path: root/camel/camel-pgp-context.c

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
 *  Authors: Jeffrey Stedfast <fejj@ximian.com>
 *
 *  Copyright 2001 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 "camel-pgp-context.h"

#include "camel-stream-fs.h"
#include "camel-stream-mem.h"

#include "camel-operation.h"

#include "camel-charset-map.h"

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <dirent.h>

#include <ctype.h>

#include <signal.h>
#include <sys/ioctl.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <termios.h>
#include <unistd.h>

#include <ctype.h>

#include <iconv.h>
#include <gal/unicode/gunicode.h>
#include <gal/util/e-iconv.h>

#define d(x)

struct _CamelPgpContextPrivate {
    CamelPgpType type;
    char *path;
};

static int                  pgp_sign (CamelCipherContext *ctx, const char *userid, CamelCipherHash hash,
                      CamelStream *istream, CamelStream *ostream, CamelException *ex);
static int                  pgp_clearsign (CamelCipherContext *context, const char *userid,
                       CamelCipherHash hash, CamelStream *istream,
                       CamelStream *ostream, CamelException *ex);
static CamelCipherValidity *pgp_verify (CamelCipherContext *context, CamelCipherHash hash,
                    CamelStream *istream, CamelStream *sigstream,
                    CamelException *ex);
static int                  pgp_encrypt (CamelCipherContext *context, gboolean sign, const char *userid,
                     GPtrArray *recipients, CamelStream *istream, CamelStream *ostream,
                     CamelException *ex);
static int                  pgp_decrypt (CamelCipherContext *context, CamelStream *istream,
                     CamelStream *ostream, CamelException *ex);

static const char *pgp_hash_to_id(CamelCipherContext *context, CamelCipherHash hash);
static CamelCipherHash pgp_id_to_hash(CamelCipherContext *context, const char *id);

static CamelCipherContextClass *parent_class;

static void
camel_pgp_context_init (CamelPgpContext *context)
{
    CamelCipherContext *ciph = (CamelCipherContext *)context;

    context->priv = g_new0 (struct _CamelPgpContextPrivate, 1);

    ciph->protocol = "application/pgp-encrypted";
}

static void
camel_pgp_context_finalise (CamelObject *o)
{
    CamelPgpContext *context = (CamelPgpContext *)o;
    
    g_free (context->priv->path);
    
    g_free (context->priv);
}

static void
camel_pgp_context_class_init (CamelPgpContextClass *camel_pgp_context_class)
{
    CamelCipherContextClass *camel_cipher_context_class =
        CAMEL_CIPHER_CONTEXT_CLASS (camel_pgp_context_class);
    
    parent_class = CAMEL_CIPHER_CONTEXT_CLASS (camel_type_get_global_classfuncs (camel_cipher_context_get_type ()));
    
    camel_cipher_context_class->sign = pgp_sign;
    camel_cipher_context_class->clearsign = pgp_clearsign;
    camel_cipher_context_class->verify = pgp_verify;
    camel_cipher_context_class->encrypt = pgp_encrypt;
    camel_cipher_context_class->decrypt = pgp_decrypt;
    camel_cipher_context_class->hash_to_id = pgp_hash_to_id;
    camel_cipher_context_class->id_to_hash = pgp_id_to_hash;
}

CamelType
camel_pgp_context_get_type (void)
{
    static CamelType type = CAMEL_INVALID_TYPE;
    
    if (type == CAMEL_INVALID_TYPE) {
        type = camel_type_register (camel_cipher_context_get_type (),
                        "CamelPgpContext",
                        sizeof (CamelPgpContext),
                        sizeof (CamelPgpContextClass),
                        (CamelObjectClassInitFunc) camel_pgp_context_class_init,
                        NULL,
                        (CamelObjectInitFunc) camel_pgp_context_init,
                        (CamelObjectFinalizeFunc) camel_pgp_context_finalise);
    }
    
    return type;
}


/**
 * camel_pgp_context_new:
 * @session: CamelSession
 * @type: One of CAMEL_PGP_TYPE_PGP2, PGP5, GPG, or PGP6
 * @path: path to PGP binary
 * @remember: Remember the pgp passphrase
 *
 * This creates a new CamelPgpContext object which is used to sign,
 * verify, encrypt and decrypt streams.
 *
 * Return value: the new CamelPgpContext
 **/
CamelPgpContext *
camel_pgp_context_new (CamelSession *session, CamelPgpType type, const char *path)
{
    CamelPgpContext *context;
    
    g_return_val_if_fail (session != NULL, NULL);
    
    if (type == CAMEL_PGP_TYPE_NONE || !path || !*path)
        return NULL;
    
    context = CAMEL_PGP_CONTEXT (camel_object_new (CAMEL_PGP_CONTEXT_TYPE));
    
    camel_cipher_context_construct (CAMEL_CIPHER_CONTEXT (context), session);
    
    context->priv->type = type;
    context->priv->path = g_strdup (path);
    
    return context;
}



static const gchar *
pgp_get_type_as_string (CamelPgpType type)
{
    switch (type) {
    case CAMEL_PGP_TYPE_PGP2:
        return "PGP 2.6.x";
    case CAMEL_PGP_TYPE_PGP5:
        return "PGP 5.0";
    case CAMEL_PGP_TYPE_PGP6:
        return "PGP 6.5.8";
    case CAMEL_PGP_TYPE_GPG:
        return "GnuPG";
    default:
        g_assert_not_reached ();
        return NULL;
    }
}

static gchar *
pgp_get_passphrase (CamelSession *session, CamelPgpType pgp_type, char *userid)
{
    gchar *passphrase, *prompt;
    const char *type;
    
    type = pgp_get_type_as_string (pgp_type);
    
    if (userid)
        prompt = g_strdup_printf (_("Please enter your %s passphrase for %s"),
                      type, userid);
    else
        prompt = g_strdup_printf (_("Please enter your %s passphrase"),
                      type);
    
