gfgit/claws-mail
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity
claws-mail/src/rfc2015.c
Paul Mangan b0ab88b4bd sync with 0.8.1cvs29
2002-08-23 08:19:50 +00:00

1402 lines
36 KiB
C
Raw Blame History

/*
* Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
* Copyright (C) 2001 Werner Koch (dd9jn)
*
* 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.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#if USE_GPGME
#include "defs.h"
#include <glib.h>
#include <stdio.h>
#include <string.h>
#include <locale.h>
#include <ctype.h>
#include <gpgme.h>
#include "intl.h"
#include "procmime.h"
#include "procheader.h"
#include "base64.h"
#include "uuencode.h"
#include "unmime.h"
#include "codeconv.h"
#include "utils.h"
#include "prefs_common.h"
#include "passphrase.h"
#include "select-keys.h"
#include "sigstatus.h"
#include "rfc2015.h"
#define DIM(v) (sizeof(v)/sizeof((v)[0]))
static char *content_names[] = {
"Content-Type",
"Content-Disposition",
"Content-Transfer-Encoding",
NULL
};
static char *mime_version_name[] = {
"Mime-Version",
NULL
};
static char *create_boundary (void);
#if 0
static void dump_mimeinfo (const char *text, MimeInfo *x)
{
debug_print ("MimeInfo[%s] %p level=%d\n",
text, x, x? x->level:0 );
if (!x)
return;
debug_print (" enc=`%s' enc_type=%d mime_type=%d\n",
x->encoding, x->encoding_type, x->mime_type );
debug_print (" cont_type=`%s' cs=`%s' name=`%s' bnd=`%s'\n",
x->content_type, x->charset, x->name, x->boundary );
debug_print (" cont_disp=`%s' fname=`%s' fpos=%ld size=%u, lvl=%d\n",
x->content_disposition, x->filename, x->fpos, x->size,
x->level );
dump_mimeinfo (".main", x->main );
dump_mimeinfo (".sub", x->sub );
dump_mimeinfo (".next", x->next );
debug_print ("MimeInfo[.parent] %p\n", x );
dump_mimeinfo (".children", x->children );
dump_mimeinfo (".plaintext", x->plaintext );
}
static void dump_part ( MimeInfo *mimeinfo, FILE *fp )
{
unsigned int size = mimeinfo->size;
int c;
if (fseek (fp, mimeinfo->fpos, SEEK_SET)) {
debug_print ("dump_part: fseek error\n");
return;
}
debug_print ("--- begin dump_part ----\n");
while (size-- && (c = getc (fp)) != EOF)
putc (c, stderr);
if (ferror (fp))
debug_print ("dump_part: read error\n");
debug_print ("--- end dump_part ----\n");
}
#endif
void
rfc2015_disable_all (void)
{
/* FIXME: set a flag, so that we don't bother the user with failed
* gpgme messages */
}
void
rfc2015_secure_remove (const char *fname)
{
if (!fname)
return;
/* fixme: overwrite the file first */
remove (fname);
}
static const gchar *
sig_status_to_string (GpgmeSigStat status)
{
const gchar *result;
switch (status) {
case GPGME_SIG_STAT_NONE:
result = _("Oops: Signature not verified");
break;
case GPGME_SIG_STAT_NOSIG:
result = _("No signature found");
break;
case GPGME_SIG_STAT_GOOD:
result = _("Good signature");
break;
case GPGME_SIG_STAT_BAD:
result = _("BAD signature");
break;
case GPGME_SIG_STAT_NOKEY:
result = _("No public key to verify the signature");
break;
case GPGME_SIG_STAT_ERROR:
result = _("Error verifying the signature");
break;
case GPGME_SIG_STAT_DIFF:
result = _("Different results for signatures");
break;
default:
result = _("Error: Unknown status");
break;
}
return result;
}
static const gchar *
sig_status_with_name (GpgmeSigStat status)
{
const gchar *result;
switch (status) {
case GPGME_SIG_STAT_NONE:
