From 188e6727640b3e4e3214d8f212896ab09a24db01 Mon Sep 17 00:00:00 2001
From: Kris Kwiatkowski <contact@amongbytes.com>
Date: Wed, 14 Apr 2021 06:56:10 +0100
Subject: [PATCH] use aes_ctr_drbg crate

---
 test/katrunner/Cargo.lock  |  11 ++++
 test/katrunner/Cargo.toml  |   3 +-
 test/katrunner/src/drbg.rs | 113 -------------------------------------
 test/katrunner/src/main.rs |   4 +-
 4 files changed, 14 insertions(+), 117 deletions(-)
 delete mode 100644 test/katrunner/src/drbg.rs

diff --git a/test/katrunner/Cargo.lock b/test/katrunner/Cargo.lock
index d6f2e2ae..f8a29eb7 100644
--- a/test/katrunner/Cargo.lock
+++ b/test/katrunner/Cargo.lock
@@ -1,5 +1,15 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
+[[package]]
+name = "aes_ctr_drbg"
+version = "0.0.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d0a42e20bb5f9502c40bee62428fae5d67b5c111b4a48502bbea4b284da790d0"
+dependencies = [
+ "hex",
+ "rust-crypto",
+]
+
 [[package]]
 name = "aho-corasick"
 version = "0.7.15"
@@ -170,6 +180,7 @@ checksum = "9a3a5bfb195931eeb336b2a7b4d761daec841b97f947d34394601737a7bba5e4"
 name = "katrunner"
 version = "0.1.0"
 dependencies = [
+ "aes_ctr_drbg",
  "hex",
  "katwalk",
  "lazy_static",
diff --git a/test/katrunner/Cargo.toml b/test/katrunner/Cargo.toml
index ee1d8744..c5adb4dc 100644
--- a/test/katrunner/Cargo.toml
+++ b/test/katrunner/Cargo.toml
@@ -10,4 +10,5 @@ pqc-sys = { path = "../../src/rustapi/pqc-sys" }
 hex = "0.4.2"
 threadpool = "1.8.1"
 rust-crypto = "^0.2"
-lazy_static = "1.4.0"
\ No newline at end of file
+lazy_static = "1.4.0"
+aes_ctr_drbg = "0.0.2"
\ No newline at end of file
diff --git a/test/katrunner/src/drbg.rs b/test/katrunner/src/drbg.rs
deleted file mode 100644
index 56fdded9..00000000
--- a/test/katrunner/src/drbg.rs
+++ /dev/null
@@ -1,113 +0,0 @@
-//
-//  Modified version of AES-CTR-DRBG by Bassham & Lawrence.
-//  Copyright © 2017 Bassham, Lawrence E (Fed). All rights reserved.
-//  Rust implementation by K. Kwiatkowski. All rights reserved.
-//
-pub mod ctr {
-	use crypto::aes;
-	use crypto::buffer::{ RefReadBuffer, RefWriteBuffer, BufferResult };
-
-	pub struct DrbgCtx{
-	    pub reseed_counter: usize,
-	    pub key: [u8;32],
-	    pub ctr: [u8;16]
-	}
-
-	impl DrbgCtx {
-	    const CTR_LEN: usize = 16;
-	    const KEY_LEN: usize = 32;
-	    pub const fn new() -> Self {
-	        Self {
-	            reseed_counter: 0,
-	            key: [0; DrbgCtx::KEY_LEN],
-	            ctr: [0; DrbgCtx::CTR_LEN]
-	        }
-	    }
-
-	    fn inc(&mut self) {
-	        for i in 0..16 {
-	            let j = 15-i;
-	            if self.ctr[j] == 0xFF {
-	                self.ctr[j] = 0
-	            } else {
-	                self.ctr[j] = self.ctr[j] + 1;
-	                break;
-	            }
-	        }
-	    }
-
-	    fn process_aes_block(&self, block: &mut [u8]) {
-	        let mut e = aes::ecb_encryptor(
-	                aes::KeySize::KeySize256,
-	                &self.key,
-	                crypto::blockmodes::NoPadding);
-	        let mut r = RefReadBuffer::new(&self.ctr);
-	        let mut w = RefWriteBuffer::new(block);
-	        match e.encrypt(&mut r, &mut w, true).unwrap() {
-	            BufferResult::BufferOverflow => panic!("Wrong implementation"),
-	            BufferResult::BufferUnderflow => {}
-	        }
-	    }
-
-	    fn update(&mut self, seed: &[u8]) {
-	        let mut t = vec![0;48];
-
-	        for i in 0..3 {
-	            self.inc();
-	            self.process_aes_block(&mut t[i*16..]);
-	        }
-	        for i in 0..seed.len() {
-	            t[i] ^= seed[i];
-	        }
-	        for i in 0..32 {
-	            self.key[i] = t[i];
-	        }
-	        for i in 32..48 {
-	            self.ctr[i-32] = t[i];
-	        }
-	    }
-
-	    pub fn init(&mut self, entropy: &[u8], diversifier: Vec<u8>) {
-	        let mut m = vec![0;48];
-	        for i in 0..48 {
-	            m[i] = entropy[i];
-	        }
-	        if diversifier.len() >= 48 {
-	            for i in 0..48 {
-	                m[i] ^= diversifier[i];
-	            }
-	        }
-	        self.key = [0; DrbgCtx::KEY_LEN];
-	        self.ctr = [0; DrbgCtx::CTR_LEN];
-	        self.update(m.as_slice());
-	        self.reseed_counter = 1;
-	    }
-
-	    pub fn get_random(&mut self, data: &mut [u8]) {
-	        let mut i = 0;
-	        let mut b = vec![0; 16];
-	        let mut l = data.len();
-
-	        while l > 0 {
-	            self.inc();
-	            self.process_aes_block(&mut b);
-
-	            if l > 15 {
-	                for k in 0..16 {
-	                    data[i+k] = b[k];
-	                }
-	                i += 16;
-	                l -= 16;
-	            } else {
-	                for k in 0..l {
-	                    data[i+k] = b[k];
-	                }
-	                l = 0;
-	            }
-	        }
-
-	        self.update(Vec::new().as_slice());
-	        self.reseed_counter = self.reseed_counter+1;
-	    }
-	}
-}
diff --git a/test/katrunner/src/main.rs b/test/katrunner/src/main.rs
index 00808ec6..6e6dad92 100644
--- a/test/katrunner/src/main.rs
+++ b/test/katrunner/src/main.rs
@@ -5,14 +5,12 @@ use std::env;
 use std::path::Path;
 use threadpool::ThreadPool;
 use std::convert::TryInto;
-use drbg::ctr::DrbgCtx;
+use aes_ctr_drbg::DrbgCtx;
 use std::collections::HashMap;
 use std::thread;
 use std::sync::Mutex;
 use lazy_static::lazy_static;
 
-mod drbg;
-
 // Used for signature algorithm registration
 macro_rules! REG_SIGN {
     ($ID:expr,$F:expr) => {