    /* Use the userid as a key if possible, else be generic and use the type */
    passphrase = camel_session_get_password (session, prompt, TRUE,
                         NULL, userid ? userid : type,
                         NULL);
    g_free (prompt);
    
    return passphrase;
}

static void
pgp_forget_passphrase (CamelSession *session, CamelPgpType pgp_type, char *userid)
{
    const char *type = NULL;
    
    if (!userid)
        type = pgp_get_type_as_string (pgp_type);
    
    camel_session_forget_password (session, NULL, userid ? userid : type, NULL);
}

static void
pass_free (char *passphrase)
{
    if (passphrase) {
        memset (passphrase, 0, strlen (passphrase));
        g_free (passphrase);
    }
}

static int
cleanup_child (pid_t child)
{
    int status;
    pid_t wait_result;
    sigset_t mask, omask;
    
    /* PGP5 closes fds before exiting, meaning this might be called
     * too early. So wait a bit for the result.
     */
    sigemptyset (&mask);
    sigaddset (&mask, SIGALRM);
    sigprocmask (SIG_BLOCK, &mask, &omask);
    alarm (1);
    wait_result = waitpid (child, &status, 0);
    alarm (0);
    sigprocmask (SIG_SETMASK, &omask, NULL);
    
    if (wait_result == -1 && errno == EINTR) {
        /* The child is hanging: send a friendly reminder. */
        kill (child, SIGTERM);
        sleep (1);
        wait_result = waitpid (child, &status, WNOHANG);
        if (wait_result == 0) {
            /* Still hanging; use brute force. */
            kill (child, SIGKILL);
            sleep (1);
            wait_result = waitpid (child, &status, WNOHANG);
        }
    }
    
    if (wait_result != -1 && WIFEXITED (status))
        return WEXITSTATUS (status);
    else
        return -1;
}

static void
cleanup_before_exec (int fd)
{
    int maxfd, i;
    
    maxfd = sysconf (_SC_OPEN_MAX);
    if (maxfd < 0)
        return;
    
    /* Loop over all fds. */
    for (i = 0; i < maxfd; i++) {
        if ((STDIN_FILENO != i) &&
            (STDOUT_FILENO != i) &&
            (STDERR_FILENO != i) &&
            (fd != i))
            close (i);
    }
}

static int
crypto_exec_with_passwd (const char *path, char *argv[], const char *input, int inlen,
             int passwd_fds[], const char *passphrase,
             char **output, int *outlen, char **diagnostics)
{
    gboolean eof_seen, diag_eof_seen, passwd_eof_seen, input_eof_seen;
    size_t passwd_remaining, passwd_incr, input_remaining, input_incr;
    size_t size, alloc_size, diag_size, diag_alloc_size;
    int select_result, read_len, write_len, cancel_fd;
    int fds[6], *ip_fds, *op_fds, *diag_fds;
    const char *passwd_next, *input_next;
    char *buf = NULL, *diag_buf = NULL;
    fd_set fdset, write_fdset;
    struct timeval timeout;
    size_t tmp_len;
    pid_t child;
    int i;
    
    if (camel_operation_cancel_check (NULL)) {
        errno = EINTR;
        return -1;
    }
    
    for (i = 0; i < 6; i++)
        fds[i] = -1;
    
    ip_fds = fds;
    op_fds = fds + 2;
    diag_fds = fds + 4;
    
    if ((pipe (ip_fds) == -1) || (pipe (op_fds) == -1) || (pipe (diag_fds) == -1)) {
        *diagnostics = g_strdup_printf ("Couldn't create pipe to %s: %s",
                        path, g_strerror (errno));
        
        for (i = 0; i < 6; i++)
            close (fds[i]);
        
        close (passwd_fds[0]);
        close (passwd_fds[1]);
        
        return -1;
    }
    
    if (!(child = fork ())) {
        /* In child */
        
        if ((dup2 (ip_fds[0], STDIN_FILENO) < 0 ) ||
            (dup2 (op_fds[1], STDOUT_FILENO) < 0 ) ||
            (dup2 (diag_fds[1], STDERR_FILENO) < 0 )) {
            _exit (255);
        }
        
        /* Dissociate from evolution-mail's controlling
         * terminal so that pgp/gpg won't be able to read from
         * it: PGP 2 will fall back to asking for the password
         * on /dev/tty if the passed-in password is incorrect.
         * This will make that fail rather than hanging.
         */
        setsid ();
        
        /* Close excess fds */
        cleanup_before_exec (passwd_fds[0]);
        
        execvp (path, argv);
        fprintf (stderr, "Could not execute %s: %s\n", argv[0],
             g_strerror (errno));
        _exit (255);
    } else if (child < 0) {
        *diagnostics = g_strdup_printf ("Cannot fork %s: %s",
                        argv[0], g_strerror (errno));
        return -1;
    }
    
    /* Parent */
    close (ip_fds[0]);
    close (op_fds[1]);
    close (diag_fds[1]);
    close (passwd_fds[0]);
    
    fcntl (ip_fds[1], F_SETFL, O_NONBLOCK);
    fcntl (op_fds[0], F_SETFL, O_NONBLOCK);
    fcntl (diag_fds[0], F_SETFL, O_NONBLOCK);
    
    timeout.tv_sec = 10; /* timeout in seconds */
    timeout.tv_usec = 0;
    
    size = diag_size = 0;
    alloc_size = 4096;
    diag_alloc_size = 1024;
    eof_seen = diag_eof_seen = FALSE;
    
    buf = g_malloc (alloc_size);
    diag_buf = g_malloc (diag_alloc_size);
    
    passwd_next = passphrase;
    passwd_remaining = passphrase ? strlen (passphrase) : 0;
    passwd_incr = fpathconf (passwd_fds[1], _PC_PIPE_BUF);
    /* Use a reasonable default value on error. */
    if (passwd_incr <= 0)
        passwd_incr = 1024;
    passwd_eof_seen = FALSE;
    
    input_next = input;
    input_remaining = inlen;
    input_incr = fpathconf (ip_fds[1], _PC_PIPE_BUF);
    if (input_incr <= 0)
        input_incr = 1024;
    input_eof_seen = FALSE;
    
    cancel_fd = camel_operation_cancel_fd (NULL);
    
    while (!(eof_seen && diag_eof_seen)) {
        int max = 0;
        
