OSX/sec/SOSCircle/SecureObjectSync/SOSPeerInfoDER.m

   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     return CFDataCreateWithDER(kCFAllocatorDefault, SOSPeerInfoGetDEREncodedSize(peer, error), ^uint8_t*(size_t size, uint8_t *buffer) {
  47         return SOSPeerInfoEncodeToDER(peer, error, buffer, (uint8_t *) buffer + size);
  48     });
  49 }
  50
  51
  52
  53 SOSPeerInfoRef SOSPeerInfoCreateFromDER(CFAllocatorRef allocator, CFErrorRef* error,
  54                                         const uint8_t** der_p, const uint8_t *der_end) {
  55     SOSPeerInfoRef pi = SOSPeerInfoAllocate(allocator);
  56     SecKeyRef pubKey = NULL;
  57     const uint8_t *sequence_end;
  58
  59     CFPropertyListRef pl = NULL;
  60
  61     pi->gestalt = NULL;
  62     pi->version = 0; // TODO: Encode this in the DER
  63     *der_p = ccder_decode_constructed_tl(CCDER_CONSTRUCTED_SEQUENCE, &sequence_end, *der_p, der_end);
  64     *der_p = der_decode_plist(allocator, kCFPropertyListImmutable, &pl, error, *der_p, sequence_end);
  65     *der_p = der_decode_data(allocator, kCFPropertyListImmutable, &pi->signature, error, *der_p, sequence_end);
  66
  67     if (*der_p == NULL || *der_p != sequence_end) {
  68         SOSCreateError(kSOSErrorBadFormat, CFSTR("Bad Format of Peer Info DER"), NULL, error);
  69         goto fail;
  70     }
  71
  72     if (CFGetTypeID(pl) != CFDictionaryGetTypeID()) {
  73         CFStringRef description = CFCopyTypeIDDescription(CFGetTypeID(pl));
  74         SOSCreateErrorWithFormat(kSOSErrorUnexpectedType, NULL, error, NULL,
  75                                  CFSTR("Expected dictionary got %@"), description);
  76         CFReleaseSafe(description);
  77         goto fail;
  78     }
  79
  80     pi->description = (CFMutableDictionaryRef) pl;
  81     CFRetain(pi->description);
  82     CFReleaseNull(pl);
  83
  84     CFNumberRef versionNumber = CFDictionaryGetValue(pi->description, sVersionKey);
  85
  86     if (versionNumber) {
  87         if (CFGetTypeID(versionNumber) != CFNumberGetTypeID()) {
  88             CFStringRef description = CFCopyTypeIDDescription(CFGetTypeID(versionNumber));
  89             SOSCreateErrorWithFormat(kSOSErrorUnexpectedType, NULL, error, NULL,
  90                                      CFSTR("Expected (version) number got %@"), description);
  91             CFReleaseSafe(description);
  92             goto fail;
  93         }
  94         CFNumberGetValue(versionNumber, kCFNumberCFIndexType, &pi->version);
  95     }
  96
  97     CFDictionaryRef gestalt = CFDictionaryGetValue(pi->description, sGestaltKey);
  98
  99     if (gestalt == NULL) {
 100         SOSCreateErrorWithFormat(kSOSErrorUnexpectedType, NULL, error, NULL,
 101                                  CFSTR("gestalt key missing"));
 102         goto fail;
 103     }
 104
 105     if (!isDictionary(gestalt)) {
 106         CFStringRef description = CFCopyTypeIDDescription(CFGetTypeID(gestalt));
 107         SOSCreateErrorWithFormat(kSOSErrorUnexpectedType, NULL, error, NULL,
 108                                  CFSTR("Expected dictionary got %@"), description);
 109         CFReleaseSafe(description);
 110         goto fail;
 111     }
 112
 113     pi->gestalt = gestalt;
 114     CFRetain(pi->gestalt);
 115
 116     pubKey = SOSPeerInfoCopyPubKey(pi, error);
 117     require_quiet(pubKey, fail);
 118
 119     pi->id = SOSCopyIDOfKey(pubKey, error);
 120     require_quiet(pi->id, fail);
 121
 122     if(pi->version >= 2) SOSPeerInfoExpandV2Data(pi, error);
 123
 124     if(!SOSPeerInfoVerify(pi, error)) {
 125         SOSCreateErrorWithFormat(kSOSErrorBadSignature, NULL, error, NULL, CFSTR("Signature doesn't validate"));
 126         if (error)
 127             secerror("Can't validate PeerInfo: %@", *error);
 128         goto fail;
 129     }
 130
 131     CFReleaseNull(pubKey);
 132     return pi;
 133
 134 fail:
 135     CFReleaseNull(pi);
 136     CFReleaseNull(pl);
 137     CFReleaseNull(pubKey);
 138
 139     return NULL;
 140 }
 141
 142 SOSPeerInfoRef SOSPeerInfoCreateFromData(CFAllocatorRef allocator, CFErrorRef* error,
 143                                          CFDataRef peerinfo_data) {
 144     const uint8_t *der = CFDataGetBytePtr(peerinfo_data);
 145     CFIndex len = CFDataGetLength(peerinfo_data);
 146     return SOSPeerInfoCreateFromDER(NULL, error, &der, der+len);
 147 }
 148