base64.cpp

AsynSocketDemo.rar网络代码,可以设置代理,ssl加密. AsynSocketDemo.rar网络代码,可以设置代理,ssl加密. AsynSocketDemo.rar网络代码,

#include "stdafx.h"

static const unsigned char alphabet[65] = 
	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
size_t b64Decode(const char *src,
		unsigned char *dst, size_t dstsize)
{
        char decoder[256];
    	int i, bits, c;

	unsigned char *pdst = dst;
	
	for (i = 0; i < 256; ++i)
		decoder[i] = 64;
    	for (i = 0; i < 64 ; ++i) 
		decoder[alphabet[i]] = i;

    	bits = 1;

	while(*src)
	{ 
		c = (unsigned char)(*(src++));
		if (c == '=')
		{
			if (bits & 0x40000)
			{
				if (dstsize < 2) break;
				*(pdst++) = (bits >> 10);
				*(pdst++) = (bits >> 2) & 0xff;
				break;
			}
			if (bits & 0x1000 && dstsize)
				*(pdst++) = (bits >> 4);
			break;
		}
		// skip invalid chars
		if (decoder[c] == 64)
			continue;
		bits = (bits << 6) + decoder[c];
		if (bits & 0x1000000) 
		{
			if (dstsize < 3) break;
			*(pdst++) = (bits >> 16);
			*(pdst++) = (bits >> 8) & 0xff;
			*(pdst++) = (bits & 0xff);
		    	bits = 1;
			dstsize -= 3;
		} 
	}
	return pdst-dst;
}

void b64Decode(string& dest, const string& src)
{
	size_t limit = src.length()/4*3;
	dest.resize(limit+2);

	unsigned size = b64Decode(src.c_str(), (unsigned char*)dest.c_str(), limit);
	dest.resize(size);
}


/* How many bytes it will take to store LEN bytes in base64.  */
#define BASE64_LENGTH(len) (4 * (((len) + 2) / 3))

/* Encode the string S of length LENGTH to base64 format and place it
   to STORE.  STORE will be 0-terminated, and must point to a writable
   buffer of at least 1+BASE64_LENGTH(length) bytes.  */
static void base64_encode (const char *s, char *store, int length)
{
	/* Conversion table.  */
	static char tbl[64] = {
		'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','+','/'
	};
	int i;
	unsigned char *p = (unsigned char *)store;

	/* Transform the 3x8 bits to 4x6 bits, as required by base64.  */
	for (i = 0; i < length; i += 3)
	{ 
		*p++ = tbl[s[0] >> 2];
		*p++ = tbl[((s[0] & 3) << 4) + (s[1] >> 4)];
		*p++ = tbl[((s[1] & 0xf) << 2) + (s[2] >> 6)];
		*p++ = tbl[s[2] & 0x3f];
		s += 3;
	}
	/* Pad the result if necessary...  */
	if (i == length + 1)
		*(p - 1) = '=';
	else if (i == length + 2)
		*(p - 1) = *(p - 2) = '=';
	/* ...and zero-terminate it.  */
	*p = '\0';
}

/* Create the authentication header contents for the `Basic' scheme.
   This is done by encoding the string `USER:PASS' in base64 and
   prepending `HEADER: Basic ' to it.  */
char * basic_authentication_encode (const char *user, const char *passwd)
{
	char *t1, *t2, *res;
	int len1 = strlen (user) + 1 + strlen (passwd);
	int len2 = BASE64_LENGTH (len1);

	t1 = (char *)malloc (len1 + 1);
	sprintf (t1, "%s:%s", user, passwd);

	res = (char *)malloc (6+len2 + 1);
	strcpy(res, "Basic ");
	t2 = res+6;
	base64_encode (t1, t2, len1);

	free(t1);
	return res;
}