        FD_ZERO (&fdset);
        if (!eof_seen) {
            FD_SET (op_fds[0], &fdset);
            max = op_fds[0];
        }
        if (!diag_eof_seen) {
            FD_SET (diag_fds[0], &fdset);
            max = MAX (max, diag_fds[0]);
        }
        if (cancel_fd != -1) {
            FD_SET (cancel_fd, &fdset);
            max = MAX (max, cancel_fd);
        }
        
        FD_ZERO (&write_fdset);
        if (!passwd_eof_seen) {
            FD_SET (passwd_fds[1], &write_fdset);
            max = MAX (max, passwd_fds[1]);
        }
        if (!input_eof_seen) {
            FD_SET (ip_fds[1], &write_fdset);
            max = MAX (max, ip_fds[1]);
        }
        
        select_result = select (max + 1, &fdset, &write_fdset,
                    NULL, &timeout);
        
        if (select_result < 0) {
            if (errno == EINTR)
                continue;
            break;
        } else if (select_result == 0) {
            /* timeout */
            break;
        }
        
        if (cancel_fd != -1 && FD_ISSET (cancel_fd, &fdset)) {
            /* user-cancelled */
            break;
        }
        
        if (FD_ISSET (op_fds[0], &fdset)) {
            /* More output is available. */
            
            if (size + 4096 > alloc_size) {
                alloc_size += 4096;
                buf = g_realloc (buf, alloc_size);
            }
            read_len = read (op_fds[0], &buf[size],
                     alloc_size - size - 1);
            if (read_len < 0) {
                if (errno == EINTR)
                    continue;
                break;
            }
            if (read_len == 0)
                eof_seen = TRUE;
            size += read_len;
        }
        
        if (FD_ISSET (diag_fds[0], &fdset) ) {
            /* More stderr is available. */
            
            if (diag_size + 1024 > diag_alloc_size) {
                diag_alloc_size += 1024;
                diag_buf = g_realloc (diag_buf,
                              diag_alloc_size);
            }
            
            read_len = read (diag_fds[0], &diag_buf[diag_size],
                     diag_alloc_size - diag_size - 1);
            if (read_len < 0) {
                if (errno == EINTR)
                    continue;
                break;
            }
            if (read_len == 0)
                diag_eof_seen = TRUE;
            diag_size += read_len;
        }
        
        if (FD_ISSET (passwd_fds[1], &write_fdset)) {
            /* Ready for more password input. */
            
            tmp_len = passwd_incr;
            if (tmp_len > passwd_remaining)
                tmp_len = passwd_remaining;
            write_len = write (passwd_fds[1], passwd_next,
                       tmp_len);
            if (write_len < 0) {
                if (errno == EINTR)
                    continue;
                break;
            }
            passwd_next += write_len;
            passwd_remaining -= write_len;
            if (passwd_remaining == 0) {
                close (passwd_fds[1]);
                passwd_eof_seen = TRUE;
            }
        }
        
        if (FD_ISSET (ip_fds[1], &write_fdset)) {
            /* Ready for more ciphertext input. */
            
            tmp_len = input_incr;
            if (tmp_len > input_remaining)
                tmp_len = input_remaining;
            write_len = write (ip_fds[1], input_next, tmp_len);
            if (write_len < 0) {
                if (errno == EINTR)
                    continue;
                break;
            }
            input_next += write_len;
            input_remaining -= write_len;
            if (input_remaining == 0 ) {
                close (ip_fds[1]);
                input_eof_seen = TRUE;
            }
        }
    }
    
    buf[size] = 0;
    diag_buf[diag_size] = 0;
    close (op_fds[0]);
    close (diag_fds[0]);
    
    if (!passwd_eof_seen)
        close (passwd_fds[1]);
    
    *output = buf;
    if (outlen)
        *outlen = size;
    *diagnostics = diag_buf;
    
    return cleanup_child (child);
}


/*----------------------------------------------------------------------*
 *                     Public crypto functions
 *----------------------------------------------------------------------*/

static char *
hash_string (CamelPgpContext *ctx, CamelCipherHash hash)
{
    if (hash == CAMEL_CIPHER_HASH_DEFAULT)
        return NULL;
    
    switch (ctx->priv->type) {
    case CAMEL_PGP_TYPE_GPG:
        switch (hash) {
        case CAMEL_CIPHER_HASH_MD2:
            return "MD2";
        case CAMEL_CIPHER_HASH_MD5:
            return "MD5";
        case CAMEL_CIPHER_HASH_SHA1:
            return "SHA1";
        case CAMEL_CIPHER_HASH_RIPEMD160:
            return "RIPEMD160";
        default:
            g_assert_not_reached ();
        }
        break;
    case CAMEL_PGP_TYPE_PGP2:
        /* FIXME: find a way to specify a hash algorithm for pgp2 */
        return NULL;
    case CAMEL_PGP_TYPE_PGP5:
    case CAMEL_PGP_TYPE_PGP6:
        switch (hash) {
        case CAMEL_CIPHER_HASH_MD2:
            return "+hashnum=5";
        case CAMEL_CIPHER_HASH_MD5:
            return "+hashnum=1";
        case CAMEL_CIPHER_HASH_SHA1:
            return "+hashnum=2";
        case CAMEL_CIPHER_HASH_RIPEMD160:
            return "+hashnum=3";
        default:
            g_assert_not_reached ();
        }
        break;
    default:
        g_assert_not_reached ();
        break;
    }
    
    return NULL;
}

static int
pgp_sign (CamelCipherContext *ctx, const char *userid, CamelCipherHash hash,
      CamelStream *istream, CamelStream *ostream, CamelException *ex)
{
    CamelPgpContext *context = CAMEL_PGP_CONTEXT (ctx);
    GByteArray *plaintext;
    CamelStream *stream;
    char *argv[20];
    char *ciphertext = NULL;
    char *diagnostics = NULL;
    char *passphrase = NULL;
    char *hash_str = NULL;
    int passwd_fds[2];
    char passwd_fd[32];
    int retval, i;
    
