OSX/sec/SOSCircle/SecureObjectSync/SOSPeerInfoDER.c

   1 //
   2 //  SOSPeerInfoDER.c
   3 //  sec
   4 //
   5 //  Created by Richard Murphy on 2/9/15.
   6 //
   7 //
   8
   9 #include <AssertMacros.h>
  10 #include <SOSPeerInfoDER.h>
  11
  12 #include <Security/SecureObjectSync/SOSPeerInfo.h>
  13 #include <Security/SecureObjectSync/SOSPeerInfoInternal.h>
  14 #include <Security/SecureObjectSync/SOSPeerInfoPriv.h>
  15 #include <Security/SecureObjectSync/SOSPeerInfoV2.h>
  16 #include <Security/SecureObjectSync/SOSInternal.h>
  17
  18 #include <utilities/der_plist.h>
  19 #include <utilities/der_plist_internal.h>
  20 #include <corecrypto/ccder.h>
  21 #include <utilities/der_date.h>
  22
  23 #include <utilities/SecCFError.h>
  24
  25 size_t SOSPeerInfoGetDEREncodedSize(SOSPeerInfoRef peer, CFErrorRef *error) {
  26     size_t plist_size = der_sizeof_plist(peer->description, error);
  27     if (plist_size == 0)
  28         return 0;
  29
  30     size_t signature_size = der_sizeof_data(peer->signature, error);
  31     if (signature_size == 0)
  32         return 0;
  33
  34     return ccder_sizeof(CCDER_CONSTRUCTED_SEQUENCE,
  35                         plist_size + signature_size);
  36 }
  37
  38 uint8_t* SOSPeerInfoEncodeToDER(SOSPeerInfoRef peer, CFErrorRef* error, const uint8_t* der, uint8_t* der_end) {
  39     if(peer->version >= 2) SOSPeerInfoPackV2Data(peer);
  40     return ccder_encode_constructed_tl(CCDER_CONSTRUCTED_SEQUENCE, der_end, der,
  41                                        der_encode_plist(peer->description, error, der,
  42                                        der_encode_data(peer->signature, error, der, der_end)));
  43 }
  44
  45 CFDataRef SOSPeerInfoCopyEncodedData(SOSPeerInfoRef peer, CFAllocatorRef allocator, CFErrorRef *error) {
  46     size_t size = SOSPeerInfoGetDEREncodedSize(peer, error);
  47     if (size == 0) return NULL;
  48
  49     uint8_t buffer[size];
  50     uint8_t* start = SOSPeerInfoEncodeToDER(peer, error, buffer, buffer + sizeof(buffer));
  51     CFDataRef result = CFDataCreate(kCFAllocatorDefault, start, size);
  52     return result;
  53 }
  54
  55
  56
  57 SOSPeerInfoRef SOSPeerInfoCreateFromDER(CFAllocatorRef allocator, CFErrorRef* error,
  58                                         const uint8_t** der_p, const uint8_t *der_end) {
  59     SOSPeerInfoRef pi = SOSPeerInfoAllocate(allocator);
  60     SecKeyRef pubKey = NULL;
  61     const uint8_t *sequence_end;
  62
  63     CFPropertyListRef pl = NULL;
  64
  65     pi->gestalt = NULL;
  66     pi->version = 0; // TODO: Encode this in the DER
  67     *der_p = ccder_decode_constructed_tl(CCDER_CONSTRUCTED_SEQUENCE, &sequence_end, *der_p, der_end);
  68     *der_p = der_decode_plist(allocator, kCFPropertyListImmutable, &pl, error, *der_p, sequence_end);
  69     *der_p = der_decode_data(allocator, kCFPropertyListImmutable, &pi->signature, error, *der_p, sequence_end);
  70
  71     if (*der_p == NULL || *der_p != sequence_end) {
  72         SOSCreateError(kSOSErrorBadFormat, CFSTR("Bad Format of Peer Info DER"), NULL, error);
  73         goto fail;
  74     }
  75
  76     if (CFGetTypeID(pl) != CFDictionaryGetTypeID()) {
  77         CFStringRef description = CFCopyTypeIDDescription(CFGetTypeID(pl));
  78         SOSCreateErrorWithFormat(kSOSErrorUnexpectedType, NULL, error, NULL,
  79                                  CFSTR("Expected dictionary got %@"), description);
  80         CFReleaseSafe(description);
  81         goto fail;
  82     }
  83
  84     pi->description = (CFMutableDictionaryRef) pl;
  85     CFRetain(pi->description);
  86     CFReleaseNull(pl);
  87
  88     CFNumberRef versionNumber = CFDictionaryGetValue(pi->description, sVersionKey);
  89
  90     if (versionNumber) {
  91         if (CFGetTypeID(versionNumber) != CFNumberGetTypeID()) {
  92             CFStringRef description = CFCopyTypeIDDescription(CFGetTypeID(versionNumber));
  93             SOSCreateErrorWithFormat(kSOSErrorUnexpectedType, NULL, error, NULL,
  94                                      CFSTR("Expected (version) number got %@"), description);
  95             CFReleaseSafe(description);
  96             goto fail;
  97         }
  98         CFNumberGetValue(versionNumber, kCFNumberCFIndexType, &pi->version);
  99     }
 100
 101     CFDictionaryRef gestalt = CFDictionaryGetValue(pi->description, sGestaltKey);
 102
 103     if (gestalt == NULL) {
 104         SOSCreateErrorWithFormat(kSOSErrorUnexpectedType, NULL, error, NULL,
 105                                  CFSTR("gestalt key missing"));
 106         goto fail;
 107     }
 108
 109     if (!isDictionary(gestalt)) {
 110         CFStringRef description = CFCopyTypeIDDescription(CFGetTypeID(gestalt));
 111         SOSCreateErrorWithFormat(kSOSErrorUnexpectedType, NULL, error, NULL,
 112                                  CFSTR("Expected dictionary got %@"), description);
 113         CFReleaseSafe(description);
 114         goto fail;
 115     }
 116
 117     pi->gestalt = gestalt;
 118     CFRetain(pi->gestalt);
 119
 120     pubKey = SOSPeerInfoCopyPubKey(pi);
 121     require_quiet(pubKey, fail);
 122
 123     pi->id = SOSCopyIDOfKey(pubKey, error);
 124     require_quiet(pi->id, fail);
 125
 126     if(pi->version >= 2) SOSPeerInfoExpandV2Data(pi, error);
 127
 128     if(!SOSPeerInfoVerify(pi, error)) {
 129         SOSCreateErrorWithFormat(kSOSErrorBadSignature, NULL, error, NULL, CFSTR("Signature doesn't validate"));
 130         if (error)
 131             secerror("Can't validate PeerInfo: %@", *error);
 132         goto fail;
 133     }
 134
 135     CFReleaseNull(pubKey);
 136     return pi;
 137
 138 fail:
 139     CFReleaseNull(pi);
 140     CFReleaseNull(pl);
 141     CFReleaseNull(pubKey);
 142
 143     return NULL;
 144 }
 145
 146 SOSPeerInfoRef SOSPeerInfoCreateFromData(CFAllocatorRef allocator, CFErrorRef* error,
 147                                          CFDataRef peerinfo_data) {
 148     const uint8_t *der = CFDataGetBytePtr(peerinfo_data);
 149     CFIndex len = CFDataGetLength(peerinfo_data);
 150     return SOSPeerInfoCreateFromDER(NULL, error, &der, der+len);
 151 }
 152