base64编解码

Base64编码表

static const char s_acBase64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";



/*
* 函数名称:	Base64Encode
* 函数功能:	base64编码
* 参    数:
* 			pucIN					-	编码前数据
* 			ulINLen					-	编码前数据长度
* 			pucOUT					-	编码后数据
* 			pucOUTLen				-	编码后数据长度
* 返 回 值:		成功返回R__OK,否则返回相应错误码
*/
unsigned int Base64Encode(const unsigned char *pucIN,  unsigned long ulINLen, unsigned char *pucOUT, unsigned long *pulOUTLen)
{
	if (NULL == pucIN || NULL == pucOUT || NULL == pulOUTLen)
	{
		return -1;
	}

	unsigned long i, len2, leven;
	unsigned char *p;
	len2 = 4 * ((ulINLen + 2) / 3);
	if (*pulOUTLen < len2 + 1)
	{
		*pulOUTLen = len2 + 1;
		return -2;
	}
	p = pucOUT;
	leven = 3*(ulINLen / 3);
	for (i = 0; i < leven; i += 3)
	{
		*pucOUT++ = s_acBase64[(pucIN[0] >> 2) & 0x3F];
		*pucOUT++ = s_acBase64[(((pucIN[0] & 3) << 4) + (pucIN[1] >> 4)) & 0x3F];
		*pucOUT++ = s_acBase64[(((pucIN[1] & 0xf) << 2) + (pucIN[2] >> 6)) & 0x3F];
		*pucOUT++ = s_acBase64[pucIN[2] & 0x3F];
		pucIN += 3;
	}
	if (i < ulINLen)
	{
		unsigned a = pucIN[0];
		unsigned b = (i+1 < ulINLen) ? pucIN[1] : 0;

		*pucOUT++ = s_acBase64[(a >> 2) & 0x3F];
		*pucOUT++ = s_acBase64[(((a & 3) << 4) + (b >> 4)) & 0x3F];
		*pucOUT++ = (i+1 < ulINLen) ? s_acBase64[(((b & 0xf) << 2)) & 0x3F] : '=';
		*pucOUT++ = '=';
	}
	*pucOUT = '\0';
	*pulOUTLen = pucOUT - p;
	return 0;
}

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base64编解码

原文：http://blog.csdn.net/wenwei19861106/article/details/26678033