示例代码已经放出！请移步使用delphi+intraweb进行微信开发1~4代码示例进行下载，虽为示例代码但是是从我项目中移出来的，封装很完备适于自行扩展和修改。
在上一讲当中我做了个简单的微信文本消息回显应用，当时是以微信明文方式实现的，其实微信推荐的是消息应该加密传输以增加安全性，所以这讲说说微信消息的加解密。
在微信的帮助页面上可以下载微信消息加解密的例程，可惜的是没有Delphi语言的示例，网上搜索一番，没有人贡献出写好的Delphi版的微信加解密算法单元，好在有官方示例的C#版的，那就按照C#的改一个吧。
微信消息是以AES算法进行的加密处理，而遗憾的是Delphi并没有内置的AES算法单元，必须找第三方实现的，不过一般第三方实现的算法都因为种种原因并不完善，需要使用者酌情修改，所以在基础算法支持上Delphi确实和.net以及java这类的开发语言比不了。
呵呵，上网找Delphi版AES算法吧。在在这里要感谢cnpack开发组，他们不但推出一流的delphi开发环境增强组件还有开源组件包cnvcl，这个组件包中有SHA1、AES、MD5等多种算法单元，我打开AES算法单元查看，发现封装的很完美，ECB、CBC模式均支持，呵呵，幸福了
。
参考C#示例代码一通修改测试，省略几昼夜苦干的吐槽终于开花结果：
呵呵，这个或者是网上目前唯一的开源的Delphi版的微信加解密算法单元吧，激动！
,
WXBizMsgCrypt_ValidateSignature_Error = -40001,
WXBizMsgCrypt_ParseXml_Error = -40002,
WXBizMsgCrypt_ComputeSignature_Error = -40003,
WXBizMsgCrypt_IllegalAesKey = -40004,
WXBizMsgCrypt_ValidateAppid_Error = -40005,
WXBizMsgCrypt_EncryptAES_Error = -40006,
WXBizMsgCrypt_DecryptAES_Error = -40007,
WXBizMsgCrypt_IllegalBuffer = -40008,
WXBizMsgCrypt_EncodeBase64_Error = -40009,
WXBizMsgCrypt_DecodeBase64_Error = -40010
);
;
lstBt := P^[DecodeStream.Size - 1];
AllKCS7ByteCount := block_size - (block_size - Ord(lstBt));
if (AllKCS7ByteCount > 0) and (AllKCS7ByteCount < DecodeStream.Size) then
begin
if P^[DecodeStream.Size - AllKCS7ByteCount] = lstBt then
Result := DecodeStream.Size - AllKCS7ByteCount
else
Result := DecodeStream.Size;
end else
Result := DecodeStream.Size;
end;
begin
try
aEncodingAESKeyStr := AnsiString(sEncodingAESKey + );
Move(aEncodingAESKeyBts[0], IvBts[0], 16);
], Length(InputBts));
Move(aEncodingAESKeyBts[0], AesKey, Length(aEncodingAESKeyBts));
Move(IvBts[0], Iv, Length(IvBts));
InputStream.Position := 0;
DecryptAESStreamCBC(InputStream, 0,
AesKey, Iv, DecodeStream);
P := PByteArray(DecodeStream.Memory);
iDecodeDataLen := GetRealDataLenWithoutKCS7Bytes;
iLen := P^[16] shl 24 + P^[17] shl 16 + P^[18] shl 8 + P^[19];
SetLength(bMsg, iLen);
SetLength(bAppid, iDecodeDataLen - 20 - iLen);
Move(P^[20], bMsg[0], iLen);
Move(P^[20 + iLen], bAppid[0], iDecodeDataLen - 20 - iLen);
Result := TEncoding.UTF8.GetString(bMsg);
cpid := TEncoding.UTF8.GetString(bAppid);
finally
InputStream.Free;
DecodeStream.Free;
end;
except
raise Exception.Create() then
codeLen := 16;
strLst := TStringList.Create;
try
ExtractStrings([ to codeLen - 1 do
begin
randValue := Random(strLst.Count);
code := code + strLst[randValue];
end;
Result := code;
finally
strLst.Free;
end;
end;
function KCS7Encoder(text_length: Integer): TBytes;
var
block_size, amount_to_pad: Integer;
pad_chr: Char;
tmp: string;
i: Integer;
begin
block_size := 32;
) then
amount_to_pad := block_size;
to amount_to_pad - 1 do
tmp := tmp + pad_chr;
Result := BytesOf(tmp);
end;
begin
aEncodingAESKeyStr := AnsiString(sEncodingAESKey + );
Move(aEncodingAESKeyBts[0], IvBts[0], 16);
Randcode := CreateRandCode(16);
bRand := TEncoding.UTF8.GetBytes(Randcode);
bAppid := TEncoding.UTF8.GetBytes(cpid);
btmpMsg := TEncoding.UTF8.GetBytes(sMsg);
SetLength(bMsgLen, 4);
bMsgLen[0] := (Length(btmpMsg) shr 24) and $FF;
bMsgLen[1] := (Length(btmpMsg) shr 16) and $FF;
