OSX/sec/securityd/SecCAIssuerRequest.c

   1 /*
   2  * Copyright (c) 2009-2016 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 /*
  25  * SecCAIssuerRequest.c - asynchronous CAIssuer request fetching engine.
  26  */
  27
  28
  29 #include "SecCAIssuerRequest.h"
  30 #include "SecCAIssuerCache.h"
  31
  32 #include <Security/SecInternal.h>
  33 #include <Security/SecCMS.h>
  34 #include <CoreFoundation/CFURL.h>
  35 #include <CFNetwork/CFHTTPMessage.h>
  36 #include <utilities/debugging.h>
  37 #include <Security/SecCertificateInternal.h>
  38 #include <securityd/asynchttp.h>
  39 #include <stdlib.h>
  40
  41 /* CA Issuer lookup code. */
  42
  43 typedef struct SecCAIssuerRequest *SecCAIssuerRequestRef;
  44 struct SecCAIssuerRequest {
  45     asynchttp_t http;   /* Must be first field. */
  46     SecCertificateRef certificate;
  47     CFArrayRef issuers; /* NONRETAINED */
  48     CFIndex issuerIX;
  49     void *context;
  50     void (*callback)(void *, CFArrayRef);
  51 };
  52
  53 static void SecCAIssuerRequestRelease(SecCAIssuerRequestRef request) {
  54     CFRelease(request->certificate);
  55     asynchttp_free(&request->http);
  56     free(request);
  57 }
  58
  59 static bool SecCAIssuerRequestIssue(SecCAIssuerRequestRef request) {
  60     while (request->issuerIX < CFArrayGetCount(request->issuers)) {
  61         CFURLRef issuer = CFArrayGetValueAtIndex(request->issuers,
  62                                                  request->issuerIX++);
  63         CFStringRef scheme = CFURLCopyScheme(issuer);
  64         if (scheme) {
  65             if (CFEqual(CFSTR("http"), scheme)) {
  66                 CFHTTPMessageRef msg = CFHTTPMessageCreateRequest(kCFAllocatorDefault,
  67                                                                   CFSTR("GET"), issuer, kCFHTTPVersion1_1);
  68                 if (msg) {
  69                     secinfo("caissuer", "%@", msg);
  70                     bool done = asynchttp_request(msg, 0, &request->http);
  71                     CFRelease(msg);
  72                     if (done == false) {
  73                         CFRelease(scheme);
  74                         return done;
  75                     }
  76                 }
  77                 secdebug("caissuer", "failed to get %@", issuer);
  78             } else {
  79                 secnotice("caissuer", "skipping unsupported uri %@", issuer);
  80             }
  81             CFRelease(scheme);
  82         }
  83     }
  84
  85     /* No more issuers left to try, we're done. */
  86     secdebug("caissuer", "no request issued");
  87     request->callback(request->context, NULL);
  88     SecCAIssuerRequestRelease(request);
  89     return true;
  90 }
  91
  92 /* Releases parent unconditionally, and return a CFArrayRef containing
  93    parent if the normalized subject of parent matches the normalized issuer
  94    of certificate. */
  95 static CFArrayRef SecCAIssuerConvertToParents(SecCertificateRef certificate,
  96     SecCertificateRef parent) {
  97     CFDataRef nic = SecCertificateGetNormalizedIssuerContent(certificate);
  98     CFArrayRef parents = NULL;
  99     if (parent) {
 100         CFDataRef parent_nic = SecCertificateGetNormalizedSubjectContent(parent);
 101         if (nic && parent_nic && CFEqual(nic, parent_nic)) {
 102             const void *ventry = parent;
 103             parents = CFArrayCreate(NULL, &ventry, 1, &kCFTypeArrayCallBacks);
 104         }
 105         CFRelease(parent);
 106     }
 107     return parents;
 108 }
 109
 110 #define SECONDS_PER_DAY (86400.0)
 111 static void SecCAIssuerRequestCompleted(asynchttp_t *http,
 112     CFTimeInterval maxAge) {
 113     /* Cast depends on http being first field in struct SecCAIssuerRequest. */
