diff --git a/deltachat-ffi/src/lib.rs b/deltachat-ffi/src/lib.rs
index 7b8786861..5d0f08366 100644
--- a/deltachat-ffi/src/lib.rs
+++ b/deltachat-ffi/src/lib.rs
@@ -17,7 +17,7 @@ use std::ptr;
 use std::str::FromStr;
 
 use deltachat::contact::Contact;
-use deltachat::dc_tools::{as_str, dc_strdup, StrExt};
+use deltachat::dc_tools::{as_str, dc_strdup, OsStrExt, StrExt};
 use deltachat::*;
 
 // as C lacks a good and portable error handling,
@@ -2013,6 +2013,9 @@ pub unsafe extern "C" fn dc_msg_get_file(msg: *mut dc_msg_t) -> *mut libc::c_cha
     }
     let ffi_msg = &*msg;
     message::dc_msg_get_file(&*ffi_msg.context, &ffi_msg.message)
+        .and_then(|p| p.to_c_string().ok())
+        .map(|cs| dc_strdup(cs.as_ptr()))
+        .unwrap_or_else(|| dc_strdup(ptr::null()))
 }
 
 #[no_mangle]
diff --git a/src/dc_imex.rs b/src/dc_imex.rs
index 4726c74f0..6f3fdf277 100644
--- a/src/dc_imex.rs
+++ b/src/dc_imex.rs
@@ -269,54 +269,48 @@ pub unsafe fn dc_continue_key_transfer(
     setup_code: *const libc::c_char,
 ) -> bool {
     let mut success = false;
-    let mut filename: *mut libc::c_char = ptr::null_mut();
-    let mut filecontent: *mut libc::c_char = ptr::null_mut();
-    let mut filebytes: size_t = 0i32 as size_t;
     let mut armored_key: *mut libc::c_char = ptr::null_mut();
-    let mut norm_sc: *mut libc::c_char = ptr::null_mut();
+    let norm_sc;
     if msg_id <= 9i32 as libc::c_uint || setup_code.is_null() {
         return false;
     }
+
     let msg = dc_get_msg(context, msg_id);
-    if msg.is_err()
-        || !dc_msg_is_setupmessage(msg.as_ref().unwrap())
-        || {
-            filename = dc_msg_get_file(context, msg.as_ref().unwrap());
-            filename.is_null()
-        }
-        || *filename.offset(0isize) as libc::c_int == 0i32
-    {
-        error!(context, "Message is no Autocrypt Setup Message.",);
-    } else if 0
-        == dc_read_file(
-            context,
-            filename,
-            &mut filecontent as *mut *mut libc::c_char as *mut *mut libc::c_void,
-            &mut filebytes,
-        )
-        || filecontent.is_null()
-        || filebytes <= 0
-    {
-        error!(context, "Cannot read Autocrypt Setup Message file.",);
-    } else {
-        norm_sc = dc_normalize_setup_code(context, setup_code);
-        if norm_sc.is_null() {
-            warn!(context, "Cannot normalize Setup Code.",);
-        } else {
-            armored_key = dc_decrypt_setup_file(context, norm_sc, filecontent);
-            if armored_key.is_null() {
-                warn!(context, "Cannot decrypt Autocrypt Setup Message.",);
-            } else if set_self_key(context, armored_key, 1) {
-                /*set default*/
-                /* error already logged */
-                success = true
+    if msg.is_err() {
+        error!(context, "Message is no Autocrypt Setup Message.");
+        return false;
+    }
+    let msg = msg.unwrap();
+    if !dc_msg_is_setupmessage(&msg) {
+        error!(context, "Message is no Autocrypt Setup Message.");
+        return false;
+    }
+
+    if let Some(filename) = dc_msg_get_file(context, &msg) {
+        if let Some(buf) = dc_read_file_safe(context, filename) {
+            norm_sc = dc_normalize_setup_code(context, setup_code);
+            if norm_sc.is_null() {
+                warn!(context, "Cannot normalize Setup Code.",);
+            } else {
+                armored_key = dc_decrypt_setup_file(context, norm_sc, buf.as_ptr().cast());
+                if armored_key.is_null() {
+                    warn!(context, "Cannot decrypt Autocrypt Setup Message.",);
+                } else if set_self_key(context, armored_key, 1) {
+                    /*set default*/
+                    /* error already logged */
+                    success = true
+                }
             }
+        } else {
+            error!(context, "Cannot read Autocrypt Setup Message file.",);
+            return false;
         }
+    } else {
+        error!(context, "Message is no Autocrypt Setup Message.");
+        return false;
     }
 