result = _("Oops: Signature not verified");
break;
case GPGME_SIG_STAT_NOSIG:
result = _("No signature found");
break;
case GPGME_SIG_STAT_GOOD:
result = _("Good signature from \"%s\"");
break;
case GPGME_SIG_STAT_BAD:
result = _("BAD signature from \"%s\"");
break;
case GPGME_SIG_STAT_NOKEY:
result = _("No public key to verify the signature");
break;
case GPGME_SIG_STAT_ERROR:
result = _("Error verifying the signature");
break;
case GPGME_SIG_STAT_DIFF:
result = _("Different results for signatures");
break;
default:
result = _("Error: Unknown status");
break;
}
return result;
}
static void
sig_status_for_key(GString *str, GpgmeCtx ctx, GpgmeSigStat status,
GpgmeKey key, const gchar *fpr)
{
gint idx = 0;
const char *uid;
uid = gpgme_key_get_string_attr (key, GPGME_ATTR_USERID, NULL, idx);
if (uid == NULL) {
g_string_sprintfa (str, "%s\n",
sig_status_to_string (status));
if ((fpr != NULL) && (*fpr != '\0'))
g_string_sprintfa (str, "Key fingerprint: %s\n", fpr);
g_string_append (str, _("Cannot find user ID for this key."));
return;
}
g_string_sprintfa (str, sig_status_with_name (status), uid);
g_string_append (str, "\n");
while (1) {
uid = gpgme_key_get_string_attr (key, GPGME_ATTR_USERID,
NULL, ++idx);
if (uid == NULL)
break;
g_string_sprintfa (str, _(" aka \"%s\"\n"),
uid);
}
}
static gchar *
sig_status_full (GpgmeCtx ctx)
{
GString *str;
gint sig_idx = 0;
GpgmeError err;
GpgmeSigStat status;
GpgmeKey key;
const char *fpr;
time_t created;
struct tm *ctime_val;
char ctime_str[80];
gchar *retval;
str = g_string_new ("");
fpr = gpgme_get_sig_status (ctx, sig_idx, &status, &created);
while (fpr != NULL) {
if (created != 0) {
ctime_val = localtime (&created);
strftime (ctime_str, sizeof (ctime_str), "%c",
ctime_val);
g_string_sprintfa (str,
_("Signature made at %s\n"),
ctime_str);
}
err = gpgme_get_sig_key (ctx, sig_idx, &key);
if (err != 0) {
g_string_sprintfa (str, "%s\n",
sig_status_to_string (status));
if ((fpr != NULL) && (*fpr != '\0'))
g_string_sprintfa (str,
_("Key fingerprint: %s\n"),
fpr);
} else {
sig_status_for_key (str, ctx, status, key, fpr);
gpgme_key_unref (key);
}
g_string_append (str, "\n\n");
fpr = gpgme_get_sig_status (ctx, ++sig_idx, &status, &created);
}
retval = str->str;
g_string_free (str, FALSE);
return retval;
}
static void check_signature (MimeInfo *mimeinfo, MimeInfo *partinfo, FILE *fp)
{
GpgmeCtx ctx = NULL;
GpgmeError err;
GpgmeData sig = NULL, text = NULL;
GpgmeSigStat status = GPGME_SIG_STAT_NONE;
GpgmegtkSigStatus statuswindow = NULL;
const char *result = NULL;
if (prefs_common.gpg_signature_popup)
statuswindow = gpgmegtk_sig_status_create ();
err = gpgme_new (&ctx);
if (err) {
debug_print ("gpgme_new failed: %s\n", gpgme_strerror (err));
goto leave;
}
/* don't include the last character (LF). It does not belong to the
* signed text */
err = gpgme_data_new_from_filepart (&text, NULL, fp,
mimeinfo->children->fpos,
mimeinfo->children->size ?
(mimeinfo->children->size - 1) : 0 );
if (!err)
err = gpgme_data_new_from_filepart (&sig, NULL, fp,
partinfo->fpos, partinfo->size);
if (err) {
debug_print ("gpgme_data_new_from_filepart failed: %s\n",
gpgme_strerror (err));
goto leave;
}
err = gpgme_op_verify (ctx, sig, text, &status);
if (err) {
debug_print ("gpgme_op_verify failed: %s\n", gpgme_strerror (err));
goto leave;
}
/* FIXME: check what the heck this sig_status_full stuff is.
