path: root/camel/providers/pop3/camel-pop3-store.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/* camel-pop3-store.c : class for a pop3 store */

/* 
 * Authors:
 *   Dan Winship <danw@ximian.com>
 *   Michael Zucchi <notzed@ximian.com>
 *
 * Copyright (C) 2000-2002 Ximian, Inc. (www.ximian.com)
 *
 * 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 <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>

#include "camel-operation.h"

#include "camel-pop3-store.h"
#include "camel-pop3-folder.h"
#include "camel-stream-buffer.h"
#include "camel-session.h"
#include "camel-exception.h"
#include "camel-url.h"
#include "e-util/md5-utils.h"
#include "camel-pop3-engine.h"
#include "camel-sasl.h"
#include "camel-data-cache.h"
#include "camel-tcp-stream.h"
#include "camel-tcp-stream-raw.h"
#ifdef HAVE_SSL
#include "camel-tcp-stream-ssl.h"
#endif

/* Specified in RFC 1939 */
#define POP3_PORT 110

static CamelStoreClass *parent_class = NULL;

static void finalize (CamelObject *object);

static gboolean pop3_connect (CamelService *service, CamelException *ex);
static gboolean pop3_disconnect (CamelService *service, gboolean clean, CamelException *ex);
static GList *query_auth_types (CamelService *service, CamelException *ex);

static CamelFolder *get_folder (CamelStore *store, const char *folder_name, 
                guint32 flags, CamelException *ex);

static void init_trash (CamelStore *store);
static CamelFolder *get_trash  (CamelStore *store, CamelException *ex);

static void
camel_pop3_store_class_init (CamelPOP3StoreClass *camel_pop3_store_class)
{
    CamelServiceClass *camel_service_class =
        CAMEL_SERVICE_CLASS (camel_pop3_store_class);
    CamelStoreClass *camel_store_class =
        CAMEL_STORE_CLASS (camel_pop3_store_class);

    parent_class = CAMEL_STORE_CLASS (camel_type_get_global_classfuncs (camel_store_get_type ()));
    
    /* virtual method overload */
    camel_service_class->query_auth_types = query_auth_types;
    camel_service_class->connect = pop3_connect;
    camel_service_class->disconnect = pop3_disconnect;

    camel_store_class->get_folder = get_folder;
    camel_store_class->init_trash = init_trash;
    camel_store_class->get_trash = get_trash;
}



static void
camel_pop3_store_init (gpointer object, gpointer klass)
{
    ;
}

CamelType
camel_pop3_store_get_type (void)
{
    static CamelType camel_pop3_store_type = CAMEL_INVALID_TYPE;

    if (!camel_pop3_store_type) {
        camel_pop3_store_type = camel_type_register (CAMEL_STORE_TYPE,
                                 "CamelPOP3Store",
                                 sizeof (CamelPOP3Store),
                                 sizeof (CamelPOP3StoreClass),
                                 (CamelObjectClassInitFunc) camel_pop3_store_class_init,
                                 NULL,
                                 (CamelObjectInitFunc) camel_pop3_store_init,
                                 finalize);
    }

    return camel_pop3_store_type;
}

static void
finalize (CamelObject *object)
{
    CamelPOP3Store *pop3_store = CAMEL_POP3_STORE (object);

    /* force disconnect so we dont have it run later, after we've cleaned up some stuff */
    /* SIGH */

    camel_service_disconnect((CamelService *)pop3_store, TRUE, NULL);

    if (pop3_store->engine)
        camel_object_unref((CamelObject *)pop3_store->engine);
    if (pop3_store->cache)
        camel_object_unref((CamelObject *)pop3_store->cache);
}

enum {
    USE_SSL_NEVER,
    USE_SSL_ALWAYS,
    USE_SSL_WHEN_POSSIBLE
};

static gboolean
connect_to_server (CamelService *service, int ssl_mode, int try_starttls, int *stls_support, CamelException *ex)
{
    CamelPOP3Store *store = CAMEL_POP3_STORE (service);
    CamelStream *tcp_stream;
    CamelPOP3Command *pc;
    struct hostent *h;
    int clean_quit;
    int ret, port;
    
    h = camel_service_gethost (service, ex);
    if (!h)
        return FALSE;
    
    port = service->url->port ? service->url->port : 110;
    
