rustify new_data_part() and related sanitizations

src/dc_mimefactory.rs

@@ -2,7 +2,6 @@ use std::path::Path;
 use std::ptr;
 
 use chrono::TimeZone;
-use libc::free;
 use mmime::clist::*;
 use mmime::mailimf_types::*;
 use mmime::mailimf_types_helper::*;
@@ -535,7 +534,7 @@ pub unsafe fn dc_mimefactory_render(
                 meta.type_0 = Viewtype::Image;
                 meta.param.set(Param::File, grpimage);
 
-                let res = build_body_file(context, &meta, "group-image");
+                let res = build_body_file(context, &meta, "group-image")?;
                 meta_part = res.0;
                 let filename_as_sent = res.1;
                 if !meta_part.is_null() {
@@ -610,10 +609,8 @@ pub unsafe fn dc_mimefactory_render(
                         24 * 1024 * 1024 / 4 * 3 / 1000 / 1000,
                     );
                 } else {
-                    let (file_part, _) = build_body_file(context, &factory.msg, "");
-                    if !file_part.is_null() {
-                        mailmime_smart_add_part(message, file_part);
-                    }
+                    let (file_part, _) = build_body_file(context, &factory.msg, "")?;
+                    mailmime_smart_add_part(message, file_part);
                 }
             }
             if !meta_part.is_null() {
@@ -699,8 +696,7 @@ pub unsafe fn dc_mimefactory_render(
                 factory.msg.rfc724_mid
             );
 
-            let content_type_0 =
-                wrapmime::new_mailmime_content_type("message/disposition-notification");
+            let content_type_0 = wrapmime::new_content_type("message/disposition-notification")?;
             let mime_fields_0: *mut mailmime_fields =
                 mailmime_fields_new_encoding(MAILMIME_MECHANISM_8BIT as libc::c_int);
             let mach_mime_part: *mut mailmime = mailmime_new_empty(content_type_0, mime_fields_0);
@@ -816,10 +812,14 @@ fn get_subject(
 }
 
 #[allow(non_snake_case)]
-fn build_body_file(context: &Context, msg: &Message, base_name: &str) -> (*mut mailmime, String) {
+fn build_body_file(
+    context: &Context,
+    msg: &Message,
+    base_name: &str,
+) -> Result<(*mut mailmime, String), Error> {
     let path_filename = match msg.param.get(Param::File) {
         None => {
-            return (ptr::null_mut(), "".to_string());
+            bail!("msg has no filename");
         }
         Some(path) => path,
     };
@@ -913,23 +913,16 @@ fn build_body_file(context: &Context, msg: &Message, base_name: &str) -> (*mut m
                 }
             }
         }
-        let content = wrapmime::new_mailmime_content_type(&mimetype);
-        let filename_encoded = dc_encode_header_words(&filename_to_send).strdup();
-        clist_insert_after(
-            (*content).ct_parameters,
-            (*(*content).ct_parameters).last,
-            mailmime_param_new_with_data(
-                b"name\x00" as *const u8 as *const libc::c_char as *mut libc::c_char,
-                filename_encoded,
-            ) as *mut libc::c_void,
-        );
-        free(filename_encoded as *mut libc::c_void);
+        let content = wrapmime::new_content_type(&mimetype)?;
+        let filename_encoded = dc_encode_header_words(&filename_to_send);
+        wrapmime::append_ct_param(content, "name", &filename_encoded)?;
+
         let mime_sub = mailmime_new_empty(content, mime_fields);
         let abs_path = dc_get_abs_path(context, path_filename)
             .to_c_string()
             .unwrap();
         mailmime_set_body_file(mime_sub, dc_strdup(abs_path.as_ptr()));
-        (mime_sub, filename_to_send)
+        Ok((mime_sub, filename_to_send))
     }
 }
 

src/e2ee.rs

@@ -252,16 +252,16 @@ impl EncryptHelper {
                     ptr::null_mut(),
                     0 as libc::size_t,
                     "multipart/encrypted",
-                    -1,
-                );
+                    MAILMIME_MECHANISM_BASE64,
+                )?;
                 let content: *mut mailmime_content = (*encrypted_part).mm_content_type;
                 wrapmime::append_ct_param(content, "protocol", "application/pgp-encrypted")?;
                 let version_mime: *mut mailmime = new_data_part(
                     VERSION_CONTENT.as_mut_ptr() as *mut libc::c_void,
                     strlen(VERSION_CONTENT.as_mut_ptr()),
                     "application/pgp-encrypted",
-                    MAILMIME_MECHANISM_7BIT as i32,
-                );
+                    MAILMIME_MECHANISM_7BIT,
+                )?;
                 mailmime_smart_add_part(encrypted_part, version_mime);
 
