From e7f03687dc28a0191b8ee69660c4cb4d781e499a Mon Sep 17 00:00:00 2001
From: Hatter Jiang <jht5945@gmail.com>
Date: Sun, 12 Mar 2023 22:05:55 +0800
Subject: [PATCH] feat: use fake random

---
 __crypto/yubikey-rs-demo/src/main.rs | 31 ++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/__crypto/yubikey-rs-demo/src/main.rs b/__crypto/yubikey-rs-demo/src/main.rs
index 8d7b819..c11b6b6 100644
--- a/__crypto/yubikey-rs-demo/src/main.rs
+++ b/__crypto/yubikey-rs-demo/src/main.rs
@@ -1,6 +1,6 @@
+use elliptic_curve::rand_core::{CryptoRng, Error, RngCore};
 use p256::{ecdh::EphemeralSecret, PublicKey};
 use p256::elliptic_curve::sec1::{FromEncodedPoint, ToEncodedPoint};
-use rand::rngs::OsRng;
 use rust_util::{failure_and_exit, information, warning, XResult};
 use yubikey::certificate::PublicKeyInfo;
 use yubikey::Context;
@@ -40,6 +40,32 @@ impl EphemeralKeyBytes {
     }
 }
 
+struct FakeRandom;
+
+impl CryptoRng for FakeRandom {}
+
+impl RngCore for FakeRandom {
+    fn next_u32(&mut self) -> u32 {
+        todo!()
+    }
+
+    fn next_u64(&mut self) -> u64 {
+        todo!()
+    }
+
+    fn fill_bytes(&mut self, dest: &mut [u8]) {
+        println!("Fill random dest len: {}", dest.len());
+        for i in 0..dest.len() {
+            dest[i]= 0x01;
+        }
+    }
+
+    fn try_fill_bytes(&mut self, _dest: &mut [u8]) -> Result<(), Error> {
+        todo!()
+    }
+}
+
+
 fn main() -> XResult<()> {
     let mut readers = Context::open()?;
     let reader = readers.iter()?.next().unwrap_or_else(|| failure_and_exit!("No reader!"));
@@ -47,7 +73,8 @@ fn main() -> XResult<()> {
 
     information!("Yubikey serial: {}", yubikey.serial().0);
 
-    let esk = EphemeralSecret::random(&mut OsRng);
+    // let esk = EphemeralSecret::random(&mut rand::rngs::OsRng);
+    let esk = EphemeralSecret::random(&mut FakeRandom);
     let epk = esk.public_key();
     let epk_bytes = EphemeralKeyBytes::from_public_key(&epk);