#ifdef HAVE_SSL
    if (camel_url_get_param (service->url, "use_ssl")) {
        if (try_starttls)
            tcp_stream = camel_tcp_stream_ssl_new_raw (service, service->url->host);
        else {
            port = service->url->port ? service->url->port : 995;
            tcp_stream = camel_tcp_stream_ssl_new (service, service->url->host);
        }
    } else {
        tcp_stream = camel_tcp_stream_raw_new ();
    }
#else
    tcp_stream = camel_tcp_stream_raw_new ();
#endif /* HAVE_SSL */
    
    ret = camel_tcp_stream_connect (CAMEL_TCP_STREAM (tcp_stream), h, port);
    camel_free_host (h);
    if (ret == -1) {
        if (errno == EINTR)
            camel_exception_set (ex, CAMEL_EXCEPTION_USER_CANCEL,
                         _("Connection cancelled"));
        else
            camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                          _("Could not connect to %s (port %d): %s"),
                          service->url->host, port, g_strerror (errno));
        return FALSE;
    }
    
    /* parent class connect initialization */
    if (CAMEL_SERVICE_CLASS (parent_class)->connect (service, ex) == FALSE) {
        camel_object_unref (CAMEL_OBJECT (tcp_stream));
        return FALSE;
    }
    
    store->engine = camel_pop3_engine_new (tcp_stream);
    
#ifdef HAVE_SSL
    if (store->engine) {
        if (stls_support)
            *stls_support = store->engine->capa & CAMEL_POP3_CAP_STLS;
        
        if (ssl_mode == USE_SSL_WHEN_POSSIBLE) {
            if (store->engine->capa & CAMEL_POP3_CAP_STLS)
                goto starttls;
        } else if (ssl_mode == USE_SSL_ALWAYS) {
            if (try_starttls) {
                if (store->engine->capa & CAMEL_POP3_CAP_STLS) {
                /* attempt to toggle STARTTLS mode */
                    goto starttls;
                } else {
                /* server doesn't support STARTTLS, abort */
                    camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                                  _("Failed to connect to POP server %s in secure mode: %s"),
                                  service->url->host, _("SSL/TLS extension not supported."));
                    /* we have the possibility of quitting cleanly here */
                    clean_quit = TRUE;
                    goto stls_exception;
                }
            }
        }
    }
#endif /* HAVE_SSL */
    
    camel_object_unref (CAMEL_OBJECT (tcp_stream));
    
    return store->engine != NULL;
    
#ifdef HAVE_SSL
 starttls:
    /* as soon as we send a STLS command, all hope is lost of a clean QUIT if problems arise */
    clean_quit = FALSE;
    
    pc = camel_pop3_engine_command_new (store->engine, 0, NULL, NULL, "STLS\r\n");
    while (camel_pop3_engine_iterate (store->engine, NULL) > 0)
        ;
    
    ret = pc->state == CAMEL_POP3_COMMAND_OK;
    camel_pop3_engine_command_free (store->engine, pc);
    
    if (ret == FALSE) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Failed to connect to POP server %s in secure mode: %s"),
                      service->url->host, store->engine->line);
        goto stls_exception;
    }
    
    /* Okay, now toggle SSL/TLS mode */
    ret = camel_tcp_stream_ssl_enable_ssl (CAMEL_TCP_STREAM_SSL (tcp_stream));
    
    camel_object_unref (CAMEL_OBJECT (tcp_stream));
    
    if (ret == -1) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Failed to connect to POP server %s in secure mode: %s"),
                      service->url->host, _("SSL negotiations failed"));
        goto stls_exception;
    }
    
