add profanity-specific CAfile

The profanity-internal mechanism to allow connecting to a server isn't
easily portable to cURL. Therefor introduce a profanity-specific CAfile
which is managed individually and will be configured in libcurl calls.

Signed-off-by: Steffen Jaeckel <jaeckel-floss@eyet-services.de>

src/config/cafile.c

@@ -0,0 +1,106 @@
+/*
+ * cafile.c
+ * vim: expandtab:ts=4:sts=4:sw=4
+ *
+ * Copyright (C) 2022 Steffen Jaeckel <jaeckel-floss@eyet-services.de>
+ *
+ * This file is part of Profanity.
+ *
+ * Profanity 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Profanity 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 Profanity.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link the code of portions of this program with the OpenSSL library under
+ * certain conditions as described in each individual source file, and
+ * distribute linked combinations including the two.
+ *
+ * You must obey the GNU General Public License in all respects for all of the
+ * code used other than OpenSSL. If you modify file(s) with this exception, you
+ * may extend this exception to your version of the file(s), but you are not
+ * obligated to do so. If you do not wish to do so, delete this exception
+ * statement from your version. If you delete this exception statement from all
+ * source files in the program, then also delete it here.
+ *
+ */
+
+#include <fcntl.h>
+#include <glib.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/wait.h>
+
+#include "common.h"
+#include "config/files.h"
+#include "log.h"
+
+static gchar*
+_cafile_name(void)
+{
+    gchar* certs_dir = files_get_data_path(DIR_CERTS);
+    if (!create_dir(certs_dir)) {
+        g_free(certs_dir);
+        return NULL;
+    }
+    gchar* filename = g_strdup_printf("%s/CAfile.pem", certs_dir);
+    g_free(certs_dir);
+    return filename;
+}
+
+void
+cafile_add(const TLSCertificate* cert)
+{
+    if (!cert->pem) {
+        log_error("[CAfile] can't store cert with fingerprint %s: PEM is empty", cert->fingerprint);
+        return;
+    }
+    gchar* cafile = _cafile_name();
+    if (!cafile)
+        return;
+    gchar *contents = NULL, *new_contents = NULL;
+    gsize length;
+    GError* glib_error = NULL;
+    if (g_file_test(cafile, G_FILE_TEST_EXISTS)) {
+        if (!g_file_get_contents(cafile, &contents, &length, &glib_error)) {
+            log_error("[CAfile] could not read from %s: %s", cafile, glib_error ? glib_error->message : "No GLib error given");
+            goto out;
+        }
+        if (strstr(contents, cert->fingerprint)) {
+            log_debug("[CAfile] fingerprint %s already stored", cert->fingerprint);
+            goto out;
+        }
+    }
+    const char* header = "# Profanity CAfile\n# DO NOT EDIT - this file is automatically generated";
+    new_contents = g_strdup_printf("%s\n\n# %s\n%s", contents ? contents : header, cert->fingerprint, cert->pem);
+    if (!g_file_set_contents(cafile, new_contents, -1, &glib_error))
+        log_error("[CAfile] could not write to %s: %s", cafile, glib_error ? glib_error->message : "No GLib error given");
+out:
+    g_free(new_contents);
+    g_free(contents);
+    g_free(cafile);
+}
+
+gchar*
+cafile_get_name(void)
+{
+    gchar* cafile = _cafile_name();
+    if (!g_file_test(cafile, G_FILE_TEST_EXISTS)) {
+        /* That's no problem!
+         * There's no need to have a profanity-specific CAfile if all CA's
+         * of servers you're trying to connect to are in your OS trust-store
+         */
+        log_debug("[CAfile] file %s not created yet", cafile);
+        g_free(cafile);
+        cafile = NULL;
+    }
+    return cafile;
+}

src/config/cafile.h

@@ -0,0 +1,45 @@
+/*
+ * cafile.h
+ * vim: expandtab:ts=4:sts=4:sw=4
+ *
+ * Copyright (C) 2022 Steffen Jaeckel <jaeckel-floss@eyet-services.de>
+ *
+ * This file is part of Profanity.
+ *
+ * Profanity 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Profanity 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 Profanity.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ * In addition, as a special exception, the copyright holders give permission to
+ * link the code of portions of this program with the OpenSSL library under
+ * certain conditions as described in each individual source file, and
+ * distribute linked combinations including the two.
+ *
+ * You must obey the GNU General Public License in all respects for all of the
+ * code used other than OpenSSL. If you modify file(s) with this exception, you
+ * may extend this exception to your version of the file(s), but you are not
+ * obligated to do so. If you do not wish to do so, delete this exception
+ * statement from your version. If you delete this exception statement from all
+ * source files in the program, then also delete it here.
+ *
+ */
+
+#ifndef CONFIG_CAFILE_H
+#define CONFIG_CAFILE_H
+
+#include <glib.h>
+#include "tlscerts.h"
+
+void cafile_add(const TLSCertificate* cert);
+gchar* cafile_get_name(void);
+
+#endif

src/config/files.h

@@ -59,6 +59,7 @@
 #define DIR_DATABASE  "database"
 #define DIR_DOWNLOADS "downloads"
 #define DIR_EDITOR    "editor"
+#define DIR_CERTS     "certs"
 
 void files_create_directories(void);