keychain/ot/OTBottledPeer.m

   1 /*
   2  * Copyright (c) 2017 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #import "OTBottledPeer.h"
  25
  26 #if OCTAGON
  27 #import <SecurityFoundation/SFEncryptionOperation.h>
  28 #import <SecurityFoundation/SFSigningOperation.h>
  29 #import <SecurityFoundation/SFDigestOperation.h>
  30 #import <SecurityFoundation/SFKey.h>
  31 #import <SecurityFoundation/SFKey_Private.h>
  32
  33 #import <Security/SecKeyPriv.h>
  34
  35 #import <corecrypto/cchkdf.h>
  36 #import <corecrypto/ccsha2.h>
  37 #import <corecrypto/ccec.h>
  38
  39 #import <utilities/debugging.h>
  40
  41 #import <CommonCrypto/CommonRandomSPI.h>
  42
  43 #if 0
  44 #import "OTBottle.h"
  45 #import "OTBottleContents.h"
  46 #endif
  47
  48 #import "OTDefines.h"
  49 #import "OTPrivateKey.h"
  50 #import "OTPrivateKey+SF.h"
  51 #import "OTAuthenticatedCiphertext.h"
  52 #import "OTAuthenticatedCiphertext+SF.h"
  53
  54 @interface OTBottledPeer ()
  55
  56 @property (nonatomic, strong) NSString* peerID;
  57 @property (nonatomic, strong) NSString* spID;
  58 @property (nonatomic, strong) SFECKeyPair* peerSigningKey;
  59 @property (nonatomic, strong) SFECKeyPair* peerEncryptionKey;
  60 @property (nonatomic, strong) NSData* data;
  61
  62 @end
  63
  64 @implementation OTBottledPeer
  65
  66 + (SFAuthenticatedEncryptionOperation *) encryptionOperation
  67 {
  68     SFAESKeySpecifier *keySpecifier = [[SFAESKeySpecifier alloc] initWithBitSize:SFAESKeyBitSize256];
  69     return [[SFAuthenticatedEncryptionOperation alloc] initWithKeySpecifier:keySpecifier];
  70 }
  71
  72 // Given a peer's details including private key material, and
  73 // the keys generated from the escrow secret, encrypt the peer private keys,
  74 // make a bottled peer object and serialize it into data.
  75 - (nullable instancetype) initWithPeerID:(NSString * _Nullable)peerID
  76                                     spID:(NSString * _Nullable)spID
  77                           peerSigningKey:(SFECKeyPair *)peerSigningKey
  78                        peerEncryptionKey:(SFECKeyPair *)peerEncryptionKey
  79                               escrowKeys:(OTEscrowKeys *)escrowKeys
  80                                    error:(NSError**)error
  81 {
  82     self = [super init];
  83     if (self) {
  84 #if 0
  85         // Serialize the peer private keys into "contents"
  86         OTBottleContents *contentsObj = [[OTBottleContents alloc] init];
  87         contentsObj.peerSigningPrivKey = [OTPrivateKey fromECKeyPair:peerSigningKey];
  88         contentsObj.peerEncryptionPrivKey = [OTPrivateKey fromECKeyPair:peerEncryptionKey];
  89         NSData *clearContentsData = contentsObj.data;
  90
  91         // Encrypt the contents
  92         SFAuthenticatedEncryptionOperation *op = [OTBottledPeer encryptionOperation];
  93         SFAuthenticatedCiphertext* cipher = [op encrypt:clearContentsData withKey:escrowKeys.symmetricKey error:error];
  94         if (!cipher) {
  95             return nil;
  96         }
  97
  98         // Serialize the whole thing
  99         OTBottle *obj = [[OTBottle alloc] init];
 100         obj.peerID = peerID;
 101         obj.spID = spID;
 102         obj.escrowedSigningSPKI    = [escrowKeys.signingKey.publicKey encodeSubjectPublicKeyInfo];
 103         obj.escrowedEncryptionSPKI = [escrowKeys.encryptionKey.publicKey encodeSubjectPublicKeyInfo];
 104         obj.peerSigningSPKI        = [peerSigningKey.publicKey encodeSubjectPublicKeyInfo];
 105         obj.peerEncryptionSPKI     = [peerEncryptionKey.publicKey encodeSubjectPublicKeyInfo];
 106         obj.contents = [OTAuthenticatedCiphertext fromSFAuthenticatedCiphertext:cipher];
 107
 108         _peerID = [peerID copy];
 109         _spID = [spID copy];
 110         _peerSigningKey = peerSigningKey;
 111         _peerEncryptionKey = peerEncryptionKey;
 112         _data = obj.data;
 113 #endif
 114     }
 115     return self;
 116 }
 117
 118 // Deserialize a bottle and decrypt the contents (peer keys)
 119 // using the keys generated from the escrow secret.
