sec/Security/SecOTRMath.h

   1 //
   2 //  OTRMath.h
   3 //  libsecurity_libSecOTR
   4 //
   5 //  Created by Mitch Adler on 1/28/11.
   6 //  Copyright 2011 Apple Inc. All rights reserved.
   7 //
   8
   9 #ifndef _SECOTRMATH_H_
  10 #define _SECOTRMATH_H_
  11
  12 #include <CoreFoundation/CFBase.h>
  13
  14 #include <corecrypto/ccn.h>
  15 #include <corecrypto/ccaes.h>
  16 #include <corecrypto/ccmode.h>
  17
  18 #define kOTRAuthKeyBytes 16
  19 #define kOTRAuthMACKeyBytes 32
  20
  21 #define kOTRMessageKeyBytes 16
  22 #define kOTRMessageMacKeyBytes 20
  23
  24 #define kExponentiationBits 1536
  25 #define kExponentiationUnits ccn_nof(kExponentiationBits)
  26 #define kExponentiationBytes ((kExponentiationBits+7)/8)
  27
  28 #define kSHA256HMAC160Bits  160
  29 #define kSHA256HMAC160Bytes (kSHA256HMAC160Bits/8)
  30
  31 // Result and exponent are expected to be kExponentiationUnits big.
  32 void OTRExponentiate(cc_unit* res, const cc_unit* base, const cc_unit* exponent);
  33 void OTRGroupExponentiate(cc_unit* result, const cc_unit* exponent);
  34
  35 OSStatus GetRandomBytesInLSBs(size_t bytesOfRandomness, size_t n, cc_unit* place);
  36 OSStatus FillWithRandomBytes(size_t n, cc_unit* place);
  37
  38 typedef enum {
  39     kSSID = 0x00,
  40     kCs = 0x01,
  41     kM1 = 0x02,
  42     kM2 = 0x03,
  43     kM1Prime = 0x04,
  44     kM2Prime = 0x05
  45 } KeyType;
  46
  47
  48 void DeriveOTR256BitsFromS(KeyType whichKey, size_t sSize, const cc_unit* s, size_t keySize, uint8_t* key);
  49 void DeriveOTR128BitPairFromS(KeyType whichHalf, size_t sSize, const cc_unit* s,
  50                               size_t firstKeySize, uint8_t* firstKey,
  51                               size_t secondKeySize, uint8_t* secondKey);
  52 void DeriveOTR64BitsFromS(KeyType whichKey, size_t sSize, const cc_unit* s,
  53                           size_t firstKeySize, uint8_t* firstKey);
  54
  55
  56 void AES_CTR_HighHalf_Transform(size_t keySize, const uint8_t* key,
  57                                 uint64_t highHalf,
  58                                 size_t howMuch, const uint8_t* from,
  59                                 uint8_t* to);
  60
  61 void AES_CTR_IV0_Transform(size_t keySize, const uint8_t* key,
  62                            size_t howMuch, const uint8_t* from,
  63                            uint8_t* to);
  64
  65 #endif