    /* check for the now unsupported pgp 2.6.x type */
    if (context->priv->type == CAMEL_PGP_TYPE_PGP2) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
                     "PGP 2.6.x is no longer supported.");
        return -1;
    }
    
    /* get the plaintext in a form we can use */
    plaintext = g_byte_array_new ();
    stream = camel_stream_mem_new ();
    camel_stream_mem_set_byte_array (CAMEL_STREAM_MEM (stream), plaintext);
    camel_stream_write_to_stream (istream, stream);
    camel_object_unref (CAMEL_OBJECT (stream));
    
    if (!plaintext->len) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
                     _("Cannot sign this message: no plaintext to sign"));
        goto exception;
    }
    
    passphrase = pgp_get_passphrase (ctx->session, context->priv->type, (char *) userid);
    if (!passphrase) {
        camel_exception_set (ex, CAMEL_EXCEPTION_USER_CANCEL,
                     _("Cannot sign this message: no password provided"));
        goto exception;
    }
    
    if (pipe (passwd_fds) < 0) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Cannot sign this message: couldn't create pipe to GPG/PGP: %s"),
                      g_strerror (errno));
        goto exception;
    }
    
    hash_str = hash_string (context, hash);
    
    i = 0;
    switch (context->priv->type) {
    case CAMEL_PGP_TYPE_GPG:
        argv[i++] = "gpg";
        
        argv[i++] = "--sign";
        argv[i++] = "-b";
        if (hash_str) {
            argv[i++] = "--digest-algo";
            argv[i++] = hash_str;
        }
        
        if (userid) {
            argv[i++] = "-u";
            argv[i++] = (char *) userid;
        }
        
        argv[i++] = "--verbose";
        argv[i++] = "--no-secmem-warning";
        argv[i++] = "--no-greeting";
        argv[i++] = "--yes";
        argv[i++] = "--always-trust";
        argv[i++] = "--batch";
        
        argv[i++] = "--armor";
        
        argv[i++] = "--output";
        argv[i++] = "-";            /* output to stdout */
        
        argv[i++] = "--passphrase-fd";
        sprintf (passwd_fd, "%d", passwd_fds[0]);
        argv[i++] = passwd_fd;
        break;
    case CAMEL_PGP_TYPE_PGP5:
        argv[i++] = "pgps";
        
        if (hash_str)
            argv[i++] = hash_str;
        
        if (userid) {
            argv[i++] = "-u";
            argv[i++] = (char *) userid;
        }
        
        argv[i++] = "-b";  /* -b means break off (detach) the signature */
        argv[i++] = "-f";  /* -f means act as a unix-style filter */
        argv[i++] = "-v";  /* -v means verbose diagnostic messages */
        argv[i++] = "-z";  /* FIXME: do we want this option!? */
        argv[i++] = "-a";  /* -a means ascii armor */
        argv[i++] = "-o";  /* -o specifies an output stream */
        argv[i++] = "-";   /* ...in this case, stdout */
        
        sprintf (passwd_fd, "PGPPASSFD=%d", passwd_fds[0]);
        putenv (passwd_fd);
        break;
    case CAMEL_PGP_TYPE_PGP2:
    case CAMEL_PGP_TYPE_PGP6:
        argv[i++] = "pgp";
        
        if (hash_str)
            argv[i++] = hash_str;
        
        if (userid) {
            argv[i++] = "-u";
            argv[i++] = (char *) userid;
        }
        
        argv[i++] = "-f";  /* -f means act as a unix-style filter */
        argv[i++] = "-l";  /* -l means show longer more descriptive diagnostic messages */
        argv[i++] = "-a";  /* -a means ascii armor */
        argv[i++] = "-o";  /* -o specifies an output stream */
        argv[i++] = "-";   /* ...in this case, stdout */
        
        argv[i++] = "-sb"; /* create a detached signature */
        sprintf (passwd_fd, "PGPPASSFD=%d", passwd_fds[0]);
        putenv (passwd_fd);
        break;
    default:
        g_assert_not_reached ();
        break;
    }
    
    argv[i++] = NULL;
    
    retval = crypto_exec_with_passwd (context->priv->path, argv,
                      plaintext->data, plaintext->len,
                      passwd_fds, passphrase,
                      &ciphertext, NULL,
                      &diagnostics);
    
    g_byte_array_free (plaintext, TRUE);
    pass_free (passphrase);
    
    if (retval != 0 || !*ciphertext) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM, diagnostics);
        g_free (diagnostics);
        g_free (ciphertext);
        pgp_forget_passphrase (ctx->session, context->priv->type, (char *) userid);
        
        return -1;
    }
    
    g_free (diagnostics);
    
    camel_stream_write (ostream, ciphertext, strlen (ciphertext));
    g_free (ciphertext);
    
    return 0;
    
 exception:
    
    g_byte_array_free (plaintext, TRUE);
    
    if (passphrase) {
        pgp_forget_passphrase (ctx->session, context->priv->type, (char *) userid);
        pass_free (passphrase);
    }
    
    return -1;
}


static int
pgp_clearsign (CamelCipherContext *ctx, const char *userid, CamelCipherHash hash,
           CamelStream *istream, CamelStream *ostream, CamelException *ex)
{
    CamelPgpContext *context = CAMEL_PGP_CONTEXT (ctx);
    GByteArray *plaintext;
    CamelStream *stream;
    char *argv[20];
    char *ciphertext = NULL;
    char *diagnostics = NULL;
    char *passphrase = NULL;
    char *hash_str = NULL;
    int passwd_fds[2];
    char passwd_fd[32];
    int retval, i;
    
