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[apple/security.git] / keychain / SecureObjectSync / SOSBackupSliceKeyBag.m
diff --git a/keychain/SecureObjectSync/SOSBackupSliceKeyBag.m b/keychain/SecureObjectSync/SOSBackupSliceKeyBag.m
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+/*
+ * Copyright (c) 2015-2017 Apple Inc. All Rights Reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ *
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this
+ * file.
+ *
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
+ *
+ * @APPLE_LICENSE_HEADER_END@
+ */
+
+
+// Our Header
+
+#include <Security/SecureObjectSync/SOSBackupSliceKeyBag.h>
+
+
+// Needed headers for implementation
+#include "AssertMacros.h"
+#include <utilities/SecCFWrappers.h>
+#include <utilities/SecAKSWrappers.h>
+#include <utilities/SecBuffer.h>
+#include <utilities/SecCFError.h>
+#include <utilities/der_set.h>
+#include <utilities/der_plist_internal.h>
+#include <Security/SecRandom.h>
+#include <Security/SecureObjectSync/SOSPeerInfo.h>
+#include "keychain/SecureObjectSync/SOSPeerInfoCollections.h"
+#include "keychain/SecureObjectSync/SOSInternal.h"
+
+#include <corecrypto/ccec.h>
+#include <corecrypto/ccsha2.h>
+#include <corecrypto/ccrng.h>
+
+#include <limits.h>
+
+#include <Security/SecRecoveryKey.h>
+#include "SOSKeyedPubKeyIdentifier.h"
+#include "keychain/SecureObjectSync/SOSInternal.h"
+#include "SecADWrapper.h"
+#include "SecCFAllocator.h"
+
+CFStringRef bskbRkbgPrefix = CFSTR("RK");
+
+CFDataRef SOSRKNullKey(void) {
+    static CFDataRef localNullKey = NULL;
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        localNullKey = CFDataCreate(kCFAllocatorDefault, (const UInt8*) "nullkey", 8);
+    });
+    return localNullKey;
+}
+
+//
+// MARK: Type creation
+//
+
+CFGiblisFor(SOSBackupSliceKeyBag);
+
+const int kAKSBagSecretLength = 32;
+
+struct __OpaqueSOSBackupSliceKeyBag {
+    CFRuntimeBase           _base;
+
+    CFDataRef               aks_bag;
+
+    CFSetRef                peers;
+    CFDictionaryRef         wrapped_keys;
+};
+
+static void SOSBackupSliceKeyBagDestroy(CFTypeRef aObj) {
+    SOSBackupSliceKeyBagRef vb = (SOSBackupSliceKeyBagRef) aObj;
+
+    CFReleaseNull(vb->aks_bag);
+    CFReleaseNull(vb->peers);
+    CFReleaseNull(vb->wrapped_keys);
+}
+
+static CFSetRef SOSBackupSliceKeyBagCopyPeerNames(SOSBackupSliceKeyBagRef bksb) {
+    CFMutableSetRef retval = CFSetCreateMutableForCFTypes(kCFAllocatorDefault);
+    if(!retval) return NULL;
+    CFSetForEach(bksb->peers, ^(const void *value) {
+        SOSPeerInfoRef pi = (SOSPeerInfoRef) value;
+        CFSetAddValue(retval, SOSPeerInfoGetPeerName(pi));
+    });
+    return retval;
+}
+
+static CFStringRef SOSBackupSliceKeyBagCopyFormatDescription(CFTypeRef aObj, CFDictionaryRef formatOptions) {
+    SOSBackupSliceKeyBagRef vb = (SOSBackupSliceKeyBagRef) aObj;
+
+    CFMutableStringRef retval = CFStringCreateMutable(kCFAllocatorDefault, 0);
+    
+    CFSetRef peerIDs = SOSBackupSliceKeyBagCopyPeerNames(vb);
+    CFStringSetPerformWithDescription(peerIDs, ^(CFStringRef description) {
+        CFStringAppendFormat(retval, NULL, CFSTR("<SOSBackupSliceKeyBag@%p %ld %@"), vb, vb->peers ? CFSetGetCount(vb->peers) : 0, description);
+    });
+    CFReleaseNull(peerIDs);
+    CFStringAppend(retval, CFSTR(">"));
+
+    return retval;
+}
+
+
+//
+// MARK: Encode/Decode
+//
+
+const uint8_t* der_decode_BackupSliceKeyBag(CFAllocatorRef allocator,
+                                            SOSBackupSliceKeyBagRef* BackupSliceKeyBag, CFErrorRef *error,
+                                            const uint8_t* der, const uint8_t *der_end) {
+    if (der == NULL) return der;
+
+    const uint8_t *result = NULL;
+    SOSBackupSliceKeyBagRef vb = CFTypeAllocate(SOSBackupSliceKeyBag, struct __OpaqueSOSBackupSliceKeyBag, allocator);
+    require_quiet(SecAllocationError(vb, error, CFSTR("View 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_data(kCFAllocatorDefault, kCFPropertyListImmutable, &vb->aks_bag, error, der, sequence_end);