 120 - (nullable instancetype) initWithData:(NSData *)data
 121                             escrowKeys:(OTEscrowKeys *)escrowKeys
 122                                  error:(NSError**)error
 123 {
 124     self = [super init];
 125     if (self) {
 126 #if 0
 127         NSError* localError =nil;
 128         // Deserialize the whole thing
 129         OTBottle *obj = [[OTBottle alloc] initWithData:data];
 130         if (!obj) {
 131             secerror("octagon: failed to deserialize data into OTBottle");
 132             if(error){
 133                 *error = [NSError errorWithDomain:OctagonErrorDomain code:OTErrorDeserializationFailure userInfo:@{NSLocalizedDescriptionKey: @"Failed to deserialize bottle peer"}];
 134             }
 135             return nil;
 136
 137
 138         // Decrypt contents
 139         SFAuthenticatedEncryptionOperation *op = [OTBottledPeer encryptionOperation];
 140         SFAuthenticatedCiphertext* ciphertext = [obj.contents asSFAuthenticatedCiphertext];
 141         NSData* clearContentsData = [op decrypt:ciphertext withKey:escrowKeys.symmetricKey error:&localError];
 142         if (!clearContentsData || clearContentsData.length == 0) {
 143             secerror("octagon: could not decrypt bottle contents: %@", localError);
 144             if(error){
 145                 *error = localError;
 146             }
 147             return nil;
 148         }
 149
 150         // Deserialize contents into private peer keys
 151         OTBottleContents *contentsObj = [[OTBottleContents alloc] initWithData:clearContentsData];
 152         if (!contentsObj) {
 153             secerror("octagon: could not deserialize bottle contents");
 154             if(error){
 155                 *error = [NSError errorWithDomain:OctagonErrorDomain code:OTErrorDeserializationFailure userInfo:@{NSLocalizedDescriptionKey: @"Failed to deserialize bottle contents"}];
 156             }
 157             return nil;
 158         }
 159
 160         _peerID = obj.peerID;
 161         _spID = obj.spID;
 162         if (self.keyType != OTPrivateKey_KeyType_EC_NIST_CURVES) {
 163             return nil;
 164         }
 165         return [[SFECKeyPair alloc] initWithSecKey:[EscrowKeys createSecKey:self.keyData]];
 166
 167         _peerSigningKey    = [contentsObj.peerSigningPrivKey asECKeyPair];
 168         _peerEncryptionKey = [contentsObj.peerEncryptionPrivKey asECKeyPair];
 169         if (!_peerSigningKey || !_peerEncryptionKey) {
 170             secerror("octagon: could not get private EC keys from bottle contents");
 171             if(error){
 172                 *error = [NSError errorWithDomain:OctagonErrorDomain code:OTErrorPrivateKeyFailure userInfo:@{NSLocalizedDescriptionKey: @"Failed to instantiate octagon peer keys"}];
 173             }
 174             return nil;
 175         }
 176         _data = [data copy];
 177
 178         SFECPublicKey *peerSigningPubKey = [SFECPublicKey keyWithSubjectPublicKeyInfo:obj.peerSigningSPKI];
 179         SFECPublicKey *peerEncryptionPubKey = [SFECPublicKey keyWithSubjectPublicKeyInfo:obj.peerEncryptionSPKI];
 180
 181         // Check the private keys match the public keys
 182         if (![_peerSigningKey.publicKey isEqual:peerSigningPubKey]) {
 183             secerror("octagon: public and private peer signing keys do not match");
 184             if(error){
 185                 *error = [NSError errorWithDomain:OctagonErrorDomain code:OTErrorPrivateKeyFailure userInfo:@{NSLocalizedDescriptionKey: @"public and private peer signing keys do not match"}];
 186             }
 187             return nil;
 188         }
 189         if (![_peerEncryptionKey.publicKey isEqual:peerEncryptionPubKey]) {
 190             secerror("octagon: public and private peer encryption keys do not match");
 191             if(error){
 192                 *error = [NSError errorWithDomain:OctagonErrorDomain code:OTErrorPrivateKeyFailure userInfo:@{NSLocalizedDescriptionKey: @"public and private peer encryption keys do not match"}];
 193             }
 194             return nil;
 195         }
 196 #endif
 197     }
 198     return self;
 199 }
 200
 201 @end
 202
 203 #endif
 204
 205