prove, use DEV_MODE for testing/debug

Author: nuke-web3

README.md

@@ -4,7 +4,11 @@ To build all methods and execute the method within the zkVM, run the following
 command:
 
 ```bash
-cargo run
+# Run full proof
+cargo r -r
+
+# Execution ONLY testing
+RISC0_DEV_MODE=1 cargo r
 ```
 
 ### Executing the Project Locally in Development Mode
@@ -14,6 +18,6 @@ During development, faster iteration upon code changes can be achieved by levera
 Put together, the command to run your project in development mode while getting execution statistics is:
 
 ```bash
-RUST_LOG="[executor]=info" RISC0_DEV_MODE=1 cargo run
+RUST_LOG="info" RISC0_DEV_MODE=1 cargo r
 ```
 

host/src/main.rs

@@ -1,11 +1,11 @@
-use chacha20::cipher::{KeyIvInit, StreamCipher};
+use chacha20::cipher::{KeyIvInit, StreamCipher, StreamCipherSeek};
 use chacha20::ChaCha20;
 use hex_literal::hex;
 
 // These constants represent the RISC-V ELF and the image ID generated by risc0-build.
 // The ELF is used for proving and the ID is used for verification.
 use methods::{GUEST_ENCRYPT_ELF, GUEST_ENCRYPT_ID};
-use risc0_zkvm::{default_executor, ExecutorEnv};
+use risc0_zkvm::{default_prover, ExecutorEnv};
 
 fn main() {
     // Initialize tracing. In order to view logs, run `RUST_LOG=info cargo run`
@@ -40,26 +40,32 @@ fn main() {
         .unwrap();
 
     // testing Execution ONLY
-    let prover = default_executor();
+    let prover = default_prover();
 
     // Proof information by proving the specified ELF binary.
     // This struct contains the receipt along with statistics about execution of the guest
-    let prove_info = prover.execute(env, GUEST_ENCRYPT_ELF).unwrap();
+    let prove_info = prover.prove(env, GUEST_ENCRYPT_ELF).unwrap();
 
     // extract the receipt.
-    // let receipt = prove_info.receipt;
+    let receipt = prove_info.receipt;
 
-    // let output: [u8; 16]  = receipt.journal.decode().unwrap();
-
-    let output: [u8; 16] = prove_info.journal.decode().unwrap();
-    println!("output bytes: {:?}", output);
+    let mut output: [u8; 16] = receipt.journal.decode().unwrap();
+    println!("zkVM output bytes: {:?}", output);
 
     let ciphertext = hex!("e405626e 4f1236b3 670ee428 332ea20e");
     println!("expected output bytes: {:?}", ciphertext);
 
-    // // The receipt was verified at the end of proving, but the below code is an
-    // // example of how someone else could verify this receipt.
-    // receipt
-    //     .verify(GUEST_ENCRYPT_ID)
-    //     .unwrap();
+    // The receipt was verified at the end of proving, but the below code is an
+    // example of how someone else could verify this receipt.
+    receipt
+        .verify(GUEST_ENCRYPT_ID)
+        .unwrap();
+    println!("Reciept from zkVM OK!");
+    
+    // ChaCha ciphers support seeking
+    cipher.seek(0u32);
+
+    // decrypt ciphertext by applying keystream again
+    cipher.apply_keystream(&mut output);
+    assert_eq!(output, plaintext);
 }

methods/guest/src/main.rs

@@ -1,12 +1,12 @@
 use risc0_zkvm::guest::env;
 
 fn main() {
-    // TODO: Implement your guest code here
-
-    // read the input
-
     let plaintext: [u8; 16] = env::read();
     let keystream: [u8; 16] = env::read();
+
+    // TODO:
+    // - Hash plaintext & commit?
+    // - Hash keystream & commit?
 
     let mut buffer = plaintext.clone();
     xor_arrays(&plaintext,&keystream, &mut buffer);
@@ -15,13 +15,15 @@ fn main() {
     env::commit(&buffer);
 }
 
+/// UNSAFE: We demand input and output arrays here are the SAME length. 
 fn xor_arrays(arr1: &[u8], arr2: &[u8], output: &mut [u8]) {
     // assert_eq!(arr1.len(), arr2.len(), "Arrays must have the same length");
     // assert_eq!(arr1.len(), output.len(), "Output array must have the same length");
 
     for i in 0..arr1.len() {
+        // We assume that input arrays are the same length, skipping checks to save cycles
         unsafe {
             *output.get_unchecked_mut(i) = arr1.get_unchecked(i) ^ arr2.get_unchecked(i);
         }
     }
-}
+}