下面是一段C++  RC2加密   要求要用java 重写  能互相加密解密

QSBEncryptRc2::QSBEncryptRc2()

{

EncryKey = "DingXin Communication Key 20080613";

}

//解密失败时返回失败描述

AnsiString QSBEncryptRc2::GetDecryptErrMsg()

{

int ErrorCode;

AnsiString ErrMsg;

ErrorCode = GetLastError();

switch( ErrorCode )

{

case ERROR_INVALID_HANDLE:

ErrMsg = "其中一个参数是非法句柄";

break;

case NTE_BAD_ALGID:

ErrMsg = "不支持的加密算法";

break;

case NTE_BAD_DATA:

ErrMsg = "解密的数据非法";

break;

case NTE_BAD_FLAGS:

ErrMsg = "标识参数不为0";

break;

case NTE_BAD_HASH:

ErrMsg = "哈希参数非法";

break;

case NTE_BAD_KEY:

ErrMsg = "密钥是非法句柄";

break;

case NTE_BAD_LEN:

ErrMsg = "解密数据内存太小";

break;

case NTE_BAD_UID:

ErrMsg = "找不到CSP上下文";

break;

case NTE_DOUBLE_ENCRYPT:

ErrMsg = "应用企图解密已经解密的数据";

break;

case NTE_FAIL:

ErrMsg = "程序由于未知原因结束";

break;

default:

ErrMsg = "未知错误";

}

return ErrMsg;

}

//加密失败时返回失败描述

AnsiString QSBEncryptRc2::GetEncrytErrMsg()

{

int ErrorCode;

AnsiString ErrMsg;

ErrorCode = GetLastError();

switch( ErrorCode )

{

case ERROR_INVALID_HANDLE:

ErrMsg = "其中一个参数是非法句柄";

break;

case ERROR_INVALID_PARAMETER:

ErrMsg = "非法参数";

break;

case NTE_BAD_ALGID:

ErrMsg = "不支持的加密算法";

break;

case NTE_BAD_DATA:

ErrMsg = "解密的数据非法";

break;

case NTE_BAD_FLAGS:

ErrMsg = "标识参数不为0";

break;

case NTE_BAD_HASH:

ErrMsg = "哈希参数非法";

break;

case NTE_BAD_KEY:

ErrMsg = "密钥是非法句柄";

break;

case NTE_BAD_LEN:

ErrMsg = "解密数据内存太小";

break;

case NTE_BAD_UID:

ErrMsg = "找不到CSP上下文";

break;

case NTE_DOUBLE_ENCRYPT:

ErrMsg = "应用企图加密已经加密的数据";

break;

case NTE_NO_MEMORY:

ErrMsg = "内存不足";

break;

case NTE_FAIL:

ErrMsg = "程序由于未知原因结束";

break;

default:

ErrMsg = "未知错误";

}

return ErrMsg;

}

//加密数据

void QSBEncryptRc2::EncryptData(QSBBlob &inData,QSBBlob &outData)

{

HCRYPTPROV hProv = 0;

HCRYPTHASH hHash = 0;

HCRYPTKEY hKey = 0;

DWORD dwCurrLen,dwLength;

BYTE pbBuffer[BUFFER_SIZE];

DWORD dwCount;

int  eof;

const char *ptr;

DWORD  nLen;

DWORD  nEncryCount;

AnsiString ErrMsg;

try

{

//连接CSP

if(!CryptAcquireContext(&hProv, TEXT("DingXinKey"), 0, PROV_RSA_FULL, 0))

{

//如KEY CONTAINER不存在,则重新创建一个

if( GetLastError() == (DWORD)NTE_BAD_KEYSET )

{

if(!CryptAcquireContext(&hProv, TEXT("DingXinKey"), 0, PROV_RSA_FULL,

CRYPT_NEWKEYSET))

throw QSBException(003,"创建KEY CONTAINER失败");

}

else

throw QSBException(003,"连接CSP失败");

}

//序列化密码

if(!CryptCreateHash(hProv, CALG_MD5, 0, 0, &hHash))

throw QSBException(003,"创建序列对象失败");

dwLength = strlen(EncryKey.c_str());

if(!CryptHashData(hHash, (BYTE *)EncryKey.c_str(), dwLength, 0))

throw QSBException(003,"序列化密码失败");

if(!CryptDeriveKey(hProv, CALG_RC2, hHash, CRYPT_EXPORTABLE, &hKey))

throw QSBException(003,"创建密钥失败");

