clippy lints

bin/build.sh

@@ -17,7 +17,7 @@ cargo build --release --bin omegaupload-server
 # Prepare assets for upload to webserver
 mkdir -p dist/static
 # Move everything that's not index.html into a `static` subdir
-find dist -type f -exec mv {} dist/static/ ";"
+find dist -not -name index.html -type f -exec mv {} dist/static/ ";"
 
 strip target/release/omegaupload-server
 cp target/release/omegaupload-server dist/omegaupload-server

common/src/base64.rs

@@ -6,6 +6,11 @@ pub fn encode(input: impl AsRef<[u8]>) -> String {
 }
 
 /// URL-safe Base64 decoding.
+///
+/// # Errors
+///
+/// Returns an error if a buffer cannot be decoded, such as if there's an
+/// incorrect number of bytes.
 pub fn decode(input: impl AsRef<[u8]>) -> Result<Vec<u8>, DecodeError> {
     base64::decode_config(input, URL_SAFE)
 }

common/src/crypto.rs

@@ -6,7 +6,7 @@ use chacha20poly1305::aead::generic_array::GenericArray;
 use chacha20poly1305::aead::{AeadInPlace, NewAead};
 use chacha20poly1305::XChaCha20Poly1305;
 use chacha20poly1305::XNonce;
-use rand::{thread_rng, Rng};
+use rand::{CryptoRng, Rng};
 use secrecy::{ExposeSecret, Secret, SecretVec, Zeroize};
 use typenum::Unsigned;
 
@@ -27,6 +27,7 @@ pub enum Error {
 pub struct Key(chacha20poly1305::Key);
 
 impl Key {
+    /// Encloses a secret key in a secret `Key` struct.
     pub fn new_secret(vec: Vec<u8>) -> Option<Secret<Self>> {
         chacha20poly1305::Key::from_exact_iter(vec.into_iter())
             .map(Self)
@@ -58,11 +59,14 @@ impl Zeroize for Key {
     }
 }
 
-/// Seals the provided message with an optional message. The resulting sealed
+/// Seals the provided message with an optional password, returning the secret
-/// message has the nonce used to encrypt the message appended to it as well as
+/// key used to encrypt the message and mutating the buffer to contain necessary
-/// a salt string used to derive the key. In other words, the modified buffer is
+/// metadata.
-/// one of the following to possibilities, depending if there was a password
+///
-/// provided:
+/// The resulting sealed message has the nonce used to encrypt the message
+/// appended to it as well as a salt string used to derive the key. In other
+/// words, the modified buffer is one of the following to possibilities,
+/// depending if there was a password provided:
 ///
 /// ```
 /// modified = C(message, rng_key, nonce) || nonce
@@ -77,6 +81,17 @@ impl Zeroize for Key {
 ///     `XChaCha20Poly1305`.
 ///  - `rng_key` represents a randomly generated key.
 ///  - `kdf(pw, salt)` represents a key derived from Argon2.
+///  - `nonce` represents a randomly generated nonce.
+///
+/// Note that the lengths for the nonce, key, and salt follow recommended
+/// values. As of writing this doc (2021-10-31), the nonce size is 24 bytes, the
+/// salt size is 16 bytes, and the key size is 32 bytes.
+///
+/// # Errors
+///
+/// This message will return an error if and only if there was a problem
+/// encrypting the message or deriving a secret key from the password, if one
+/// was provided.
 pub fn seal_in_place(
     message: &mut Vec<u8>,
     pw: Option<SecretVec<u8>>,
@@ -104,6 +119,12 @@ pub fn seal_in_place(
     Ok(key)
 }
 
+/// Opens a message that has been sealed with `seal_in_place`.
+///
+/// # Errors
+///
+/// Returns an error if there was a decryption failure or if there was a problem
+/// deriving a secret key from the password.
 pub fn open_in_place(
     data: &mut Vec<u8>,
     key: &Secret<Key>,
@@ -140,10 +161,9 @@ pub fn open_in_place(
     Ok(())
 }
 
-/// Securely generates a random key and nonce.
 #[must_use]
 fn gen_key_nonce() -> (Secret<Key>, Nonce) {
-    let mut rng = thread_rng();
+    let mut rng = get_csrng();
     let mut key = GenericArray::default();
     rng.fill(key.as_mut_slice());
     let mut nonce = Nonce::default();
@@ -154,15 +174,9 @@ fn gen_key_nonce() -> (Secret<Key>, Nonce) {
 // Type alias; to ensure that we're consistent on what the inner impl is.
 type NonceImpl = XNonce;
 
-#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+#[derive(Clone, Copy, PartialEq, Eq, Debug, Default)]
 struct Nonce(NonceImpl);
 
-impl Default for Nonce {
-    fn default() -> Self {
-        Self(GenericArray::default())
-    }
-}
-
 impl Deref for Nonce {
     type Target = NonceImpl;
 
@@ -207,7 +221,7 @@ impl Salt {
 
     fn random() -> Self {
         let mut salt = [0_u8; Self::SIZE];
-        thread_rng().fill(&mut salt);
+        get_csrng().fill(&mut salt);
         Self(salt)
     }
 }
@@ -227,3 +241,12 @@ fn kdf(password: &SecretVec<u8>) -> Result<(Secret<Key>, Salt), argon2::Error> {
 
