/*
 * Copyright 2009-2017 Alibaba Cloud All rights reserved.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <alibabacloud/core/HmacSha1Signer.h>
#ifdef _WIN32
#include <windows.h>
#include <wincrypt.h>
#else
#include <openssl/hmac.h>
#endif

using namespace AlibabaCloud;

HmacSha1Signer::HmacSha1Signer() :
	Signer(HmacSha1, "HMAC-SHA1", "1.0")
{
}

HmacSha1Signer::~HmacSha1Signer()
{
}

std::string HmacSha1Signer::generate(const std::string & src, const std::string & secret) const
{
	if (src.empty())
		return std::string();

#ifdef _WIN32
	typedef struct _my_blob {
		BLOBHEADER hdr;
		DWORD dwKeySize;
		BYTE rgbKeyData[];
	}my_blob;

	DWORD kbLen = sizeof(my_blob) + secret.size();
	my_blob * kb = (my_blob *)LocalAlloc(LPTR, kbLen);
	kb->hdr.bType = PLAINTEXTKEYBLOB;
	kb->hdr.bVersion = CUR_BLOB_VERSION;
	kb->hdr.reserved = 0;
	kb->hdr.aiKeyAlg = CALG_RC2;
	kb->dwKeySize = secret.size();
	memcpy(&kb->rgbKeyData, secret.c_str(), secret.size());

	HCRYPTPROV hProv = 0;
	HCRYPTKEY hKey = 0;
	HCRYPTHASH hHmacHash = 0;
	BYTE pbHash[32];
	DWORD dwDataLen = 32;
	HMAC_INFO HmacInfo;
	ZeroMemory(&HmacInfo, sizeof(HmacInfo));
	HmacInfo.HashAlgid = CALG_SHA1;

	CryptAcquireContext(&hProv, NULL, MS_ENHANCED_PROV, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT | CRYPT_NEWKEYSET);
	CryptImportKey(hProv, (BYTE*)kb, kbLen, 0, CRYPT_IPSEC_HMAC_KEY, &hKey);
	CryptCreateHash(hProv, CALG_HMAC, hKey, 0, &hHmacHash);
	CryptSetHashParam(hHmacHash, HP_HMAC_INFO, (BYTE*)&HmacInfo, 0);
	CryptHashData(hHmacHash, (BYTE*)(src.c_str()), src.size(), 0);
	CryptGetHashParam(hHmacHash, HP_HASHVAL, pbHash, &dwDataLen, 0);

	LocalFree(kb);
	CryptDestroyHash(hHmacHash);
	CryptDestroyKey(hKey);
	CryptReleaseContext(hProv, 0);

	DWORD dlen = 0;
	CryptBinaryToString(pbHash, dwDataLen, CRYPT_STRING_BASE64 | CRYPT_STRING_NOCRLF, NULL, &dlen);
	char* dest = new char[dlen];
	CryptBinaryToString(pbHash, dwDataLen, CRYPT_STRING_BASE64 | CRYPT_STRING_NOCRLF, dest, &dlen);

	std::string ret = std::string(dest, dlen);
	delete dest;
	return ret;
#else
	unsigned char md[EVP_MAX_BLOCK_LENGTH];
	unsigned int mdLen = EVP_MAX_BLOCK_LENGTH;

	if (HMAC(EVP_sha1(), secret.c_str(), secret.size(),
		reinterpret_cast<const unsigned char*>(src.c_str()), src.size(),
		md, &mdLen) == nullptr)
		return std::string();

	char encodedData[100];
	EVP_EncodeBlock(reinterpret_cast<unsigned char*>(encodedData), md, mdLen);
	return encodedData;
#endif
}