+    vb->peers = SOSPeerInfoSetCreateFromArrayDER(kCFAllocatorDefault, &kSOSPeerSetCallbacks, error,
+                                                 &der, der_end);
+    der = der_decode_dictionary(kCFAllocatorDefault, kCFPropertyListImmutable, &vb->wrapped_keys, error, der, sequence_end);
+
+    require_quiet(SecRequirementError(der == der_end, error, CFSTR("Extra space in sequence")), fail);
+
+    if (BackupSliceKeyBag)
+        CFTransferRetained(*BackupSliceKeyBag, vb);
+
+    result = der;
+
+fail:
+    CFReleaseNull(vb);
+    return result;
+}
+
+size_t der_sizeof_BackupSliceKeyBag(SOSBackupSliceKeyBagRef BackupSliceKeyBag, CFErrorRef *error) {
+    size_t result = 0;
+
+    require_quiet(SecRequirementError(BackupSliceKeyBag != NULL, error, CFSTR("Null BackupSliceKeyBag")), fail);
+    require_quiet(BackupSliceKeyBag != NULL, fail); // this is redundant with what happens in SecRequirementError, but the analyzer can't understand that.
+    require_quiet(SecRequirementError(BackupSliceKeyBag->aks_bag != NULL, error, CFSTR("null aks_bag in BackupSliceKeyBag")), fail);
+    require_quiet(BackupSliceKeyBag->aks_bag != NULL, fail); // this is redundant with what happens in SecRequirementError, but the analyzer can't understand that.
+
+    size_t bag_size = der_sizeof_data(BackupSliceKeyBag->aks_bag, error);
+    require_quiet(bag_size, fail);
+
+    size_t peers_size = SOSPeerInfoSetGetDEREncodedArraySize(BackupSliceKeyBag->peers, error);
+    require_quiet(peers_size, fail);
+
+    size_t wrapped_keys_size = der_sizeof_dictionary(BackupSliceKeyBag->wrapped_keys, error);
+    require_quiet(wrapped_keys_size, fail);
+
+    result = ccder_sizeof(CCDER_CONSTRUCTED_SEQUENCE, bag_size + peers_size + wrapped_keys_size);
+
+fail:
+    return result;
+}
+
+uint8_t* der_encode_BackupSliceKeyBag(SOSBackupSliceKeyBagRef set, CFErrorRef *error,
+                                      const uint8_t *der, uint8_t *der_end) {
+    uint8_t *result = NULL;
+    if (der_end == NULL) return der_end;
+
+    require_quiet(SecRequirementError(set != NULL, error, CFSTR("Null set passed to encode")), fail);
+    require_quiet(set, fail); // Silence the NULL warning.
+
+    require_quiet(SecRequirementError(set->aks_bag != NULL, error, CFSTR("Null set passed to encode")), fail);
+    require_quiet(set->aks_bag, fail); // Silence the warning.
+
+    der_end = ccder_encode_constructed_tl(CCDER_CONSTRUCTED_SEQUENCE, der_end, der,
+              der_encode_data(set->aks_bag, error, der,
+              SOSPeerInfoSetEncodeToArrayDER(set->peers, error, der,
+              der_encode_dictionary(set->wrapped_keys, error, der, der_end))));
+
+    require_quiet(der_end == der, fail);
+
+    result = der_end;
+fail:
+    return result;
+}
+
+
+
+SOSBackupSliceKeyBagRef SOSBackupSliceKeyBagCreateFromData(CFAllocatorRef allocator, CFDataRef data, CFErrorRef *error) {
+    SOSBackupSliceKeyBagRef result = NULL;
+    SOSBackupSliceKeyBagRef decodedBag = NULL;
+
+    const uint8_t *der = CFDataGetBytePtr(data);
+    const uint8_t *der_end = der + CFDataGetLength(data);
+
+    der = der_decode_BackupSliceKeyBag(allocator, &decodedBag, error, der, der_end);
+
+    require_quiet(SecRequirementError(der == der_end, error, CFSTR("Didn't consume all data supplied")), fail);
+
+    CFTransferRetained(result, decodedBag);
+
+fail:
+    CFReleaseNull(decodedBag);
+    return result;
+}
+
+//
+// MARK: Construction
+//
+
+bool SOSBSKBIsGoodBackupPublic(CFDataRef publicKey, CFErrorRef *error) {
+    bool result = false;
+
+    ccec_pub_ctx_decl_cp(SOSGetBackupKeyCurveParameters(), pub_key);
+
+    int cc_result = ccec_compact_import_pub(SOSGetBackupKeyCurveParameters(), CFDataGetLength(publicKey), CFDataGetBytePtr(publicKey), pub_key);
+
+    require_action_quiet(cc_result == 0, exit, SOSErrorCreate(kSOSErrorDecodeFailure, error, NULL, CFSTR("Unable to decode public key: %@"), publicKey));
+
+    result = true;
+exit:
+    return result;
+
+}
+
+
+static CFDataRef SOSCopyECWrapped(CFDataRef publicKey, CFDataRef secret, CFErrorRef *error) {
+    CFDataRef result = NULL;
+
+    ccec_pub_ctx_decl_cp(SOSGetBackupKeyCurveParameters(), pub_key);
