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 version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 * 
 * 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.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "e-passwords.h"
#include <libgnome/gnome-config.h>
#include <libgnome/gnome-i18n.h>
#include <gtk/gtkentry.h>
#include <gtk/gtkbox.h>
#include <gtk/gtkcheckbutton.h>
#include <gtk/gtkmessagedialog.h>

static char *decode_base64 (char *base64);

static GHashTable *passwords = NULL;
static char *component_name = 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);

/**
 * e_passwords_init:
 *
 * Initializes the e_passwords routines. Must be called before any other
 * e_passwords_* function.
 **/
void
e_passwords_init (const char *component)
{
    /* create the per-session hash table */
    passwords = g_hash_table_new (g_str_hash, g_str_equal);

    component_name = g_strdup (component);
}

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

/**
 * e_passwords_shutdown:
 *
 * Cleanup routine to call before exiting.
 **/
void
e_passwords_shutdown ()
{
    /* shouldn't need this really - everything is synchronous */
    gnome_config_private_sync_file ("/Evolution");

    /* and destroy our per session hash */
    g_hash_table_foreach_remove (passwords, free_entry, NULL);
    g_hash_table_destroy (passwords);
    passwords = NULL;

    g_free (component_name);
    component_name = NULL;
}


/**
 * e_passwords_forget_passwords:
 *
 * Forgets all cached passwords, in memory and on disk.
 **/
void
e_passwords_forget_passwords ()
{
    gnome_config_private_clean_section ("/Evolution/Passwords");
    gnome_config_private_sync_file ("/Evolution");

    /* free up the session passwords */
    g_hash_table_foreach_remove (passwords, free_entry, NULL);
}

/**
 * e_passwords_clear_component_passwords:
 *
 * Forgets all disk cached passwords.
 **/
void
e_passwords_clear_component_passwords ()
{
    char *path;

    path = g_strdup_printf ("/Evolution/Passwords-%s", component_name);

    gnome_config_private_clean_section (path);
    gnome_config_private_sync_file ("/Evolution");

    g_free (path);
}

static char *
password_path (const char *key)
{
    char *keycopy, *path;
    int i;
    keycopy = g_strdup (key);

    for (i = 0; i < strlen (keycopy); i ++)
        if (keycopy[i] == '/' || keycopy[i] =='=')
            keycopy[i] = '_';
    
    path = g_strdup_printf ("/Evolution/Passwords-%s/%s", component_name, keycopy);

    g_free (keycopy);

    return path;
}

/**
 * e_passwords_remember_password:
 * @key: the key
 *
 * Saves the password associated with @key to disk.
 **/
void
e_passwords_remember_password (const char *key)
{
    gpointer okey, value;
    char *path, *pass64;
    int len, state, save;

    if (!g_hash_table_lookup_extended (passwords, key, &okey, &value))
        return;

    /* add it to the on-disk cache of passwords */
    path = password_path (okey);

    len = strlen (value);
    pass64 = g_malloc0 ((len + 2) * 4 / 3 + 1);
    state = save = 0;
    base64_encode_close (value, len, FALSE, pass64, &state, &save);

    printf ("remembering password for (%s): %s\n", path, pass64);

    gnome_config_private_set_string (path, pass64);
    g_free (path);
    g_free (pass64);

    /* now remove it from our session hash */
    g_hash_table_remove (passwords, key);
    g_free (okey);
    g_free (value);

    gnome_config_private_sync_file ("/Evolution");
}

/**
 * e_passwords_forget_password:
 * @key: the key
 *
 * Forgets the password associated with @key, in memory and on disk.
 **/
void
e_passwords_forget_password (const char *key)
{
    gpointer okey, value;
    char *path;

    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);
    }

    /* clear it in the on disk db */
    path = password_path (key);
    gnome_config_private_clean_key (path);
    gnome_config_private_sync_file ("/Evolution");
    g_free (path);
}

/**
 * e_passwords_get_password:
 * @key: the key
 *
 * Return value: the password associated with @key, or %NULL.  Caller
 * must free the returned password.
 **/
char *
e_passwords_get_password (const char *key)
{
    char *path, *passwd = g_hash_table_lookup (passwords, key);
    char *encoded = NULL;
    
    if (passwd)
        return g_strdup (passwd);
    