    /* check for the now unsupported pgp 2.6.x type */
    if (context->priv->type == CAMEL_PGP_TYPE_PGP2) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
                     "PGP 2.6.x is no longer supported.");
        return -1;
    }
    
    /* get the plaintext in a form we can use */
    plaintext = g_byte_array_new ();
    stream = camel_stream_mem_new ();
    camel_stream_mem_set_byte_array (CAMEL_STREAM_MEM (stream), plaintext);
    camel_stream_write_to_stream (istream, stream);
    camel_object_unref (CAMEL_OBJECT (stream));
    
    if (!plaintext->len) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
                     _("Cannot sign this message: no plaintext to clearsign"));
        goto exception;
    }
    
    passphrase = pgp_get_passphrase (ctx->session, context->priv->type, (char *) userid);
    if (!passphrase) {
        camel_exception_set (ex, CAMEL_EXCEPTION_USER_CANCEL,
                     _("Cannot sign this message: no password provided"));
        goto exception;
    }
    
    if (pipe (passwd_fds) < 0) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Cannot sign this message: couldn't create pipe to GPG/PGP: %s"),
                      g_strerror (errno));
        goto exception;
    }
    
    hash_str = hash_string (context, hash);
    
    i = 0;
    switch (context->priv->type) {
    case CAMEL_PGP_TYPE_GPG:
        argv[i++] = "gpg";
        
        argv[i++] = "--clearsign";
        
        if (hash_str) {
            argv[i++] = "--digest-algo";
            argv[i++] = hash_str;
        }
        
        if (userid) {
            argv[i++] = "-u";
            argv[i++] = (char *) userid;
        }
        
        argv[i++] = "--verbose";
        argv[i++] = "--no-secmem-warning";
        argv[i++] = "--no-greeting";
        argv[i++] = "--yes";
        argv[i++] = "--always-trust";
        argv[i++] = "--batch";
        
        argv[i++] = "--armor";
        
        argv[i++] = "--output";
        argv[i++] = "-";            /* output to stdout */
        
        argv[i++] = "--passphrase-fd";
        sprintf (passwd_fd, "%d", passwd_fds[0]);
        argv[i++] = passwd_fd;
        break;
    case CAMEL_PGP_TYPE_PGP5:
        argv[i++] = "pgps";
        
        if (hash_str)
            argv[i++] = hash_str;
        
        if (userid) {
            argv[i++] = "-u";
            argv[i++] = (char *) userid;
        }
        
        argv[i++] = "-f";  /* -f means act as a unix-style filter */
        argv[i++] = "-v";  /* -v means verbose diagnostic messages */
        argv[i++] = "-z";  /* FIXME: do we want this option!? */
        argv[i++] = "-a";  /* -a means ascii armor */
        argv[i++] = "-o";  /* -o specifies an output stream */
        argv[i++] = "-";   /* ...in this case, stdout */
        
        sprintf (passwd_fd, "PGPPASSFD=%d", passwd_fds[0]);
        putenv (passwd_fd);
        break;
    case CAMEL_PGP_TYPE_PGP2:
    case CAMEL_PGP_TYPE_PGP6:
        argv[i++] = "pgp";
        
        if (hash_str)
            argv[i++] = hash_str;
        
        if (userid) {
            argv[i++] = "-u";
            argv[i++] = (char *) userid;
        }
        
        argv[i++] = "-f";  /* -f means act as a unix-style filter */
        argv[i++] = "-l";  /* -l means show longer more descriptive diagnostic messages */
        argv[i++] = "-a";  /* -a means ascii armor */
        argv[i++] = "-o";  /* -o specifies an output stream */
        argv[i++] = "-";   /* ...in this case, stdout */
        
        argv[i++] = "-st";
        sprintf (passwd_fd, "PGPPASSFD=%d", passwd_fds[0]);
        putenv (passwd_fd);
        break;
    default:
        g_assert_not_reached ();
        break;
    }
    
    argv[i++] = NULL;
    
    retval = crypto_exec_with_passwd (context->priv->path, argv,
                      plaintext->data, plaintext->len,
                      passwd_fds, passphrase,
                      &ciphertext, NULL,
                      &diagnostics);
    
    g_byte_array_free (plaintext, TRUE);
    pass_free (passphrase);
    
    if (retval != 0 || !*ciphertext) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM, diagnostics);
        g_free (diagnostics);
        g_free (ciphertext);
        pgp_forget_passphrase (ctx->session, context->priv->type, (char *) userid);
    }
    
    g_free (diagnostics);
    
    camel_stream_write (ostream, ciphertext, strlen (ciphertext));
    g_free (ciphertext);
    
    return 0;
    
 exception:
    
    g_byte_array_free (plaintext, TRUE);
    
    if (passphrase) {
        pgp_forget_passphrase (ctx->session, context->priv->type, (char *) userid);
        pass_free (passphrase);
    }
    
    return -1;
}


static char *
swrite (CamelStream *istream)
{
    CamelStream *ostream;
    char *template;
    int fd;
    
    template = g_strdup ("/tmp/evolution-pgp.XXXXXX");
    fd = mkstemp (template);
    if (fd == -1) {
        g_free (template);
        return NULL;
    }
    
    ostream = camel_stream_fs_new_with_fd (fd);
    camel_stream_write_to_stream (istream, ostream);
    camel_object_unref (CAMEL_OBJECT (ostream));
    
    return template;
}


static CamelCipherValidity *
pgp_verify (CamelCipherContext *ctx, CamelCipherHash hash, CamelStream *istream,
        CamelStream *sigstream, CamelException *ex)
{
    CamelPgpContext *context = CAMEL_PGP_CONTEXT (ctx);
    CamelCipherValidity *valid = NULL;
    GByteArray *plaintext;
    CamelStream *stream;
    char *argv[20];
    char *cleartext = NULL;
    char *diagnostics = NULL;
    int passwd_fds[2];
    char *sigfile = NULL;
    int retval, i, clearlen;
    