+
+    int cc_result = ccec_compact_import_pub(SOSGetBackupKeyCurveParameters(), CFDataGetLength(publicKey), CFDataGetBytePtr(publicKey), pub_key);
+
+    require_action_quiet(cc_result == 0, exit, SOSErrorCreate(kSOSErrorDecodeFailure, error, NULL, CFSTR("Unable to decode public key: %@"), publicKey));
+
+    result = SOSCopyECWrappedData(pub_key, secret, error);
+
+exit:
+    return result;
+}
+
+
+static CFDictionaryRef SOSBackupSliceKeyBagCopyWrappedKeys(SOSBackupSliceKeyBagRef vb, CFDataRef secret, CFDictionaryRef additionalKeys, CFErrorRef *error) {
+    CFDictionaryRef result = NULL;
+    CFMutableDictionaryRef wrappedKeys = CFDictionaryCreateMutableForCFTypes(kCFAllocatorDefault);
+
+    __block bool success = true;
+    CFSetForEach(vb->peers, ^(const void *value) {
+        SOSPeerInfoRef pi = (SOSPeerInfoRef) value;
+        if (isSOSPeerInfo(pi)) {
+            CFStringRef id = SOSPeerInfoGetPeerID(pi);
+            CFDataRef backupKey = SOSPeerInfoCopyBackupKey(pi);
+
+            if (backupKey) {
+                CFErrorRef wrapError = NULL;
+                CFDataRef wrappedKey = SOSCopyECWrapped(backupKey, secret, &wrapError);
+                if (wrappedKey) {
+                    CFDictionaryAddValue(wrappedKeys, id, wrappedKey);
+                    CFDataPerformWithHexString(backupKey, ^(CFStringRef backupKeyString) {
+                        CFDataPerformWithHexString(wrappedKey, ^(CFStringRef wrappedKeyString) {
+                            secnotice("bskb", "Add for id: %@, bk: %@, wrapped: %@", id, backupKeyString, wrappedKeyString);
+                        });
+                    });
+                } else {
+                    CFDataPerformWithHexString(backupKey, ^(CFStringRef backupKeyString) {
+                        secnotice("bskb", "Failed at id: %@, bk: %@ error: %@", id, backupKeyString, wrapError);
+                    });
+                    CFErrorPropagate(wrapError, error);
+                    success = false;
+                }
+                CFReleaseNull(wrappedKey);
+                CFReleaseNull(backupKey);
+            } else {
+                secnotice("bskb", "Skipping id %@, no backup key.", id);
+            }
+
+        }
+    });
+
+    CFDictionaryForEach(additionalKeys, ^(const void *key, const void *value) {
+        CFStringRef prefix = asString(key, NULL);
+        CFDataRef backupKey = asData(value, NULL);
+        if (backupKey) {
+            CFDataRef wrappedKey = NULL;
+            CFErrorRef localError = NULL;
+            CFStringRef id = SOSKeyedPubKeyIdentifierCreateWithData(prefix, backupKey);
+            require_quiet(id, done);
+
+            wrappedKey = SOSCopyECWrapped(backupKey, secret, &localError);
+            require_quiet(wrappedKey, done);
+
+            CFDictionaryAddValue(wrappedKeys, id, wrappedKey);
+
+        done:
+            if (!localError) {
+                CFDataPerformWithHexString(backupKey, ^(CFStringRef backupKeyString) {
+                    CFDataPerformWithHexString(wrappedKey, ^(CFStringRef wrappedKeyString) {
+                        secnotice("bskb", "Add for bk: %@, wrapped: %@", backupKeyString, wrappedKeyString);
+                    });
+                });
+            } else {
+                CFDataPerformWithHexString(backupKey, ^(CFStringRef backupKeyString) {
+                    secnotice("bskb", "Failed at bk: %@ error: %@", backupKeyString, localError);
+                });
+                CFErrorPropagate(localError, error);
+                success = false;
+            }
+            CFReleaseNull(wrappedKey);
+            CFReleaseNull(id);
+        } else {
+            secnotice("bskb", "Skipping %@, not data.", value);
+        }
+    });
+
+    if (success)
+        CFTransferRetained(result, wrappedKeys);
+
+    CFReleaseNull(wrappedKeys);
+    return result;
+}
+
+static bool SOSBackupSliceKeyBagCreateBackupBag(SOSBackupSliceKeyBagRef vb, CFDictionaryRef/*CFDataRef*/ additionalKeys, CFErrorRef* error) {
+    CFReleaseNull(vb->aks_bag);
+
+    // Choose a random key.
