unit SHA1;
interface
uses
Sysutils, Tools;
type
TSHA1Digest=
array[0..19]
of byte;
TSHA1Context=
record
Hash:
array[0..4]
of DWord;
Hi, Lo: integer;
Buffer:
array[0..63]
of byte;
Index: integer;
end;
function SHA1SelfTest: boolean;
procedure SHA1Init(
var Context: TSHA1Context);
procedure SHA1Update(
var Context: TSHA1Context; Buffer: pointer; Len: integer);
procedure SHA1Final(
var Context: TSHA1Context;
var Digest: TSHA1Digest);
//******************************************************************************
implementation
{$R-}
function SHA1SelfTest: boolean;
const
s: string= '
abc';
OutDigest: TSHA1Digest=
($a9,$99,$3e,$36,$47,$06,$81,$6a,$ba,$3e,$25,$71,$78,$50,$c2,$6c,$9c,$d0,$d8,$9d);
var
Context: TSHA1Context;
Digest: TSHA1Digest;
begin
SHA1Init(Context);
SHA1Update(Context,@s[1],length(s));
SHA1Final(Context,Digest);
if CompareMem(@Digest,@OutDigest,Sizeof(Digest))
then
Result:= true
else
Result:= false;
end;
//******************************************************************************
function F1(x, y, z: DWord): DWord;
begin
Result:= z
xor (x
and (y
xor z));
end;
function F2(x, y, z: DWord): DWord;
begin
Result:= x
xor y
xor z;
end;
function F3(x, y, z: DWord): DWord;
begin
Result:= (x
and y)
or (z
and (x
or y));
end;
//******************************************************************************
function RB(A: DWord): DWord;
begin
Result:= (A
shr 24)
or ((A
shr 8)
and $FF00)
or ((A
shl 8)
and $FF0000)
or (A
shl 24);
end;
procedure SHA1Compress(
var Data: TSHA1Context);
var
A, B, C, D, E, T: DWord;
W:
array[0..79]
of DWord;
i: integer;
begin
Move(Data.Buffer,W,Sizeof(Data.Buffer));
for i:= 0
to 15
do
W[i]:= RB(W[i]);
for i:= 16
to 79
do
W[i]:= LRot32(W[i-3]
xor W[i-8]
xor W[i-14]
xor W[i-16],1);
A:= Data.Hash[0]; B:= Data.Hash[1]; C:= Data.Hash[2]; D:= Data.Hash[3]; E:= Data.Hash[4];
for i:= 0
to 19
do
begin
T:= LRot32(A,5) + F1(B,C,D) + E + W[i] + $5A827999;
E:= D; D:= C; C:= LRot32(B,30); B:= A; A:= T;
end;
for i:= 20
to 39
do
begin
T:= LRot32(A,5) + F2(B,C,D) + E + W[i] + $6ED9EBA1;
E:= D; D:= C; C:= LRot32(B,30); B:= A; A:= T;
end;
for i:= 40
to 59
do
begin
T:= LRot32(A,5) + F3(B,C,D) + E + W[i] + $8F1BBCDC;
E:= D; D:= C; C:= LRot32(B,30); B:= A; A:= T;
end;
for i:= 60
to 79
do
begin
T:= LRot32(A,5) + F2(B,C,D) + E + W[i] + $CA62C1D6;
E:= D; D:= C; C:= LRot32(B,30); B:= A; A:= T;
end;
Data.Hash[0]:= Data.Hash[0] + A;
Data.Hash[1]:= Data.Hash[1] + B;
Data.Hash[2]:= Data.Hash[2] + C;
Data.Hash[3]:= Data.Hash[3] + D;
Data.Hash[4]:= Data.Hash[4] + E;
FillChar(W,Sizeof(W),0);
FillChar(Data.Buffer,Sizeof(Data.Buffer),0);
end;
//******************************************************************************
procedure SHA1Init(
var Context: TSHA1Context);
begin
Context.Hi:= 0; Context.Lo:= 0;
Context.
Index:= 0;
FillChar(Context.Buffer,Sizeof(Context.Buffer),0);
Context.Hash[0]:= $67452301;
Context.Hash[1]:= $EFCDAB89;
Context.Hash[2]:= $98BADCFE;
Context.Hash[3]:= $10325476;
Context.Hash[4]:= $C3D2E1F0;
end;
//******************************************************************************
procedure SHA1UpdateLen(
var Context: TSHA1Context; Len: integer);
var
i, k: integer;
begin
for k:= 0
to 7
do
begin
i:= Context.Lo;
Inc(Context.Lo,Len);
if Context.Lo< i
then
Inc(Context.Hi);
end;
end;
//******************************************************************************
procedure SHA1Update(
var Context: TSHA1Context; Buffer: pointer; Len: integer);
type
PByte= ^Byte;
begin
SHA1UpdateLen(Context,Len);
while Len> 0
do
begin
Context.Buffer[Context.
Index]:= PByte(Buffer)^;
Inc(PByte(Buffer));
Inc(Context.
Index);
Dec(Len);
if Context.Index= 64
then
begin
Context.
Index:= 0;
SHA1Compress(Context);
end;
end;
end;
//******************************************************************************
procedure SHA1Final(
var Context: TSHA1Context;
var Digest: TSHA1Digest);
type
PDWord= ^DWord;
begin
Context.Buffer[Context.
Index]:= $80;
if Context.
Index>= 56
then
SHA1Compress(Context);
PDWord(@Context.Buffer[56])^:= RB(Context.Hi);
PDWord(@Context.Buffer[60])^:= RB(Context.Lo);
SHA1Compress(Context);
Context.Hash[0]:= RB(Context.Hash[0]);
Context.Hash[1]:= RB(Context.Hash[1]);
Context.Hash[2]:= RB(Context.Hash[2]);
Context.Hash[3]:= RB(Context.Hash[3]);
Context.Hash[4]:= RB(Context.Hash[4]);
Move(Context.Hash,Digest,Sizeof(Digest));
FillChar(Context,Sizeof(Context),0);
end;
end.