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Diffstat (limited to 'src/signer.cc')
| -rw-r--r-- | src/signer.cc | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/src/signer.cc b/src/signer.cc new file mode 100644 index 00000000..999ee594 --- /dev/null +++ b/src/signer.cc @@ -0,0 +1,135 @@ +/* + Copyright (C) 2013 Carl Hetherington <cth@carlh.net> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + 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 General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + +*/ + +#include <libxml++/libxml++.h> +#include <xmlsec/xmldsig.h> +#include <xmlsec/dl.h> +#include <xmlsec/app.h> +#include "signer.h" +#include "exceptions.h" + +using std::string; +using std::list; +using boost::shared_ptr; +using namespace libdcp; + +/** @param signer_key Filename of private key to sign with */ +void +Signer::sign (xmlpp::Element* parent, bool interop) const +{ + add_signer (parent, "dsig"); + + xmlpp::Element* signature = parent->add_child("Signature", "dsig"); + + { + xmlpp::Element* signed_info = signature->add_child ("SignedInfo", "dsig"); + signed_info->add_child("CanonicalizationMethod", "dsig")->set_attribute ("Algorithm", "http://www.w3.org/TR/2001/REC-xml-c14n-20010315"); + + if (interop) { + signed_info->add_child("SignatureMethod", "dsig")->set_attribute("Algorithm", "http://www.w3.org/2000/09/xmldsig#rsa-sha1"); + } else { + signed_info->add_child("SignatureMethod", "dsig")->set_attribute("Algorithm", "http://www.w3.org/2001/04/xmldsig-more#rsa-sha256"); + } + + { + xmlpp::Element* reference = signed_info->add_child("Reference", "dsig"); + reference->set_attribute ("URI", ""); + { + xmlpp::Element* transforms = reference->add_child("Transforms", "dsig"); + transforms->add_child("Transform", "dsig")->set_attribute ( + "Algorithm", "http://www.w3.org/2000/09/xmldsig#enveloped-signature" + ); + } + reference->add_child("DigestMethod", "dsig")->set_attribute("Algorithm", "http://www.w3.org/2000/09/xmldsig#sha1"); + /* This will be filled in by the signing later */ + reference->add_child("DigestValue", "dsig"); + } + } + + add_signature_value (signature, "dsig"); +} + + +/** Sign an XML node. This function takes a certificate chain (to prove that the sender is bona fide) and + * a private key with which to sign the node. + * + * @param parent Node to sign. + * @param certificates Certificate chain for the signer. + * @param signer_key Filename of the private key of the signer. + * @param ns Namespace to use for the signature XML nodes. + */ +void +Signer::add_signature_value (xmlpp::Element* parent, string ns) const +{ + parent->add_child("SignatureValue", ns); + + /* Add the certificate chain to a KeyInfo child node of parent */ + xmlpp::Element* key_info = parent->add_child("KeyInfo", ns); + list<shared_ptr<Certificate> > c = _certificates.leaf_to_root (); + for (list<shared_ptr<Certificate> >::iterator i = c.begin(); i != c.end(); ++i) { + xmlpp::Element* data = key_info->add_child("X509Data", ns); + + { + xmlpp::Element* serial = data->add_child("X509IssuerSerial", ns); + serial->add_child("X509IssuerName", ns)->add_child_text((*i)->issuer ()); + serial->add_child("X509SerialNumber", ns)->add_child_text((*i)->serial ()); + } + + data->add_child("X509Certificate", ns)->add_child_text((*i)->certificate()); + } + + xmlSecDSigCtxPtr signature_context = xmlSecDSigCtxCreate (0); + if (signature_context == 0) { + throw MiscError ("could not create signature context"); + } + + signature_context->signKey = xmlSecCryptoAppKeyLoad (_key.c_str(), xmlSecKeyDataFormatPem, 0, 0, 0); + if (signature_context->signKey == 0) { + throw FileError ("could not load private key file", _key); + } + + /* XXX: set key name to the file name: is this right? */ + if (xmlSecKeySetName (signature_context->signKey, reinterpret_cast<const xmlChar *> (_key.c_str())) < 0) { + throw MiscError ("could not set key name"); + } + + if (xmlSecDSigCtxSign (signature_context, parent->cobj ()) < 0) { + throw MiscError ("could not sign"); + } + + xmlSecDSigCtxDestroy (signature_context); +} + +void +Signer::add_signer (xmlpp::Element* parent, string ns) const +{ + xmlpp::Element* signer = parent->add_child("Signer"); + + { + xmlpp::Element* data = signer->add_child("X509Data", ns); + + { + xmlpp::Element* serial_element = data->add_child("X509IssuerSerial", ns); + serial_element->add_child("X509IssuerName", ns)->add_child_text (_certificates.leaf()->issuer()); + serial_element->add_child("X509SerialNumber", ns)->add_child_text (_certificates.leaf()->serial()); + } + + data->add_child("X509SubjectName", ns)->add_child_text (_certificates.leaf()->subject()); + } +} |