+    PerformWithBufferAndClear(kAKSBagSecretLength, ^(size_t size, uint8_t *buffer) {
+        CFDataRef secret = NULL;
+
+        require_quiet(SecError(SecRandomCopyBytes(kSecRandomDefault, size, buffer), error, CFSTR("SecRandom falied!")), fail);
+
+        secret = CFDataCreateWithBytesNoCopy(kCFAllocatorDefault, buffer, size, kCFAllocatorNull);
+
+        CFAssignRetained(vb->wrapped_keys, SOSBackupSliceKeyBagCopyWrappedKeys(vb, secret, additionalKeys, error));
+        CFAssignRetained(vb->aks_bag, SecAKSCopyBackupBagWithSecret(size, buffer, error));
+
+    fail:
+        CFReleaseSafe(secret);
+    });
+
+    return vb->aks_bag != NULL;
+}
+
+
+CFDataRef SOSBSKBCopyEncoded(SOSBackupSliceKeyBagRef BackupSliceKeyBag, CFErrorRef* error) {
+    CFDataRef result = NULL;
+    CFMutableDataRef encoded = NULL;
+
+    size_t encodedSize = der_sizeof_BackupSliceKeyBag(BackupSliceKeyBag, error);
+    require_quiet(encodedSize, fail);
+
+    encoded = CFDataCreateMutableWithScratch(kCFAllocatorDefault, encodedSize);
+    require_quiet(SecAllocationError(encoded, error, CFSTR("Faild to create scratch")), fail);
+
+    uint8_t *encode_to = CFDataGetMutableBytePtr(encoded);
+    uint8_t *encode_to_end = encode_to + CFDataGetLength(encoded);
+    require_quiet(encode_to == der_encode_BackupSliceKeyBag(BackupSliceKeyBag, error, encode_to, encode_to_end), fail);
+
+    CFTransferRetained(result, encoded);
+
+fail:
+    CFReleaseSafe(encoded);
+    return result;
+}
+
+static CFSetRef SOSBackupSliceKeyBagCreatePeerSet(CFAllocatorRef allocator, CFSetRef peers) {
+    CFMutableSetRef result = CFSetCreateMutableForSOSPeerInfosByID(allocator);
+
+    CFSetForEach(peers, ^(const void *value) {
+        CFSetAddValue(result, value);
+    });
+
+    return result;
+}
+
+SOSBackupSliceKeyBagRef SOSBackupSliceKeyBagCreate(CFAllocatorRef allocator, CFSetRef peers, CFErrorRef* error) {
+    CFMutableDictionaryRef additionalKeys = CFDictionaryCreateMutableForCFTypes(kCFAllocatorDefault);
+
+    SOSBackupSliceKeyBagRef result = SOSBackupSliceKeyBagCreateWithAdditionalKeys(allocator, peers, additionalKeys, NULL);
+
+    CFReleaseNull(additionalKeys);
+
+    return result;
+}
+
+SOSBackupSliceKeyBagRef SOSBackupSliceKeyBagCreateWithAdditionalKeys(CFAllocatorRef allocator,
+                                                                     CFSetRef /*SOSPeerInfoRef*/ peers,
+                                                                     CFDictionaryRef /*CFStringRef (prefix) CFDataRef (keydata) */ additionalKeys,
+                                                                     CFErrorRef* error) {
+    SOSBackupSliceKeyBagRef result = NULL;
+    SOSBackupSliceKeyBagRef vb = CFTypeAllocate(SOSBackupSliceKeyBag, struct __OpaqueSOSBackupSliceKeyBag, allocator);
+    require_quiet(SecAllocationError(vb, error, CFSTR("View bag allocation failed")), fail);
+
+    require_quiet(SecRequirementError(CFSetGetCount(peers) > 0, error, CFSTR("Need peers")), fail);
+
+    vb->peers = SOSBackupSliceKeyBagCreatePeerSet(allocator, peers);
+    vb->wrapped_keys = CFDictionaryCreateMutableForCFTypes(allocator);
+
+    require_quiet(SOSBackupSliceKeyBagCreateBackupBag(vb, additionalKeys, error), fail);
+
+    CFTransferRetained(result, vb);
+
+fail:
+    CFReleaseNull(vb);
+    return result;
+}
+
+
+SOSBackupSliceKeyBagRef SOSBackupSliceKeyBagCreateDirect(CFAllocatorRef allocator, CFDataRef aks_bag, CFErrorRef *error)
+{
+    SOSBackupSliceKeyBagRef result = NULL;
+    SOSBackupSliceKeyBagRef vb = CFTypeAllocate(SOSBackupSliceKeyBag, struct __OpaqueSOSBackupSliceKeyBag, allocator);
