/* from imtest.c -- IMAP/IMSP test client
 * Cyrus IMAPd 1.5.2 <URL:ftp://ftp.andrew.cmu.edu/pub/cyrus-mail/cyrus-imapd-v1.5.2.tar.gz>
 *
 * Copyright 1996, Carnegie Mellon University.  All Rights Reserved.
 * 
 * This software is made available for academic and research
 * purposes only.  No commercial license is hereby granted.
 * Copying and other reproduction is authorized only for research,
 * education, and other non-commercial purposes.  No warranties,
 * either expressed or implied, are made regarding the operation,
 * use, or results of the software.  Such a release does not permit
 * use of the code for commercial purposes or benefits by anyone
 * without specific, additional permission by the owner of the code.
 *
 * Author: Chris Newman <chrisn+@cmu.edu>
 * Start Date: 2/16/93
 */

/* base64 tables
 */
static char basis_64[] =
   "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static char index_64[128] = {
    -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
    -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,-1,
    -1,-1,-1,-1, -1,-1,-1,-1, -1,-1,-1,62, -1,-1,-1,63,
    52,53,54,55, 56,57,58,59, 60,61,-1,-1, -1,-1,-1,-1,
    -1, 0, 1, 2,  3, 4, 5, 6,  7, 8, 9,10, 11,12,13,14,
    15,16,17,18, 19,20,21,22, 23,24,25,-1, -1,-1,-1,-1,
    -1,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
    41,42,43,44, 45,46,47,48, 49,50,51,-1, -1,-1,-1,-1
};
#define CHAR64(c)  (((c) < 0 || (c) > 127) ? -1 : index_64[(c)])

void to64(out, in, inlen)
    unsigned char *out, *in;
    int inlen;
{
    unsigned char oval;
    
    while (inlen >= 3) {
	*out++ = basis_64[in[0] >> 2];
	*out++ = basis_64[((in[0] << 4) & 0x30) | (in[1] >> 4)];
	*out++ = basis_64[((in[1] << 2) & 0x3c) | (in[2] >> 6)];
	*out++ = basis_64[in[2] & 0x3f];
	in += 3;
	inlen -= 3;
    }
    if (inlen > 0) {
	*out++ = basis_64[in[0] >> 2];
	oval = (in[0] << 4) & 0x30;
	if (inlen > 1) oval |= in[1] >> 4;
	*out++ = basis_64[oval];
	*out++ = (inlen < 2) ? '=' : basis_64[(in[1] << 2) & 0x3c];
	*out++ = '=';
    }
    *out = '\0';
}

int from64(out, in)
    char *out, *in;
{
    int len = 0;
    int c1, c2, c3, c4;

    if (in[0] == '+' && in[1] == ' ') in += 2;
    if (*in == '\r') return (0);
    do {
	c1 = in[0];
	if (CHAR64(c1) == -1) return (-1);
	c2 = in[1];
	if (CHAR64(c2) == -1) return (-1);
	c3 = in[2];
	if (c3 != '=' && CHAR64(c3) == -1) return (-1); 
	c4 = in[3];
	if (c4 != '=' && CHAR64(c4) == -1) return (-1);
	in += 4;
	*out++ = (CHAR64(c1) << 2) | (CHAR64(c2) >> 4);
	++len;
	if (c3 != '=') {
	    *out++ = ((CHAR64(c2) << 4) & 0xf0) | (CHAR64(c3) >> 2);
	    ++len;
	    if (c4 != '=') {
		*out++ = ((CHAR64(c3) << 6) & 0xc0) | CHAR64(c4);
		++len;
	    }
	}
    } while (*in != '\r' && c4 != '=');

    return (len);
}