OSX/libsecurity_keychain/xpc-tsa/main-tsa.m

   1 /*
   2  * Copyright (c) 2012,2014 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #include <sysexits.h>
  25 #include "timestampclient.h"
  26 #include <syslog.h>
  27 #include <Security/SecTask.h>
  28 #include <xpc/private.h>
  29
  30 struct connection_info {
  31     xpc_connection_t peer;
  32     int processed;
  33     int done;
  34 };
  35
  36 xpc_object_t keychain_prefs_path = NULL;
  37 xpc_object_t home = NULL;
  38
  39 extern xpc_object_t
  40 xpc_create_reply_with_format(xpc_object_t original, const char * format, ...);
  41
  42 void finalize_connection(void *not_used);
  43 void handle_connection_event(const xpc_connection_t peer);
  44 void handle_request_event(struct connection_info *info, xpc_object_t event);
  45
  46 #ifndef NDEBUG
  47     #define xpctsa_secinfo(format...) \
  48         do {  \
  49             syslog(LOG_WARNING, format);  \
  50         } while (0)
  51     #define xpctsaNSLog(format...) \
  52         do {  \
  53             NSLog(format);  \
  54         } while (0)
  55
  56 #else
  57     //empty
  58     #define xpctsa_secinfo(format...)
  59     #define xpctsaNSLog(format...)
  60 #endif
  61 #define xpctsaDebug(args...)                    xpctsa_secinfo(args)
  62
  63 /*
  64     These came from:
  65
  66 #include <OSServices/NetworkUtilities.h>
  67
  68     I have no idea why they aren't more accessible.
  69 */
  70
  71 #define kHTTPResponseCodeContinue             100
  72 #define kHTTPResponseCodeOK                   200
  73 #define kHTTPResponseCodeNoContent            204
  74 #define kHTTPResponseCodeBadRequest           400
  75 #define kHTTPResponseCodeUnauthorized         401
  76 #define kHTTPResponseCodeForbidden            403
  77 #define kHTTPResponseCodeConflict             409
  78 #define kHTTPResponseCodeExpectationFailed    417
  79 #define kHTTPResponseCodeServFail             500
  80 #define kHTTPResponseCodeInsufficientStorage  507
  81
  82 //
  83 // Turn a CFString into a UTF8-encoded C string.
  84 //
  85 static char *cfStringToCString(CFStringRef inStr)
  86 {
  87         if (!inStr)
  88                 return "";
  89         CFRetain(inStr);        // compensate for release on exit
  90
  91         // need to extract into buffer
  92         CFIndex length = CFStringGetLength(inStr);  // in 16-bit character units
  93     size_t len = 6 * length + 1;
  94         char *buffer = malloc(len);                 // pessimistic
  95         if (!CFStringGetCString(inStr, buffer, len, kCFStringEncodingUTF8))
  96         buffer[0]=0;
  97
  98     CFRelease(inStr);
  99         return buffer;
 100 }
 101
 102 static void debugShowTSAResponseInfo(NSURLResponse *response, NSData *data, NSError *err)
 103 {
 104 #ifndef NDEBUG
 105     if (response)
 106     {
 107         NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse *)response;
 108         NSInteger statusCode = [httpResponse statusCode];
 109         NSDictionary *headers = [httpResponse allHeaderFields];
 110         NSString *errStr2 = [NSHTTPURLResponse localizedStringForStatusCode:(NSInteger)statusCode];
 111
 112         xpctsaNSLog(@"TSA Response: %d, %@, %@", (int)statusCode, errStr2, headers);
 113     }
 114
 115     if (err)
 116     {   xpctsaNSLog(@"TSARequestCompletionBlock error: %@", err); }
 117
 118     if (data)
 119     {
 120         xpctsaDebug("TSARequestCompletionBlock: Data (%lu bytes)",(unsigned long)[data length]);
 121         xpctsaNSLog(@"TSARequestCompletionBlock: Data (%lu bytes)",(unsigned long)[data length]);
 122
 123         NSString *path = @"/tmp/tsaresp.rsp";
 124         NSDataWritingOptions writeOptionsMask = 0;
 125         NSError *errorPtr = NULL;
 126         [data writeToFile:path options:writeOptionsMask error:&errorPtr];
 127         if (errorPtr)
 128         {
 129             xpctsaNSLog(@"TSA Response error dumping response: %@", errorPtr);
 130             [errorPtr release];
 131         }
 132     }
 133 #endif
 134 }
 135
 136 /*
 137  * Check whether the caller can access the network. Currently, this applies
 138  * only to applications running under App Sandbox.
