/*

Ultima Online login encryption algorithm 0.1
by Luigi Auriemma
e-mail: aluigi@autistici.org
web:    aluigi.org


Created only for the first part of the login mechanism used in my uologin
program.
Based on Ultima Online version 5.01d patch 23


    Copyright 2005,2006 Luigi Auriemma

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA

    http://www.gnu.org/licenses/gpl.txt

*/

unsigned short uolentable[] = {
    0x0068, 0x0005, 0x0007, 0x8000, 0x0002, 0x0005, 0x0005, 0x0007,
    0x000e, 0x0005, 0x000b, 0x0007, 0x8000, 0x0003, 0x8000, 0x003d,
    0x00d7, 0x8000, 0x8000, 0x000a, 0x0006, 0x0009, 0x8000, 0x8000,
    0x8000, 0x8000, 0x8000, 0x0025, 0x8000, 0x0005, 0x0004, 0x0008,
    0x0013, 0x0008, 0x0003, 0x001a, 0x0007, 0x0014, 0x0005, 0x0002,
    0x0005, 0x0001, 0x0005, 0x0002, 0x0002, 0x0011, 0x000f, 0x000a,
    0x0005, 0x8000, 0x0002, 0x0002, 0x000a, 0x028d, 0x8000, 0x0008,
    0x0007, 0x0009, 0x8000, 0x8000, 0x8000, 0x0002, 0x0025, 0x8000,
    0x00c9, 0x8000, 0x8000, 0x0229, 0x02c9, 0x0005, 0x8000, 0x000b,
    0x0049, 0x005d, 0x0005, 0x0009, 0x8000, 0x8000, 0x0006, 0x0002,
    0x8000, 0x8000, 0x8000, 0x0002, 0x000c, 0x0001, 0x000b, 0x006e,
    0x006a, 0x8000, 0x8000, 0x0004, 0x0002, 0x0049, 0x8000, 0x0031,
    0x0005, 0x0009, 0x000f, 0x000d, 0x0001, 0x0004, 0x8000, 0x0015,
    0x8000, 0x8000, 0x0003, 0x0009, 0x0013, 0x0003, 0x000e, 0x8000,
    0x001c, 0x8000, 0x0005, 0x0002, 0x8000, 0x0023, 0x0010, 0x0011,
    0x8000, 0x0009, 0x8000, 0x0002, 0x8000, 0x000d, 0x0002, 0x8000,
    0x003e, 0x8000, 0x0002, 0x0027, 0x0045, 0x0002, 0x8000, 0x8000,
    0x0042, 0x8000, 0x8000, 0x8000, 0x000b, 0x8000, 0x8000, 0x8000,
    0x0013, 0x0041, 0x8000, 0x0063, 0x8000, 0x0009, 0x8000, 0x0002,
    0x8000, 0x001a, 0x8000, 0x0102, 0x0135, 0x0033, 0x8000, 0x8000,
    0x0003, 0x0009, 0x0009, 0x0009, 0x0095, 0x8000, 0x8000, 0x0004,
    0x8000, 0x8000, 0x0005, 0x8000, 0x8000, 0x8000, 0x8000, 0x000d,
    0x8000, 0x8000, 0x8000, 0x8000, 0x8000, 0x0040, 0x0009, 0x8000,
    0x8000, 0x0003, 0x0006, 0x0009, 0x0003, 0x8000, 0x8000, 0x8000,
    0x0024, 0x8000, 0x8000, 0x8000, 0x0006, 0x00cb, 0x0001, 0x0031,
    0x0002, 0x0006, 0x0006, 0x0007, 0x8000, 0x0001, 0x8000, 0x004e,
    0x8000, 0x0002, 0x0019, 0x8000, 0x8000, 0x8000, 0x8000, 0x8000,
    0x8000, 0x010c, 0x8000, 0x8000, 0x0009, 0x8000
};

struct {
    unsigned int    e1;
    unsigned int    e2;
    unsigned int    e3;
    unsigned int    e4;
} uoenc;



void uocalcenc(unsigned int ip) {
    unsigned int    pi = ~ip;

    uoenc.e1 = ((pi ^ 0x00001357) << 16) | ((ip ^ 0xffffaaaa) & 0x0000ffff);
    uoenc.e2 = ((ip ^ 0x43210000) >> 16) | ((pi ^ 0xabcdffff) & 0xffff0000);
    uoenc.e3 = (((ip ^ pi) & 0x0f0f0f0f) ^ ip) ^ 0xa76e25ea;
    uoenc.e4 = (((ip ^ pi) & 0x0f0f0f0f) ^ pi) ^ 0xf4bc319d;
}



unsigned short uopcklen(unsigned char *data) {
//    unsigned short  num;
//    if(*data < 222) {
//        num = uolentable[*data] >> 15;
//        if(num) return(*(unsigned short *)(data + 1));
//    }
//    return(uolentable[*data]);

    if(*data < 222) {
        return(uolentable[*data]);
    }
    return(0);
}



    /* it's the same for both encryption and decryption */
void uoencrypt(unsigned char *data, int len) {
    unsigned int    t1,
                    t2;

    for(; len--; data++) {
        *data   ^= uoenc.e1;
        t1       = uoenc.e1;
        t2       = uoenc.e2;
        uoenc.e1 = ((t1 >> 1) | (t2 << 31)) ^ 0xa2417e7f;
        t2       = ((t2 >> 1) | (t1 << 31)) ^ 0x2eaba7ec;
        uoenc.e2 = ((t2 >> 1) | (t1 << 31)) ^ 0x2eaba7ed;
    }
}



int uobuildlogin(unsigned char *buff, unsigned char *user, unsigned char *pass) {
    int     len;

    buff[0] = 0x80;
    strncpy(buff + 1,      user, 30);
    strncpy(buff + 1 + 30, pass, 31);
    len = uopcklen(buff);
    uoencrypt(buff, len);
    return(len);
}