* it should better go into sigstatus.c */
g_free (partinfo->sigstatus_full);
partinfo->sigstatus_full = sig_status_full (ctx);
leave:
result = gpgmegtk_sig_status_to_string(status);
debug_print("verification status: %s\n", result);
if (prefs_common.gpg_signature_popup)
gpgmegtk_sig_status_update (statuswindow, ctx);
g_free (partinfo->sigstatus);
partinfo->sigstatus = g_strdup (result);
gpgme_data_release (sig);
gpgme_data_release (text);
gpgme_release (ctx);
if (prefs_common.gpg_signature_popup)
gpgmegtk_sig_status_destroy (statuswindow);
}
/*
* Copy a gpgme data object to a temporary file and
* return this filename
*/
#if 0
static char *
copy_gpgmedata_to_temp (GpgmeData data, guint *length)
{
static int id;
char *tmp;
FILE *fp;
char buf[100];
size_t nread;
GpgmeError err;
tmp = g_strdup_printf("%s%cgpgtmp.%08x",
get_mime_tmp_dir(), G_DIR_SEPARATOR, ++id );
if ((fp = fopen(tmp, "wb")) == NULL) {
FILE_OP_ERROR(tmp, "fopen");
g_free(tmp);
return NULL;
}
err = gpgme_data_rewind ( data );
if (err)
debug_print ("gpgme_data_rewind failed: %s\n", gpgme_strerror (err));
while (!(err = gpgme_data_read (data, buf, 100, &nread))) {
fwrite ( buf, nread, 1, fp );
}
if (err != GPGME_EOF)
debug_print ("gpgme_data_read failed: %s\n", gpgme_strerror (err));
fclose (fp);
*length = nread;
return tmp;
}
#endif
static GpgmeData
pgp_decrypt (MimeInfo *partinfo, FILE *fp)
{
GpgmeCtx ctx = NULL;
GpgmeError err;
GpgmeData cipher = NULL, plain = NULL;
struct passphrase_cb_info_s info;
memset (&info, 0, sizeof info);
err = gpgme_new (&ctx);
if (err) {
debug_print ("gpgme_new failed: %s\n", gpgme_strerror (err));
goto leave;
}
err = gpgme_data_new_from_filepart (&cipher, NULL, fp,
partinfo->fpos, partinfo->size);
if (err) {
debug_print ("gpgme_data_new_from_filepart failed: %s\n",
gpgme_strerror (err));
goto leave;
}
err = gpgme_data_new (&plain);
if (err) {
debug_print ("gpgme_new failed: %s\n", gpgme_strerror (err));
goto leave;
}
if (!getenv("GPG_AGENT_INFO")) {
info.c = ctx;
gpgme_set_passphrase_cb (ctx, gpgmegtk_passphrase_cb, &info);
}
err = gpgme_op_decrypt (ctx, cipher, plain);
leave:
gpgme_data_release (cipher);
if (err) {
gpgmegtk_free_passphrase();
debug_print ("decryption failed: %s\n", gpgme_strerror (err));
gpgme_data_release (plain);
plain = NULL;
}
else
debug_print ("** decryption succeeded\n");
gpgme_release (ctx);
return plain;
}
MimeInfo * rfc2015_find_signature (MimeInfo *mimeinfo)
{
MimeInfo *partinfo;
int n = 0;
if (!mimeinfo)
return NULL;
if (g_strcasecmp (mimeinfo->content_type, "multipart/signed"))
return NULL;
debug_print ("** multipart/signed encountered\n");
/* check that we have at least 2 parts of the correct type */
for (partinfo = mimeinfo->children;
partinfo != NULL; partinfo = partinfo->next) {
if (++n > 1 && !g_strcasecmp (partinfo->content_type,
"application/pgp-signature"))
break;
}
return partinfo;
}
gboolean rfc2015_has_signature (MimeInfo *mimeinfo)
{
return rfc2015_find_signature (mimeinfo) != NULL;
}
void rfc2015_check_signature (MimeInfo *mimeinfo, FILE *fp)
{
MimeInfo *partinfo;
partinfo = rfc2015_find_signature (mimeinfo);
if (!partinfo)
return;
#if 0
g_message ("** yep, it is a pgp signature");
dump_mimeinfo ("gpg-signature", partinfo );
dump_part (partinfo, fp );
dump_mimeinfo ("signed text", mimeinfo->children );
dump_part (mimeinfo->children, fp);
#endif
check_signature (mimeinfo, partinfo, fp);
}
int rfc2015_is_encrypted (MimeInfo *mimeinfo)
{
if (!mimeinfo)
return 0;
if (g_strcasecmp (mimeinfo->content_type, "multipart/encrypted"))
return 0;
/* fixme: we should check the protocol parameter */
return 1;
}
gboolean rfc2015_msg_is_encrypted (const gchar *file)
{
FILE *fp;
MimeInfo *mimeinfo;
int ret;
if ((fp = fopen(file, "rb")) == NULL)
return FALSE;
mimeinfo = procmime_scan_mime_header(fp);
if(!mimeinfo) {
fclose(fp);
return FALSE;
}
ret = rfc2015_is_encrypted(mimeinfo);
procmime_mimeinfo_free_all(mimeinfo);
return ret != 0 ? TRUE : FALSE;
}
static int
name_cmp(const char *a, const char *b)
{
