implement RFE 3239, 'Remove "Content-Disposition: attachment" from PGP/MIME signed...
[claws.git] / src / plugins / pgpmime / pgpmime.c
index 67628d06701f6822099bd766482d51efe1b48d4a..b9a3d7dfef5ebda13768ee662e833214da36d350 100644 (file)
@@ -1,10 +1,10 @@
 /*
- * Sylpheed -- a GTK+ based, lightweight, and fast e-mail client
- * Copyright (C) 1999-2006 Hiroyuki Yamamoto & the Claws Mail team
+ * Claws Mail -- a GTK+ based, lightweight, and fast e-mail client
+ * Copyright (C) 1999-2014 the Claws Mail team
  *
  * 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
+ * the Free Software Foundation; either version 3 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ * 
  */
 
 #ifdef HAVE_CONFIG_H
 #  include "config.h"
+#include "claws-features.h"
 #endif
 
 #ifdef USE_GPGME
@@ -39,6 +40,7 @@
 #include <plugins/pgpcore/sgpgme.h>
 #include <plugins/pgpcore/prefs_gpg.h>
 #include <plugins/pgpcore/passphrase.h>
+#include <plugins/pgpcore/pgp_utils.h>
 
 #include "prefs_common.h"
 
@@ -61,13 +63,17 @@ static gint pgpmime_check_signature(MimeInfo *mimeinfo);
 static PrivacyDataPGP *pgpmime_new_privacydata()
 {
        PrivacyDataPGP *data;
+       gpgme_error_t err;
 
        data = g_new0(PrivacyDataPGP, 1);
        data->data.system = &pgpmime_system;
        data->done_sigtest = FALSE;
        data->is_signed = FALSE;
        data->sigstatus = NULL;
-       gpgme_new(&data->ctx);
+       if ((err = gpgme_new(&data->ctx)) != GPG_ERR_NO_ERROR) {
+               g_warning(_("Couldn't initialize GPG context, %s"), gpgme_strerror(err));
+               return NULL;
+       }
        
        return data;
 }
@@ -86,7 +92,7 @@ static gboolean pgpmime_is_signed(MimeInfo *mimeinfo)
        const gchar *protocol;
        PrivacyDataPGP *data = NULL;
        
-       g_return_val_if_fail(mimeinfo != NULL, FALSE);
+       cm_return_val_if_fail(mimeinfo != NULL, FALSE);
        if (mimeinfo->privacy != NULL) {
                data = (PrivacyDataPGP *) mimeinfo->privacy;
                if (data->done_sigtest)
@@ -122,9 +128,10 @@ static gboolean pgpmime_is_signed(MimeInfo *mimeinfo)
                data = pgpmime_new_privacydata();
                mimeinfo->privacy = (PrivacyData *) data;
        }
-       
-       data->done_sigtest = TRUE;
-       data->is_signed = TRUE;
+       if (data != NULL) {
+               data->done_sigtest = TRUE;
+               data->is_signed = TRUE;
+       }
 
        return TRUE;
 }
@@ -169,10 +176,15 @@ static gint pgpmime_check_signature(MimeInfo *mimeinfo)
        gchar *textstr;
        gpgme_data_t sigdata = NULL, textdata = NULL;
        gpgme_error_t err;
-       g_return_val_if_fail(mimeinfo != NULL, -1);
-       g_return_val_if_fail(mimeinfo->privacy != NULL, -1);
+       cm_return_val_if_fail(mimeinfo != NULL, -1);
+       cm_return_val_if_fail(mimeinfo->privacy != NULL, -1);
        data = (PrivacyDataPGP *) mimeinfo->privacy;
-       gpgme_new(&data->ctx);
+       if ((err = gpgme_new(&data->ctx)) != GPG_ERR_NO_ERROR) {
+               debug_print(("Couldn't initialize GPG context, %s"), gpgme_strerror(err));
+               privacy_set_error(_("Couldn't initialize GPG context, %s"), gpgme_strerror(err));
+               return 0;
+       }
+
        
        debug_print("Checking PGP/MIME signature\n");
 
