Security/sec/securityd/SecCAIssuerRequest.c

   1 /*
   2  *  SecCAIssuerRequest.c
   3  *  Security
   4  *
   5  *  Copyright (c) 2009-2014 Apple Inc.. All Rights Reserved.
   6  *
   7  */
   8 /*
   9  * Copyright (c) 2009-2014 Apple Inc. All Rights Reserved.
  10  *
  11  * @APPLE_LICENSE_HEADER_START@
  12  *
  13  * This file contains Original Code and/or Modifications of Original Code
  14  * as defined in and that are subject to the Apple Public Source License
  15  * Version 2.0 (the 'License'). You may not use this file except in
  16  * compliance with the License. Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_HEADER_END@
  29  */
  30
  31 /*
  32  * SecCAIssuerRequest.c - asynchronous CAIssuer request fetching engine.
  33  */
  34
  35
  36 #include "SecCAIssuerRequest.h"
  37 #include "SecCAIssuerCache.h"
  38
  39 #include <Security/SecInternal.h>
  40 #include <CoreFoundation/CFURL.h>
  41 #include <CFNetwork/CFHTTPMessage.h>
  42 #include <utilities/debugging.h>
  43 #include <Security/SecCertificateInternal.h>
  44 #include <securityd/asynchttp.h>
  45 #include <stdlib.h>
  46
  47 /* CA Issuer lookup code. */
  48
  49 typedef struct SecCAIssuerRequest *SecCAIssuerRequestRef;
  50 struct SecCAIssuerRequest {
  51     asynchttp_t http;   /* Must be first field. */
  52     SecCertificateRef certificate;
  53     CFArrayRef issuers; /* NONRETAINED */
  54     CFIndex issuerIX;
  55     void *context;
  56     void (*callback)(void *, CFArrayRef);
  57 };
  58
  59 static void SecCAIssuerRequestRelease(SecCAIssuerRequestRef request) {
  60     CFRelease(request->certificate);
  61     asynchttp_free(&request->http);
  62     free(request);
  63 }
  64
  65 static bool SecCAIssuerRequestIssue(SecCAIssuerRequestRef request) {
  66     while (request->issuerIX < CFArrayGetCount(request->issuers)) {
  67         CFURLRef issuer = CFArrayGetValueAtIndex(request->issuers,
  68                                                  request->issuerIX++);
  69         CFStringRef scheme = CFURLCopyScheme(issuer);
  70         if (scheme) {
  71             if (CFEqual(CFSTR("http"), scheme)) {
  72                 CFHTTPMessageRef msg = CFHTTPMessageCreateRequest(kCFAllocatorDefault,
  73                                                                   CFSTR("GET"), issuer, kCFHTTPVersion1_1);
  74                 if (msg) {
  75                     secdebug("caissuer", "%@", msg);
  76                     bool done = asynchttp_request(msg, &request->http);
  77                     CFRelease(msg);
  78                     if (done == false) {
  79                         CFRelease(scheme);
  80                         return done;
  81                     }
  82                 }
  83                 secdebug("caissuer", "failed to get %@", issuer);
  84             } else {
  85                 secdebug("caissuer", "skipping unsupported uri %@", issuer);
  86             }
  87             CFRelease(scheme);
  88         }
  89     }
  90
  91     /* No more issuers left to try, we're done. */
  92     secdebug("caissuer", "no request issued");
  93     request->callback(request->context, NULL);
  94     SecCAIssuerRequestRelease(request);
  95     return true;
  96 }
  97
  98 /* Releases parent unconditionally, and return a CFArrayRef containing
  99    parent if the normalized subject of parent matches the normalized issuer
 100    of certificate. */
 101 static CFArrayRef SecCAIssuerConvertToParents(SecCertificateRef certificate,
 102     SecCertificateRef parent) {
 103     CFDataRef nic = SecCertificateGetNormalizedIssuerContent(certificate);
 104     CFArrayRef parents = NULL;
 105     if (parent) {
 106       CFDataRef parent_nic = SecCertificateGetNormalizedSubjectContent(parent);
 107       if (parent_nic && CFEqual(nic, parent_nic)) {
 108             const void *ventry = parent;
 109             parents = CFArrayCreate(NULL, &ventry, 1, &kCFTypeArrayCallBacks);
 110         }
 111         CFRelease(parent);
 112     }
 113     return parents;
 114 }
 115
 116 #define SECONDS_PER_DAY (86400.0)
 117 static void SecCAIssuerRequestCompleted(asynchttp_t *http,
 118     CFTimeInterval maxAge) {
 119     /* Cast depends on http being first field in struct SecCAIssuerRequest. */
