Security/sec/SOSCircle/SecureObjectSync/SOSAccountCloudParameters.c

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