1  /*
  2   * Copyright (c) 2011-2014 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  
 25  #ifndef _SECOTRSESSION_H_
 26  #define _SECOTRSESSION_H_
 27  
 28  #include <CoreFoundation/CFBase.h>
 29  #include <CoreFoundation/CFData.h>
 30  
 31  #include <Security/SecOTR.h>
 32  
 33  __BEGIN_DECLS
 34  
 35  // MARK: MessageTypes
 36  
 37  enum SecOTRSMessageKind {
 38      kOTRNegotiationPacket,
 39      kOTRDataPacket,
 40      kOTRUnknownPacket
 41  };
 42  
 43  // MARK: OTR Session
 44  
 45  enum SecOTRCreateFlags {
 46      kSecOTRSendTextMessages = 1 << 0, // OTR messages will be encoded as Base-64 with header/footer per the standard, not just given back in binary
 47      kSecOTRUseAppleCustomMessageFormat = 1 << 1, // OTR Messages will be encoded without revealing MAC keys and as compact as we can (P-256)
 48      kSecOTRIncludeHashesInMessages = 1 << 2,
 49      kSecOTRSlowRoll = 1 << 3,
 50  };
 51  
 52  /*!
 53   @typedef
 54   @abstract   OTRSessions encapsulate a commuincaiton between to parties using the
 55               otr protocol.
 56   @discussion Sessions start with IDs. One end sends a start packet (created with AppendStartPacket).
 57               Both sides process packets they exchange on the negotiation channel.
 58   */
 59  typedef struct _SecOTRSession* SecOTRSessionRef;
 60  
 61  SecOTRSessionRef SecOTRSessionCreateFromID(CFAllocatorRef allocator,
 62                                             SecOTRFullIdentityRef myID,
 63                                             SecOTRPublicIdentityRef theirID);
 64  
 65  SecOTRSessionRef SecOTRSessionCreateFromIDAndFlags(CFAllocatorRef allocator,
 66                                             SecOTRFullIdentityRef myID,
 67                                             SecOTRPublicIdentityRef theirID,
 68                                             uint32_t flags);
 69  
 70  SecOTRSessionRef SecOTRSessionCreateFromData(CFAllocatorRef allocator, CFDataRef data);
 71  
 72      void SecOTRSessionReset(SecOTRSessionRef session);
 73  OSStatus SecOTRSAppendSerialization(SecOTRSessionRef publicID, CFMutableDataRef serializeInto);
 74  
 75  OSStatus SecOTRSAppendStartPacket(SecOTRSessionRef session, CFMutableDataRef appendInitiatePacket);
 76  
 77  OSStatus SecOTRSAppendRestartPacket(SecOTRSessionRef session, CFMutableDataRef appendPacket);
 78  
 79  OSStatus SecOTRSProcessPacket(SecOTRSessionRef session,
 80                                CFDataRef incomingPacket,
 81                                CFMutableDataRef negotiationResponse);
 82      
 83  bool SecOTRSIsForKeys(SecOTRSessionRef session, SecKeyRef myPublic, SecKeyRef theirPublic);
 84  bool SecOTRSGetIsReadyForMessages(SecOTRSessionRef session);
 85  bool SecOTRSGetIsIdle(SecOTRSessionRef session);
 86  
 87  enum SecOTRSMessageKind SecOTRSGetMessageKind(SecOTRSessionRef session, CFDataRef incomingPacket);
 88  
 89  /*!
 90   @function
 91   @abstract   Precalculates keys for current key sets to save time when sending or receiving.
 92   @param      session                OTRSession receiving message
 93   */
 94  void SecOTRSPrecalculateKeys(SecOTRSessionRef session);
 95      
 96  /*!
 97   @function
 98   @abstract   Encrypts and Signs a message with OTR credentials.
 99   @param      session                OTRSession receiving message
100   @param      sourceMessage          Cleartext message to protect
101   @param      protectedMessage       Data to append the encoded protected message to
102   @result     OSStatus               errSecAuthFailed -> bad signature, no data appended.
103   */
104  
105  OSStatus SecOTRSSignAndProtectMessage(SecOTRSessionRef session,
106                                        CFDataRef sourceMessage,
107                                        CFMutableDataRef protectedMessage);
108  
109  /*!
110   @function
111   @abstract   Verifies and exposes a message sent via OTR
112   @param      session                OTRSession receiving message
113   @param      incomingMessage        Encoded message
114   @param      exposedMessageContents Data to append the exposed message to
115   @result     OSStatus               errSecAuthFailed -> bad signature, no data appended.
116   */
117  
118  OSStatus SecOTRSVerifyAndExposeMessage(SecOTRSessionRef session,
119                                         CFDataRef incomingMessage,
120                                         CFMutableDataRef exposedMessageContents);
121  
122  
123  
124  const char *SecOTRPacketTypeString(CFDataRef message);
125  
126  CFDataRef SecOTRSessionCreateRemote(CFDataRef publicPeerId, CFErrorRef *error);
127  bool SecOTRSessionProcessPacketRemote(CFDataRef sessionData, CFDataRef inputPacket, CFDataRef* outputSessionData, CFDataRef* outputPacket, bool *readyForMessages, CFErrorRef *error);
128  
129  bool SecOTRSessionIsSessionInAwaitingState(SecOTRSessionRef session);
130  
131  __END_DECLS
132  
133  #endif