freeswitch/libs/xmlrpc-c/lib/libutil/base64.c

#include <string.h>

#include "int.h"
#include "xmlrpc-c/base64_int.h"



void
xmlrpc_base64Encode(const char * const chars,
                    char *       const base64) {

    /* 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','+','/'
    };

    unsigned int i;
    uint32_t length;
    char * p;
    const char * s;
    
    length = strlen(chars);  /* initial value */
    s = &chars[0];  /* initial value */
    p = &base64[0];  /* initial value */
    /* 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';
}