     free(armored_key as *mut libc::c_void);
-    free(filecontent as *mut libc::c_void);
-    free(filename as *mut libc::c_void);
     free(norm_sc as *mut libc::c_void);
 
     success
diff --git a/src/message.rs b/src/message.rs
index a4432407c..26fddb155 100644
--- a/src/message.rs
+++ b/src/message.rs
@@ -1,5 +1,5 @@
 use std::ffi::CString;
-use std::path::Path;
+use std::path::{Path, PathBuf};
 use std::ptr;
 
 use deltachat_derive::{FromSql, ToSql};
@@ -269,15 +269,10 @@ pub unsafe fn dc_get_msg_info(context: &Context, msg_id: u32) -> *mut libc::c_ch
         _ => {}
     }
 
-    let p = dc_msg_get_file(context, &msg);
-    if !p.is_null() && 0 != *p.offset(0isize) as libc::c_int {
-        ret += &format!(
-            "\nFile: {}, {}, bytes\n",
-            as_str(p),
-            dc_get_filebytes(context, as_path(p)) as libc::c_int,
-        );
+    if let Some(path) = dc_msg_get_file(context, &msg) {
+        let bytes = dc_get_filebytes(context, &path);
+        ret += &format!("\nFile: {}, {}, bytes\n", path.display(), bytes);
     }
-    free(p as *mut libc::c_void);
 
     if msg.type_0 != Viewtype::Text {
         ret += "Type: ";
@@ -378,17 +373,10 @@ pub fn dc_msg_guess_msgtype_from_suffix(path: &Path) -> Option<(Viewtype, &str)>
     KNOWN.get(extension).map(|x| *x)
 }
 
-pub unsafe fn dc_msg_get_file(context: &Context, msg: &Message) -> *mut libc::c_char {
-    let mut file_abs = ptr::null_mut();
-
-    if let Some(file_rel) = msg.param.get(Param::File) {
-        file_abs = dc_get_abs_path(context, file_rel);
-    }
-    if !file_abs.is_null() {
-        file_abs
-    } else {
-        dc_strdup(0 as *const libc::c_char)
-    }
+pub unsafe fn dc_msg_get_file(context: &Context, msg: &Message) -> Option<PathBuf> {
+    msg.param
+        .get(Param::File)
+        .map(|f| dc_get_abs_path_safe(context, f))
 }
 
 /**
@@ -896,29 +884,16 @@ pub fn dc_msg_is_setupmessage(msg: &Message) -> bool {
 }
 
 pub unsafe fn dc_msg_get_setupcodebegin(context: &Context, msg: &Message) -> *mut libc::c_char {
-    let mut filename: *mut libc::c_char = ptr::null_mut();
-    let mut buf: *mut libc::c_char = ptr::null_mut();
-    let mut buf_bytes: size_t = 0i32 as size_t;
     // just a pointer inside buf, MUST NOT be free()'d
     let mut buf_headerline: *const libc::c_char = ptr::null();
     // just a pointer inside buf, MUST NOT be free()'d
     let mut buf_setupcodebegin: *const libc::c_char = ptr::null();
     let mut ret: *mut libc::c_char = ptr::null_mut();
     if dc_msg_is_setupmessage(msg) {
-        filename = dc_msg_get_file(context, msg);
-        if !(filename.is_null() || *filename.offset(0isize) as libc::c_int == 0i32) {
-            if !(0
-                == dc_read_file(
-                    context,
-                    filename,
-                    &mut buf as *mut *mut libc::c_char as *mut *mut libc::c_void,
-                    &mut buf_bytes,
-                )
-                || buf.is_null()
-                || buf_bytes <= 0)
-            {
+        if let Some(filename) = dc_msg_get_file(context, msg) {
+            if let Some(mut buf) = dc_read_file_safe(context, filename) {
                 if dc_split_armored_data(
-                    buf,
+                    buf.as_mut_ptr().cast(),
                     &mut buf_headerline,
                     &mut buf_setupcodebegin,
                     ptr::null_mut(),
@@ -934,8 +909,6 @@ pub unsafe fn dc_msg_get_setupcodebegin(context: &Context, msg: &Message) -> *mu
             }
         }
     }
-    free(filename as *mut libc::c_void);
-    free(buf as *mut libc::c_void);
     if !ret.is_null() {
         ret
     } else {