ones-oidc 0.2.5

use jsonwebtoken::EncodingKey;
use std::fs::File;
use std::io::Read;
use std::path::Path;

/// Reads contents of a file at the given path into a byte vector
fn read_file(path: &str) -> Result<Vec<u8>, std::io::Error> {
    let path = Path::new(path);
    if !path.exists() {
        return Err(std::io::Error::new(
            std::io::ErrorKind::NotFound,
            "File not found",
        ));
    }
    let mut file = File::open(path)?;
    let mut contents = Vec::new();
    file.read_to_end(&mut contents)?;
    Ok(contents)
}

/// Converts raw bytes into a JWT encoding key
fn bytes_to_encoding_key(bytes: Vec<u8>) -> EncodingKey {
    EncodingKey::from_rsa_pem(&bytes).unwrap_or_else(|_| {
        panic!("Invalid key format - ensure the file contains a valid RSA PEM key")
    })
}

/// Reads and parses a private key file at the given path
///
/// # Arguments
/// * `path` - Path to the RSA private key file in PEM format
///
/// # Returns
/// * `Result<EncodingKey, std::io::Error>` - The parsed encoding key or an IO error
pub fn read_private_key(path: &str) -> Result<EncodingKey, std::io::Error> {
    let bytes = read_file(path)?;
    Ok(bytes_to_encoding_key(bytes))
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    #[should_panic(expected = "No such file or directory")]
    fn test_invalid_path() {
        read_private_key("nonexistent.key").unwrap();
    }
}