Files

88 lines
2.6 KiB
C++

// OpenVPN -- An application to securely tunnel IP networks
// over a single port, with support for SSL/TLS-based
// session authentication and key exchange,
// packet encryption, packet authentication, and
// packet compression.
//
// Copyright (C) 2012-2017 OpenVPN Inc.
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License Version 3
// as published by the Free Software Foundation.
//
// This program 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program in the COPYING file.
// If not, see <http://www.gnu.org/licenses/>.
// Verify a PKCS7 signature
#ifndef OPENVPN_OPENSSL_SIGN_PKCS7VERIFY_H
#define OPENVPN_OPENSSL_SIGN_PKCS7VERIFY_H
#include <string>
#include <openssl/ssl.h>
#include <openssl/bio.h>
#include <openssl/pkcs7.h>
#include <openvpn/common/cleanup.hpp>
#include <openvpn/openssl/pki/x509.hpp>
#include <openvpn/openssl/util/error.hpp>
namespace openvpn {
namespace OpenSSLSign {
/*
* Verify PKCS7 signature.
* On success, return.
* On fail, throw exception.
*/
inline void verify_pkcs7(const OpenSSLPKI::X509& cert,
const std::string& sig,
const std::string& data)
{
STACK_OF(X509) *x509_stack = nullptr;
BIO *in = nullptr;
PKCS7 *p7 = nullptr;
auto clean = Cleanup([&]() {
if (x509_stack)
sk_X509_free(x509_stack);
if (in)
BIO_free(in);
if (p7)
PKCS7_free(p7);
});
/* create x509_stack from cert */
x509_stack = sk_X509_new_null();
sk_X509_push(x509_stack, cert.obj());
/* get signature */
in = BIO_new_mem_buf(sig.c_str(), sig.length());
p7 = PEM_read_bio_PKCS7(in, NULL, NULL, NULL);
if (!p7)
throw OpenSSLException("OpenSSLSign::verify_pkcs7: failed to parse pkcs7 signature");
BIO_free(in);
in = nullptr;
/* get data */
in = BIO_new_mem_buf(data.c_str(), data.length());
/* OpenSSL 1.0.2e and higher no longer allows calling PKCS7_verify
with both data and content. Empty out the content. */
p7->d.sign->contents->d.ptr = 0;
/* do the verify */
if (PKCS7_verify(p7, x509_stack, NULL, in, NULL, PKCS7_NOVERIFY) != 1)
throw OpenSSLException("OpenSSLSign::verify_pkcs7: verification failed");
}
}
}
#endif