    /* not part of the session hash, look it up in the on disk db */
    path = password_path (key);

    encoded = gnome_config_private_get_string_with_default (path, NULL);
    
    printf ("getting password for (%s): %s\n", path, encoded);
    
    g_free (path);

    if (!encoded)
        return NULL;
    
    passwd = decode_base64 (encoded);
    g_free (encoded);
    
    return passwd;
}

/**
 * e_passwords_add_password:
 * @key: a key
 * @passwd: the password for @key
 *
 * This stores the @key/@passwd pair in the current session's password
 * hash.
 **/
void
e_passwords_add_password (const char *key, const char *passwd)
{
    gpointer okey, value;

    /* FIXME: shouldn't this be g_return_if_fail? */
    if (!key || !passwd)
        return;

    if (g_hash_table_lookup_extended (passwords, key, &okey, &value)) {
        g_hash_table_remove (passwords, key);
        g_free (okey);
        g_free (value);
    }

    g_hash_table_insert (passwords, g_strdup (key), g_strdup (passwd));
}


static void
entry_activate (GtkEntry *entry, GtkDialog *dialog)
{
    gtk_dialog_response (dialog, GTK_RESPONSE_OK);
}

/**
 * e_passwords_ask_password:
 * @title: title for the password dialog
 * @key: key to store the password under
 * @prompt: prompt string
 * @secret: whether or not the password text should be ***ed out
 * @remember_type: whether or not to offer to remember the password,
 * and for how long.
 * @remember: on input, the default state of the remember checkbox.
 * on output, the state of the checkbox when the dialog was closed.
 * @parent: parent window of the dialog, or %NULL
 *
 * Asks the user for a password.
 *
 * Return value: the password, which the caller must free, or %NULL if
 * the user cancelled the operation. *@remember will be set if the
 * return value is non-%NULL and @remember_type is not
 * E_PASSWORDS_DO_NOT_REMEMBER.
 **/
char *
e_passwords_ask_password (const char *title, const char *key,
              const char *prompt, gboolean secret,
              EPasswordsRememberType remember_type,
              gboolean *remember,
              GtkWindow *parent)
{
    GtkWidget *dialog;
    GtkWidget *check = NULL, *entry;
    char *password;
    int response;

    dialog = gtk_message_dialog_new (parent,
                     0,
                     GTK_MESSAGE_QUESTION,
                     GTK_BUTTONS_OK_CANCEL,
                     prompt);

    gtk_window_set_title (GTK_WINDOW (dialog), title);

    gtk_dialog_set_default_response (GTK_DIALOG (dialog), GTK_RESPONSE_OK);

    /* Password entry */
    entry = gtk_entry_new();
    if (secret)
        gtk_entry_set_visibility (GTK_ENTRY(entry), FALSE);

    gtk_box_pack_start (GTK_BOX (GTK_DIALOG (dialog)->vbox), 
                entry, FALSE, FALSE, 4);
    gtk_widget_show (entry);
    gtk_widget_grab_focus (entry);

    g_signal_connect (entry, "activate",
              G_CALLBACK (entry_activate), dialog);

    /* Remember the password? */
    if (remember_type != E_PASSWORDS_DO_NOT_REMEMBER) {
        const char *label;

        if (remember_type == E_PASSWORDS_REMEMBER_FOREVER)
            label = _("Remember this password");
        else
            label = _("Remember this password for the remainder of this session");
        check = gtk_check_button_new_with_label (label);
        gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (check),
                          *remember);

        gtk_box_pack_end (GTK_BOX (GTK_DIALOG (dialog)->vbox),
                  check, TRUE, FALSE, 4);
        gtk_widget_show (check);
    }

    response = gtk_dialog_run (GTK_DIALOG (dialog));

    if (response == GTK_RESPONSE_OK) {
        password = gtk_editable_get_chars (GTK_EDITABLE (entry), 0, -1);
        if (remember_type != E_PASSWORDS_DO_NOT_REMEMBER) {
            *remember = gtk_toggle_button_get_active (GTK_TOGGLE_BUTTON (check));

            if (*remember || remember_type == E_PASSWORDS_REMEMBER_FOREVER)
                e_passwords_add_password (key, password);
            if (*remember && remember_type == E_PASSWORDS_REMEMBER_FOREVER)
                e_passwords_remember_password (key);
        }
    } else
        password = NULL;

    gtk_widget_destroy (dialog);

    return password;
}



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;
}