for( ; *a && *b; a++, b++) {
if(*a != *b
&& toupper(*(unsigned char *)a) != toupper(*(unsigned char *)b))
return 1;
}
return *a != *b;
}
static int
headerp(char *p, char **names)
{
int i, c;
char *p2;
p2 = strchr(p, ':');
if(!p2 || p == p2) {
return 0;
}
if(p2[-1] == ' ' || p2[-1] == '\t') {
return 0;
}
if(!names[0])
return 1;
c = *p2;
*p2 = 0;
for(i = 0 ; names[i] != NULL; i++) {
if(!name_cmp (names[i], p))
break;
}
*p2 = c;
return names[i] != NULL;
}
#define DECRYPTION_ABORT() \
{ \
procmime_mimeinfo_free_all(tmpinfo); \
msginfo->decryption_failed = 1; \
return; \
}
void rfc2015_decrypt_message (MsgInfo *msginfo, MimeInfo *mimeinfo, FILE *fp)
{
static int id;
MimeInfo *tmpinfo, *partinfo;
int ver_ok = 0;
char *fname;
GpgmeData plain;
FILE *dstfp;
size_t nread;
char buf[BUFFSIZE];
GpgmeError err;
g_return_if_fail (msginfo != NULL);
g_return_if_fail (mimeinfo != NULL);
g_return_if_fail (fp != NULL);
g_return_if_fail (mimeinfo->mime_type == MIME_MULTIPART);
debug_print ("** decrypting multipart/encrypted message\n");
/* skip headers */
if (fseek(fp, mimeinfo->fpos, SEEK_SET) < 0)
perror("fseek");
tmpinfo = procmime_scan_mime_header(fp);
if (!tmpinfo || tmpinfo->mime_type != MIME_MULTIPART) {
DECRYPTION_ABORT();
}
procmime_scan_multipart_message(tmpinfo, fp);
/* check that we have the 2 parts */
partinfo = tmpinfo->children;
if (!partinfo || !partinfo->next) {
DECRYPTION_ABORT();
}
if (!g_strcasecmp (partinfo->content_type, "application/pgp-encrypted")) {
/* Fixme: check that the version is 1 */
ver_ok = 1;
}
partinfo = partinfo->next;
if (ver_ok &&
!g_strcasecmp (partinfo->content_type, "application/octet-stream")) {
if (partinfo->next)
g_warning ("oops: pgp_encrypted with more than 2 parts");
}
else {
DECRYPTION_ABORT();
}
debug_print ("** yep, it is pgp encrypted\n");
plain = pgp_decrypt (partinfo, fp);
if (!plain) {
DECRYPTION_ABORT();
}
fname = g_strdup_printf("%s%cplaintext.%08x",
get_mime_tmp_dir(), G_DIR_SEPARATOR, ++id);
if ((dstfp = fopen(fname, "wb")) == NULL) {
FILE_OP_ERROR(fname, "fopen");
g_free(fname);
DECRYPTION_ABORT();
}
/* write the orginal header to the new file */
if (fseek(fp, tmpinfo->fpos, SEEK_SET) < 0)
perror("fseek");
while (fgets(buf, sizeof(buf), fp)) {
if (headerp (buf, content_names))
continue;
if (buf[0] == '\r' || buf[0] == '\n')
break;
fputs (buf, dstfp);
}
err = gpgme_data_rewind (plain);
if (err)
debug_print ("gpgme_data_rewind failed: %s\n", gpgme_strerror (err));
while (!(err = gpgme_data_read (plain, buf, sizeof(buf), &nread))) {
fwrite (buf, nread, 1, dstfp);
}
if (err != GPGME_EOF) {
debug_print ("gpgme_data_read failed: %s\n", gpgme_strerror (err));
}
fclose (dstfp);
procmime_mimeinfo_free_all(tmpinfo);
msginfo->plaintext_file = fname;
msginfo->decryption_failed = 0;
}
#undef DECRYPTION_ABORT
/*
* plain contains an entire mime object.
* Encrypt it and return an GpgmeData object with the encrypted version of
* the file or NULL in case of error.
*/
static GpgmeData
pgp_encrypt ( GpgmeData plain, GpgmeRecipients rset )
{
GpgmeCtx ctx = NULL;
GpgmeError err;
GpgmeData cipher = NULL;
err = gpgme_new (&ctx);
if (!err)
err = gpgme_data_new (&cipher);
if (!err) {
gpgme_set_armor (ctx, 1);
err = gpgme_op_encrypt (ctx, rset, plain, cipher);
}
if (err) {
debug_print ("encryption failed: %s\n", gpgme_strerror (err));
gpgme_data_release (cipher);
cipher = NULL;
}
else {
debug_print ("** encryption succeeded\n");
}
gpgme_release (ctx);
return cipher;
}
/*
* Create and return a list of keys matching a key id
*/
GSList *rfc2015_create_signers_list (const char *keyid)
{
GSList *key_list = NULL;
GpgmeCtx list_ctx = NULL;
GSList *p;
GpgmeError err;
GpgmeKey key;
err = gpgme_new (&list_ctx);
if (err)
goto leave;
err = gpgme_op_keylist_start (list_ctx, keyid, 1);
if (err)
goto leave;
while ( !(err = gpgme_op_keylist_next (list_ctx, &key)) ) {
key_list = g_slist_append (key_list, key);
}
if (err != GPGME_EOF)
goto leave;
err = 0;
if (key_list == NULL) {
debug_print ("no keys found for keyid \"%s\"\n", keyid);
}
leave:
if (err) {
debug_print ("rfc2015_create_signers_list failed: %s\n", gpgme_strerror (err));
for (p = key_list; p != NULL; p = p->next)
gpgme_key_unref ((GpgmeKey) p->data);
g_slist_free (key_list);
}
if (list_ctx)
gpgme_release (list_ctx);
return err ? NULL : key_list;
}
/*
* Encrypt the file by extracting all recipients and finding the
* encryption keys for all of them. The file content is then replaced
* by the encrypted one. */
int
rfc2015_encrypt (const char *file, GSList *recp_list, gboolean ascii_armored)
{
FILE *fp = NULL;
char buf[BUFFSIZE];
int i, clineidx, saved_last;
char *clines[3] = {NULL};
GpgmeError err;
GpgmeData header = NULL;
GpgmeData plain = NULL;
GpgmeData cipher = NULL;
GpgmeRecipients rset = NULL;
size_t nread;
int mime_version_seen = 0;
char *boundary = create_boundary ();
/* Create the list of recipients */
rset = gpgmegtk_recipient_selection (recp_list);
if (!rset) {
debug_print ("error creating recipient list\n" );
goto failure;
}
/* Open the source file */
if ((fp = fopen(file, "rb")) == NULL) {
FILE_OP_ERROR(file, "fopen");
goto failure;
}
err = gpgme_data_new (&header);
if (!err)
err = gpgme_data_new (&plain);
if (err) {
debug_print ("gpgme_data_new failed: %s\n", gpgme_strerror (err));
goto failure;
}
/* get the content header lines from the source */
clineidx=0;
saved_last = 0;
while (!err && fgets(buf, sizeof(buf), fp)) {
/* fixme: check for overlong lines */
if (headerp (buf, content_names)) {
if (clineidx >= DIM (clines)) {
debug_print ("rfc2015_encrypt: too many content lines\n");
goto failure;
}
clines[clineidx++] = g_strdup (buf);
saved_last = 1;
continue;
}
if (saved_last) {
saved_last = 0;
if (*buf == ' ' || *buf == '\t') {
char *last = clines[clineidx-1];
clines[clineidx-1] = g_strconcat (last, buf, NULL);
g_free (last);
continue;
}
}
if (headerp (buf, mime_version_name))
mime_version_seen = 1;
if (buf[0] == '\r' || buf[0] == '\n')
break;
err = gpgme_data_write (header, buf, strlen (buf));
}
if (ferror (fp)) {
FILE_OP_ERROR (file, "fgets");
goto failure;
}
/* write them to the temp data and add the rest of the message */
for (i = 0; !err && i < clineidx; i++) {
debug_print ("%% %s:%d: cline=`%s'", __FILE__ ,__LINE__, clines[i]);
err = gpgme_data_write (plain, clines[i], strlen (clines[i]));
}
if (!err)
err = gpgme_data_write (plain, "\r\n", 2);
while (!err && fgets(buf, sizeof(buf), fp)) {
err = gpgme_data_write (plain, buf, strlen (buf));
}
if (ferror (fp)) {
FILE_OP_ERROR (file, "fgets");
goto failure;
}
if (err) {
debug_print ("gpgme_data_write failed: %s\n", gpgme_strerror (err));
goto failure;
}
cipher = pgp_encrypt (plain, rset);
gpgme_data_release (plain); plain = NULL;
gpgme_recipients_release (rset); rset = NULL;
if (!cipher)
goto failure;
/* we have the encrypted message available in cipher and now we
* are going to rewrite the source file. To be sure that file has
* been truncated we use an approach which should work everywhere:
* close the file and then reopen it for writing. It is important
* that this works, otherwise it may happen that parts of the
* plaintext are still in the file (The encrypted stuff is, due to
* compression, usually shorter than the plaintext).
*
* Yes, there is a race condition here, but everyone, who is so
* stupid to store the temp file with the plaintext in a public
* directory has to live with this anyway. */
if (fclose (fp)) {
FILE_OP_ERROR(file, "fclose");
goto failure;
}
if ((fp = fopen(file, "wb")) == NULL) {
FILE_OP_ERROR(file, "fopen");
goto failure;
}
/* Write the header, append new content lines, part 1 and part 2 header */
err = gpgme_data_rewind (header);
if (err) {
debug_print ("gpgme_data_rewind failed: %s\n", gpgme_strerror (err));
goto failure;
}
while (!(err = gpgme_data_read (header, buf, BUFFSIZE, &nread))) {
fwrite (buf, nread, 1, fp);
}
if (err != GPGME_EOF) {
debug_print ("gpgme_data_read failed: %s\n", gpgme_strerror (err));
goto failure;
}
if (ferror (fp)) {
FILE_OP_ERROR (file, "fwrite");
goto failure;
}
gpgme_data_release (header); header = NULL;