@@ -185,16 +197,17 @@ static gint pgpmime_check_signature(MimeInfo *mimeinfo)
        parent = procmime_mimeinfo_parent(mimeinfo);
 
        fp = g_fopen(parent->data.filename, "rb");
-       g_return_val_if_fail(fp != NULL, SIGNATURE_INVALID);
+       cm_return_val_if_fail(fp != NULL, SIGNATURE_INVALID);
        
        boundary = g_hash_table_lookup(parent->typeparameters, "boundary");
        if (!boundary) {
                privacy_set_error(_("Signature boundary not found."));
+               fclose(fp);
                return 0;
        }
        textstr = get_canonical_content(fp, boundary);
 
-       err = gpgme_data_new_from_mem(&textdata, textstr, strlen(textstr), 0);
+       err = gpgme_data_new_from_mem(&textdata, textstr, (size_t)strlen(textstr), 0);
        if (err) {
                debug_print ("gpgme_data_new_from_mem failed: %s\n",
                    gpgme_strerror (err));
@@ -227,12 +240,8 @@ static SignatureStatus pgpmime_get_sig_status(MimeInfo *mimeinfo)
 {
        PrivacyDataPGP *data = (PrivacyDataPGP *) mimeinfo->privacy;
        
-       g_return_val_if_fail(data != NULL, SIGNATURE_INVALID);
+       cm_return_val_if_fail(data != NULL, SIGNATURE_INVALID);
 
-       if (data->sigstatus == NULL && 
-           prefs_gpg_get_config()->auto_check_signatures)
-               pgpmime_check_signature(mimeinfo);
-       
        return sgpgme_sigstat_gpgme_to_privacy(data->ctx, data->sigstatus);
 }
 
@@ -240,25 +249,17 @@ static gchar *pgpmime_get_sig_info_short(MimeInfo *mimeinfo)
 {
        PrivacyDataPGP *data = (PrivacyDataPGP *) mimeinfo->privacy;
        
-       g_return_val_if_fail(data != NULL, g_strdup("Error"));
+       cm_return_val_if_fail(data != NULL, g_strdup("Error"));
 
-       if (data->sigstatus == NULL && 
-           prefs_gpg_get_config()->auto_check_signatures)
-               pgpmime_check_signature(mimeinfo);
-       
        return sgpgme_sigstat_info_short(data->ctx, data->sigstatus);
 }
 
 static gchar *pgpmime_get_sig_info_full(MimeInfo *mimeinfo)
 {
        PrivacyDataPGP *data = (PrivacyDataPGP *) mimeinfo->privacy;
-       
-       g_return_val_if_fail(data != NULL, g_strdup("Error"));
 
-       if (data->sigstatus == NULL && 
-           prefs_gpg_get_config()->auto_check_signatures)
-               pgpmime_check_signature(mimeinfo);
-       
+       cm_return_val_if_fail(data != NULL, g_strdup("Error"));
+
        return sgpgme_sigstat_info_full(data->ctx, data->sigstatus);
 }
 
@@ -266,7 +267,10 @@ static gboolean pgpmime_is_encrypted(MimeInfo *mimeinfo)
 {
        MimeInfo *tmpinfo;
        const gchar *tmpstr;
-       
+       const gchar *begin_indicator = "-----BEGIN PGP MESSAGE-----";
+       const gchar *end_indicator = "-----END PGP MESSAGE-----";
+       gchar *textdata;
+
        if (mimeinfo->type != MIMETYPE_MULTIPART)
                return FALSE;
        if (g_ascii_strcasecmp(mimeinfo->subtype, "encrypted"))
@@ -289,6 +293,21 @@ static gboolean pgpmime_is_encrypted(MimeInfo *mimeinfo)
        if (g_ascii_strcasecmp(tmpinfo->subtype, "octet-stream"))
                return FALSE;
        
+       textdata = get_part_as_string(tmpinfo);
+       if (!textdata)
+               return FALSE;
+       
+       if (!pgp_locate_armor_header(textdata, begin_indicator)) {
+               g_free(textdata);
+               return FALSE;
+       }
+       if (!pgp_locate_armor_header(textdata, end_indicator)) {
+               g_free(textdata);
+               return FALSE;
+       }
+
+       g_free(textdata);
+
        return TRUE;
 }
 