bMsgLen[2] := (Length(btmpMsg) shr 8) and $FF;
bMsgLen[3] := Length(btmpMsg) and $FF;
SetLength(bMsg, Length(bRand) + Length(bAppid) + Length(btmpMsg) + Length(bMsgLen));
Move(bRand[0], bMsg[0], Length(bRand));
Move(bMsgLen[0], bMsg[Length(bRand)], Length(bMsgLen));
Move(btmpMsg[0], bMsg[Length(bRand) + Length(bMsgLen)], Length(btmpMsg));
Move(bAppid[0], bMsg[Length(bRand) + Length(bMsgLen) + Length(btmpMsg)], Length(bAppid));
- Length(bMsg) mod 32);
Move(bMsg[0], msg[0], Length(bMsg));
pad := KCS7Encoder(Length(bMsg));
Move(pad[0], msg[Length(bMsg)], Length(pad));
], AesKey, Length(aEncodingAESKeyBts));
Move(IvBts[0], Iv, Length(IvBts));
InputStream := TMemoryStream.Create;
OutputStream := TMemoryStream.Create;
try
InputStream.Write(msg[0], Length(msg));
InputStream.Position := 0;
EncryptAESStreamCBC(InputStream, 0, AesKey, Iv, OutputStream);
Result := string(EncodeBase64(OutputStream.Memory, OutputStream.Size));
finally
InputStream.Free;
OutputStream.Free;
end;
end;
function TWxMsgCrypt.CreateRandCode(codeLen: Integer): string;
var
codeSerial, code: string;
strLst: TStringList;
randValue, i: Integer;
begin
codeSerial := ) then
codeLen := 16;
strLst := TStringList.Create;
try
ExtractStrings([ to codeLen - 1 do
begin
randValue := Random(strLst.Count);
code := code + strLst[randValue];
end;
Result := code;
finally
strLst.Free;
end;
end;
function TWxMsgCrypt.DecryptMsg(const sToken, sTimeStamp, sNonce, sMsgEncrypt, sSigture,
sAppID, sEncodingAESKey: string; var sMsg: string): WXBizMsgCryptErrorCode;
var
ret: WXBizMsgCryptErrorCode;
cpid: string;
function VerifySignature: WXBizMsgCryptErrorCode;
var
hash: string;
aStr: AnsiString;
AL: TStringList;
i: Integer;
begin
AL := TStringList.Create;
try
AL.Add(sToken);
AL.Add(sTimeStamp);
AL.Add(sNonce);
AL.Add(sMsgEncrypt);
AL.Sort;
hash := to AL.Count - 1 do
hash := hash + AL[i];
aStr := AnsiString(hash);
hash := LowerCase(SHA1Print(SHA1StringA(aStr)));
finally
AL.Free;
end;
if (hash = sSigture) then
Result := WXBizMsgCrypt_OK
else
Result := WXBizMsgCrypt_ValidateSignature_Error;
end;
begin
sMsg := ) then
begin
Result := WXBizMsgCryptErrorCode.WXBizMsgCrypt_IllegalAesKey;
Exit;
end;
);
AL.Add(wxNonce);
AL.Sort;
hash := to AL.Count - 1 do
hash := hash + AL[i];
aStr := AnsiString(hash);
hash := LowerCase(SHA1Print(SHA1StringA(aStr)));
finally
AL.Free;
end;
Result := hash;
end;
begin
sMsgEncrypt := ) then
begin
Result := WXBizMsgCryptErrorCode.WXBizMsgCrypt_IllegalAesKey;
Exit;
end;
//encrypt
try
EncryptField := AES_encrypt(sEncodingAESKey, sMsg, sAppID);
except
on E: Exception do
begin
if E.Message = '1' then
Result := WXBizMsgCrypt_DecryptAES_Error
else
Result := WXBizMsgCrypt_EncryptAES_Error;
Exit;
end;
end;
//gen signature
try
hash := GenSignature;
except
Result := WXBizMsgCrypt_ComputeSignature_Error;
Exit;
end;
//xml
sMsgEncrypt := '<xml><Encrypt><![CDATA[' + EncryptField + ']]></Encrypt>' +
'<MsgSignature><![CDATA[' + hash + ']]></MsgSignature>' +
'<TimeStamp><![CDATA[' + wxDt + ']]></TimeStamp>' +
'<Nonce><![CDATA[' + wxNonce + ']]></Nonce></xml>';
Result := WXBizMsgCrypt_OK;
end;
end.
呵呵，看看效果图吧：