 139  */
 140 static bool callerHasNetworkEntitlement(audit_token_t auditToken)
 141 {
 142     bool result = true; /* until proven otherwise */
 143     SecTaskRef task = SecTaskCreateWithAuditToken(NULL, auditToken);
 144     if(task != NULL) {
 145         CFTypeRef appSandboxValue = SecTaskCopyValueForEntitlement(task,
 146                                     CFSTR("com.apple.security.app-sandbox"),
 147                                     NULL);
 148         if(appSandboxValue != NULL) {
 149             if(!CFEqual(kCFBooleanFalse, appSandboxValue)) {
 150                 CFTypeRef networkClientValue = SecTaskCopyValueForEntitlement(task,
 151                                                CFSTR("com.apple.security.network.client"),
 152                                                NULL);
 153                 if(networkClientValue != NULL) {
 154                     result = (!CFEqual(kCFBooleanFalse, networkClientValue));
 155                     CFRelease(networkClientValue);
 156                 } else {
 157                     result = false;
 158                 }
 159             }
 160             CFRelease(appSandboxValue);
 161         }
 162         CFRelease(task);
 163     }
 164     return result;
 165 }
 166
 167 static void communicateWithTimeStampingServer(xpc_object_t event, const char *requestData, size_t requestLength, const char *tsaURL)
 168 {
 169     if ((requestLength==0) || !tsaURL)
 170         return;
 171
 172     xpctsaDebug("Request Length: %ld, URL: %s", requestLength, tsaURL);
 173
 174     __block CFDataRef tsaReq = CFDataCreate(kCFAllocatorDefault, (const unsigned char *)requestData, requestLength);
 175
 176     // The completion block is called when we have a response
 177     TSARequestCompletionBlock reqCompletionBlock =
 178     ^(NSURLResponse *response, NSData *data, NSError *err)
 179     {
 180         xpc_object_t tsaError = NULL;
 181         xpc_object_t tsaStatusCode = NULL;
 182         NSString *errStr = NULL;
 183
 184         debugShowTSAResponseInfo(response, data, err);
 185
 186         /*
 187             Handle errors first. The bad responses seen so far tend to
 188             return a bad HTTP status code rather than setting the "err"
 189             parameter. In this case, the "data" parameter contains the
 190             HTML of the error response, which we do not want to try to
 191             parse as ASN.1 data.
 192         */
 193
 194         if (response)
 195         {
 196             NSHTTPURLResponse *httpResponse = (NSHTTPURLResponse*)response;
 197             NSInteger statusCode = [httpResponse statusCode];
 198             if (statusCode != kHTTPResponseCodeOK)
 199             {
 200                 errStr = [NSHTTPURLResponse localizedStringForStatusCode:(NSInteger)statusCode];
 201                 tsaStatusCode = xpc_int64_create((int64_t)statusCode);
 202                 xpctsaNSLog(@"TSA Response-b: %d, %@", (int)statusCode, errStr);
 203             }
 204         }
 205
 206         if (err && !errStr)
 207         {
 208             errStr = [err description];
 209             if (!tsaStatusCode)
 210             {
 211                 NSInteger statusCode = [err code];
 212                 tsaStatusCode = xpc_int64_create((int64_t)statusCode);
 213             }
 214         }
 215
 216         if (errStr)
 217         {
 218             const char *cerrstr = cfStringToCString((CFStringRef)errStr);
 219             tsaError = xpc_string_create(cerrstr);
 220             xpctsaNSLog(@"TSA Response-c: %@", errStr);
 221         }
 222
 223         size_t length = (errStr || !data) ? 0 : [data length];
 224         xpc_object_t tsaReply = data ? xpc_data_create([data bytes], length) : NULL;
 225         xpc_connection_t peer = xpc_dictionary_get_remote_connection(event);
 226         xpc_object_t reply = NULL;
 227         if (tsaError && tsaReply && tsaStatusCode) {
 228             reply = xpc_create_reply_with_format(event, "{TimeStampReply: %value, TimeStampError: %value, TimeStampStatus: %value}",
 229                                                  tsaReply, tsaError, tsaStatusCode);
 230         } else if (tsaReply) {
 231             reply = xpc_create_reply_with_format(event, "{TimeStampReply: %value}", tsaReply);
 232         } else {
 233             reply = xpc_create_reply_with_format(event, "{}");
 234         }
 235         xpc_connection_send_message(peer, reply);
 236         xpc_release(reply);
 237
 238         if (tsaReq)
 239             CFRelease(tsaReq);
 240         if (tsaReply)
 241             xpc_release(tsaReply);
 242         if (tsaError)
 243             xpc_release(tsaError);
 244         if (tsaStatusCode)
 245             xpc_release(tsaStatusCode);
 246     };
 247
 248     sendTSARequest(tsaReq, tsaURL, reqCompletionBlock);
 249 }
 250
 251 void handle_request_event(struct connection_info *info, xpc_object_t event)
 252 {
 253     xpc_connection_t peer = xpc_dictionary_get_remote_connection(event);
 254     xpc_type_t xtype = xpc_get_type(event);
 255
 256     if (info->done)
 257     {
 258         xpctsaDebug("event %p while done", event);
 259         return;
 260     }
 261         if (xtype == XPC_TYPE_ERROR)
 262     {
 263                 if (event == XPC_ERROR_TERMINATION_IMMINENT) {
 264                         // launchd would like us to die, but we have open transactions.   When we finish with them xpc_service_main
 265                         // will exit for us, so there is nothing for us to do here.