+    require_quiet(SecAllocationError(vb, error, CFSTR("View bag allocation failed")), fail);
+
+    require_quiet(SecRequirementError(aks_bag, error, CFSTR("Need aks bag")), fail);
+
+    vb->aks_bag = CFRetainSafe(aks_bag);
+    vb->peers = CFSetCreateMutableForSOSPeerInfosByID(allocator);
+    vb->wrapped_keys = CFDictionaryCreateMutableForCFTypes(allocator);
+
+    CFTransferRetained(result, vb);
+
+fail:
+    CFReleaseNull(vb);
+    return result;
+}
+
+//
+// MARK: Use
+//
+
+bool SOSBSKBIsDirect(SOSBackupSliceKeyBagRef backupSliceKeyBag)
+{
+    return 0 == CFSetGetCount(backupSliceKeyBag->peers);
+}
+
+CFDataRef SOSBSKBCopyAKSBag(SOSBackupSliceKeyBagRef backupSliceKeyBag, CFErrorRef* error)
+{
+    return CFRetainSafe(backupSliceKeyBag->aks_bag);
+}
+
+CFSetRef SOSBSKBGetPeers(SOSBackupSliceKeyBagRef backupSliceKeyBag){
+    return backupSliceKeyBag->peers;
+}
+
+int SOSBSKBCountPeers(SOSBackupSliceKeyBagRef backupSliceKeyBag) {
+    return (backupSliceKeyBag->peers) ? (int) CFSetGetCount(backupSliceKeyBag->peers): 0;
+}
+
+bool SOSBSKBPeerIsInKeyBag(SOSBackupSliceKeyBagRef backupSliceKeyBag, SOSPeerInfoRef pi) {
+    return CFSetGetValue(backupSliceKeyBag->peers, pi) != NULL;
+}
+
+
+
+bool SOSBKSBKeyIsInKeyBag(SOSBackupSliceKeyBagRef backupSliceKeyBag, CFDataRef publicKey) {
+    bool result = false;
+    CFStringRef keyID = SOSCopyIDOfDataBuffer(publicKey, NULL);
+    require_quiet(keyID, done);
+
+    result = CFDictionaryContainsKey(backupSliceKeyBag->wrapped_keys, keyID);
+
+done:
+    CFReleaseSafe(keyID);
+    return result;
+}
+
+bool SOSBKSBPeerBackupKeyIsInKeyBag(SOSBackupSliceKeyBagRef backupSliceKeyBag, SOSPeerInfoRef pi) {
+    bool result = false;
+    CFDataRef bskbBackupKey = NULL;
+
+    CFDataRef backupKey = SOSPeerInfoCopyBackupKey(pi);
+    SOSPeerInfoRef backupPI = asSOSPeerInfo(CFSetGetValue(backupSliceKeyBag->peers, pi));
+    if(backupPI) {
+        bskbBackupKey = SOSPeerInfoCopyBackupKey(backupPI);
+    }
+    result = CFEqualSafe(backupKey, bskbBackupKey);
+    CFReleaseNull(bskbBackupKey);
+    CFReleaseNull(backupKey);
+    return result;
+}
+
+// returns true if all peers in (peers) and only those peers have matching backupKeys in the BSKB
+bool SOSBSKBAllPeersBackupKeysAreInKeyBag(SOSBackupSliceKeyBagRef backupSliceKeyBag, CFSetRef peers) {
+    __block bool result = false;
+    if(backupSliceKeyBag && peers) {
+        result = (SOSBSKBCountPeers(backupSliceKeyBag) == CFSetGetCount(peers));
+        if(result) {
+            CFSetForEach(peers, ^(const void *value) {
+                SOSPeerInfoRef pi = asSOSPeerInfo(value);
+                result &= pi && SOSBKSBPeerBackupKeyIsInKeyBag(backupSliceKeyBag, pi);
+            });
+        }
+    }
+    return result;
+}
+
+bool SOSBKSBPrefixedKeyIsInKeyBag(SOSBackupSliceKeyBagRef backupSliceKeyBag, CFStringRef prefix, CFDataRef publicKey) {
+    bool result = false;
+    CFStringRef kpkid = SOSKeyedPubKeyIdentifierCreateWithData(prefix, publicKey);
+    require_quiet(kpkid, done);
+    
+    result = CFDictionaryContainsKey(backupSliceKeyBag->wrapped_keys, kpkid);
+    
+done:
+    CFReleaseSafe(kpkid);
+    return result;
+
+}
+
+
+
+bskb_keybag_handle_t SOSBSKBLoadLocked(SOSBackupSliceKeyBagRef backupSliceKeyBag,
+                                       CFErrorRef *error)
+{
+#if !TARGET_HAS_KEYSTORE
+    return bad_keybag_handle;
+#else
+    keybag_handle_t result = bad_keybag_handle;
+    keybag_handle_t bag_handle = bad_keybag_handle;
+
+    require_quiet(SecRequirementError(backupSliceKeyBag->aks_bag, error,
