1 /**
2 * Licensed to the University Corporation for Advanced Internet
3 * Development, Inc. (UCAID) under one or more contributor license
4 * agreements. See the NOTICE file distributed with this work for
5 * additional information regarding copyright ownership.
6 *
7 * UCAID licenses this file to you under the Apache License,
8 * Version 2.0 (the "License"); you may not use this file except
9 * in compliance with the License. You may obtain a copy of the
10 * License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
17 * either express or implied. See the License for the specific
18 * language governing permissions and limitations under the License.
19 */
20
21 /**
22 * MessageFlowRule.cpp
23 *
24 * SAML replay and freshness checking SecurityPolicyRule.
25 */
26
27 #include "internal.h"
28 #include "exceptions.h"
29 #include "binding/SecurityPolicy.h"
30 #include "binding/SecurityPolicyRule.h"
31
32 #include <xmltooling/logging.h>
33 #include <xmltooling/XMLToolingConfig.h>
34 #include <xmltooling/util/ReplayCache.h>
35 #include <xmltooling/util/XMLHelper.h>
36 #include <xercesc/util/XMLUniDefs.hpp>
37
38 using namespace opensaml;
39 using namespace xmltooling::logging;
40 using namespace xmltooling;
41 using namespace std;
42
43 namespace opensaml {
44 class SAML_DLLLOCAL MessageFlowRule : public SecurityPolicyRule
45 {
46 public:
47 MessageFlowRule(const DOMElement* e);
~MessageFlowRule()48 virtual ~MessageFlowRule() {}
49
getType() const50 const char* getType() const {
51 return MESSAGEFLOW_POLICY_RULE;
52 }
53 bool evaluate(const XMLObject& message, const GenericRequest* request, SecurityPolicy& policy) const;
54
55 private:
56 logging::Category& m_log;
57 bool m_checkReplay, m_correlation, m_blockUnsolicited;
58 time_t m_expires;
59 };
60
MessageFlowRuleFactory(const DOMElement * const & e,bool)61 SecurityPolicyRule* SAML_DLLLOCAL MessageFlowRuleFactory(const DOMElement* const & e, bool)
62 {
63 return new MessageFlowRule(e);
64 }
65
66 static const XMLCh blockUnsolicited[] = UNICODE_LITERAL_16(b,l,o,c,k,U,n,s,o,l,i,c,i,t,e,d);
67 static const XMLCh checkReplay[] = UNICODE_LITERAL_11(c,h,e,c,k,R,e,p,l,a,y);
68 static const XMLCh checkCorrelation[] = UNICODE_LITERAL_16(c,h,e,c,k,C,o,r,r,e,l,a,t,i,o,n);
69 static const XMLCh expires[] = UNICODE_LITERAL_7(e,x,p,i,r,e,s);
70 };
71
MessageFlowRule(const DOMElement * e)72 MessageFlowRule::MessageFlowRule(const DOMElement* e) : SecurityPolicyRule(e),
73 m_log(logging::Category::getInstance(SAML_LOGCAT ".SecurityPolicyRule.MessageFlow")),
74 m_checkReplay(XMLHelper::getAttrBool(e, true, checkReplay)),
75 m_correlation(XMLHelper::getAttrBool(e, false, checkCorrelation)),
76 m_blockUnsolicited(XMLHelper::getAttrBool(e, false, blockUnsolicited)),
77 m_expires(XMLHelper::getAttrInt(e, XMLToolingConfig::getConfig().clock_skew_secs, expires))
78 {
79 if (m_blockUnsolicited && !m_correlation) {
80 m_correlation = true;
81 m_log.info("enabling request/response correlation checking to block unsolicited responses");
82 }
83 }
84
evaluate(const XMLObject & message,const GenericRequest * request,SecurityPolicy & policy) const85 bool MessageFlowRule::evaluate(const XMLObject& message, const GenericRequest* request, SecurityPolicy& policy) const
86 {
87 if (!SecurityPolicyRule::evaluate(message, request, policy)) {
88 return false;
89 }
90
91 Category& log=Category::getInstance(SAML_LOGCAT ".SecurityPolicyRule.MessageFlow");
92 log.debug("evaluating message flow policy (correlation %s, replay checking %s, expiration %lu)",
93 m_correlation ? "on" : "off", m_checkReplay ? "on" : "off", m_expires);
94
95 time_t now = policy.getTime();
96 time_t skew = XMLToolingConfig::getConfig().clock_skew_secs;
97 time_t issueInstant = policy.getIssueInstant();
98 if (issueInstant == 0) {
99 issueInstant = now;
100 }
101 else {
102 if (issueInstant > now + skew) {
103 log.warnStream() << "rejected not-yet-valid message, timestamp (" << issueInstant <<
104 "), newest allowed (" << now + skew << ")" << logging::eol;
105 throw SecurityPolicyException("Message rejected, was issued in the future.");
106 }
107 else if (issueInstant < now - skew - m_expires) {
108 log.warnStream() << "rejected expired message, timestamp (" << issueInstant <<
109 "), oldest allowed (" << (now - skew - m_expires) << ")" << logging::eol;
110 throw SecurityPolicyException("Message expired, was issued too long ago.");
111 }
112 }
113
114 if (m_correlation) {
115 if (policy.getCorrelationID() && *(policy.getCorrelationID())) {
116 if (XMLString::equals(policy.getCorrelationID(), policy.getInResponseTo())) {
117 log.debug("request/response correlation validated");
118 }
119 else {
120 auto_ptr_char requestID(policy.getCorrelationID());
121 log.warn("response correlation ID did not match request ID (%s)", requestID.get());
122 throw SecurityPolicyException("Rejecting non-correlated response to request ID.");
123 }
124 }
125 else if (policy.getInResponseTo() && *(policy.getInResponseTo())) {
126 log.warn("request/response correlation failed due to lack of request ID to compare");
127 throw SecurityPolicyException("Response correlation failed with lack of correlation ID.");
128 }
129 else if (m_blockUnsolicited) {
130 log.warn("unsolicited response rejected by policy");
131 throw SecurityPolicyException("Unsolicited response rejected by policy.");
132 }
133 else {
134 log.debug("unsolicited message accepted");
135 }
136 }
137 else {
138 log.debug("ignoring InResponseTo, correlation checking is disabled");
139 }
140
141 // Check replay.
142 if (m_checkReplay) {
143 const XMLCh* id = policy.getMessageID();
144 if (!id || !*id)
145 return false;
146
147 ReplayCache* replayCache = XMLToolingConfig::getConfig().getReplayCache();
148 if (!replayCache) {
149 log.warn("no ReplayCache available, skipping requested replay check");
150 return false;
151 }
152
153 auto_ptr_char temp(id);
154 if (!replayCache->check("MessageFlow", temp.get(), issueInstant + skew + m_expires)) {
155 log.error("replay detected of message ID (%s)", temp.get());
156 throw SecurityPolicyException("Rejecting replayed message ID ($1).", params(1,temp.get()));
157 }
158 return true;
159 }
160 return false;
161 }
162