 266                         return;
 267                 }
 268
 269         if (!info->done) {
 270             info->done = true;
 271             xpc_release(info->peer);
 272         }
 273         if (peer == NULL && XPC_ERROR_CONNECTION_INVALID == event && 0 != info->processed) {
 274             // this is a normal shutdown on a connection that has processed at least
 275             // one request.   Nothing intresting to log.
 276             return;
 277         }
 278                 xpctsaDebug("listener event error (connection %p): %s", peer, xpc_dictionary_get_string(event, XPC_ERROR_KEY_DESCRIPTION));
 279         }
 280     else
 281     if (xtype == XPC_TYPE_DICTIONARY)
 282     {
 283         size_t length = 0;
 284         const char *operation = xpc_dictionary_get_string(event, "operation");
 285         audit_token_t auditToken  = {};
 286         xpc_connection_get_audit_token(peer, &auditToken);
 287
 288         if (operation && !strcmp(operation, "TimeStampRequest"))
 289         {
 290             if (callerHasNetworkEntitlement(auditToken)) {
 291                 xpctsaDebug("Handling TimeStampRequest event");
 292                 const void *requestData = xpc_dictionary_get_data(event, "TimeStampRequest", &length);
 293                 const char *url = xpc_dictionary_get_string(event, "ServerURL");
 294
 295                 communicateWithTimeStampingServer(event, requestData, length, url);
 296             }
 297             else
 298                 xpctsaDebug("No network entitlement for pid %d", xpc_connection_get_pid(peer));
 299         }
 300         else
 301             xpctsaDebug("Unknown op=%s request from pid %d", operation, xpc_connection_get_pid(peer));
 302     }
 303     else
 304         xpctsaDebug("Unhandled request event=%p type=%p", event, xtype);
 305 }
 306
 307 void finalize_connection(void *not_used)
 308 {
 309         xpc_transaction_end();
 310 }
 311
 312 void handle_connection_event(const xpc_connection_t peer)
 313 {
 314     __block struct connection_info info;
 315     info.peer = peer;
 316     info.processed = 0;
 317     info.done = false;
 318
 319     xpc_connection_set_event_handler(peer, ^(xpc_object_t event)
 320     {
 321         handle_request_event(&info, event);
 322     });
 323
 324     //  unlike dispatch objects xpc objects don't need a context set in order to run a finalizer.   (we use our finalizer to
 325     // end the transaction we are about to begin...this keeps xpc from idle exiting us while we have a live connection)
 326     xpc_connection_set_finalizer_f(peer, finalize_connection);
 327     xpc_transaction_begin();
 328
 329     // enable the peer connection to receive messages
 330     xpc_connection_resume(peer);
 331     xpc_retain(peer);
 332 }
 333
 334 int main(int argc, const char *argv[])
 335 {
 336     char *wait4debugger = getenv("WAIT4DEBUGGER");
 337     if (wait4debugger && !strcasecmp("YES", wait4debugger))
 338     {
 339         syslog(LOG_ERR, "Waiting for debugger");
 340         kill(getpid(), SIGSTOP);
 341     }
 342
 343     xpc_main(handle_connection_event);
 344
 345     return EX_OSERR;
 346 }
 347