+                                      CFSTR("No aks bag to load")), exit);
+    require_quiet(SecRequirementError(CFDataGetLength(backupSliceKeyBag->aks_bag) < INT_MAX, error,
+                                      CFSTR("No aks bag to load")), exit);
+
+    kern_return_t aks_result;
+    aks_result = aks_load_bag(CFDataGetBytePtr(backupSliceKeyBag->aks_bag),
+                              (int) CFDataGetLength(backupSliceKeyBag->aks_bag),
+                              &bag_handle);
+    require_quiet(SecKernError(aks_result, error,
+                               CFSTR("aks_load_bag failed: %d"), aks_result), exit);
+
+    result = bag_handle;
+    bag_handle = bad_keybag_handle;
+
+exit:
+    if (bag_handle != bad_keybag_handle) {
+        (void) aks_unload_bag(bag_handle);
+    }
+
+    return result;
+#endif
+
+}
+
+static keybag_handle_t SOSBSKBLoadAndUnlockBagWithSecret(SOSBackupSliceKeyBagRef backupSliceKeyBag,
+                                                           size_t secretSize, const uint8_t *secret,
+                                                           CFErrorRef *error)
+{
+#if !TARGET_HAS_KEYSTORE
+    return bad_keybag_handle;
+#else
+    keybag_handle_t result = bad_keybag_handle;
+    keybag_handle_t bag_handle = bad_keybag_handle;
+
+    require_quiet(SecRequirementError(backupSliceKeyBag->aks_bag, error,
+                                      CFSTR("No aks bag to load")), exit);
+    require_quiet(SecRequirementError(CFDataGetLength(backupSliceKeyBag->aks_bag) < INT_MAX, error,
+                                      CFSTR("No aks bag to load")), exit);
+    require_quiet(SecRequirementError(secretSize <= INT_MAX, error,
+                                      CFSTR("secret too big")), exit);
+
+    kern_return_t aks_result;
+    aks_result = aks_load_bag(CFDataGetBytePtr(backupSliceKeyBag->aks_bag),
+                              (int) CFDataGetLength(backupSliceKeyBag->aks_bag),
+                              &bag_handle);
+    require_quiet(SecKernError(aks_result, error,
+                               CFSTR("aks_load_bag failed: %d"), aks_result), exit);
+
+    aks_result = aks_unlock_bag(bag_handle, secret, (int) secretSize);
+    require_quiet(SecKernError(aks_result, error,
+                               CFSTR("failed to unlock bag: %d"), aks_result), exit);
+
+    result = bag_handle;
+    bag_handle = bad_keybag_handle;
+
+exit:
+    if (bag_handle != bad_keybag_handle) {
+        (void) aks_unload_bag(bag_handle);
+    }
+
+    return result;
+#endif
+}
+
+keybag_handle_t SOSBSKBLoadAndUnlockWithPeerIDAndSecret(SOSBackupSliceKeyBagRef backupSliceKeyBag,
+                                                        CFStringRef peerID, CFDataRef peerSecret,
+                                                        CFErrorRef *error)
+{
+    __block keybag_handle_t result = bad_keybag_handle;
+
+    CFDataRef lookedUpData = CFDictionaryGetValue(backupSliceKeyBag->wrapped_keys, peerID);
+    require_quiet(SecRequirementError(lookedUpData != NULL, error, CFSTR("%@ has no wrapped key in %@"), peerID, backupSliceKeyBag), exit);
+
+    require_quiet(SOSPerformWithDeviceBackupFullKey(SOSGetBackupKeyCurveParameters(), peerSecret, error, ^(ccec_full_ctx_t fullKey) {
+        SOSPerformWithUnwrappedData(fullKey, lookedUpData, error, ^(size_t size, uint8_t *buffer) {
+            result = SOSBSKBLoadAndUnlockBagWithSecret(backupSliceKeyBag, size, buffer, error);
+        });
+    }), exit);
+
+exit:
+    return result;
+}
+
+
