Improve security

src/common.c

@@ -942,3 +942,14 @@ prof_get_version(void)
         return g_strdup_printf("%s", PACKAGE_VERSION);
     }
 }
+
+void
+prof_wipe_string(char* str)
+{
+    if (str) {
+        volatile char* p = (volatile char*)str;
+        while (*p) {
+            *p++ = 0;
+        }
+    }
+}

src/common.h

@@ -135,6 +135,8 @@ free_keyfile(prof_keyfile_t* keyfile);
         resource = NULL;         \
     } while (0)
 
+void prof_wipe_string(char* str);
+
 typedef enum {
     CONTACT_OFFLINE,
     CONTACT_ONLINE,

src/config/account.c

@@ -180,6 +180,7 @@ account_free(ProfAccount* account)
 
     free(account->name);
     free(account->jid);
+    prof_wipe_string(account->password);
     free(account->password);
     free(account->eval_password);
     free(account->resource);

src/omemo/crypto.c

@@ -210,7 +210,7 @@ omemo_encrypt_func(signal_buffer** output, int cipher, const uint8_t* key, size_
         assert(FALSE);
     }
 
-    padded_plaintext = malloc(plaintext_len + padding);
+    padded_plaintext = gcry_malloc_secure(plaintext_len + padding);
     memcpy(padded_plaintext, plaintext, plaintext_len);
     memset(padded_plaintext + plaintext_len, padding, padding);
 
@@ -219,7 +219,7 @@ omemo_encrypt_func(signal_buffer** output, int cipher, const uint8_t* key, size_
     gcry_cipher_encrypt(hd, ciphertext, ciphertext_len, padded_plaintext, plaintext_len + padding);
 
     *output = signal_buffer_create(ciphertext, ciphertext_len);
-    free(padded_plaintext);
+    gcry_free(padded_plaintext);
     free(ciphertext);
 
     gcry_cipher_close(hd);
@@ -268,17 +268,26 @@ omemo_decrypt_func(signal_buffer** output, int cipher, const uint8_t* key, size_
     }
 
     plaintext_len = ciphertext_len;
-    plaintext = malloc(plaintext_len);
+    plaintext = gcry_malloc_secure(plaintext_len);
     gcry_cipher_decrypt(hd, plaintext, plaintext_len, ciphertext, ciphertext_len);
 
     switch (cipher) {
     case SG_CIPHER_AES_CBC_PKCS5:
+        if (plaintext_len == 0) {
+            ret = SG_ERR_UNKNOWN;
+            goto out;
+        }
         padding = plaintext[plaintext_len - 1];
         break;
     default:
         assert(FALSE);
     }
 
+    if (padding == 0 || padding > 16 || padding > plaintext_len) {
+        ret = SG_ERR_UNKNOWN;
+        goto out;
+    }
+
     for (int i = 0; i < padding; i++) {
         if (plaintext[plaintext_len - 1 - i] != padding) {
             ret = SG_ERR_UNKNOWN;
@@ -289,7 +298,7 @@ omemo_decrypt_func(signal_buffer** output, int cipher, const uint8_t* key, size_
     *output = signal_buffer_create(plaintext, plaintext_len - padding);
 
 out:
-    free(plaintext);
+    gcry_free(plaintext);
 
     gcry_cipher_close(hd);
 

src/pgp/gpg.c

@@ -101,10 +101,12 @@ _p_gpg_close(void)
     key_ac = NULL;
 
     if (passphrase) {
+        prof_wipe_string(passphrase);
         GFREE_SET_NULL(passphrase);
     }
 
     if (passphrase_attempt) {
+        prof_wipe_string(passphrase_attempt);
         GFREE_SET_NULL(passphrase_attempt);
     }
 }

src/tools/aesgcm_download.c

@@ -30,6 +30,7 @@
 #include "ui/ui.h"
 #include "ui/window.h"
 #include "common.h"
+#include "log.h"
 
 void*
 aesgcm_file_get(void* userdata)
@@ -116,30 +117,35 @@ aesgcm_file_get(void* userdata)
                                    "Downloading '%s' failed: Failed to decrypt "
                                    "file (%s).",
                                    aesgcm_dl->url, gcry_strerror(crypt_res));
+        log_error("OMEMO: AESGCM download file integrity check failed for '%s': %s",
+                  aesgcm_dl->url, gcry_strerror(crypt_res));
+        remove(aesgcm_dl->filename);
     } else {
         http_print_transfer_update(aesgcm_dl->window, aesgcm_dl->id, THEME_ONLINE, ENTRY_COMPLETED,
                                    "Downloading '%s': done\nSaved to '%s'",
                                    aesgcm_dl->url, aesgcm_dl->filename);
         win_mark_received(aesgcm_dl->window, aesgcm_dl->id);
-    }
 
-    if (aesgcm_dl->cmd_template != NULL) {
-        gchar** argv = format_call_external_argv(aesgcm_dl->cmd_template,
-                                                 aesgcm_dl->filename,
-                                                 aesgcm_dl->filename);
-
-        // TODO: Log the error.
-        if (!call_external(argv)) {
-            http_print_transfer_update(aesgcm_dl->window, aesgcm_dl->id, THEME_ERROR, ENTRY_ERROR,
-                                       "Downloading '%s' failed: Unable to call "
-                                       "command '%s' with file at '%s' (%s).",
-                                       aesgcm_dl->url,
-                                       aesgcm_dl->cmd_template,
-                                       aesgcm_dl->filename,
-                                       "TODO: Log the error");
+        if (aesgcm_dl->cmd_template != NULL) {
+            gchar** argv = format_call_external_argv(aesgcm_dl->cmd_template,
+                                                     aesgcm_dl->filename,
+                                                     aesgcm_dl->filename);
+
+            if (!call_external(argv)) {
+                http_print_transfer_update(aesgcm_dl->window, aesgcm_dl->id, THEME_ERROR, ENTRY_ERROR,
+                                           "Downloading '%s' failed: Unable to call "
+                                           "command '%s' with file at '%s' (%s).",
+                                           aesgcm_dl->url,
+                                           aesgcm_dl->cmd_template,
+                                           aesgcm_dl->filename,
+                                           "Failed to run command");
+            }
+
+            g_strfreev(argv);
         }
+    }
 
-        g_strfreev(argv);
+    if (aesgcm_dl->cmd_template != NULL) {
         free(aesgcm_dl->cmd_template);
     }
 

src/xmpp/session.c

@@ -616,6 +616,7 @@ static void
 _session_free_internals(void)
 {
     FREE_SET_NULL(saved_account.name);
+    prof_wipe_string(saved_account.passwd);
     FREE_SET_NULL(saved_account.passwd);
     GFREE_SET_NULL(reconnect.altdomain);
     if (last_moods) {
@@ -630,6 +631,7 @@ _session_free_saved_details(void)
 {
     FREE_SET_NULL(saved_details.name);
     FREE_SET_NULL(saved_details.jid);
+    prof_wipe_string(saved_details.passwd);
     FREE_SET_NULL(saved_details.passwd);
     FREE_SET_NULL(saved_details.altdomain);
     FREE_SET_NULL(saved_details.tls_policy);