 120     SecCAIssuerRequestRef request = (SecCAIssuerRequestRef)http;
 121     CFDataRef data = (request->http.response ?
 122         CFHTTPMessageCopyBody(request->http.response) : NULL);
 123     if (data) {
 124         SecCertificateRef parent = SecCertificateCreateWithData(NULL, data);
 125         CFRelease(data);
 126         if (parent) {
 127             /* We keep responses in the cache for at least 7 days, or longer
 128              if the http response tells us to keep it around for more. */
 129             if (maxAge < SECONDS_PER_DAY * 7)
 130                 maxAge = SECONDS_PER_DAY * 7;
 131             CFAbsoluteTime expires = CFAbsoluteTimeGetCurrent() + maxAge;
 132             CFURLRef issuer = CFArrayGetValueAtIndex(request->issuers,
 133                                                      request->issuerIX - 1);
 134             SecCAIssuerCacheAddCertificate(parent, issuer, expires);
 135             CFArrayRef parents = SecCAIssuerConvertToParents(
 136                 request->certificate, parent);
 137             if (parents) {
 138                 secdebug("caissuer", "response: %@ good", http->response);
 139                 request->callback(request->context, parents);
 140                 CFRelease(parents);
 141                 SecCAIssuerRequestRelease(request);
 142                 return;
 143             }
 144         }
 145     }
 146
 147     secdebug("caissuer", "response: %@ not parent, trying next caissuer",
 148         http->response);
 149     SecCAIssuerRequestIssue(request);
 150 }
 151
 152 static CFArrayRef SecCAIssuerRequestCacheCopyParents(SecCertificateRef cert,
 153     CFArrayRef issuers) {
 154     CFIndex ix = 0, ex = CFArrayGetCount(issuers);
 155     for (;ix < ex; ++ix) {
 156         CFURLRef issuer = CFArrayGetValueAtIndex(issuers, ix);
 157         CFStringRef scheme = CFURLCopyScheme(issuer);
 158         if (scheme) {
 159             if (CFEqual(CFSTR("http"), scheme)) {
 160                 CFArrayRef parents = SecCAIssuerConvertToParents(cert,
 161                     SecCAIssuerCacheCopyMatching(issuer));
 162                 if (parents) {
 163                     secdebug("caissuer", "cache hit, for %@ no request issued", issuer);
 164                     CFRelease(scheme);
 165                     return parents;
 166                 }
 167             }
 168             CFRelease(scheme);
 169         }
 170     }
 171     return NULL;
 172 }
 173
 174 bool SecCAIssuerCopyParents(SecCertificateRef certificate, dispatch_queue_t queue,
 175     void *context, void (*callback)(void *, CFArrayRef)) {
 176     CFArrayRef issuers = SecCertificateGetCAIssuers(certificate);
 177     if (!issuers) {
 178         /* certificate has no caissuer urls, we're done. */
 179         callback(context, NULL);
 180         return true;
 181     }
 182
 183     CFArrayRef parents = SecCAIssuerRequestCacheCopyParents(certificate, issuers);
 184     if (parents) {
 185         callback(context, parents);
 186         CFReleaseSafe(parents);
 187         return true;
 188     }
 189
 190     /* Cache miss, let's issue a network request. */
 191     SecCAIssuerRequestRef request =
 192         (SecCAIssuerRequestRef)calloc(1, sizeof(*request));
 193     request->http.queue = queue;
 194     request->http.completed = SecCAIssuerRequestCompleted;
 195     CFRetain(certificate);
 196     request->certificate = certificate;
 197     request->issuers = issuers;
 198     request->issuerIX = 0;
 199     request->context = context;
 200     request->callback = callback;
 201
 202     return SecCAIssuerRequestIssue(request);
 203 }
 204