                 // we assume that ctext_v is not dropped until the end
@@ -270,8 +270,8 @@ impl EncryptHelper {
                     ctext_v.as_ptr() as *mut libc::c_void,
                     ctext_v.len(),
                     "application/octet-stream",
-                    MAILMIME_MECHANISM_7BIT as i32,
-                );
+                    MAILMIME_MECHANISM_7BIT,
+                )?;
                 mailmime_smart_add_part(encrypted_part, ctext_part);
                 (*in_out_message).mm_data.mm_message.mm_msg_mime = encrypted_part;
                 (*encrypted_part).mm_parent = in_out_message;
@@ -421,95 +421,38 @@ impl E2eeHelper {
     }
 }
 
-unsafe fn new_data_part(
+fn new_data_part(
     data: *mut libc::c_void,
     data_bytes: libc::size_t,
-    default_content_type: &str,
-    default_encoding: libc::c_int,
-) -> *mut mailmime {
-    let mut ok_to_continue = true;
-    let mut encoding: *mut mailmime_mechanism = ptr::null_mut();
-    let content: *mut mailmime_content;
-    let mime: *mut mailmime;
-    let mime_fields: *mut mailmime_fields;
-    let encoding_type: libc::c_int;
-    let mut do_encoding: libc::c_int;
+    content_type: &str,
+    default_encoding: u32,
+) -> Result<*mut mailmime> {
+    let content = new_content_type(&content_type)?;
+    unsafe {
+        let mut encoding: *mut mailmime_mechanism = ptr::null_mut();
+        if wrapmime::content_type_needs_encoding(content) {
+            encoding = mailmime_mechanism_new(default_encoding as i32, ptr::null_mut());
+            ensure!(!encoding.is_null(), "failed to create encoding");
+        }
+        let mime_fields = mailmime_fields_new_with_data(
+            encoding,
+            ptr::null_mut(),
+            ptr::null_mut(),
+            ptr::null_mut(),
+            ptr::null_mut(),
+        );
+        ensure!(!mime_fields.is_null(), "internal mime error");
 
-    let content_type = if default_content_type.is_empty() {
-        "application/octet-stream"
-    } else {
-        default_content_type
-    };
-    content = new_mailmime_content_type(&content_type);
-    if content.is_null() {
-        ok_to_continue = false;
-    } else {
-        do_encoding = 1i32;
-        if (*(*content).ct_type).tp_type == MAILMIME_TYPE_COMPOSITE_TYPE as libc::c_int {
-            let composite: *mut mailmime_composite_type;
-            composite = (*(*content).ct_type).tp_data.tp_composite_type;
-            match (*composite).ct_type {
-                1 => {
-                    if strcasecmp(
-                        (*content).ct_subtype,
-                        b"rfc822\x00" as *const u8 as *const libc::c_char,
-                    ) == 0i32
-                    {
-                        do_encoding = 0i32
-                    }
-                }
-                2 => do_encoding = 0i32,
-                _ => {}
-            }
-        }
-        if 0 != do_encoding {
-            if default_encoding == -1i32 {
-                encoding_type = MAILMIME_MECHANISM_BASE64 as libc::c_int
-            } else {
-                encoding_type = default_encoding
-            }
-            encoding = mailmime_mechanism_new(encoding_type, ptr::null_mut());
-            if encoding.is_null() {
-                ok_to_continue = false;
-            }
-        }
-        if ok_to_continue {
-            mime_fields = mailmime_fields_new_with_data(
-                encoding,
-                ptr::null_mut(),
-                ptr::null_mut(),
-                ptr::null_mut(),
-                ptr::null_mut(),
-            );
-            if mime_fields.is_null() {
-                ok_to_continue = false;
-            } else {
-                mime = mailmime_new_empty(content, mime_fields);
-                if mime.is_null() {
-                    mailmime_fields_free(mime_fields);
-                    mailmime_content_free(content);
-                } else {
-                    if !data.is_null()
-                        && data_bytes > 0
-                        && (*mime).mm_type == MAILMIME_SINGLE as libc::c_int
-                    {
-                        mailmime_set_body_text(mime, data as *mut libc::c_char, data_bytes);
-                    }
-                    return mime;
-                }
-            }
-        }
-    }
+        let mime = mailmime_new_empty(content, mime_fields);
+        ensure!(!mime.is_null(), "internal mime error");
 