if (!mime_version_seen)
fputs ("MIME-Version: 1\r\n", fp);
if (ascii_armored) {
fprintf(fp,
"Content-Type: text/plain; charset=US-ASCII\r\n"
"Content-Transfer-Encoding: 7bit\r\n"
"\r\n");
} else {
fprintf (fp,
"Content-Type: multipart/encrypted;"
" protocol=\"application/pgp-encrypted\";\r\n"
" boundary=\"%s\"\r\n"
"\r\n"
"--%s\r\n"
"Content-Type: application/pgp-encrypted\r\n"
"\r\n"
"Version: 1\r\n"
"\r\n"
"--%s\r\n"
"Content-Type: application/octet-stream\r\n"
"\r\n",
boundary, boundary, boundary);
}
/* append the encrypted stuff */
err = gpgme_data_rewind (cipher);
if (err) {
debug_print ("** gpgme_data_rewind on cipher failed: %s\n",
gpgme_strerror (err));
goto failure;
}
while (!(err = gpgme_data_read (cipher, buf, BUFFSIZE, &nread))) {
fwrite (buf, nread, 1, fp);
}
if (err != GPGME_EOF) {
debug_print ("** gpgme_data_read failed: %s\n", gpgme_strerror (err));
goto failure;
}
/* and the final boundary */
if (!ascii_armored) {
fprintf (fp,
"\r\n"
"--%s--\r\n",
boundary);
}
fflush (fp);
if (ferror (fp)) {
FILE_OP_ERROR (file, "fwrite");
goto failure;
}
fclose (fp);
gpgme_data_release (cipher);
return 0;
failure:
if (fp)
fclose (fp);
gpgme_data_release (header);
gpgme_data_release (plain);
gpgme_data_release (cipher);
gpgme_recipients_release (rset);
g_free (boundary);
return -1; /* error */
}
/*
* plain contains an entire mime object. Sign it and return an
* GpgmeData object with the signature of it or NULL in case of error.
* r_siginfo returns an XML object with information about the signature.
*/
static GpgmeData
pgp_sign (GpgmeData plain, GSList *key_list, gboolean clearsign,
char **r_siginfo)
{
GSList *p;
GpgmeCtx ctx = NULL;
GpgmeError err;
GpgmeData sig = NULL;
struct passphrase_cb_info_s info;
*r_siginfo = NULL;
memset (&info, 0, sizeof info);
err = gpgme_new (&ctx);
if (err)
goto leave;
err = gpgme_data_new (&sig);
if (err)
goto leave;
if (!getenv("GPG_AGENT_INFO")) {
info.c = ctx;
gpgme_set_passphrase_cb (ctx, gpgmegtk_passphrase_cb, &info);
}
gpgme_set_textmode (ctx, 1);
gpgme_set_armor (ctx, 1);
gpgme_signers_clear (ctx);
for (p = key_list; p != NULL; p = p->next) {
err = gpgme_signers_add (ctx, (GpgmeKey) p->data);
if (err)
goto leave;
}
for (p = key_list; p != NULL; p = p->next)
gpgme_key_unref ((GpgmeKey) p->data);
g_slist_free (key_list);
if (err)
goto leave;
err = gpgme_op_sign
(ctx, plain, sig,
clearsign ? GPGME_SIG_MODE_CLEAR : GPGME_SIG_MODE_DETACH);
if (!err)
*r_siginfo = gpgme_get_op_info (ctx, 0);
leave:
if (err) {
gpgmegtk_free_passphrase();
debug_print ("signing failed: %s\n", gpgme_strerror (err));
gpgme_data_release (sig);
sig = NULL;
}
else {
debug_print ("signing succeeded\n");
}
gpgme_release (ctx);
return sig;
}
/*
* Find TAG in XML and return a pointer into xml set just behind the
* closing angle. Return NULL if not found.
*/
static const char *
find_xml_tag (const char *xml, const char *tag)
{
int taglen = strlen (tag);
const char *s = xml;
while ( (s = strchr (s, '<')) ) {
s++;
if (!strncmp (s, tag, taglen)) {
const char *s2 = s + taglen;
if (*s2 == '>' || isspace (*(const unsigned char*)s2) ) {
/* found */
while (*s2 && *s2 != '>') /* skip attributes */
s2++;
/* fixme: do need to handle angles inside attribute vallues? */
return *s2? (s2+1):NULL;
}
}
while (*s && *s != '>') /* skip to end of tag */
s++;
}
return NULL;
}
/*
* Extract the micalg from an GnupgOperationInfo XML container.
*/
static char *
extract_micalg (char *xml)
{
const char *s;
s = find_xml_tag (xml, "GnupgOperationInfo");
if (s) {
const char *s_end = find_xml_tag (s, "/GnupgOperationInfo");
s = find_xml_tag (s, "signature");
if (s && s_end && s < s_end) {
const char *s_end2 = find_xml_tag (s, "/signature");
if (s_end2 && s_end2 < s_end) {
s = find_xml_tag (s, "micalg");
if (s && s < s_end2) {
s_end = strchr (s, '<');
if (s_end) {
char *p = g_malloc (s_end - s + 1);
memcpy (p, s, s_end - s);
p[s_end-s] = 0;
return p;
}
}
}
}
}
return NULL;
}
/*
* Sign the file and replace its content with the signed one.
