path: root/e-util/e-passwords.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */

/*
 * e-passwords.c
 *
 * Copyright (C) 2001 Ximian, Inc.
 */

/*
 * 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.
 */

#include "e-passwords.h"
#include <libgnome/gnome-config.h>

static char *decode_base64 (char *base64);

static GHashTable *passwords = NULL;

static int base64_encode_close(unsigned char *in, int inlen, gboolean break_lines, unsigned char *out, int *state, int *save);
static int base64_encode_step(unsigned char *in, int len, gboolean break_lines, unsigned char *out, int *state, int *save);

void
e_passwords_init ()
{
    char *key, *value;
    void *iter;

    passwords = g_hash_table_new (g_str_hash, g_str_equal);

    iter = gnome_config_private_init_iterator ("/Evolution/Passwords");
    if (iter) {
        while (gnome_config_iterator_next (iter, &key, &value)) {
            g_hash_table_insert (passwords,
                         decode_base64 (key),
                         decode_base64 (value));
            g_free (key);
            g_free (value);
        }
    }
}

static gboolean
free_entry (gpointer key, gpointer value, gpointer user_data)
{
    g_free (key);
    memset (value, 0, strlen (value));
    g_free (value);
    return TRUE;
}

void
e_passwords_shutdown ()
{
    gnome_config_sync ();
    g_hash_table_foreach_remove (passwords, free_entry, NULL);
    g_hash_table_destroy (passwords);
    passwords = NULL;
}


void
e_passwords_forget_passwords ()
{
    g_hash_table_foreach_remove (passwords, free_entry, NULL);
    gnome_config_private_clean_section ("/Evolution/Passwords");
    gnome_config_sync ();
}

static void
maybe_remember_password (gpointer key, gpointer password, gpointer url)
{
    char *path, *key64, *pass64;
    int len, state, save;
    
    len = strlen (url);
    if (strncmp (key, url, len) != 0)
        return;
    
    len = strlen (key);
    key64 = g_malloc0 ((len + 2) * 4 / 3 + 1);
    state = save = 0;
    base64_encode_close (key, len, FALSE, key64, &state, &save);
    path = g_strdup_printf ("/Evolution/Passwords/%s", key64);
    g_free (key64);
    
    len = strlen (password);
    pass64 = g_malloc0 ((len + 2) * 4 / 3 + 1);
    state = save = 0;
    base64_encode_close (password, len, FALSE, pass64, &state, &save);
    
    gnome_config_private_set_string (path, pass64);
    g_free (path);
    g_free (pass64);
}

void
e_passwords_remember_password (const char *url)
{
    g_hash_table_foreach (passwords, maybe_remember_password, (gpointer)url);
}

void
e_passwords_forget_password (const char *key)
{
    gpointer okey, value;
    
    if (g_hash_table_lookup_extended (passwords, key, &okey, &value)) {
        g_hash_table_remove (passwords, key);
        memset (value, 0, strlen (value));
        g_free (okey);
        g_free (value);
    }
}

const char *
e_passwords_get_password (const char *key)
{
    return g_hash_table_lookup (passwords, key);
}

void
e_passwords_add_password (const char *key, const char *passwd)
{
    g_hash_table_insert (passwords, (gpointer)key, (gpointer)passwd);
}

static char *base64_alphabet =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

static unsigned char camel_mime_base64_rank[256] = {
    255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
    255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
    255,255,255,255,255,255,255,255,255,255,255, 62,255,255,255, 63,
     52, 53, 54, 55, 56, 57, 58, 59, 60, 61,255,255,255,  0,255,255,
    255,  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, 25,255,255,255,255,255,
    255, 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, 51,255,255,255,255,255,
    255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
    255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
    255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
    255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
    255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
    255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
    255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
    255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,
};

/* call this when finished encoding everything, to
   flush off the last little bit */
static int
base64_encode_close(unsigned char *in, int inlen, gboolean break_lines, unsigned char *out, int *state, int *save)
{
    int c1, c2;
    unsigned char *outptr = out;

    if (inlen>0)
        outptr += base64_encode_step(in, inlen, break_lines, outptr, state, save);

    c1 = ((unsigned char *)save)[1];
    c2 = ((unsigned char *)save)[2];
    
    switch (((char *)save)[0]) {
    case 2:
        outptr[2] = base64_alphabet[ ( (c2 &0x0f) << 2 ) ];
        g_assert(outptr[2] != 0);
        goto skip;
    case 1:
        outptr[2] = '=';
    skip:
        outptr[0] = base64_alphabet[ c1 >> 2 ];
        outptr[1] = base64_alphabet[ c2 >> 4 | ( (c1&0x3) << 4 )];
        outptr[3] = '=';
        outptr += 4;
        break;
    }
    if (break_lines)
        *outptr++ = '\n';