-    if ok_to_continue == false {
-        if !encoding.is_null() {
-            mailmime_mechanism_free(encoding);
-        }
-        if !content.is_null() {
-            mailmime_content_free(content);
+        if (*mime).mm_type == MAILMIME_SINGLE as libc::c_int {
+            if !data.is_null() && data_bytes > 0 {
+                mailmime_set_body_text(mime, data as *mut libc::c_char, data_bytes);
+            }
         }
+        return Ok(mime);
     }
-    ptr::null_mut()
 }
 
 /// Load public key from database or generate a new one.

src/wrapmime.rs

@@ -5,6 +5,7 @@ use crate::error::Error;
 use mmime::clist::*;
 use mmime::mailimf_types::*;
 use mmime::mailimf_types_helper::*;
+use mmime::mailmime::*;
 use mmime::mailmime_disposition::*;
 use mmime::mailmime_types::*;
 use mmime::mailmime_types_helper::*;
@@ -60,7 +61,7 @@ pub fn build_body_text(text: &str) -> Result<*mut mailmime, Error> {
     let mime_fields: *mut mailmime_fields;
     let message_part: *mut mailmime;
 
-    let content = new_mailmime_content_type("text/plain");
+    let content = new_content_type("text/plain")?;
     append_ct_param(content, "charset", "utf-8")?;
 
     unsafe {
@@ -92,18 +93,15 @@ pub fn append_ct_param(
     Ok(())
 }
 
-pub fn new_mailmime_content_type(content_type: &str) -> *mut mailmime_content {
+pub fn new_content_type(content_type: &str) -> Result<*mut mailmime_content, Error> {
     let ct = CString::new(content_type).unwrap();
     let content: *mut mailmime_content;
     // mailmime_content_new_with_str only parses but does not retain/own ct
-    //
     unsafe {
         content = mailmime_content_new_with_str(ct.as_ptr());
     }
-    if content.is_null() {
-        panic!("mailimf failed to allocate");
-    }
-    content
+    ensure!(!content.is_null(), "mailimf failed to allocate");
+    Ok(content)
 }
 
 pub fn set_body_text(part: *mut mailmime, text: &str) -> Result<(), Error> {
@@ -116,3 +114,39 @@ pub fn set_body_text(part: *mut mailmime, text: &str) -> Result<(), Error> {
     }
     Ok(())
 }
+
+pub fn content_type_needs_encoding(content: *const mailmime_content) -> bool {
+    unsafe {
+        if (*(*content).ct_type).tp_type == MAILMIME_TYPE_COMPOSITE_TYPE as libc::c_int {
+            let composite = (*(*content).ct_type).tp_data.tp_composite_type;
+            match (*composite).ct_type as u32 {
+                MAILMIME_COMPOSITE_TYPE_MESSAGE => as_str((*content).ct_subtype) != "rfc822",
+                MAILMIME_COMPOSITE_TYPE_MULTIPART => false,
+                _ => false,
+            }
+        } else {
+            true
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_needs_encoding() {
+        assert!(content_type_needs_encoding(
+            new_content_type("text/plain").unwrap()
+        ));
+        assert!(content_type_needs_encoding(
+            new_content_type("application/octect-stream").unwrap()
+        ));
+        assert!(!content_type_needs_encoding(
+            new_content_type("multipart/encrypted").unwrap()
+        ));
+        assert!(content_type_needs_encoding(
+            new_content_type("application/pgp-encrypted").unwrap()
+        ));
+    }
+}