//加密文件

outData.ClearContent();

ptr  = inData.GetBlobPtr();

nLen = inData.GetBlobLength();

dwCurrLen = 0;

do

{

if( nLen-dwCurrLen>BLOCK_SIZE )

{

memcpy(pbBuffer,ptr+dwCurrLen,BLOCK_SIZE );

eof = false;

nEncryCount=BLOCK_SIZE;

}

else

{

memcpy(pbBuffer,ptr+dwCurrLen,nLen-dwCurrLen );

eof = true;

nEncryCount=nLen-dwCurrLen;

}

dwCount = nEncryCount;

if(!CryptEncrypt(hKey, 0, eof, 0, pbBuffer, &dwCount,BUFFER_SIZE))

{

ErrMsg.sprintf("加密失败:%s",GetEncrytErrMsg().c_str() );

throw QSBException(003,ErrMsg.c_str() );

}

outData.AppendBlobContent(pbBuffer,dwCount);

dwCurrLen += nEncryCount;

}

while(dwCurrLen

}

__finally

{

if(hHash != 0)

CryptDestroyHash(hHash);

if(hKey != 0)

CryptDestroyKey(hKey);

if(hProv != 0)

CryptReleaseContext(hProv,0);

}

}

//解密数据

void QSBEncryptRc2::DecryptData(QSBBlob &inData,QSBBlob &outData)

{

HCRYPTPROV hProv = 0;

HCRYPTHASH hHash = 0;

HCRYPTKEY hKey = 0;

DWORD dwCurrLen,dwLength;

BYTE pbBuffer[BUFFER_SIZE];

DWORD dwCount;

int  eof;

const char *ptr;

DWORD  nLen;

DWORD  nDecryCount;

AnsiString ErrMsg;

try

{

//连接CSP

if(!CryptAcquireContext(&hProv, TEXT("DingXinKey"), 0, PROV_RSA_FULL, 0))

{

//如KEY CONTAINER不存在,则重新创建一个

if( GetLastError() == (DWORD)NTE_BAD_KEYSET )

{

if(!CryptAcquireContext(&hProv, TEXT("DingXinKey"), 0, PROV_RSA_FULL,

CRYPT_NEWKEYSET))

throw QSBException(003,"创建KEY CONTAINER失败");

}

else

throw QSBException(003,"连接CSP失败");

}

//序列化密码

if(!CryptCreateHash(hProv, CALG_MD5, 0, 0, &hHash))

throw QSBException(003,"创建序列对象失败");

dwLength = strlen(EncryKey.c_str());

if(!CryptHashData(hHash, (BYTE *)EncryKey.c_str(), dwLength, 0))

throw QSBException(003,"序列化密码失败");

if(!CryptDeriveKey(hProv, CALG_RC2, hHash, CRYPT_EXPORTABLE, &hKey))

throw QSBException(003,"创建密钥失败");

//解密文件

outData.ClearContent();

ptr  = inData.GetBlobPtr();

nLen = inData.GetBlobLength();

dwCurrLen = 0;

do

{

if( nLen-dwCurrLen>BLOCK_SIZE )

{

memcpy(pbBuffer,ptr+dwCurrLen,BLOCK_SIZE );

eof = false;

nDecryCount=BLOCK_SIZE;

}

else

{

memcpy(pbBuffer,ptr+dwCurrLen,nLen-dwCurrLen );

eof = true;

nDecryCount=nLen-dwCurrLen;

}

dwCount = nDecryCount;

if(!CryptDecrypt(hKey, 0, eof, 0, pbBuffer, &dwCount))

{

ErrMsg.sprintf("解密数据失败:%s",GetDecryptErrMsg().c_str());

throw QSBException(003,ErrMsg.c_str());

}

outData.AppendBlobContent(pbBuffer,dwCount);

dwCurrLen += nDecryCount;

}

while(dwCurrLen

}

__finally

{

if(hHash != 0)

CryptDestroyHash(hHash);

if(hKey != 0)

CryptDestroyKey(hKey);

if(hProv != 0)

CryptReleaseContext(hProv,0);

}

}