@@ -307,11 +326,12 @@ static MimeInfo *pgpmime_decrypt(MimeInfo *mimeinfo)
        gpgme_error_t err;
 
        if ((err = gpgme_new(&ctx)) != GPG_ERR_NO_ERROR) {
-       privacy_set_error(_("Couldn't initialize GPG context, %s"), gpgme_strerror(err));
+               debug_print(("Couldn't initialize GPG context, %s"), gpgme_strerror(err));
+               privacy_set_error(_("Couldn't initialize GPG context, %s"), gpgme_strerror(err));
                return NULL;
        }
        
-       g_return_val_if_fail(pgpmime_is_encrypted(mimeinfo), NULL);
+       cm_return_val_if_fail(pgpmime_is_encrypted(mimeinfo), NULL);
        
        encinfo = (MimeInfo *) g_node_nth_child(mimeinfo->node, 1)->data;
 
@@ -338,12 +358,42 @@ static MimeInfo *pgpmime_decrypt(MimeInfo *mimeinfo)
                return NULL;
        }
 
-       fprintf(dstfp, "MIME-Version: 1.0\n");
+       if (fprintf(dstfp, "MIME-Version: 1.0\n") < 0) {
+               FILE_OP_ERROR(fname, "fprintf");
+               fclose(dstfp);
+               privacy_set_error(_("Couldn't write to decrypted file %s"), fname);
+               g_free(fname);
+               gpgme_data_release(plain);
+               gpgme_release(ctx);
+               debug_print("can't open!\n");
+               return NULL;
+       }
+
+       chars = sgpgme_data_release_and_get_mem(plain, &len);
+       if (len > 0) {
+               if (fwrite(chars, 1, len, dstfp) < len) {
+                       FILE_OP_ERROR(fname, "fwrite");
+                       g_free(chars);
+                       fclose(dstfp);
+                       privacy_set_error(_("Couldn't write to decrypted file %s"), fname);
+                       g_free(fname);
+                       gpgme_data_release(plain);
+                       gpgme_release(ctx);
+                       debug_print("can't open!\n");
+                       return NULL;
+               }
+       }
+       g_free(chars);
 
-       chars = gpgme_data_release_and_get_mem(plain, &len);
-       if (len > 0)
-               fwrite(chars, len, 1, dstfp);
-       fclose(dstfp);
+       if (fclose(dstfp) == EOF) {
+               FILE_OP_ERROR(fname, "fclose");
+               privacy_set_error(_("Couldn't close decrypted file %s"), fname);
+               g_free(fname);
+               gpgme_data_release(plain);
+               gpgme_release(ctx);
+               debug_print("can't open!\n");
+               return NULL;
+       }
 
        parseinfo = procmime_scan_file(fname);
        g_free(fname);
@@ -372,22 +422,24 @@ static MimeInfo *pgpmime_decrypt(MimeInfo *mimeinfo)
                        data = pgpmime_new_privacydata();
                        decinfo->privacy = (PrivacyData *) data;        
                }
-               data->done_sigtest = TRUE;
-               data->is_signed = TRUE;
-               data->sigstatus = sigstat;
-               if (data->ctx)
-                       gpgme_release(data->ctx);
-               data->ctx = ctx;
+               if (data != NULL) {
+                       data->done_sigtest = TRUE;
+                       data->is_signed = TRUE;
+                       data->sigstatus = sigstat;
+                       if (data->ctx)
+                               gpgme_release(data->ctx);
+                       data->ctx = ctx;
+               }
        } else
                gpgme_release(ctx);
 
        return decinfo;
 }
 
-gboolean pgpmime_sign(MimeInfo *mimeinfo, PrefsAccount *account)
+gboolean pgpmime_sign(MimeInfo *mimeinfo, PrefsAccount *account, const gchar *from_addr)
 {
        MimeInfo *msgcontent, *sigmultipart, *newinfo;
-       gchar *textstr, *micalg;
+       gchar *textstr, *micalg = NULL;
        FILE *fp;
        gchar *boundary = NULL;
        gchar *sigcontent;
@@ -451,19 +503,24 @@ gboolean pgpmime_sign(MimeInfo *mimeinfo, PrefsAccount *account)
 
        fclose(fp);
 