    /* check for the now unsupported pgp 2.6.x type */
    if (context->priv->type == CAMEL_PGP_TYPE_PGP2) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
                     "PGP 2.6.x is no longer supported.");
        return NULL;
    }
    
    /* get the plaintext in a form we can use */
    plaintext = g_byte_array_new ();
    stream = camel_stream_mem_new ();
    camel_stream_mem_set_byte_array (CAMEL_STREAM_MEM (stream), plaintext);
    camel_stream_write_to_stream (istream, stream);
    camel_object_unref (CAMEL_OBJECT (stream));
    
    if (!plaintext->len) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
                     _("Cannot verify this message: no plaintext to verify"));
        goto exception;
    }
    
    if (pipe (passwd_fds) < 0) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Cannot verify this message: couldn't create pipe to GPG/PGP: %s"),
                      g_strerror (errno));
        goto exception;
    }
    
    if (sigstream != NULL) {
        /* We are going to verify a detached signature so save
           the signature to a temp file. */
        sigfile = swrite (sigstream);
        if (!sigfile) {
            camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                          _("Cannot verify this message: couldn't create temp file: %s"),
                          g_strerror (errno));
            goto exception;
        }
    }
    
    i = 0;
    switch (context->priv->type) {
    case CAMEL_PGP_TYPE_GPG:
        argv[i++] = "gpg";
        
        argv[i++] = "--verbose";
        argv[i++] = "--no-secmem-warning";
        argv[i++] = "--no-greeting";
        argv[i++] = "--no-tty";
        if (!camel_session_is_online (ctx->session))
            argv[i++] = "--no-auto-key-retrieve";
        
        argv[i++] = "--yes";
        argv[i++] = "--batch";
        
        argv[i++] = "--verify";
        
        if (sigstream != NULL)
            argv[i++] = sigfile;
        
        argv[i++] = "-";
        break;
    case CAMEL_PGP_TYPE_PGP5:
        argv[i++] = "pgpv";
        
        argv[i++] = "-z";
        
        if (sigstream != NULL)
            argv[i++] = sigfile;
        
        argv[i++] = "-f";
        
        break;
    case CAMEL_PGP_TYPE_PGP2:
    case CAMEL_PGP_TYPE_PGP6:
        argv[i++] = "pgp";
        
        if (sigstream != NULL)
            argv[i++] = sigfile;
        
        argv[i++] = "-f";
        
        break;
    default:
        g_assert_not_reached ();
        break;
    }
    
    argv[i++] = NULL;
    
    clearlen = 0;
    retval = crypto_exec_with_passwd (context->priv->path, argv,
                      plaintext->data, plaintext->len,
                      passwd_fds, NULL,
                      &cleartext, &clearlen,
                      &diagnostics);
    
    g_byte_array_free (plaintext, TRUE);
    
    /* cleanup */
    if (sigfile) {
        unlink (sigfile);
        g_free (sigfile);
    }
    
    valid = camel_cipher_validity_new ();
    
    if (retval != 0) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM, diagnostics);
        
        camel_cipher_validity_set_valid (valid, FALSE);
    } else {
        camel_cipher_validity_set_valid (valid, TRUE);
    }
    
    if (diagnostics) {
        const char *locale;
        char *desc, *outbuf;
        size_t inlen, outlen;
        iconv_t cd;
        
        inlen = strlen (diagnostics);
        outlen = inlen * 4;
        
        desc = outbuf = g_new (unsigned char, outlen + 1);
        
        locale = e_iconv_locale_charset ();
        if (!locale)
            locale = "iso-8859-1";
        
        cd = e_iconv_open ("UTF-8", locale);
        if (cd != (iconv_t) -1) {
            const char *inbuf;
            size_t ret;
            
            inbuf = diagnostics;
            ret = e_iconv (cd, &inbuf, &inlen, &outbuf, &outlen);
            if (ret != (size_t) -1) {
                e_iconv (cd, NULL, 0, &outbuf, &outlen);
            }
            e_iconv_close (cd);
            
            *outbuf = '\0';
        } else {
            const char *inptr, *inend;
            
            g_warning ("CamelPgpContext::pgp_verify: cannot convert from %s to UTF-8", locale);
            
            inptr = diagnostics;
            inend = inptr + inlen;
            
            while (inptr && inptr < inend && g_unichar_validate (g_utf8_get_char (inptr))) {
                *outbuf++ = g_utf8_get_char (inptr) & 0xff;
                inptr = g_utf8_next_char (inptr);
            }
            
            *outbuf = '\0';
        }
        
        camel_cipher_validity_set_description (valid, desc);
        g_free (desc);
    }
    
    g_free (diagnostics);
    g_free (cleartext);
    
    return valid;
    
 exception:
    
    g_byte_array_free (plaintext, TRUE);
    
    return NULL;
}


static int
pgp_encrypt (CamelCipherContext *ctx, gboolean sign, const char *userid, GPtrArray *recipients,
         CamelStream *istream, CamelStream *ostream, CamelException *ex)
{
    CamelPgpContext *context = CAMEL_PGP_CONTEXT (ctx);
    GByteArray *plaintext;
    CamelStream *stream;
    GPtrArray *argv;
    int retval, r;
    char *ciphertext = NULL;
    char *diagnostics = NULL;
    int passwd_fds[2];
    char passwd_fd[32];
    char *passphrase = NULL;
    
