2 * Copyright 2001-2007 Internet2
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
18 * SimpleSigningRule.cpp
20 * Blob-oriented signature checking SecurityPolicyRule
24 #include "exceptions.h"
25 #include "binding/HTTPRequest.h"
26 #include "binding/SimpleSigningRule.h"
27 #include "saml2/core/Assertions.h"
28 #include "saml2/metadata/Metadata.h"
29 #include "saml2/metadata/MetadataProvider.h"
31 #include <log4cpp/Category.hh>
32 #include <xercesc/util/Base64.hpp>
34 using namespace opensaml::saml2md;
35 using namespace opensaml;
36 using namespace xmltooling;
37 using namespace log4cpp;
40 using xmlsignature::KeyInfo;
43 SecurityPolicyRule* SAML_DLLLOCAL SimpleSigningRuleFactory(const DOMElement* const & e)
45 return new SimpleSigningRule(e);
48 // Appends a raw parameter=value pair to the string.
49 static bool appendParameter(string& s, const char* data, const char* name)
51 const char* start = strstr(data,name);
56 const char* end = strchr(start,'&');
58 s.append(start, end-start);
66 void SimpleSigningRule::evaluate(const XMLObject& message, const GenericRequest* request, SecurityPolicy& policy) const
68 Category& log=Category::getInstance(SAML_LOGCAT".SecurityPolicyRule.SimpleSigning");
69 log.debug("evaluating simple signing policy");
71 if (!policy.getIssuerMetadata()) {
72 log.debug("ignoring message, no issuer metadata supplied");
75 else if (!policy.getTrustEngine()) {
76 log.debug("ignoring message, no TrustEngine supplied");
80 const HTTPRequest* httpRequest = dynamic_cast<const HTTPRequest*>(request);
81 if (!request || !httpRequest) {
82 log.debug("ignoring message, no HTTP protocol request available");
86 const char* signature = request->getParameter("Signature");
88 log.debug("ignoring unsigned message");
92 const char* sigAlgorithm = request->getParameter("SigAlg");
94 log.error("SigAlg parameter not found, no way to verify the signature");
100 if (!strcmp(httpRequest->getMethod(), "GET")) {
101 // We have to construct a string containing the signature input by accessing the
102 // request directly. We can't use the decoded parameters because we need the raw
103 // data and URL-encoding isn't canonical.
105 // NOTE: SimpleSign for GET means Redirect binding, which means we verify over the
106 // base64-encoded message directly.
108 pch = httpRequest->getQueryString();
109 if (!appendParameter(input, pch, "SAMLRequest="))
110 appendParameter(input, pch, "SAMLResponse=");
111 appendParameter(input, pch, "RelayState=");
112 appendParameter(input, pch, "SigAlg=");
115 // With POST, the input string is concatenated from the decoded form controls.
116 // GET should be this way too, but I messed up the spec, sorry.
118 // NOTE: SimpleSign for POST means POST binding, which means we verify over the
119 // base64-decoded XML. This sucks, because we have to decode the base64 directly.
120 // Serializing the XMLObject doesn't guarantee the signature will verify (this is
121 // why XMLSignature exists, and why this isn't really "simpler").
124 pch = httpRequest->getParameter("SAMLRequest");
126 XMLByte* decoded=Base64::decode(reinterpret_cast<const XMLByte*>(pch),&x);
128 log.warn("unable to decode base64 in POST binding message");
131 input = string("SAMLRequest=") + reinterpret_cast<const char*>(decoded);
132 XMLString::release(&decoded);
135 pch = httpRequest->getParameter("SAMLResponse");
136 XMLByte* decoded=Base64::decode(reinterpret_cast<const XMLByte*>(pch),&x);
138 log.warn("unable to decode base64 in POST binding message");
141 input = string("SAMLResponse=") + reinterpret_cast<const char*>(decoded);
142 XMLString::release(&decoded);
145 pch = httpRequest->getParameter("RelayState");
147 input = input + "&RelayState=" + pch;
148 input = input + "&SigAlg=" + sigAlgorithm;
151 // Check for KeyInfo, but defensively (we might be able to run without it).
152 KeyInfo* keyInfo=NULL;
153 pch = request->getParameter("KeyInfo");
156 istringstream kstrm(pch);
157 DOMDocument* doc = XMLToolingConfig::getConfig().getParser().parse(kstrm);
158 XercesJanitor<DOMDocument> janitor(doc);
159 XMLObject* kxml = XMLObjectBuilder::buildOneFromElement(doc->getDocumentElement(), true);
161 if (!(keyInfo=dynamic_cast<KeyInfo*>(kxml)))
164 catch (XMLToolingException& ex) {
165 log.warn("Failed to load KeyInfo from message: %s", ex.what());
169 auto_ptr<KeyInfo> kjanitor(keyInfo);
170 auto_ptr_XMLCh alg(sigAlgorithm);
172 if (!policy.getTrustEngine()->validate(
173 alg.get(), signature, keyInfo, input.c_str(), input.length(),
174 *(policy.getIssuerMetadata()), policy.getMetadataProvider()->getKeyResolver()
176 log.error("unable to verify message signature with supplied trust engine");
180 log.debug("signature verified against message issuer");
181 policy.setSecure(true);