-       gpgme_data_new_from_mem(&gpgtext, textstr, strlen(textstr), 0);
+       gpgme_data_new_from_mem(&gpgtext, textstr, (size_t)strlen(textstr), 0);
        gpgme_data_new(&gpgsig);
-       gpgme_new(&ctx);
+       if ((err = gpgme_new(&ctx)) != GPG_ERR_NO_ERROR) {
+               debug_print(("Couldn't initialize GPG context, %s"), gpgme_strerror(err));
+               privacy_set_error(_("Couldn't initialize GPG context, %s"), gpgme_strerror(err));
+               return FALSE;
+       }
        gpgme_set_textmode(ctx, 1);
        gpgme_set_armor(ctx, 1);
        gpgme_signers_clear (ctx);
 
-       if (!sgpgme_setup_signers(ctx, account)) {
+       if (!sgpgme_setup_signers(ctx, account, from_addr)) {
                gpgme_release(ctx);
                return FALSE;
        }
 
-       if (getenv("GPG_AGENT_INFO")) {
+       prefs_gpg_enable_agent(prefs_gpg_get_config()->use_gpg_agent);
+       if (getenv("GPG_AGENT_INFO") && prefs_gpg_get_config()->use_gpg_agent) {
                debug_print("GPG_AGENT_INFO environment defined, running without passphrase callback\n");
        } else {
                info.c = ctx;
@@ -487,8 +544,8 @@ gboolean pgpmime_sign(MimeInfo *mimeinfo, PrefsAccount *account)
        if (result && result->signatures) {
                gpgme_new_signature_t sig = result->signatures;
                if (gpgme_get_protocol(ctx) == GPGME_PROTOCOL_OpenPGP) {
-                       micalg = g_strdup_printf("PGP-%s", gpgme_hash_algo_name(
-                               result->signatures->hash_algo));
+                       micalg = g_strdup_printf("pgp-%s", g_ascii_strdown(gpgme_hash_algo_name(
+                               result->signatures->hash_algo),-1));
                } else {
                        micalg = g_strdup(gpgme_hash_algo_name(
                                result->signatures->hash_algo));
@@ -516,14 +573,15 @@ gboolean pgpmime_sign(MimeInfo *mimeinfo, PrefsAccount *account)
                return FALSE;
        }
 
-       gpgme_release(ctx);
-       sigcontent = gpgme_data_release_and_get_mem(gpgsig, &len);
+       sigcontent = sgpgme_data_release_and_get_mem(gpgsig, &len);
        gpgme_data_release(gpgtext);
        g_free(textstr);
 
        if (sigcontent == NULL || len <= 0) {
-               g_warning("gpgme_data_release_and_get_mem failed");
+               g_warning("sgpgme_data_release_and_get_mem failed");
                privacy_set_error(_("Data signing failed, no contents."));
+               g_free(micalg);
+               g_free(sigcontent);
                return FALSE;
        }
 
@@ -534,18 +592,15 @@ gboolean pgpmime_sign(MimeInfo *mimeinfo, PrefsAccount *account)
        newinfo = procmime_mimeinfo_new();
        newinfo->type = MIMETYPE_APPLICATION;
        newinfo->subtype = g_strdup("pgp-signature");
-       g_hash_table_insert(newinfo->typeparameters, g_strdup("name"),
-                            g_strdup("signature.asc"));
+       newinfo->description = g_strdup(_("OpenPGP digital signature"));
        newinfo->content = MIMECONTENT_MEM;
-       newinfo->disposition = DISPOSITIONTYPE_ATTACHMENT;
-       g_hash_table_insert(newinfo->dispositionparameters, g_strdup("filename"),
-                           g_strdup("signature.asc"));
        newinfo->data.mem = g_malloc(len + 1);
        g_memmove(newinfo->data.mem, sigcontent, len);
        newinfo->data.mem[len] = '\0';
        g_node_append(sigmultipart->node, newinfo->node);
 
        g_free(sigcontent);
+       gpgme_release(ctx);
 
        return TRUE;
 }
@@ -554,6 +609,23 @@ gchar *pgpmime_get_encrypt_data(GSList *recp_names)
        return sgpgme_get_encrypt_data(recp_names, GPGME_PROTOCOL_OpenPGP);
 }
 