    /* check for the now unsupported pgp 2.6.x type */
    if (context->priv->type == CAMEL_PGP_TYPE_PGP2) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
                     "PGP 2.6.x is no longer supported.");
        return -1;
    }
    
    /* get the plaintext in a form we can use */
    plaintext = g_byte_array_new ();
    stream = camel_stream_mem_new ();
    camel_stream_mem_set_byte_array (CAMEL_STREAM_MEM (stream), plaintext);
    camel_stream_write_to_stream (istream, stream);
    camel_object_unref (CAMEL_OBJECT (stream));
    
    if (!plaintext->len) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
                     _("Cannot encrypt this message: no plaintext to encrypt"));
        goto exception;
    }
    
    if (sign) {
        /* we only need a passphrase if we intend on signing */
        passphrase = pgp_get_passphrase (ctx->session, context->priv->type,
                         (char *) userid);
        if (!passphrase) {
            camel_exception_set (ex, CAMEL_EXCEPTION_USER_CANCEL,
                         _("Cannot encrypt this message: no password provided"));
            goto exception;
        }
    }
    
    if (pipe (passwd_fds) < 0) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Cannot encrypt this message: couldn't create pipe to GPG/PGP: %s"),
                      g_strerror (errno));
        
        goto exception;
    }
    
    /* check to make sure we have recipients */
    if (recipients->len == 0) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
                     _("Cannot encrypt this message: no recipients specified"));
        
        goto exception;
    }
    
    argv = g_ptr_array_new ();
    
    switch (context->priv->type) {
    case CAMEL_PGP_TYPE_GPG:
        g_ptr_array_add (argv, "gpg");
        
        g_ptr_array_add (argv, "--verbose");
        g_ptr_array_add (argv, "--no-secmem-warning");
        g_ptr_array_add (argv, "--no-greeting");
        g_ptr_array_add (argv, "--yes");
        g_ptr_array_add (argv, "--always-trust");
        g_ptr_array_add (argv, "--batch");
        
        g_ptr_array_add (argv, "--armor");
        
        for (r = 0; r < recipients->len; r++) {
            g_ptr_array_add (argv, "-r");
            g_ptr_array_add (argv, recipients->pdata[r]);
        }
        
        g_ptr_array_add (argv, "--output");
        g_ptr_array_add (argv, "-");            /* output to stdout */
        
        g_ptr_array_add (argv, "--encrypt");
        
        if (sign) {
            g_ptr_array_add (argv, "--sign");
            
            g_ptr_array_add (argv, "-u");
            g_ptr_array_add (argv, (char *) userid);
            
            g_ptr_array_add (argv, "--passphrase-fd");
            sprintf (passwd_fd, "%d", passwd_fds[0]);
            g_ptr_array_add (argv, passwd_fd);
        }
        break;
    case CAMEL_PGP_TYPE_PGP5:
        g_ptr_array_add (argv, "pgpe");
        
        for (r = 0; r < recipients->len; r++) {
            g_ptr_array_add (argv, "-r");
            g_ptr_array_add (argv, recipients->pdata[r]);
        }
        
        g_ptr_array_add (argv, "-f");
        g_ptr_array_add (argv, "-z");
        g_ptr_array_add (argv, "-a");
        g_ptr_array_add (argv, "-o");
        g_ptr_array_add (argv, "-");        /* output to stdout */
        
        if (sign) {
            g_ptr_array_add (argv, "-s");
            
            g_ptr_array_add (argv, "-u");
            g_ptr_array_add (argv, (gchar *) userid);
            
            sprintf (passwd_fd, "PGPPASSFD=%d", passwd_fds[0]);
            putenv (passwd_fd);
        }
        break;
    case CAMEL_PGP_TYPE_PGP2:
    case CAMEL_PGP_TYPE_PGP6:
        g_ptr_array_add (argv, "pgp");
        g_ptr_array_add (argv, "-f");
        g_ptr_array_add (argv, "-e");
        g_ptr_array_add (argv, "-a");
        g_ptr_array_add (argv, "-o");
        g_ptr_array_add (argv, "-");
        
        for (r = 0; r < recipients->len; r++)
            g_ptr_array_add (argv, recipients->pdata[r]);
        
        if (sign) {
            g_ptr_array_add (argv, "-s");
            
            g_ptr_array_add (argv, "-u");
            g_ptr_array_add (argv, (gchar *) userid);
            
            sprintf (passwd_fd, "PGPPASSFD=%d", passwd_fds[0]);
            putenv (passwd_fd);
        }
        break;
    default:
        g_assert_not_reached ();
        break;
    }
    
    g_ptr_array_add (argv, NULL);
    
    retval = crypto_exec_with_passwd (context->priv->path,
                      (char **) argv->pdata,
                      plaintext->data, plaintext->len,
                      passwd_fds, passphrase,
                      &ciphertext, NULL,
                      &diagnostics);
    
    g_byte_array_free (plaintext, TRUE);
    
    pass_free (passphrase);
    g_ptr_array_free (argv, TRUE);
    
    if (retval != 0 || !*ciphertext) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM, diagnostics);
        g_free (diagnostics);
        g_free (ciphertext);
        if (sign)
            pgp_forget_passphrase (ctx->session, context->priv->type,
                           (char *) userid);
        
        return -1;
    }
    
    g_free (diagnostics);
    
    camel_stream_write (ostream, ciphertext, strlen (ciphertext));
    g_free (ciphertext);
    
    return 0;
    
 exception:
    
    g_byte_array_free (plaintext, TRUE);
    
    if (sign) {
        pass_free (passphrase);
        pgp_forget_passphrase (ctx->session, context->priv->type, (char *) userid);
    }
    
    return -1;
}


static int
pgp_decrypt (CamelCipherContext *ctx, CamelStream *istream,
         CamelStream *ostream, CamelException *ex)
{
    CamelPgpContext *context = CAMEL_PGP_CONTEXT (ctx);
    GByteArray *ciphertext;
    CamelStream *stream;
    char *argv[15];
    char *plaintext = NULL;
    int plainlen;
    char *diagnostics = NULL;
    char *passphrase = NULL;
    int passwd_fds[2];
    char passwd_fd[32];
    int retval, i;
    
