Release v1.0.0: protocol freeze, replay testing, fuzzing and audit readiness

shared/src/vm.rs

@@ -0,0 +1,67 @@
+use crate::protocol::StackState;
+
+/// Executes a raw VM mathematical instruction program bytecode slice.
+///
+/// This implements the mathematical stack machine interpreter used by the client
+/// to generate the attestation stack state.
+///
+/// # Arguments
+/// * `program` - The raw VM instruction program bytecode.
+pub fn execute(program: &[u8]) -> StackState {
+    let mut stack: Vec<u32> = Vec::new();
+    let mut ip: usize = 0;
+    while ip < program.len() {
+        let op = program[ip];
+        ip += 1;
+        match op {
+            0x00 => {
+                if ip + 4 > program.len() {
+                    break;
+                }
+                let val = u32::from_le_bytes([
+                    program[ip],
+                    program[ip + 1],
+                    program[ip + 2],
+                    program[ip + 3],
+                ]);
+                ip += 4;
+                stack.push(val);
+            }
+            0x01..=0x07 => {
+                if stack.len() < 2 {
+                    break;
+                }
+                let b = stack.pop().unwrap();
+                let a = stack.pop().unwrap();
+                let r = match op {
+                    0x01 => a.wrapping_add(b),
+                    0x02 => a.wrapping_sub(b),
+                    0x03 => a.wrapping_mul(b),
+                    0x04 => a ^ b,
+                    0x05 => a & b,
+                    0x06 => a | b,
+                    0x07 => a.rotate_left(b % 32),
+                    _ => unreachable!(),
+                };
+                stack.push(r);
+            }
+            0x08 => {
+                if stack.is_empty() {
+                    break;
+                }
+                let a = stack.pop().unwrap();
+                stack.push(!a);
+            }
+            0x09 => {
+                let r = crate::hashing::hash_stack(&stack);
+                stack.clear();
+                stack.push(r);
+            }
+            _ => break,
+        }
+    }
+    StackState {
+        stack,
+        ip: ip as u16,
+    }
+}

shared/tests/proptests.rs

@@ -0,0 +1,17 @@
+use proptest::prelude::*;
+
+proptest! {
+    #[test]
+    fn test_vm_execute_never_panics(ref program in any::<Vec<u8>>()) {
+        // VM execution should be totally robust and never panic on any random input stream.
+        let state = shared::vm::execute(program);
+        // The instruction pointer (ip) should not exceed the program length
+        assert!(state.ip as usize <= program.len());
+    }
+
+    #[test]
+    fn test_gene_environment_roundtrip_never_panics(ref data in any::<Vec<u8>>()) {
+        // Try to decode random bytes. It should either succeed or fail gracefully, never panic.
+        let _ = shared::gene::decode_environment(data);
+    }
+}