+keybag_handle_t SOSBSKBLoadAndUnlockWithPeerSecret(SOSBackupSliceKeyBagRef backupSliceKeyBag,
+                                                   SOSPeerInfoRef peer, CFDataRef peerSecret,
+                                                   CFErrorRef *error)
+{
+    return SOSBSKBLoadAndUnlockWithPeerIDAndSecret(backupSliceKeyBag, SOSPeerInfoGetPeerID(peer), peerSecret, error);
+}
+
+keybag_handle_t SOSBSKBLoadAndUnlockWithDirectSecret(SOSBackupSliceKeyBagRef backupSliceKeyBag,
+                                                     CFDataRef secret,
+                                                     CFErrorRef *error)
+{
+    keybag_handle_t result = bad_keybag_handle;
+    require_quiet(SecRequirementError(SOSBSKBIsDirect(backupSliceKeyBag), error, CFSTR("Not direct bag")), exit);
+
+    result = SOSBSKBLoadAndUnlockBagWithSecret(backupSliceKeyBag,
+                                               CFDataGetLength(secret),
+                                               CFDataGetBytePtr(secret),
+                                               error);
+
+exit:
+    return result;
+}
+
+#include <Security/SecRecoveryKey.h>
+
+static bool SOSPerformWithRecoveryKeyFullKey(CFDataRef wrappingSecret, CFErrorRef *error, void (^operation)(ccec_full_ctx_t fullKey, CFStringRef keyID)) {
+    bool     result = false;
+
+    CFStringRef keyID = NULL;
+    NSError *nserror = NULL;
+    SecRecoveryKey *sRecKey = NULL;
+    NSData* fullKeyBytes = NULL;
+    NSData* pubKeyBytes = NULL;
+    CFStringRef restoreKeySecret = CFStringCreateWithBytes(SecCFAllocatorZeroize(), CFDataGetBytePtr(wrappingSecret), CFDataGetLength(wrappingSecret), kCFStringEncodingUTF8, false);
+    require_action_quiet(restoreKeySecret, errOut, SOSErrorCreate(kSOSErrorDecodeFailure, error, NULL, CFSTR("Unable to create key string from data.")));
+
+    sRecKey = SecRKCreateRecoveryKeyWithError((__bridge NSString *)(restoreKeySecret), &nserror);
+    if(!sRecKey) {
+        if (error)
+            *error = (CFErrorRef)CFBridgingRetain(nserror);
+        goto errOut;
+    }
+
+    require_action_quiet(sRecKey, errOut, SOSErrorCreate(kSOSErrorDecodeFailure, error, NULL, CFSTR("Unable to create recovery key from string.")));
+    
+    fullKeyBytes = SecRKCopyBackupFullKey(sRecKey);
+    pubKeyBytes = SecRKCopyBackupPublicKey(sRecKey);
+    require_action_quiet(fullKeyBytes && pubKeyBytes, errOut, SOSErrorCreate(kSOSErrorDecodeFailure, error, NULL, CFSTR("Unable to get recovery key public and private keys.")));
+    keyID = SOSCopyIDOfDataBuffer(((__bridge CFDataRef) pubKeyBytes), error);
+    require_quiet(keyID, errOut);
+    {
+        size_t keysize = ccec_compact_import_priv_size(CFDataGetLength((__bridge CFDataRef)fullKeyBytes));
+        ccec_const_cp_t cp = ccec_curve_for_length_lookup(keysize, ccec_cp_256(), ccec_cp_384(), ccec_cp_521());
+        ccec_full_ctx_decl_cp(cp, fullKey);
+        int res = ccec_compact_import_priv(cp, CFDataGetLength((__bridge CFDataRef)fullKeyBytes), CFDataGetBytePtr((__bridge CFDataRef)fullKeyBytes), fullKey);
+        if(res == 0) {
+            operation(fullKey, keyID);
+            result = true;
+            ccec_full_ctx_clear_cp(cp, fullKey);
+        }
+    }
+    if(!result) SOSErrorCreate(kSOSErrorProcessingFailure, error, NULL, CFSTR("Unable to perform crypto operation from fullKeyBytes."));
+
+errOut:
+    CFReleaseNull(keyID);
+    CFReleaseNull(restoreKeySecret);
+    return result;
+}
+
+bskb_keybag_handle_t SOSBSKBLoadAndUnlockWithWrappingSecret(SOSBackupSliceKeyBagRef backupSliceKeyBag,