    /* check for the now unsupported pgp 2.6.x type */
    if (context->priv->type == CAMEL_PGP_TYPE_PGP2) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
                     "PGP 2.6.x is no longer supported.");
        return -1;
    }
    
    /* get the ciphertext in a form we can use */
    ciphertext = g_byte_array_new ();
    stream = camel_stream_mem_new ();
    camel_stream_mem_set_byte_array (CAMEL_STREAM_MEM (stream), ciphertext);
    camel_stream_write_to_stream (istream, stream);
    camel_object_unref (CAMEL_OBJECT (stream));
    
    if (!ciphertext->len) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM,
                     _("Cannot decrypt this message: no ciphertext to decrypt"));
        
        goto exception;
    }
    
    passphrase = pgp_get_passphrase (ctx->session, context->priv->type, NULL);
    if (!passphrase) {
        camel_exception_set (ex, CAMEL_EXCEPTION_USER_CANCEL,
                     _("Cannot decrypt this message: no password provided"));
        
        goto exception;
    }
    
    if (pipe (passwd_fds) < 0) {
        camel_exception_setv (ex, CAMEL_EXCEPTION_SYSTEM,
                      _("Cannot decrypt this message: couldn't create pipe to GPG/PGP: %s"),
                      g_strerror (errno));
        
        goto exception;
    }
    
    i = 0;
    switch (context->priv->type) {
    case CAMEL_PGP_TYPE_GPG:
        argv[i++] = "gpg";
        
        argv[i++] = "--verbose";
        argv[i++] = "--no-secmem-warning";
        argv[i++] = "--no-greeting";
        argv[i++] = "--yes";
        argv[i++] = "--batch";
        
        if (!camel_session_is_online (ctx->session))
            argv[i++] = "--no-auto-key-retrieve";
        
        argv[i++] = "--output";
        argv[i++] = "-";            /* output to stdout */
        
        argv[i++] = "--decrypt";
        
        argv[i++] = "--passphrase-fd";
        sprintf (passwd_fd, "%d", passwd_fds[0]);
        argv[i++] = passwd_fd;
        break;
    case CAMEL_PGP_TYPE_PGP5:
        argv[i++] = "pgpv";
        
        argv[i++] = "-f";
        argv[i++] = "+batchmode=1";
        
        sprintf (passwd_fd, "PGPPASSFD=%d", passwd_fds[0]);
        putenv (passwd_fd);
        break;
    case CAMEL_PGP_TYPE_PGP2:
    case CAMEL_PGP_TYPE_PGP6:
        argv[i++] = "pgp";
        
        argv[i++] = "-f";
        
        sprintf (passwd_fd, "PGPPASSFD=%d", passwd_fds[0]);
        putenv (passwd_fd);
        break;
    default:
        g_assert_not_reached ();
        break;
    }
    
    argv[i++] = NULL;
    
    retval = crypto_exec_with_passwd (context->priv->path, argv,
                      ciphertext->data, ciphertext->len,
                      passwd_fds, passphrase,
                      &plaintext, &plainlen,
                      &diagnostics);
    
    g_byte_array_free (ciphertext, TRUE);
    pass_free (passphrase);
    
    /* gpg returns '1' if it succeedes in decrypting but can't verify the signature */
    if (retval != 0 || (context->priv->type == CAMEL_PGP_TYPE_GPG && retval == 1) || !*plaintext) {
        camel_exception_set (ex, CAMEL_EXCEPTION_SYSTEM, diagnostics);
        g_free (plaintext);
        g_free (diagnostics);
        
        pgp_forget_passphrase (ctx->session, context->priv->type, NULL);
        
        return -1;
    }
    
    g_free (diagnostics);
    
    camel_stream_write (ostream, plaintext, plainlen);
    g_free (plaintext);
    
    return 0;
    
 exception:
    
    g_byte_array_free (ciphertext, TRUE);
    
    if (passphrase) {
        pgp_forget_passphrase (ctx->session, context->priv->type, NULL);
        pass_free (passphrase);
    }
    
    return -1;
}

/* this has a 1:1 relationship to CamelCipherHash */
static char *name_table[] = {
    "pgp-sha1",     /* we use sha1 as the 'default' */
    "pgp-md2",
    "pgp-md5",
    "pgp-sha1",
    "pgp-ripemd160",
};

static const char *pgp_hash_to_id(CamelCipherContext *context, CamelCipherHash hash)
{
    /* if we dont know, just use default? */
    if (hash > sizeof(name_table)/sizeof(name_table[0]))
        hash = CAMEL_CIPHER_HASH_DEFAULT;

    return name_table[hash];
}

static CamelCipherHash pgp_id_to_hash(CamelCipherContext *context, const char *id)
{
    int i;
    unsigned char *tmpid, *o;
    const char *in;
    unsigned char c;

    if (id == NULL)
        return CAMEL_CIPHER_HASH_DEFAULT;

    tmpid = alloca(strlen(id)+1);
    in = id;
    o = tmpid;
    while ((c = (unsigned char)*in++))
        *o++ = tolower(c);

    for (i=1;i<sizeof(name_table)/sizeof(name_table[0]);i++) {
        if (!strcmp(name_table[i], tmpid))
            return i;
    }

    return CAMEL_CIPHER_HASH_DEFAULT;
}