 114     SecCAIssuerRequestRef request = (SecCAIssuerRequestRef)http;
 115     CFDataRef data = (request->http.response ?
 116         CFHTTPMessageCopyBody(request->http.response) : NULL);
 117     if (data) {
 118         /* RFC5280 4.2.2.1:
 119         "accessLocation MUST be a uniformResourceIdentifier and the URI
 120         MUST point to either a single DER encoded certificate as speci-
 121         fied in [RFC2585] or a collection of certificates in a BER or
 122         DER encoded "certs-only" CMS message as specified in [RFC2797]." */
 123
 124         /* DER-encoded certificate */
 125         SecCertificateRef parent = SecCertificateCreateWithData(NULL, data);
 126
 127         /* "certs-only" CMS Message */
 128         if (!parent) {
 129             CFArrayRef certificates = NULL;
 130             certificates = SecCMSCertificatesOnlyMessageCopyCertificates(data);
 131             if (certificates && CFArrayGetCount(certificates) == 1) {
 132                 parent = (SecCertificateRef)CFRetainSafe(CFArrayGetValueAtIndex(certificates, 0));
 133             }
 134             CFReleaseNull(certificates);
 135         }
 136
 137         /* Retry in case the certificate is in PEM format. Some CAs
 138          incorrectly return a PEM encoded cert, despite RFC 5280 4.2.2.1 */
 139         if (!parent) {
 140             parent = SecCertificateCreateWithPEM(NULL, data);
 141         }
 142         CFRelease(data);
 143         if (parent) {
 144             /* We keep responses in the cache for at least 7 days, or longer
 145              if the http response tells us to keep it around for more. */
 146             if (maxAge < SECONDS_PER_DAY * 7)
 147                 maxAge = SECONDS_PER_DAY * 7;
 148             CFAbsoluteTime expires = CFAbsoluteTimeGetCurrent() + maxAge;
 149             CFURLRef issuer = CFArrayGetValueAtIndex(request->issuers,
 150                                                      request->issuerIX - 1);
 151             SecCAIssuerCacheAddCertificate(parent, issuer, expires);
 152             CFArrayRef parents = SecCAIssuerConvertToParents(
 153                 request->certificate, parent); /* note: this releases parent */
 154             if (parents) {
 155                 secdebug("caissuer", "response: %@ good", http->response);
 156                 request->callback(request->context, parents);
 157                 CFRelease(parents);
 158                 SecCAIssuerRequestRelease(request);
 159                 return;
 160             }
 161         }
 162     }
 163
 164     secdebug("caissuer", "response: %@ not parent, trying next caissuer",
 165         http->response);
 166     SecCAIssuerRequestIssue(request);
 167 }
 168
 169 static CFArrayRef SecCAIssuerRequestCacheCopyParents(SecCertificateRef cert,
 170     CFArrayRef issuers) {
 171     CFIndex ix = 0, ex = CFArrayGetCount(issuers);
 172     for (;ix < ex; ++ix) {
 173         CFURLRef issuer = CFArrayGetValueAtIndex(issuers, ix);
 174         CFStringRef scheme = CFURLCopyScheme(issuer);
 175         if (scheme) {
 176             if (CFEqual(CFSTR("http"), scheme)) {
 177                 CFArrayRef parents = SecCAIssuerConvertToParents(cert,
 178                     SecCAIssuerCacheCopyMatching(issuer));
 179                 if (parents) {
 180                     secdebug("caissuer", "cache hit, for %@ no request issued", issuer);
 181                     CFRelease(scheme);
 182                     return parents;
 183                 }
 184             }
 185             CFRelease(scheme);
 186         }
 187     }
 188     return NULL;
 189 }
 190
 191 bool SecCAIssuerCopyParents(SecCertificateRef certificate, dispatch_queue_t queue,
 192     void *context, void (*callback)(void *, CFArrayRef)) {
 193     CFArrayRef issuers = SecCertificateGetCAIssuers(certificate);
 194     if (!issuers) {
 195         /* certificate has no caissuer urls, we're done. */
 196         callback(context, NULL);
 197         return true;
 198     }
 199
 200     CFArrayRef parents = SecCAIssuerRequestCacheCopyParents(certificate, issuers);
 201     if (parents) {
 202         callback(context, parents);
 203         CFReleaseSafe(parents);
 204         return true;
 205     }
 206
 207     /* Cache miss, let's issue a network request. */
 208     SecCAIssuerRequestRef request =
 209         (SecCAIssuerRequestRef)calloc(1, sizeof(*request));
 210     request->http.queue = queue;
 211     request->http.completed = SecCAIssuerRequestCompleted;
 212     CFRetain(certificate);
 213     request->certificate = certificate;
 214     request->issuers = issuers;
 215     request->issuerIX = 0;
 216     request->context = context;
 217     request->callback = callback;
 218
 219     return SecCAIssuerRequestIssue(request);
 220 }
 221