*/
int
rfc2015_sign (const char *file, GSList *key_list)
{
FILE *fp = NULL;
char buf[BUFFSIZE];
int i, clineidx, saved_last;
char *clines[3] = {NULL};
GpgmeError err;
GpgmeData header = NULL;
GpgmeData plain = NULL;
GpgmeData sigdata = NULL;
size_t nread;
int mime_version_seen = 0;
char *boundary = create_boundary ();
char *micalg = NULL;
char *siginfo;
/* Open the source file */
if ((fp = fopen(file, "rb")) == NULL) {
FILE_OP_ERROR(file, "fopen");
goto failure;
}
err = gpgme_data_new (&header);
if (!err)
err = gpgme_data_new (&plain);
if (err) {
debug_print ("gpgme_data_new failed: %s\n", gpgme_strerror (err));
goto failure;
}
/* get the content header lines from the source */
clineidx = 0;
saved_last = 0;
while (!err && fgets(buf, sizeof(buf), fp)) {
/* fixme: check for overlong lines */
if (headerp (buf, content_names)) {
if (clineidx >= DIM (clines)) {
debug_print ("rfc2015_sign: too many content lines\n");
goto failure;
}
clines[clineidx++] = g_strdup (buf);
saved_last = 1;
continue;
}
if (saved_last) {
saved_last = 0;
if (*buf == ' ' || *buf == '\t') {
char *last = clines[clineidx - 1];
clines[clineidx - 1] = g_strconcat (last, buf, NULL);
g_free (last);
continue;
}
}
if (headerp (buf, mime_version_name))
mime_version_seen = 1;
if (buf[0] == '\r' || buf[0] == '\n')
break;
err = gpgme_data_write (header, buf, strlen (buf));
}
if (ferror (fp)) {
FILE_OP_ERROR (file, "fgets");
goto failure;
}
/* write them to the temp data and add the rest of the message */
for (i = 0; !err && i < clineidx; i++) {
err = gpgme_data_write (plain, clines[i], strlen (clines[i]));
}
if (!err)
err = gpgme_data_write (plain, "\r\n", 2 );
while (!err && fgets(buf, sizeof(buf), fp)) {
err = gpgme_data_write (plain, buf, strlen (buf));
}
if (ferror (fp)) {
FILE_OP_ERROR (file, "fgets");
goto failure;
}
if (err) {
debug_print ("gpgme_data_write failed: %s\n", gpgme_strerror (err));
goto failure;
}
sigdata = pgp_sign (plain, key_list, FALSE, &siginfo);
if (siginfo) {
micalg = extract_micalg (siginfo);
free (siginfo);
}
if (!sigdata)
goto failure;
/* we have the signed message available in sigdata and now we are
* going to rewrite the original file. To be sure that file has
* been truncated we use an approach which should work everywhere:
* close the file and then reopen it for writing. */
if (fclose (fp)) {
FILE_OP_ERROR(file, "fclose");
goto failure;
}
if ((fp = fopen(file, "wb")) == NULL) {
FILE_OP_ERROR(file, "fopen");
goto failure;
}
/* Write the rfc822 header and add new content lines */
err = gpgme_data_rewind (header);
if (err)
debug_print ("gpgme_data_rewind failed: %s\n", gpgme_strerror (err));
while (!(err = gpgme_data_read (header, buf, BUFFSIZE, &nread))) {
fwrite (buf, nread, 1, fp);
}
if (err != GPGME_EOF) {
debug_print ("gpgme_data_read failed: %s\n", gpgme_strerror (err));
goto failure;
}
if (ferror (fp)) {
FILE_OP_ERROR (file, "fwrite");
goto failure;
}
gpgme_data_release (header);
header = NULL;
if (!mime_version_seen)
fputs ("MIME-Version: 1.0\r\n", fp);
fprintf (fp, "Content-Type: multipart/signed; "
"protocol=\"application/pgp-signature\";\r\n");
if (micalg)
fprintf (fp, " micalg=\"%s\";", micalg);
fprintf (fp, " boundary=\"%s\"\r\n", boundary);
/* Part 1: signed material */
fprintf (fp, "\r\n"
"--%s\r\n",
boundary);
err = gpgme_data_rewind (plain);
if (err) {
debug_print ("gpgme_data_rewind on plain failed: %s\n",
gpgme_strerror (err));
goto failure;
}
while (!(err = gpgme_data_read (plain, buf, BUFFSIZE, &nread))) {
fwrite (buf, nread, 1, fp);
}
if (err != GPGME_EOF) {
debug_print ("gpgme_data_read failed: %s\n", gpgme_strerror (err));
goto failure;
}
/* Part 2: signature */
fprintf (fp, "\r\n"
"--%s\r\n",
boundary);
fputs ("Content-Type: application/pgp-signature\r\n"
"\r\n", fp);
err = gpgme_data_rewind (sigdata);
if (err) {
debug_print ("gpgme_data_rewind on sigdata failed: %s\n",
gpgme_strerror (err));
goto failure;
}
while (!(err = gpgme_data_read (sigdata, buf, BUFFSIZE, &nread))) {
fwrite (buf, nread, 1, fp);
}
if (err != GPGME_EOF) {
debug_print ("gpgme_data_read failed: %s\n", gpgme_strerror (err));
goto failure;
}
/* Final boundary */
fprintf (fp, "\r\n"
"--%s--\r\n",
boundary);
fflush (fp);
if (ferror (fp)) {
FILE_OP_ERROR (file, "fwrite");
goto failure;
}
fclose (fp);
gpgme_data_release (header);
gpgme_data_release (plain);
gpgme_data_release (sigdata);
g_free (boundary);
g_free (micalg);
return 0;
failure:
if (fp)
fclose (fp);
gpgme_data_release (header);
gpgme_data_release (plain);
gpgme_data_release (sigdata);
g_free (boundary);
g_free (micalg);
return -1; /* error */
}
/*
* Sign the file with clear text and replace its content with the signed one.