    *save = 0;
    *state = 0;

    return outptr-out;
}

/*
  performs an 'encode step', only encodes blocks of 3 characters to the
  output at a time, saves left-over state in state and save (initialise to
  0 on first invocation).
*/
static int
base64_encode_step(unsigned char *in, int len, gboolean break_lines, unsigned char *out, int *state, int *save)
{
    register unsigned char *inptr, *outptr;

    if (len<=0)
        return 0;

    inptr = in;
    outptr = out;

    if (len + ((char *)save)[0] > 2) {
        unsigned char *inend = in+len-2;
        register int c1, c2, c3;
        register int already;

        already = *state;

        switch (((char *)save)[0]) {
        case 1: c1 = ((unsigned char *)save)[1]; goto skip1;
        case 2: c1 = ((unsigned char *)save)[1];
            c2 = ((unsigned char *)save)[2]; goto skip2;
        }
        
        /* yes, we jump into the loop, no i'm not going to change it, it's beautiful! */
        while (inptr < inend) {
            c1 = *inptr++;
        skip1:
            c2 = *inptr++;
        skip2:
            c3 = *inptr++;
            *outptr++ = base64_alphabet[ c1 >> 2 ];
            *outptr++ = base64_alphabet[ c2 >> 4 | ( (c1&0x3) << 4 ) ];
            *outptr++ = base64_alphabet[ ( (c2 &0x0f) << 2 ) | (c3 >> 6) ];
            *outptr++ = base64_alphabet[ c3 & 0x3f ];
            /* this is a bit ugly ... */
            if (break_lines && (++already)>=19) {
                *outptr++='\n';
                already = 0;
            }
        }

        ((char *)save)[0] = 0;
        len = 2-(inptr-inend);
        *state = already;
    }

    if (len>0) {
        register char *saveout;

        /* points to the slot for the next char to save */
        saveout = & (((char *)save)[1]) + ((char *)save)[0];

        /* len can only be 0 1 or 2 */
        switch(len) {
        case 2: *saveout++ = *inptr++;
        case 1: *saveout++ = *inptr++;
        }
        ((char *)save)[0]+=len;
    }

    return outptr-out;
}


/**
 * base64_decode_step: decode a chunk of base64 encoded data
 * @in: input stream
 * @len: max length of data to decode
 * @out: output stream
 * @state: holds the number of bits that are stored in @save
 * @save: leftover bits that have not yet been decoded
 *
 * Decodes a chunk of base64 encoded data
 **/
static int
base64_decode_step(unsigned char *in, int len, unsigned char *out, int *state, unsigned int *save)
{
    register unsigned char *inptr, *outptr;
    unsigned char *inend, c;
    register unsigned int v;
    int i;

    inend = in+len;
    outptr = out;

    /* convert 4 base64 bytes to 3 normal bytes */
    v=*save;
    i=*state;
    inptr = in;
    while (inptr<inend) {
        c = camel_mime_base64_rank[*inptr++];
        if (c != 0xff) {
            v = (v<<6) | c;
            i++;
            if (i==4) {
                *outptr++ = v>>16;
                *outptr++ = v>>8;
                *outptr++ = v;
                i=0;
            }
        }
    }

    *save = v;
    *state = i;

    /* quick scan back for '=' on the end somewhere */
    /* fortunately we can drop 1 output char for each trailing = (upto 2) */
    i=2;
    while (inptr>in && i) {
        inptr--;
        if (camel_mime_base64_rank[*inptr] != 0xff) {
            if (*inptr == '=')
                outptr--;
            i--;
        }
    }

    /* if i!= 0 then there is a truncation error! */
    return outptr-out;
}

static char *
decode_base64 (char *base64)
{
    char *plain, *pad = "==";
    int len, out, state, save;
    
    len = strlen (base64);
    plain = g_malloc0 (len);
    state = save = 0;
    out = base64_decode_step (base64, len, plain, &state, &save);
    if (len % 4) {
        base64_decode_step (pad, 4 - len % 4, plain + out,
                    &state, &save);
    }
    
    return plain;
}