Make media extension parsing safer (#459)

Only keep it if contains letters and numbers only, otherwise remove it.

To be merged before #452
This commit is contained in:
Baptiste Gelez 2019-03-06 14:09:43 +01:00 committed by GitHub
parent 2a188abfa1
commit a5e0486da0
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1 changed files with 13 additions and 3 deletions

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@ -35,9 +35,19 @@ pub fn upload(user: User, data: Data, ct: &ContentType, conn: DbConn) -> Result<
let filename = fields.get("file").and_then(|v| v.into_iter().next())
.ok_or_else(|| status::BadRequest(Some("No file uploaded")))?.headers
.filename.clone();
let ext = filename.and_then(|f| f.rsplit('.').next().map(|ext| ext.to_owned()))
.unwrap_or_else(|| "png".to_owned());
let dest = format!("static/media/{}.{}", GUID::rand().to_string(), ext);
// Remove extension if it contains something else than just letters and numbers
let ext = filename
.and_then(|f| f
.rsplit('.')
.next()
.and_then(|ext| if ext.chars().any(|c| !c.is_alphanumeric()) {
None
} else {
Some(ext.to_lowercase())
})
.map(|ext| format!(".{}", ext))
).unwrap_or_default();
let dest = format!("static/media/{}{}", GUID::rand().to_string(), ext);
match fields["file"][0].data {
SavedData::Bytes(ref bytes) => fs::write(&dest, bytes).map_err(|_| status::BadRequest(Some("Couldn't save upload")))?,