keychain/SecureObjectSync/SOSAccountCloudParameters.m

   1 //
   2 //  AccountCloudParameters.c
   3 //  sec
   4 //
   5
   6 #include "SOSAccountPriv.h"
   7 #include "keychain/SecureObjectSync/SOSTransportKeyParameter.h"
   8 #include "keychain/SecureObjectSync/SOSCircleDer.h"
   9 //
  10 // Cloud Paramters encode/decode
  11 //
  12
  13 static size_t der_sizeof_cloud_parameters(SecKeyRef publicKey, CFDataRef paramters, CFErrorRef* error)
  14 {
  15     size_t public_key_size = der_sizeof_public_bytes(publicKey, error);
  16     size_t parameters_size = der_sizeof_data_or_null(paramters, error);
  17
  18     return ccder_sizeof(CCDER_CONSTRUCTED_SEQUENCE, public_key_size + parameters_size);
  19 }
  20
  21 static uint8_t* der_encode_cloud_parameters(SecKeyRef publicKey, CFDataRef paramters, CFErrorRef* error,
  22                                             const uint8_t* der, uint8_t* der_end)
  23 {
  24     uint8_t* original_der_end = der_end;
  25
  26     return ccder_encode_constructed_tl(CCDER_CONSTRUCTED_SEQUENCE, original_der_end, der,
  27                                        der_encode_public_bytes(publicKey, error, der,
  28                                                                der_encode_data_or_null(paramters, error, der, der_end)));
  29 }
  30
  31 const uint8_t* der_decode_cloud_parameters(CFAllocatorRef allocator,
  32                                                   CFIndex algorithmID, SecKeyRef* publicKey,
  33                                                   CFDataRef *pbkdfParams,
  34                                                   CFErrorRef* error,
  35                                                   const uint8_t* der, const uint8_t* der_end)
  36 {
  37     const uint8_t *sequence_end;
  38     der = ccder_decode_sequence_tl(&sequence_end, der, der_end);
  39     der = der_decode_public_bytes(allocator, algorithmID, publicKey, error, der, sequence_end);
  40     der = der_decode_data_or_null(allocator, pbkdfParams, error, der, sequence_end);
  41
  42     return der;
  43 }
  44
  45
  46 bool SOSAccountPublishCloudParameters(SOSAccount* account, CFErrorRef* error){
  47     bool success = false;
  48     CFIndex cloud_der_len = der_sizeof_cloud_parameters(account.accountKey,
  49                                                         (__bridge CFDataRef)(account.accountKeyDerivationParameters),
  50                                                         error);
  51
  52     CFMutableDataRef cloudParameters = CFDataCreateMutableWithScratch(kCFAllocatorDefault, cloud_der_len);
  53
  54     if (der_encode_cloud_parameters(account.accountKey, (__bridge CFDataRef)(account.accountKeyDerivationParameters), error,
  55                                     CFDataGetMutableBytePtr(cloudParameters),
  56                                     CFDataGetMutablePastEndPtr(cloudParameters)) != NULL) {
  57
  58         CFErrorRef changeError = NULL;
  59
  60         if ([account.key_transport SOSTransportKeyParameterPublishCloudParameters:account.key_transport data:cloudParameters err:error]) {
  61             success = true;
  62         } else {
  63             SOSCreateErrorWithFormat(kSOSErrorSendFailure, changeError, error, NULL,
  64                                      CFSTR("update parameters key failed [%@]"), cloudParameters);
  65         }
  66         CFReleaseSafe(changeError);
  67     } else {
  68         SOSCreateError(kSOSErrorEncodeFailure, CFSTR("Encoding parameters failed"), NULL, error);
  69     }
  70
  71     CFReleaseNull(cloudParameters);
  72
  73     return success;
  74 }
  75
  76 bool SOSAccountRetrieveCloudParameters(SOSAccount* account, SecKeyRef *newKey,
  77                                        CFDataRef derparms,
  78                                        CFDataRef *pbkdfParams, CFErrorRef* error) {
  79     const uint8_t *parse_end = der_decode_cloud_parameters(kCFAllocatorDefault, kSecECDSAAlgorithmID,
  80                                                            newKey, pbkdfParams, error,
  81                                                            CFDataGetBytePtr(derparms), CFDataGetPastEndPtr(derparms));
  82
  83     if (parse_end == CFDataGetPastEndPtr(derparms)) return true;
  84     return false;
  85 }
  86