// Der encoding/decoding
const uint8_t* der_decode_RecoveryKeyBag(CFAllocatorRef allocator,
SOSRecoveryKeyBagRef* RecoveryKeyBag, CFErrorRef *error,
const uint8_t* der, const uint8_t *der_end) {
if (der == NULL) return der;
const uint8_t *result = NULL;
SOSRecoveryKeyBagRef rb = CFTypeAllocate(SOSRecoveryKeyBag, struct __OpaqueSOSRecoveryKeyBag, allocator);
require_quiet(SecAllocationError(rb, error, CFSTR("Recovery bag allocation failed")), fail);
const uint8_t *sequence_end = NULL;
der = ccder_decode_sequence_tl(&sequence_end, der, der_end);
require_quiet(sequence_end == der_end, fail);
der = der_decode_string(kCFAllocatorDefault, kCFPropertyListImmutable, &rb->accountDSID, error, der, sequence_end);
rb->generation = SOSGenCountCreateFromDER(kCFAllocatorDefault, error, &der, sequence_end);
der = ccder_decode_uint64(&rb->rkbVersion, der, sequence_end);
der = der_decode_data(allocator, kCFPropertyListImmutable, &rb->recoveryKeyBag, error, der, sequence_end);
require_quiet(SecRequirementError(der == der_end, error, CFSTR("Extra space in sequence")), fail);
if (RecoveryKeyBag) CFTransferRetained(*RecoveryKeyBag, rb);
result = der;
fail:
CFReleaseNull(rb);
return result;
}
const uint8_t* der_decode_array(CFAllocatorRef allocator, CFOptionFlags mutability,
CFArrayRef* array, CFErrorRef *error,
const uint8_t* der, const uint8_t *der_end)
{
if (NULL == der)
return NULL;
CFMutableArrayRef result = CFArrayCreateMutable(allocator, 0, &kCFTypeArrayCallBacks);
const uint8_t *elements_end;
const uint8_t *current_element = ccder_decode_sequence_tl(&elements_end, der, der_end);
while (current_element != NULL && current_element < elements_end) {
CFPropertyListRef element = NULL;
current_element = der_decode_plist(allocator, mutability, &element, error, current_element, elements_end);
if (current_element) {
CFArrayAppendValue(result, element);
CFReleaseNull(element);
}
}
if (current_element) {
*array = result;
result = NULL;
}
CFReleaseNull(result);
return current_element;
}
SOSCoderRef SOSCoderCreateFromData(CFDataRef exportedData, CFErrorRef *error) {
SOSCoderRef p = calloc(1, sizeof(struct __OpaqueSOSCoder));
const uint8_t *der = CFDataGetBytePtr(exportedData);
const uint8_t *der_end = der + CFDataGetLength(exportedData);
CFDataRef otr_data = NULL;
ccder_tag tag;
require(ccder_decode_tag(&tag, der, der_end),fail);
switch (tag) {
case CCDER_OCTET_STRING: // TODO: this code is safe to delete?
{
der = der_decode_data(kCFAllocatorDefault, 0, &otr_data, error, der, der_end);
p->waitingForDataPacket = false;
}
break;
case CCDER_CONSTRUCTED_SEQUENCE:
{
const uint8_t *sequence_end = NULL;
der = ccder_decode_sequence_tl(&sequence_end, der, der_end);
require_action_quiet(sequence_end == der_end, fail, SecCFDERCreateError(kSOSErrorDecodeFailure, CFSTR("Extra data in SOS coder"), NULL, error));
der = der_decode_data(kCFAllocatorDefault, 0, &otr_data, error, der, sequence_end);
der = der_decode_bool(&p->waitingForDataPacket, der, sequence_end);
if (der != sequence_end) { // optionally a pending response
der = der_decode_data(kCFAllocatorDefault, 0, &p->pendingResponse, error, der, sequence_end);
}
}
break;
default:
SecCFDERCreateError(kSOSErrorDecodeFailure, CFSTR("Unsupported SOS Coder DER"), NULL, error);
goto fail;
}
require(der, fail);
p->sessRef = SecOTRSessionCreateFromData(NULL, otr_data);
require(p->sessRef, fail);
CFReleaseSafe(otr_data);
return p;
fail:
SOSCoderDispose(p);
CFReleaseSafe(otr_data);
return NULL;
}
static const uint8_t* der_decode_cloud_parameters(CFAllocatorRef allocator,
CFIndex algorithmID, SecKeyRef* publicKey,
CFDataRef *parameters,
CFErrorRef* error,
const uint8_t* der, const uint8_t* der_end)
{
const uint8_t *sequence_end;
der = ccder_decode_sequence_tl(&sequence_end, der, der_end);
der = der_decode_public_bytes(allocator, algorithmID, publicKey, error, der, sequence_end);
der = der_decode_data_or_null(allocator, parameters, error, der, sequence_end);
return der;
}