src/acl/ServerName.cc

   1 /*
   2  * Copyright (C) 1996-2018 The Squid Software Foundation and contributors
   3  *
   4  * Squid software is distributed under GPLv2+ license and includes
   5  * contributions from numerous individuals and organizations.
   6  * Please see the COPYING and CONTRIBUTORS files for details.
   7  */
   8
   9 /* DEBUG: section 28    Access Control */
  10
  11 #include "squid.h"
  12 #include "acl/DomainData.h"
  13 #include "acl/FilledChecklist.h"
  14 #include "acl/RegexData.h"
  15 #include "acl/ServerName.h"
  16 #include "client_side.h"
  17 #include "fde.h"
  18 #include "http/Stream.h"
  19 #include "HttpRequest.h"
  20 #include "ipcache.h"
  21 #include "SquidString.h"
  22 #include "ssl/bio.h"
  23 #include "ssl/ServerBump.h"
  24 #include "ssl/support.h"
  25 #include "URL.h"
  26
  27 // Compare function for tree search algorithms
  28 static int
  29 aclHostDomainCompare( char *const &a, char * const &b)
  30 {
  31     const char *h = static_cast<const char *>(a);
  32     const char *d = static_cast<const char *>(b);
  33     debugs(28, 7, "Match:" << h << " <>  " << d);
  34     return matchDomainName(h, d, mdnHonorWildcards);
  35 }
  36
  37 bool
  38 ACLServerNameData::match(const char *host)
  39 {
  40     if (host == NULL)
  41         return 0;
  42
  43     debugs(28, 3, "checking '" << host << "'");
  44
  45     char *h = const_cast<char *>(host);
  46     char const * const * result = domains->find(h, aclHostDomainCompare);
  47
  48     debugs(28, 3, "'" << host << "' " << (result ? "found" : "NOT found"));
  49
  50     return (result != NULL);
  51
  52 }
  53
  54 ACLData<char const *> *
  55 ACLServerNameData::clone() const
  56 {
  57     /* Splay trees don't clone yet. */
  58     assert (!domains);
  59     return new ACLServerNameData;
  60 }
  61
  62 /// A helper function to be used with Ssl::matchX509CommonNames().
  63 /// \retval 0 when the name (cn or an alternate name) matches acl data
  64 /// \retval 1 when the name does not match
  65 template<class MatchType>
  66 int
  67 check_cert_domain( void *check_data, ASN1_STRING *cn_data)
  68 {
  69     char cn[1024];
  70     ACLData<MatchType> * data = (ACLData<MatchType> *)check_data;
  71
  72     if (cn_data->length > (int)sizeof(cn) - 1)
  73         return 1; // ignore data that does not fit our buffer
  74
  75     char *s = reinterpret_cast<char *>(cn_data->data);
  76     char *d = cn;
  77     for (int i = 0; i < cn_data->length; ++i, ++d, ++s) {
  78         if (*s == '\0')
  79             return 1; // always a domain mismatch. contains 0x00
  80         *d = *s;
  81     }
  82     cn[cn_data->length] = '\0';
  83     debugs(28, 4, "Verifying certificate name/subjectAltName " << cn);
  84     if (data->match(cn))
  85         return 0;
  86     return 1;
  87 }
  88
  89 int
  90 ACLServerNameStrategy::match (ACLData<MatchType> * &data, ACLFilledChecklist *checklist)
  91 {
  92     assert(checklist != NULL && checklist->request != NULL);
  93
  94     const char *serverName = nullptr;
  95     SBuf clientSniKeeper; // because c_str() is not constant
  96     if (ConnStateData *conn = checklist->conn()) {
  97         const char *clientRequestedServerName = nullptr;
  98         clientSniKeeper = conn->tlsClientSni();
  99         if (clientSniKeeper.isEmpty()) {
 100             const char *host = checklist->request->url.host();
 101             if (host && *host) // paranoid first condition: host() is never nil
 102                 clientRequestedServerName = host;
 103         } else
 104             clientRequestedServerName = clientSniKeeper.c_str();
 105
 106         if (useConsensus) {
 107             X509 *peer_cert = conn->serverBump() ? conn->serverBump()->serverCert.get() : nullptr;
 108             // use the client requested name if it matches the server
 109             // certificate or if the certificate is not available
 110             if (!peer_cert || Ssl::checkX509ServerValidity(peer_cert, clientRequestedServerName))
 111                 serverName = clientRequestedServerName;
 112         } else if (useClientRequested)
 113             serverName = clientRequestedServerName;
 114         else { // either no options or useServerProvided
 115             if (X509 *peer_cert = (conn->serverBump() ? conn->serverBump()->serverCert.get() : nullptr))
 116                 return Ssl::matchX509CommonNames(peer_cert, (void *)data, check_cert_domain<MatchType>);
 117             if (!useServerProvided)
 118                 serverName = clientRequestedServerName;
 119         }
 120     }
 121
 122     if (!serverName)
 123         serverName = "none";
 124
 125     return data->match(serverName);
 126 }
 127
 128 const Acl::Options &
 129 ACLServerNameStrategy::options()
 130 {
 131     static const Acl::BooleanOption ClientRequested;
 132     static const Acl::BooleanOption ServerProvided;
 133     static const Acl::BooleanOption Consensus;
 134     static const Acl::Options MyOptions = {
 135         {"--client-requested", &ClientRequested},
 136         {"--server-provided", &ServerProvided},
 137         {"--consensus", &Consensus}
 138     };
 139
 140     ClientRequested.linkWith(&useClientRequested);
 141     ServerProvided.linkWith(&useServerProvided);
 142     Consensus.linkWith(&useConsensus);
 143     return MyOptions;
 144 }
 145
 146 bool
 147 ACLServerNameStrategy::valid() const
 148 {
 149     int optionCount = 0;
 150
 151     if (useClientRequested)
 152         optionCount++;
 153     if (useServerProvided)
 154         optionCount++;
 155     if (useConsensus)
 156         optionCount++;
 157
 158     if (optionCount > 1) {
 159         debugs(28, DBG_CRITICAL, "ERROR: Multiple options given for the server_name ACL");
 160         return false;
 161     }
 162     return true;
 163 }
 164