Check length (#236)

* Check length

* Remove length check

Author: guibescos

program/rust/src/deserialize.rs

@@ -16,13 +16,21 @@ use solana_program::program_error::ProgramError;
 
 /// Interpret the bytes in `data` as a value of type `T`
 pub fn load<T: Pod>(data: &[u8]) -> Result<&T, ProgramError> {
-    try_from_bytes(&data[0..size_of::<T>()]).map_err(|_| ProgramError::InvalidArgument)
+    try_from_bytes(
+        data.get(0..size_of::<T>())
+            .ok_or(ProgramError::InvalidArgument)?,
+    )
+    .map_err(|_| ProgramError::InvalidArgument)
 }
 
 /// Interpret the bytes in `data` as a mutable value of type `T`
 #[allow(unused)]
 pub fn load_mut<T: Pod>(data: &mut [u8]) -> Result<&mut T, ProgramError> {
-    try_from_bytes_mut(&mut data[0..size_of::<T>()]).map_err(|_| ProgramError::InvalidArgument)
+    try_from_bytes_mut(
+        data.get_mut(0..size_of::<T>())
+            .ok_or(ProgramError::InvalidArgument)?,
+    )
+    .map_err(|_| ProgramError::InvalidArgument)
 }
 
 /// Get the data stored in `account` as a value of type `T`

program/rust/src/processor.rs

@@ -1,5 +1,3 @@
-use std::mem::size_of;
-
 use solana_program::program_error::ProgramError;
 use solana_program::pubkey::Pubkey;
 use solana_program::sysvar::slot_history::AccountInfo;
@@ -44,11 +42,7 @@ pub fn process_instruction(
     instruction_data: &[u8],
     input: *mut u8,
 ) -> OracleResult {
-    let cmd_hdr_size = size_of::<cmd_hdr>();
-    if instruction_data.len() < cmd_hdr_size {
-        return Err(ProgramError::InvalidArgument);
-    }
-    let cmd_data = load::<cmd_hdr>(&instruction_data[..cmd_hdr_size])?;
+    let cmd_data = load::<cmd_hdr>(instruction_data)?;
 
     if cmd_data.ver_ != PC_VERSION {
         //FIXME: I am not sure what's best to do here (this is copied from C)