    /* rfc2595, section 4 states that after a successful STLS
           command, the client MUST discard prior CAPA responses */
    camel_pop3_engine_reget_capabilities (store->engine);
    
    return TRUE;
    
 stls_exception:
    if (clean_quit) {
        /* try to disconnect cleanly */
        pc = camel_pop3_engine_command_new (store->engine, 0, NULL, NULL, "QUIT\r\n");
        while (camel_pop3_engine_iterate (store->engine, NULL) > 0)
            ;
        camel_pop3_engine_command_free (store->engine, pc);
    }
    
    camel_object_unref (CAMEL_OBJECT (store->engine));
    camel_object_unref (CAMEL_OBJECT (tcp_stream));
    store->engine = NULL;
    
    return FALSE;
#endif /* HAVE_SSL */
}

static struct {
    char *value;
    int mode;
} ssl_options[] = {
    { "",              USE_SSL_ALWAYS        },
    { "always",        USE_SSL_ALWAYS        },
    { "when-possible", USE_SSL_WHEN_POSSIBLE },
    { "never",         USE_SSL_NEVER         },
    { NULL,            USE_SSL_NEVER         },
};

#define EXCEPTION_RETRY(ex) (camel_exception_get_id (ex) != CAMEL_EXCEPTION_USER_CANCEL && \
                 camel_exception_get_id (ex) != CAMEL_EXCEPTION_SERVICE_UNAVAILABLE)

static gboolean
connect_to_server_wrapper (CamelService *service, CamelException *ex)
{
#ifdef HAVE_SSL
    const char *use_ssl;
    int stls_supported;
    int i, ssl_mode;
    
    use_ssl = camel_url_get_param (service->url, "use_ssl");
    if (use_ssl) {
        for (i = 0; ssl_options[i].value; i++)
            if (!strcmp (ssl_options[i].value, use_ssl))
                break;
        ssl_mode = ssl_options[i].mode;
    } else
        ssl_mode = USE_SSL_NEVER;
    
    if (ssl_mode == USE_SSL_ALWAYS) {
        /* First try STARTTLS */
        if (!connect_to_server (service, ssl_mode, TRUE, &stls_supported, ex))
            if (!stls_supported && EXCEPTION_RETRY (ex)) {
                /* STARTTLS is unavailable - okay, now try old-style SSL */
                camel_exception_clear (ex);
                return connect_to_server (service, ssl_mode, FALSE, NULL, ex);
            } else {
                return FALSE;
            }
        }
        
        return TRUE;
    } else if (ssl_mode == USE_SSL_WHEN_POSSIBLE) {
        /* If the server supports STARTTLS, use it */
        return connect_to_server (service, ssl_mode, TRUE, NULL, ex);
    } else {
        /* User doesn't care about SSL */
        return connect_to_server (service, ssl_mode, FALSE, NULL, ex);
    }
#else
    return connect_to_server (service, USE_SSL_NEVER, FALSE, NULL, ex);
#endif
}

extern CamelServiceAuthType camel_pop3_password_authtype;
extern CamelServiceAuthType camel_pop3_apop_authtype;

static GList *
query_auth_types (CamelService *service, CamelException *ex)
{
    CamelPOP3Store *store = CAMEL_POP3_STORE (service);
    GList *types = NULL;

        types = CAMEL_SERVICE_CLASS (parent_class)->query_auth_types (service, ex);
    if (camel_exception_is_set (ex))
        return NULL;

    if (connect_to_server_wrapper (service, NULL)) {
        types = g_list_concat(types, g_list_copy(store->engine->auth));
        pop3_disconnect (service, TRUE, NULL);
    } else {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SERVICE_UNAVAILABLE,
                      _("Could not connect to POP server on %s"),
                      service->url->host);
    }

    return types;
}

/**
 * camel_pop3_store_expunge:
 * @store: the store
 * @ex: a CamelException
 *
 * Expunge messages from the store. This will result in the connection
 * being closed, which may cause later commands to fail if they can't
 * reconnect.
 **/
void
camel_pop3_store_expunge (CamelPOP3Store *store, CamelException *ex)
{
    CamelPOP3Command *pc;

    pc = camel_pop3_engine_command_new(store->engine, 0, NULL, NULL, "QUIT\r\n");
    while (camel_pop3_engine_iterate(store->engine, NULL) > 0)
        ;
    camel_pop3_engine_command_free(store->engine, pc);

