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/*
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 * LibSylph -- E-Mail client library
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 * Copyright (C) 1999-2005 Hiroyuki Yamamoto
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 *
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 * This library is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * This library is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
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 */
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#include <ctype.h>
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#define UUDECODE(c) (c=='`' ? 0 : c - ' ')
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#define N64(i) (i & ~63)
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const char uudigit[64] =
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{
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  '`', '!', '"', '#', '$', '%', '&', '\'',
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  '(', ')', '*', '+', ',', '-', '.', '/',
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  '0', '1', '2', '3', '4', '5', '6', '7',
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  '8', '9', ':', ';', '<', '=', '>', '?',
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  '@', 'A', 'B', 'C', 'D', 'E', 'F', 'G',
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  'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
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  'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
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  'X', 'Y', 'Z', '[', '\\', ']', '^', '_'
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};
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int touufrombits(unsigned char *out, const unsigned char *in, int inlen)
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{
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    int len;
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    if (inlen > 45) return -1;
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    len = (inlen * 4 + 2) / 3 + 1;
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    *out++ = uudigit[inlen];
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    for (; inlen >= 3; inlen -= 3) {
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        *out++ = uudigit[in[0] >> 2];
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        *out++ = uudigit[((in[0] << 4) & 0x30) | (in[1] >> 4)];
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        *out++ = uudigit[((in[1] << 2) & 0x3c) | (in[2] >> 6)];
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        *out++ = uudigit[in[2] & 0x3f];
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        in += 3;
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    }
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    if (inlen > 0) {
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        *out++ = uudigit[(in[0] >> 2)];
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        if (inlen == 1) {
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            *out++ = uudigit[((in[0] << 4) & 0x30)];
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        } else {
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            *out++ = uudigit[(((in[0] << 4) & 0x30) | (in[1] >> 4))] ;            
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            *out++ = uudigit[((in[1] << 2) & 0x3c)];
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        }
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    }
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    *out = '\0';
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    return len;
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}
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int fromuutobits(char *out, const char *in)
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{
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    int len, outlen, inlen;
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    register unsigned char digit1, digit2;
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    outlen = UUDECODE(in[0]);
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    in += 1;
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    if(outlen < 0 || outlen > 45)
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        return -2;
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    if(outlen == 0)
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        return 0;
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    inlen = (outlen * 4 + 2) / 3;
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    len = 0;
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    for( ; inlen>0; inlen-=4) {
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        digit1 = UUDECODE(in[0]);
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        if (N64(digit1)) return -1;
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        digit2 = UUDECODE(in[1]);
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        if (N64(digit2)) return -1;
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        out[len++] = (digit1 << 2) | (digit2 >> 4);
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        if (inlen > 2) {
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            digit1 = UUDECODE(in[2]);
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            if (N64(digit1)) return -1;
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            out[len++] = (digit2 << 4) | (digit1 >> 2);
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            if (inlen > 3) {
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                digit2 = UUDECODE(in[3]);
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                if (N64(digit2)) return -1;
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                out[len++] = (digit1 << 6) | digit2;
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            }
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        }
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        in += 4;
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    }
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    return len == outlen ? len : -3;
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}