Rename OsRng -> GetRandom, FillBytes -> Rng and add docs

Author: blackbeam

Cargo.toml

@@ -43,7 +43,7 @@ chrono = { version = "0.4.20", default-features = false, features = [
 crc32fast = "1.2"
 flate2 = { version = "1.0", default-features = false }
 frunk = { version = "0.4", optional = true }
-getrandom = "0.3"
+getrandom = { version = "0.3", features = ["std"] }
 num-bigint = { version = "0.4" }
 num-traits = { version = "0.2", features = ["i128"] }
 regex = "1.5"

src/crypto/mod.rs

@@ -14,6 +14,6 @@ pub mod rsa;
 /// It will use OAEP padding, so MySql versions prior to 8.0.5 are not supported.
 pub fn encrypt(pass: &[u8], key: &[u8]) -> Vec<u8> {
     let pub_key = self::rsa::PublicKey::from_pem(key);
-    let pad = self::rsa::Pkcs1OaepPadding::new(self::rsa::OsRng);
+    let pad = self::rsa::Pkcs1OaepPadding::new(self::rsa::GetRandom);
     pub_key.encrypt_block(pass, pad)
 }

src/crypto/rsa.rs

@@ -17,15 +17,18 @@ pub trait Padding {
     fn pub_pad(&mut self, input: impl AsRef<[u8]>, k: usize) -> Vec<u8>;
 }
 
-pub trait FillBytes {
-    type Error: std::fmt::Debug + std::fmt::Display;
+/// Represents a source of random bytes.
+pub trait Rng {
+    type Error: std::error::Error;
 
+    /// Implementor must fill all the bytes in the `dest`.
     fn fill(&mut self, dest: &mut [u8]) -> Result<(), Self::Error>;
 }
 
-pub struct OsRng;
+/// Randomness source based on the [`getrandom::fill`].
+pub struct GetRandom;
 
-impl FillBytes for OsRng {
+impl Rng for GetRandom {
     type Error = getrandom::Error;
 
     fn fill(&mut self, dest: &mut [u8]) -> Result<(), Self::Error> {
@@ -45,7 +48,7 @@ impl<T> Pkcs1Padding<T> {
     }
 }
 
-impl<T: FillBytes> Padding for Pkcs1Padding<T> {
+impl<T: Rng> Padding for Pkcs1Padding<T> {
     fn pub_pad(&mut self, input: impl AsRef<[u8]>, k: usize) -> Vec<u8> {
         let input = input.as_ref();
         let input_len = input.len();
@@ -117,7 +120,7 @@ impl<T> Pkcs1OaepPadding<T> {
     }
 }
 
-impl<T: FillBytes> Padding for Pkcs1OaepPadding<T> {
+impl<T: Rng> Padding for Pkcs1OaepPadding<T> {
     /// Will pad input according to PKCS #1 v2 with encoding parameters equal to `[]`.
     fn pub_pad(&mut self, input: impl AsRef<[u8]>, k: usize) -> Vec<u8> {
         let input = input.as_ref();
@@ -231,7 +234,7 @@ mod tests {
 
     struct Seed<'a>(&'a [u8]);
 
-    impl<'a> FillBytes for Seed<'a> {
+    impl<'a> Rng for Seed<'a> {
         type Error = std::io::Error;
 
         fn fill(&mut self, dest: &mut [u8]) -> Result<(), std::io::Error> {