    camel_service_disconnect (CAMEL_SERVICE (store), FALSE, ex);
}

static int
try_sasl(CamelPOP3Store *store, const char *mech, CamelException *ex)
{
    CamelPOP3Stream *stream = store->engine->stream;
    unsigned char *line, *resp;
    CamelSasl *sasl;
    unsigned int len;
    int ret;

    sasl = camel_sasl_new("pop3", mech, (CamelService *)store);
    if (sasl == NULL) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SERVICE_CANT_AUTHENTICATE,
                     _("Unable to connect to POP server.\n"
                       "No support for requested "
                       "authentication mechanism."));
        return -1;
    }

    if (camel_stream_printf((CamelStream *)stream, "AUTH %s\r\n", mech) == -1)
        goto ioerror;

    while (1) {
        if (camel_pop3_stream_line(stream, &line, &len) == -1)
            goto ioerror;
        if (strncmp(line, "+OK", 3) == 0)
            break;
        if (strncmp(line, "-ERR", 4) == 0) {
            camel_exception_setv(ex, CAMEL_EXCEPTION_SERVICE_CANT_AUTHENTICATE,
                         _("SASL `%s' Login failed: %s"), mech, line);
            goto done;
        }
        /* If we dont get continuation, or the sasl object's run out of work, or we dont get a challenge,
           its a protocol error, so fail, and try reset the server */
        if (strncmp(line, "+ ", 2) != 0
            || camel_sasl_authenticated(sasl)
            || (resp = camel_sasl_challenge_base64(sasl, line+2, ex)) == NULL) {
            camel_stream_printf((CamelStream *)stream, "*\r\n");
            camel_pop3_stream_line(stream, &line, &len);
            camel_exception_setv(ex, CAMEL_EXCEPTION_SERVICE_CANT_AUTHENTICATE,
                         _("SASL Protocol error"));
            goto done;
        }

        ret = camel_stream_printf((CamelStream *)stream, "%s\r\n", resp);
        g_free(resp);
        if (ret == -1)
            goto ioerror;

    }
    camel_object_unref((CamelObject *)sasl);
    return 0;

ioerror:
    camel_exception_setv(ex, CAMEL_EXCEPTION_SERVICE_CANT_AUTHENTICATE,
                 _("I/O Error: %s"), strerror(errno));
done:
    camel_object_unref((CamelObject *)sasl);
    return -1;
}

static gboolean
pop3_try_authenticate (CamelService *service, const char *errmsg,
               CamelException *ex)
{
    CamelPOP3Store *store = (CamelPOP3Store *)service;
    int status;
    CamelPOP3Command *pcu = NULL, *pcp = NULL;

    /* override, testing only */
    /*printf("Forcing authmech to 'login'\n");
    service->url->authmech = g_strdup("LOGIN");*/

    if (!service->url->passwd) {
        char *prompt;
        
        prompt = g_strdup_printf (_("%sPlease enter the POP password for %s@%s"),
                      errmsg ? errmsg : "",
                      service->url->user,
                      service->url->host);
        service->url->passwd = camel_session_get_password (camel_service_get_session (service),
                                   prompt, TRUE, service, "password", ex);
        g_free (prompt);
        if (!service->url->passwd)
            return FALSE;
    }

    if (!service->url->authmech) {
        /* pop engine will take care of pipelining ability */
        pcu = camel_pop3_engine_command_new(store->engine, 0, NULL, NULL, "USER %s\r\n", service->url->user);
        pcp = camel_pop3_engine_command_new(store->engine, 0, NULL, NULL, "PASS %s\r\n", service->url->passwd);
    } else if (strcmp(service->url->authmech, "+APOP") == 0 && store->engine->apop) {
        char *secret, md5asc[33], *d;
        unsigned char md5sum[16], *s;
        
        secret = alloca(strlen(store->engine->apop)+strlen(service->url->passwd)+1);
        sprintf(secret, "%s%s",  store->engine->apop, service->url->passwd);
        md5_get_digest(secret, strlen (secret), md5sum);

        for (s = md5sum, d = md5asc; d < md5asc + 32; s++, d += 2)
            sprintf (d, "%.2x", *s);
        
