delphi 控制台Base64加密解密

program demo;

{$APPTYPE CONSOLE}

{$R *.res}

uses

System.RTLConsts,

System.SysUtils;

const

conBase64Out: array[0..64] of AnsiChar = (

'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',

'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',

'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',

'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',

'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/', '='

);

conBase64In: array[0..127] of Byte = (

255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,

255, 255, 255, 255, 62, 255, 255, 255, 63, 52, 53, 54, 55,

56, 57, 58, 59, 60, 61, 255, 255, 255, 64, 255, 255, 255,

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,

13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,

255, 255, 255, 255, 255, 255, 26, 27, 28, 29, 30, 31, 32,

33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45,

46, 47, 48, 49, 50, 51, 255, 255, 255, 255, 255

);

function Base64Decode(const AInput: AnsiString): AnsiString;

var

nIndex, nLength, nSize: Integer;

pBuffer: PAnsiChar;

DataIn0, DataIn1, DataIn2, DataIn3: Byte;

begin

Result := '';

if AInput = '' then

Exit;

nLength := Length(AInput);

if nLength and 3 <> 0 then

raise EConvertError.Create(SInvalidStringLength);

nSize := 3 * (nLength div 4);

if AInput[nLength - 1] = '=' then

Dec(nSize);

if AInput[nLength] = '=' then

Dec(nSize);

SetLength(Result, nSize);

if nSize = 0 then

Exit;

pBuffer := PAnsiChar(Result);

nIndex := 1;

while nIndex < nLength do

begin

DataIn0 := conBase64In[Byte(AInput[nIndex])];

DataIn1 := conBase64In[Byte(AInput[nIndex + 1])];

DataIn2 := conBase64In[Byte(AInput[nIndex + 2])];

DataIn3 := conBase64In[Byte(AInput[nIndex + 3])];

pBuffer^ := AnsiChar(((DataIn0 and $3F) shl 2) + ((DataIn1 and $30) shr 4));

Inc(pBuffer);

if DataIn2 <> $40 then

begin

pBuffer^ := AnsiChar(((DataIn1 and $0F) shl 4) + ((DataIn2 and $3C) shr 2));

Inc(pBuffer);

if DataIn3 <> $40 then

begin

pBuffer^ := AnsiChar(((DataIn2 and $03) shl 6) + (DataIn3 and $3F));

Inc(pBuffer);

end;

nIndex := nIndex + 4;

end;

function Base64Encode(const AInput: AnsiString): AnsiString;

var

nIndex, nLength, nSize: Integer;

pBuffer: PAnsiChar;

begin

nLength := Length(AInput);

nSize := 4 * ((nLength + 2) div 3);

SetLength(Result, nSize);

if nSize = 0 then Exit;

pBuffer := PAnsiChar(Result);

nIndex := 1;

while nIndex <= nLength do

begin

pBuffer[0] := conBase64Out[(Byte(AInput[nIndex]) and $FC) shr 2];

if (nIndex + 1) <= nLength then

begin

pBuffer[1] := conBase64Out[((Byte(AInput[nIndex]) and $03) shl 4) +

((Byte(AInput[nIndex + 1]) and $F0) shr 4)];

if (nIndex + 2) <= nLength then

begin

pBuffer[2] := conBase64Out[((Byte(AInput[nIndex + 1]) and $0F) shl 2) +

((Byte(AInput[nIndex + 2]) and $C0) shr 6)];

pBuffer[3] := conBase64Out[(Byte(AInput[nIndex + 2]) and $3F)];

end

else begin

pBuffer[2] := conBase64Out[(Byte(AInput[nIndex + 1]) and $0F) shl 2];

pBuffer[3] := '=';

end

else begin

pBuffer[1] := conBase64Out[(Byte(AInput[nIndex]) and $03) shl 4];

pBuffer[2] := '=';

pBuffer[3] := '=';

end;

Inc(pBuffer, 4);

Inc(nIndex, 3);

end;

var

B: string;

S, T: AnsiString;

begin

B := '中国人abc';

try

S := Base64Encode(AnsiString(B));

Writeln('加密'+S);

Writeln('解密'+Base64Decode(S));

T := Base64Decode(S);

if B = T then

Writeln('test ok')

else Writeln('test error!');

except

on E: Exception do

Writeln(E.ClassName, ': ', E.Message);

end;

if DebugHook <> 0 then Readln;

end.

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