00001
00002
00003 #include "pch.h"
00004 #include "serpent.h"
00005 #include "misc.h"
00006
00007 #include "serpentp.h"
00008
00009 NAMESPACE_BEGIN(CryptoPP)
00010
00011 void Serpent_KeySchedule(word32 *k, unsigned int rounds, const byte *userKey, size_t keylen)
00012 {
00013 FixedSizeSecBlock<word32, 8> k0;
00014 GetUserKey(LITTLE_ENDIAN_ORDER, k0.begin(), 8, userKey, keylen);
00015 if (keylen < 32)
00016 k0[keylen/4] |= word32(1) << ((keylen%4)*8);
00017
00018 word32 t = k0[7];
00019 unsigned int i;
00020 for (i = 0; i < 8; ++i)
00021 k[i] = k0[i] = t = rotlFixed(k0[i] ^ k0[(i+3)%8] ^ k0[(i+5)%8] ^ t ^ 0x9e3779b9 ^ i, 11);
00022 for (i = 8; i < 4*(rounds+1); ++i)
00023 k[i] = t = rotlFixed(k[i-8] ^ k[i-5] ^ k[i-3] ^ t ^ 0x9e3779b9 ^ i, 11);
00024 k -= 20;
00025
00026 word32 a,b,c,d,e;
00027 for (i=0; i<rounds/8; i++)
00028 {
00029 afterS2(LK); afterS2(S3); afterS3(SK);
00030 afterS1(LK); afterS1(S2); afterS2(SK);
00031 afterS0(LK); afterS0(S1); afterS1(SK);
00032 beforeS0(LK); beforeS0(S0); afterS0(SK);
00033 k += 8*4;
00034 afterS6(LK); afterS6(S7); afterS7(SK);
00035 afterS5(LK); afterS5(S6); afterS6(SK);
00036 afterS4(LK); afterS4(S5); afterS5(SK);
00037 afterS3(LK); afterS3(S4); afterS4(SK);
00038 }
00039 afterS2(LK); afterS2(S3); afterS3(SK);
00040 }
00041
00042 void Serpent::Base::UncheckedSetKey(const byte *userKey, unsigned int keylen, const NameValuePairs &)
00043 {
00044 AssertValidKeyLength(keylen);
00045 Serpent_KeySchedule(m_key, 32, userKey, keylen);
00046 }
00047
00048 typedef BlockGetAndPut<word32, LittleEndian> Block;
00049
00050 void Serpent::Enc::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
00051 {
00052 word32 a, b, c, d, e;
00053
00054 Block::Get(inBlock)(a)(b)(c)(d);
00055
00056 const word32 *k = m_key;
00057 unsigned int i=1;
00058
00059 do
00060 {
00061 beforeS0(KX); beforeS0(S0); afterS0(LT);
00062 afterS0(KX); afterS0(S1); afterS1(LT);
00063 afterS1(KX); afterS1(S2); afterS2(LT);
00064 afterS2(KX); afterS2(S3); afterS3(LT);
00065 afterS3(KX); afterS3(S4); afterS4(LT);
00066 afterS4(KX); afterS4(S5); afterS5(LT);
00067 afterS5(KX); afterS5(S6); afterS6(LT);
00068 afterS6(KX); afterS6(S7);
00069
00070 if (i == 4)
00071 break;
00072
00073 ++i;
00074 c = b;
00075 b = e;
00076 e = d;
00077 d = a;
00078 a = e;
00079 k += 32;
00080 beforeS0(LT);
00081 }
00082 while (true);
00083
00084 afterS7(KX);
00085
00086 Block::Put(xorBlock, outBlock)(d)(e)(b)(a);
00087 }
00088
00089 void Serpent::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const
00090 {
00091 word32 a, b, c, d, e;
00092
00093 Block::Get(inBlock)(a)(b)(c)(d);
00094
00095 const word32 *k = m_key + 96;
00096 unsigned int i=4;
00097
00098 beforeI7(KX);
00099 goto start;
00100
00101 do
00102 {
00103 c = b;
00104 b = d;
00105 d = e;
00106 k -= 32;
00107 beforeI7(ILT);
00108 start:
00109 beforeI7(I7); afterI7(KX);
00110 afterI7(ILT); afterI7(I6); afterI6(KX);
00111 afterI6(ILT); afterI6(I5); afterI5(KX);
00112 afterI5(ILT); afterI5(I4); afterI4(KX);
00113 afterI4(ILT); afterI4(I3); afterI3(KX);
00114 afterI3(ILT); afterI3(I2); afterI2(KX);
00115 afterI2(ILT); afterI2(I1); afterI1(KX);
00116 afterI1(ILT); afterI1(I0); afterI0(KX);
00117 }
00118 while (--i != 0);
00119
00120 Block::Put(xorBlock, outBlock)(a)(d)(b)(e);
00121 }
00122
00123 NAMESPACE_END