*/
gint
rfc2015_clearsign (const gchar *file, GSList *key_list)
{
FILE *fp;
gchar buf[BUFFSIZE];
GpgmeError err;
GpgmeData text = NULL;
GpgmeData sigdata = NULL;
size_t nread;
gchar *siginfo;
if ((fp = fopen(file, "rb")) == NULL) {
FILE_OP_ERROR(file, "fopen");
goto failure;
}
err = gpgme_data_new(&text);
if (err) {
debug_print("gpgme_data_new failed: %s\n", gpgme_strerror(err));
goto failure;
}
while (!err && fgets(buf, sizeof(buf), fp)) {
err = gpgme_data_write(text, buf, strlen(buf));
}
if (ferror(fp)) {
FILE_OP_ERROR(file, "fgets");
goto failure;
}
if (err) {
debug_print("gpgme_data_write failed: %s\n", gpgme_strerror(err));
goto failure;
}
sigdata = pgp_sign(text, key_list, TRUE, &siginfo);
if (siginfo) {
g_free(siginfo);
}
if (!sigdata)
goto failure;
if (fclose(fp) == EOF) {
FILE_OP_ERROR(file, "fclose");
fp = NULL;
goto failure;
}
if ((fp = fopen(file, "wb")) == NULL) {
FILE_OP_ERROR(file, "fopen");
goto failure;
}
err = gpgme_data_rewind(sigdata);
if (err) {
debug_print("gpgme_data_rewind on sigdata failed: %s\n",
gpgme_strerror(err));
goto failure;
}
while (!(err = gpgme_data_read(sigdata, buf, sizeof(buf), &nread))) {
fwrite(buf, nread, 1, fp);
}
if (err != GPGME_EOF) {
debug_print("gpgme_data_read failed: %s\n", gpgme_strerror(err));
goto failure;
}
if (fclose(fp) == EOF) {
FILE_OP_ERROR(file, "fclose");
fp = NULL;
goto failure;
}
gpgme_data_release(text);
gpgme_data_release(sigdata);
return 0;
failure:
if (fp)
fclose(fp);
gpgme_data_release(text);
gpgme_data_release(sigdata);
return -1;
}
/****************
* Create a new boundary in a way that it is very unlikely that this
* will occur in the following text. It would be easy to ensure
* uniqueness if everything is either quoted-printable or base64
* encoded (note that conversion is allowed), but because MIME bodies
* may be nested, it may happen that the same boundary has already
* been used. We avoid scanning the message for conflicts and hope the
* best.
*
* boundary := 0*69<bchars> bcharsnospace
* bchars := bcharsnospace / " "
* bcharsnospace := DIGIT / ALPHA / "'" / "(" / ")" /
* "+" / "_" / "," / "-" / "." /
* "/" / ":" / "=" / "?"
*/
static char *
create_boundary (void)
{
static char tbl[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"1234567890'()+_,./:=?";
char buf[17];
int i, equal;
int pid;
pid = getpid();
/* We make the boundary depend on the pid, so that all running
* processed generate different values even when they have been
* started within the same second and srand48(time(NULL)) has been
* used. I can't see whether this is really an advantage but it
* doesn't do any harm.
*/
equal = -1;
for(i = 0; i < sizeof(buf) - 1; i++) {
buf[i] = tbl[(lrand48() ^ pid) % (sizeof(tbl) - 1)]; /* fill with random */
if(buf[i] == '=' && equal == -1)
equal = i;
}
buf[i] = 0;
/* now make sure that we do have the sequence "=." in it which cannot
* be matched by quoted-printable or base64 encoding */
if(equal != -1 && (equal+1) < i)
buf[equal+1] = '.';
else {
buf[0] = '=';
buf[1] = '.';
}
return g_strdup(buf);
}
#endif /* USE_GPGME */
Reference in a new issue View git blame Copy permalink