纯C:url base64

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base64.h

#ifndef __BASE64_H__
#define __BASE64_H__

#ifdef __cplusplus
extern "C" {
#endif
char * base64_encode(const unsigned char * bindata, char * base64, int binlength);
int base64_decode(const char * base64, unsigned char * bindata);

char *Base64Encode(unsigned char *in, int inLen);
unsigned char *Base64Decode(char *in, int *outLen);

#ifdef __cplusplus
}
#endif

#endif

base64.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

//const char * base64char = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
const char * base64char = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";

char * base64_encode(const unsigned char * bindata, char * base64, int binlength)
{
    int i, j;
    unsigned char current;

    for (i = 0, j = 0; i < binlength; i += 3)
    {
        current = (bindata[i] >> 2);
        current &= (unsigned char)0x3F;
        base64[j++] = base64char[(int)current];

        current = ((unsigned char)(bindata[i] << 4)) & ((unsigned char)0x30);
        if (i + 1 >= binlength)
        {
            base64[j++] = base64char[(int)current];
            base64[j++] = '=';
            base64[j++] = '=';
            break;
        }
        current |= ((unsigned char)(bindata[i + 1] >> 4)) & ((unsigned char)0x0F);
        base64[j++] = base64char[(int)current];

        current = ((unsigned char)(bindata[i + 1] << 2)) & ((unsigned char)0x3C);
        if (i + 2 >= binlength)
        {
            base64[j++] = base64char[(int)current];
            base64[j++] = '=';
            break;
        }
        current |= ((unsigned char)(bindata[i + 2] >> 6)) & ((unsigned char)0x03);
        base64[j++] = base64char[(int)current];

        current = ((unsigned char)bindata[i + 2]) & ((unsigned char)0x3F);
        base64[j++] = base64char[(int)current];
    }
    base64[j] = '\0';
    return base64;
}

int base64_decode(const char * base64, unsigned char * bindata)
{
    int i, j;
    unsigned char k;
    unsigned char temp[4];
    for (i = 0, j = 0; base64[i] != '\0'; i += 4)
    {
        memset(temp, 0xFF, sizeof(temp));
        for (k = 0; k < 64; k++)
        {
            if (base64char[k] == base64[i])
                temp[0] = k;
        }
        for (k = 0; k < 64; k++)
        {
            if (base64char[k] == base64[i + 1])
                temp[1] = k;
        }
        for (k = 0; k < 64; k++)
        {
            if (base64char[k] == base64[i + 2])
                temp[2] = k;
        }
        for (k = 0; k < 64; k++)
        {
            if (base64char[k] == base64[i + 3])
                temp[3] = k;
        }

        bindata[j++] = ((unsigned char)(((unsigned char)(temp[0] << 2)) & 0xFC)) |
            ((unsigned char)((unsigned char)(temp[1] >> 4) & 0x03));
        if (base64[i + 2] == '=')
            break;

        bindata[j++] = ((unsigned char)(((unsigned char)(temp[1] << 4)) & 0xF0)) |
            ((unsigned char)((unsigned char)(temp[2] >> 2) & 0x0F));
        if (base64[i + 3] == '=')
            break;

        bindata[j++] = ((unsigned char)(((unsigned char)(temp[2] << 6)) & 0xF0)) |
            ((unsigned char)(temp[3] & 0x3F));
    }
    return j;
}
//URL BASE 64
char *Base64Encode(unsigned char *in, int inLen)
{
    int blen = (inLen / 3 + 1) * 4 + 1;
    char *out = (char *)malloc(blen);
    memset(out, 0x00, blen);
    base64_encode((unsigned char *)in, out, inLen);
    return out;
}

unsigned char *Base64Decode(char *in,int *outLen)
{
    int xLen = 0;
    int inLen = strlen(in);
    if (inLen == 0){ return NULL; }
    if (in[inLen - 1] != '='){
        xLen = inLen / 4 * 3;
    }else{
        xLen = inLen * 6 / 8;
    }
    unsigned char *out = (unsigned char *)malloc(xLen+1);
    memset(out, 0x00, xLen+1);
    int len = base64_decode(in, out);
    *outLen = len;
    return out;
}