ruma_identifiers_validation/
mxc_uri.rs

1use std::num::NonZeroU8;
2
3use crate::{error::MxcUriError, server_name};
4
5const PROTOCOL: &str = "mxc://";
6
7pub fn validate(uri: &str) -> Result<NonZeroU8, MxcUriError> {
8    let Some(uri) = uri.strip_prefix(PROTOCOL) else {
9        return Err(MxcUriError::WrongSchema);
10    };
11
12    let Some(index) = uri.find('/') else {
13        return Err(MxcUriError::MissingSlash);
14    };
15
16    let server_name = &uri[..index];
17    let media_id = &uri[index + 1..];
18    // See: https://spec.matrix.org/v1.15/client-server-api/#security-considerations-5
19    let media_id_is_valid = media_id
20        .bytes()
21        .all(|b| matches!(b, b'0'..=b'9' | b'a'..=b'z' | b'A'..=b'Z' | b'-' | b'_' ));
22
23    if !media_id_is_valid {
24        Err(MxcUriError::MediaIdMalformed)
25    } else if server_name::validate(server_name).is_err() {
26        Err(MxcUriError::ServerNameMalformed)
27    } else {
28        Ok(NonZeroU8::new((index + 6) as u8).unwrap())
29    }
30}