     Ok((Secret::new(key), salt))
 }
+
+/// Fetches a cryptographically secure random number generator. This indirection
+/// is used for better auditing the quality of rng. Notably, this function
+/// returns a `Rng` with the `CryptoRng` marker trait, preventing
+/// non-cryptographically secure RNGs from being used.
+#[must_use]
+pub fn get_csrng() -> impl CryptoRng + Rng {
+    rand::thread_rng()
+}

server/Cargo.toml

@@ -18,7 +18,8 @@ futures = "0.3"
 # We just need to pull in whatever axum is pulling in
 headers = "*"
 lazy_static = "1"
-rand = "0.8"
+# Disable `random()` and `thread_rng()`
+rand = { version = "0.8", default_features = false }
 rocksdb = { version = "0.17", default_features = false, features = ["zstd"] }
 serde = { version = "1", features = ["derive"] }
 signal-hook = "0.3"

server/src/main.rs

@@ -16,8 +16,8 @@ use chrono::Utc;
 use futures::stream::StreamExt;
 use headers::HeaderMap;
 use lazy_static::lazy_static;
+use omegaupload_common::crypto::get_csrng;
 use omegaupload_common::{Expiration, API_ENDPOINT};
-use rand::thread_rng;
 use rand::Rng;
 use rocksdb::{ColumnFamilyDescriptor, IteratorMode};
 use rocksdb::{Options, DB};
@@ -41,6 +41,7 @@ lazy_static! {
 
 #[tokio::main]
 async fn main() -> Result<()> {
+    const INDEX_PAGE: Html<&'static str> = Html(include_str!("../../dist/index.html"));
     const PASTE_DB_PATH: &str = "database";
     const SHORT_CODE_SIZE: usize = 12;
 
@@ -68,8 +69,6 @@ async fn main() -> Result<()> {
     let root_service = service::get(ServeDir::new("static"))
         .handle_error(|_| Ok::<_, Infallible>(StatusCode::NOT_FOUND));
 
-    const INDEX_PAGE: Html<&'static str> = Html(include_str!("../../dist/index.html"));
-
     axum::Server::bind(&"0.0.0.0:8080".parse()?)
         .serve(
             Router::new()
@@ -206,7 +205,7 @@ async fn upload<const N: usize>(
     // Try finding a code; give up after 1000 attempts
     // Statistics show that this is very unlikely to happen
     for i in 0..1000 {
-        let code: ShortCode<N> = thread_rng().sample(short_code::Generator);
+        let code: ShortCode<N> = get_csrng().sample(short_code::Generator);
         let db = Arc::clone(&db);
         let key = code.as_bytes();
         let query = task::spawn_blocking(move || {

server/src/short_code.rs

@@ -1,6 +1,7 @@
 use std::fmt::Debug;
 
 use rand::prelude::Distribution;
+use rand::Rng;
 use serde::de::{Unexpected, Visitor};
 use serde::Deserialize;
 
@@ -109,7 +110,7 @@ pub struct Generator;
 const ALPHABET: &[u8; 32] = b"23456789CFGHJMPQRVWXcfghjmpqrvwx";
 
 impl Distribution<ShortCodeChar> for Generator {
-    fn sample<R: rand::Rng + ?Sized>(&self, rng: &mut R) -> ShortCodeChar {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> ShortCodeChar {
         let value = rng.gen_range(0..32);
         assert!(value < 32);
         ShortCodeChar(ALPHABET[value] as char)
@@ -117,7 +118,7 @@ impl Distribution<ShortCodeChar> for Generator {
 }
 
 impl<const N: usize> Distribution<ShortCode<N>> for Generator {
-    fn sample<R: rand::Rng + ?Sized>(&self, rng: &mut R) -> ShortCode<N> {
+    fn sample<R: Rng + ?Sized>(&self, rng: &mut R) -> ShortCode<N> {
         let mut arr = [ShortCodeChar('\0'); N];
 
         for c in arr.iter_mut() {

web/src/decrypt.rs

@@ -12,7 +12,7 @@ use web_sys::{Blob, BlobPropertyBag};
 #[derive(Clone, Serialize)]
 pub struct ArchiveMeta {
     name: String,
-    file_size: usize,
+    file_size: u64,
 }
 
 #[derive(Clone)]
@@ -86,7 +86,7 @@ pub fn decrypt(
                 match zip.by_index(i) {
                     Ok(file) => entries.push(ArchiveMeta {
                         name: file.name().to_string(),
-                        file_size: file.size() as usize,
+                        file_size: file.size(),
                     }),
                     Err(err) => match err {
                         zip::result::ZipError::UnsupportedArchive(s) => {

web/src/main.rs

@@ -96,6 +96,8 @@ fn main() {
                 Ok(Some(password)) if !password.is_empty() => {
                     break Some(SecretVec::new(password.into_bytes()));
                 }
+                // Empty message was entered.
+                Ok(Some(_)) => (),
                 // Cancel button was entered.
                 Ok(None) => {
                     render_message("This paste requires a password.".into());
@@ -112,8 +114,6 @@ fn main() {
         None
     };
 
-    log!(location().pathname().unwrap());
-
     spawn_local(async move {
         if let Err(e) = fetch_resources(request_uri, key, password).await {
             log!(e.to_string());