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uint8_t newbuf[16384];
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/* Parse DER encoded x.509 certificate */
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init_asn1_lib();
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if (ASN1_SUCCESS != (asn1_rv = asn1_create_element(*asn_defs, "PKIX1Implicit88.Certificate", &asn_cert))) {
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logger(Core, Error, "%s:%s:%d Failed to create ASN.1 parser element. Error = 0x%x (%s)\n",
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__FILE__, __func__, __LINE__, asn1_rv, asn1_strerror(asn1_rv));
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return 1;
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}
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if (ASN1_SUCCESS != (asn1_rv = asn1_der_decoding(&asn_cert, data, len, errstr))) {
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logger(Core, Error, "%s:%s:%d Failed to decode certificate object. Error = 0x%x (%s)\n",
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__FILE__, __func__, __LINE__, asn1_rv, asn1_strerror(asn1_rv));
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return 1;
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}
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if (check_pk_algo) {
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/* Get and check cert's public key algorithm */
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buflen = sizeof(buf) - 1;
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if (ASN1_SUCCESS != (asn1_rv = asn1_read_value(asn_cert, "tbsCertificate.subjectPublicKeyInfo.algorithm.algorithm", buf, (int *)&buflen))) {
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logger(Core, Error, "%s:%s:%d Failed to get cert's public key algorithm. Error = 0x%x (%s)\n",
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__FILE__, __func__, __LINE__, asn1_rv, asn1_strerror(asn1_rv));
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return 1;
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}
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if ((strncmp((char *)buf, OID_SHA_WITH_RSA_SIGNATURE, strlen(OID_SHA_WITH_RSA_SIGNATURE)) != 0)
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&& (strncmp((char *)buf, OID_MD5_WITH_RSA_SIGNATURE, strlen(OID_MD5_WITH_RSA_SIGNATURE)) != 0)) {
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logger(Core, Error, "%s:%s:%d Wrong public key algorithm: %s\n",
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__FILE__, __func__, __LINE__, buf);
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return 1;
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}
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}
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buflen = sizeof(buf) - 1;
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if (ASN1_SUCCESS != (asn1_rv = asn1_read_value(asn_cert, "tbsCertificate.subjectPublicKeyInfo.subjectPublicKey", buf, &buflen))) {
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logger(Core, Error, "%s:%s:%d Failed to get cert's public key. Error = 0x%x (%s)\n",
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__FILE__, __func__, __LINE__, asn1_rv, asn1_strerror(asn1_rv));
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return 1;
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}
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if (ASN1_SUCCESS != (asn1_rv = asn1_create_element(*asn_defs, "PKIX1Implicit88.RSAPublicKey", &asn_key))) {
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logger(Core, Error, "%s:%s:%d Failed to create ASN.1 parser element. Error = 0x%x (%s)\n",
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__FILE__, __func__, __LINE__, asn1_rv, asn1_strerror(asn1_rv));
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return 1;
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}
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// As it' a BIT STRING the len constitutes the number of BITS, not BYTES
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if (ASN1_SUCCESS != (asn1_rv = asn1_der_decoding(&asn_key, buf, buflen / 8, errstr))) {
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logger(Core, Error, "%s:%s:%d Failed to decode public key object. Error = 0x%x (%s)\n",
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__FILE__, __func__, __LINE__, asn1_rv, asn1_strerror(asn1_rv));
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return 1;
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}
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/* Get RSA public key's modulus and exponent */
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nblen = sizeof(newbuf);
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if (ASN1_SUCCESS != (asn1_rv = asn1_read_value(asn_key, "modulus", newbuf, &nblen))) {
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logger(Core, Error, "%s:%s:%d Failed to get RSA public key's modulus. Error = 0x%x (%s)\n",
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__FILE__, __func__, __LINE__, asn1_rv, asn1_strerror(asn1_rv));
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return 1;
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}
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m->size = nblen;
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if (!(m->data = malloc(m->size))) {
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logger(Core, Error, "%s:%s:%d Failed to allocate memory for modulus.\n", __FILE__, __func__, __LINE__);
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return 1;
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}
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memcpy((void *)m->data, newbuf, m->size);
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nblen = sizeof(newbuf);
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if (ASN1_SUCCESS != (asn1_rv = asn1_read_value(asn_key, "publicExponent", newbuf, &nblen))) {
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logger(Core, Error, "%s:%s:%d Failed to get RSA public key's exponent. Error = 0x%x (%s)\n",
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__FILE__, __func__, __LINE__, asn1_rv, asn1_strerror(asn1_rv));
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return 1;
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}
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e->size = nblen;
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if (!(e->data = malloc(e->size))) {
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logger(Core, Error, "%s:%s:%d Failed to allocate memory for exponent.\n", __FILE__, __func__, __LINE__);
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if (m->data) {
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free(m->data);
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}
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return 1;
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}
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memcpy((void *)e->data, newbuf, m->size);
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return 0;
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}
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