+static const gchar *pgpmime_get_encrypt_warning(void)
+{
+       if (prefs_gpg_should_skip_encryption_warning(pgpmime_system.id))
+               return NULL;
+       else
+               return _("Please note that email headers, like Subject, "
+                        "are not encrypted by the PGP/Mime system.");
+}
+
+static void pgpmime_inhibit_encrypt_warning(gboolean inhibit)
+{
+       if (inhibit)
+               prefs_gpg_add_skip_encryption_warning(pgpmime_system.id);
+       else
+               prefs_gpg_remove_skip_encryption_warning(pgpmime_system.id);
+}
+
 gboolean pgpmime_encrypt(MimeInfo *mimeinfo, const gchar *encrypt_data)
 {
        MimeInfo *msgcontent, *encmultipart, *newinfo;
@@ -574,7 +646,12 @@ gboolean pgpmime_encrypt(MimeInfo *mimeinfo, const gchar *encrypt_data)
        
        kset = g_malloc(sizeof(gpgme_key_t)*(i+1));
        memset(kset, 0, sizeof(gpgme_key_t)*(i+1));
-       gpgme_new(&ctx);
+       if ((err = gpgme_new(&ctx)) != GPG_ERR_NO_ERROR) {
+               debug_print(("Couldn't initialize GPG context, %s"), gpgme_strerror(err));
+               privacy_set_error(_("Couldn't initialize GPG context, %s"), gpgme_strerror(err));
+               g_free(kset);
+               return FALSE;
+       }
        i = 0;
        while (fprs[i] && strlen(fprs[i])) {
                gpgme_key_t key;
@@ -582,6 +659,7 @@ gboolean pgpmime_encrypt(MimeInfo *mimeinfo, const gchar *encrypt_data)
                if (err) {
                        debug_print("can't add key '%s'[%d] (%s)\n", fprs[i],i, gpgme_strerror(err));
                        privacy_set_error(_("Couldn't add GPG key %s, %s"), fprs[i], gpgme_strerror(err));
+                       g_free(kset);
                        return FALSE;
                }
                debug_print("found %s at %d\n", fprs[i], i);
@@ -610,6 +688,7 @@ gboolean pgpmime_encrypt(MimeInfo *mimeinfo, const gchar *encrypt_data)
        fp = my_tmpfile();
        if (fp == NULL) {
                privacy_set_error(_("Couldn't create temporary file, %s"), strerror(errno));
+               g_free(kset);
                return FALSE;
        }
        procmime_write_mimeinfo(encmultipart, fp);
@@ -621,21 +700,23 @@ gboolean pgpmime_encrypt(MimeInfo *mimeinfo, const gchar *encrypt_data)
        fclose(fp);
 
        /* encrypt data */
-       gpgme_data_new_from_mem(&gpgtext, textstr, strlen(textstr), 0);
+       gpgme_data_new_from_mem(&gpgtext, textstr, (size_t)strlen(textstr), 0);
        gpgme_data_new(&gpgenc);
        gpgme_set_armor(ctx, 1);
-       gpgme_data_rewind(gpgtext);
+       cm_gpgme_data_rewind(gpgtext);
        
        err = gpgme_op_encrypt(ctx, kset, GPGME_ENCRYPT_ALWAYS_TRUST, gpgtext, gpgenc);
 
-       gpgme_release(ctx);
-       enccontent = gpgme_data_release_and_get_mem(gpgenc, &len);
+       enccontent = sgpgme_data_release_and_get_mem(gpgenc, &len);
        gpgme_data_release(gpgtext);
        g_free(textstr);
+       g_free(kset);
 
        if (enccontent == NULL || len <= 0) {
-               g_warning("gpgme_data_release_and_get_mem failed");
+               g_warning("sgpgme_data_release_and_get_mem failed");
                privacy_set_error(_("Encryption failed, %s"), gpgme_strerror(err));
+               gpgme_release(ctx);
+               g_free(enccontent);
                return FALSE;
        }
 
@@ -661,6 +742,7 @@ gboolean pgpmime_encrypt(MimeInfo *mimeinfo, const gchar *encrypt_data)
        g_node_append(encmultipart->node, newinfo->node);
 
        g_free(enccontent);
+       gpgme_release(ctx);
 
        return TRUE;
 }
@@ -686,6 +768,9 @@ static PrivacySystem pgpmime_system = {
        TRUE,
        pgpmime_get_encrypt_data,
        pgpmime_encrypt,
+       pgpmime_get_encrypt_warning,
+       pgpmime_inhibit_encrypt_warning,
+       prefs_gpg_auto_check_signatures,
 };
 
 void pgpmime_init()