+                                                            CFDataRef wrappingSecret,
+                                                            CFErrorRef *error) {
+    __block keybag_handle_t result = bad_keybag_handle;
+
+    CFDataRef lookedUpData = SOSBSKBCopyRecoveryKey(backupSliceKeyBag);
+    require_quiet(SecRequirementError(lookedUpData != NULL, error, CFSTR("no recovery key found in %@"), backupSliceKeyBag), errOut);
+
+    SOSPerformWithRecoveryKeyFullKey(wrappingSecret, error, ^(ccec_full_ctx_t fullKey, CFStringRef keyID) {
+        SOSPerformWithUnwrappedData(fullKey, lookedUpData, error, ^(size_t size, uint8_t *buffer) {
+            result = SOSBSKBLoadAndUnlockBagWithSecret(backupSliceKeyBag, size, buffer, error);
+        });
+    });
+
+errOut:
+    CFReleaseSafe(lookedUpData);
+    return result;
+}
+
+// fixed for <rdar://problem/30918831> CrashTracer: secdtests at secdtests: SOSBSKBCopyAdditionalKeysWithPrefix
+static CFDictionaryRef SOSBSKBCopyAdditionalKeysWithPrefix(CFAllocatorRef allocator, SOSBackupSliceKeyBagRef bskb, CFStringRef prefix) {
+    if(!bskb || !bskb->wrapped_keys) return NULL;
+    CFMutableDictionaryRef retval = CFDictionaryCreateMutableForCFTypes(allocator);
+    if(!retval) return NULL;
+    CFDictionaryForEach(bskb->wrapped_keys, ^(const void *key, const void *value) {
+        CFStringRef kpkid = asString(key, NULL);
+        CFDataRef keyData = asData(value, NULL);
+        if(kpkid && keyData && SOSKeyedPubKeyIdentifierIsPrefixed(kpkid)) {
+            CFStringRef idPrefix = SOSKeyedPubKeyIdentifierCopyPrefix(kpkid);
+            if(CFEqualSafe(idPrefix, prefix)) {
+                CFDictionaryAddValue(retval, kpkid, keyData);
+            }
+            CFReleaseNull(idPrefix);
+        }
+    });
+    return retval;
+}
+
+static bool SOSBSKBHasPrefixedKey(SOSBackupSliceKeyBagRef bskb, CFStringRef prefix) {
+    CFDictionaryRef keyDict = SOSBSKBCopyAdditionalKeysWithPrefix(kCFAllocatorDefault, bskb, prefix);
+    bool haveKeys = keyDict && CFDictionaryGetCount(keyDict) > 0;
+    CFReleaseNull(keyDict);
+    return haveKeys;
+}
+
+CFDataRef SOSBSKBCopyRecoveryKey(SOSBackupSliceKeyBagRef bskb) {
+    if(!bskb) return NULL;
+    CFDictionaryRef keyDict = SOSBSKBCopyAdditionalKeysWithPrefix(kCFAllocatorDefault, bskb, bskbRkbgPrefix);
+    if(!keyDict) return NULL;
+    CFDataRef result = NULL;
+    if(CFDictionaryGetCount(keyDict) == 1) {
+        __block CFDataRef keyData = NULL;
+        CFDictionaryForEach(keyDict, ^(const void *key, const void *value) {
+            keyData = asData(value, NULL);
+        });
+        result = CFDataCreateCopy(kCFAllocatorDefault, keyData);
+    }
+    CFReleaseNull(keyDict);
+    return result;
+}
+
+bool SOSBSKBHasRecoveryKey(SOSBackupSliceKeyBagRef bskb) {
+    if(!bskb) return false;
+    if(SOSBSKBHasPrefixedKey(bskb, bskbRkbgPrefix)) {
+        return true;
+    }
+    // old way for RecoveryKeys
+    int keyCount = (bskb->wrapped_keys != NULL) ? (int) CFDictionaryGetCount(bskb->wrapped_keys): 0;
+    int peerCount = SOSBSKBCountPeers(bskb);
+    return !SOSBSKBIsDirect(bskb) && ((keyCount - peerCount) > 0);
+}
+
+bool SOSBSKBHasThisRecoveryKey(SOSBackupSliceKeyBagRef bskb, CFDataRef backupKey) {
+    if(backupKey) {
+        CFStringRef id = SOSKeyedPubKeyIdentifierCreateWithData(bskbRkbgPrefix, backupKey);
+        bool result = (bskb && id && CFDictionaryContainsKey(bskb->wrapped_keys, id));
+        CFReleaseNull(id);
+        return result;
+    } else {
+        return CFDictionaryGetCount(bskb->wrapped_keys) == SOSBSKBCountPeers(bskb);
+    }
+}