        pcp = camel_pop3_engine_command_new(store->engine, 0, NULL, NULL, "APOP %s %s\r\n", service->url->user, md5asc);
    } else {
        CamelServiceAuthType *auth;
        GList *l;

        l = store->engine->auth;
        while (l) {
            auth = l->data;
            if (strcmp(auth->authproto, service->url->authmech) == 0)
                return try_sasl(store, service->url->authmech, ex) == -1;
            l = l->next;
        }

        camel_exception_set (ex, CAMEL_EXCEPTION_SERVICE_CANT_AUTHENTICATE,
                     _("Unable to connect to POP server.\n"
                       "No support for requested "
                       "authentication mechanism."));
        return FALSE;
    }

    while (camel_pop3_engine_iterate(store->engine, pcp) > 0)
        ;
    status = pcp->state != CAMEL_POP3_COMMAND_OK;
    if (status) {
        camel_exception_setv(ex,  CAMEL_EXCEPTION_SERVICE_CANT_AUTHENTICATE,
                     _("Unable to connect to POP server.\nError sending password: %s"),
                     store->engine->line);
    }
    camel_pop3_engine_command_free(store->engine, pcp);

    if (pcu)
        camel_pop3_engine_command_free(store->engine, pcu);

    return status;
}

static gboolean
pop3_connect (CamelService *service, CamelException *ex)
{
    char *errbuf = NULL;
    gboolean tryagain;
    CamelPOP3Store *store = (CamelPOP3Store *)service;
    
    if (store->cache == NULL) {
        char *root;

        root = camel_session_get_storage_path(service->session, service, ex);
        if (root) {
            store->cache = camel_data_cache_new(root, 0, ex);
            g_free(root);
            if (store->cache) {
                /* Default cache expiry - 1 week or not visited in a day */
                camel_data_cache_set_expire_age(store->cache, 60*60*24*7);
                camel_data_cache_set_expire_access(store->cache, 60*60*24);
            }
        }
    }
    
    if (!connect_to_server_wrapper (service, ex))
        return FALSE;
    
    camel_exception_clear (ex);
    do {
        if (camel_exception_is_set (ex)) {
            errbuf = g_strdup_printf ("%s\n\n", camel_exception_get_description (ex));
            camel_exception_clear (ex);
            
            /* Uncache the password before prompting again. */
            camel_session_forget_password (camel_service_get_session (service),
                               service, "password", ex);
            g_free (service->url->passwd);
            service->url->passwd = NULL;
        }
        
        tryagain = pop3_try_authenticate (service, errbuf, ex);
        g_free (errbuf);
        errbuf = NULL;
    } while (tryagain);
    
    if (camel_exception_is_set (ex)) {
        camel_service_disconnect (service, TRUE, ex);
        return FALSE;
    }
    
    return TRUE;
}

static gboolean
pop3_disconnect (CamelService *service, gboolean clean, CamelException *ex)
{
    CamelPOP3Store *store = CAMEL_POP3_STORE (service);
    
    if (clean) {
        CamelPOP3Command *pc;
        
        pc = camel_pop3_engine_command_new(store->engine, 0, NULL, NULL, "QUIT\r\n");
        while (camel_pop3_engine_iterate(store->engine, NULL) > 0)
            ;
        camel_pop3_engine_command_free(store->engine, pc);
    }
    
    if (!CAMEL_SERVICE_CLASS (parent_class)->disconnect (service, clean, ex))
        return FALSE;
    
    camel_object_unref((CamelObject *)store->engine);
    store->engine = NULL;
    
    return TRUE;
}

static CamelFolder *
get_folder (CamelStore *store, const char *folder_name, guint32 flags, CamelException *ex)
{
    if (strcasecmp (folder_name, "inbox") != 0) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_FOLDER_INVALID,
                      _("No such folder `%s'."), folder_name);
        return NULL;
    }
    return camel_pop3_folder_new (store, ex);
}

static void
init_trash (CamelStore *store)
{
    /* no-op */
    ;
}

static CamelFolder *
get_trash (CamelStore *store, CamelException *ex)
{
    /* no-op */
    return NULL;
}