Check for overflows in relocatable operations (#859)

* Catch possible overflows in Relocatable::add

* Move sub implementations to trait impl

* Swap sub_usize for - operator

* Vheck possible overflows in Add<i32>

* Fix should_panic test

* remove referenced add

* Replace Relocatable methods for trait implementations

* Catch overflows in mayberelocatable operations

* Fix keccak

* Clippy

src/hint_processor/builtin_hint_processor/blake2s_utils.rs

@@ -44,11 +44,10 @@ output_ptr should point to the middle of an instance, right after initial_state,
 which should all have a value at this point, and right before the output portion which will be
 written by this function.*/
 fn compute_blake2s_func(vm: &mut VirtualMachine, output_rel: Relocatable) -> Result<(), HintError> {
-    let h = get_fixed_size_u32_array::<8>(&vm.get_integer_range(output_rel.sub_usize(26)?, 8)?)?;
-    let message =
-        get_fixed_size_u32_array::<16>(&vm.get_integer_range(output_rel.sub_usize(18)?, 16)?)?;
-    let t = felt_to_u32(vm.get_integer(output_rel.sub_usize(2)?)?.as_ref())?;
-    let f = felt_to_u32(vm.get_integer(output_rel.sub_usize(1)?)?.as_ref())?;
+    let h = get_fixed_size_u32_array::<8>(&vm.get_integer_range((output_rel - 26)?, 8)?)?;
+    let message = get_fixed_size_u32_array::<16>(&vm.get_integer_range((output_rel - 18)?, 16)?)?;
+    let t = felt_to_u32(vm.get_integer((output_rel - 2)?)?.as_ref())?;
+    let f = felt_to_u32(vm.get_integer((output_rel - 1)?)?.as_ref())?;
     let new_state =
         get_maybe_relocatable_array_from_u32(&blake2s_compress(&h, &message, t, 0, f, 0));
     let output_ptr = MaybeRelocatable::RelocatableValue(output_rel);
@@ -158,7 +157,7 @@ pub fn blake2s_add_uint256(
     //Insert second batch of data
     let data = get_maybe_relocatable_array_from_felt(&inner_data);
     vm.load_data(
-        &MaybeRelocatable::RelocatableValue(data_ptr).add_usize(4),
+        &MaybeRelocatable::RelocatableValue(data_ptr).add_usize(4)?,
         &data,
     )
     .map_err(HintError::Memory)?;
@@ -205,7 +204,7 @@ pub fn blake2s_add_uint256_bigend(
     //Insert second batch of data
     let data = get_maybe_relocatable_array_from_felt(&inner_data);
     vm.load_data(
-        &MaybeRelocatable::RelocatableValue(data_ptr).add_usize(4),
+        &MaybeRelocatable::RelocatableValue(data_ptr).add_usize(4)?,
         &data,
     )
     .map_err(HintError::Memory)?;

src/hint_processor/builtin_hint_processor/cairo_keccak/keccak_hints.rs

@@ -14,7 +14,7 @@ use crate::{
 };
 use felt::Felt;
 use num_traits::{ToPrimitive, Zero};
-use std::{borrow::Cow, collections::HashMap, ops::Add};
+use std::{borrow::Cow, collections::HashMap};
 
 // Constants in package "starkware.cairo.common.cairo_keccak.keccak".
 const BYTES_IN_WORD: &str = "starkware.cairo.common.cairo_keccak.keccak.BYTES_IN_WORD";
@@ -53,7 +53,7 @@ pub fn keccak_write_args(
         .map_err(HintError::Memory)?;
 
     let high_args: Vec<_> = high_args.into_iter().map(MaybeRelocatable::from).collect();
-    vm.write_arg(inputs_ptr.add(2_i32), &high_args)
+    vm.write_arg((inputs_ptr + 2_i32)?, &high_args)
         .map_err(HintError::Memory)?;
 
     Ok(())
@@ -145,7 +145,7 @@ pub fn block_permutation(
     let keccak_state_size_felts = keccak_state_size_felts.to_usize().unwrap();
     let values = vm
         .get_range(
-            &MaybeRelocatable::RelocatableValue(keccak_ptr.sub_usize(keccak_state_size_felts)?),
+            &MaybeRelocatable::RelocatableValue((keccak_ptr - keccak_state_size_felts)?),
             keccak_state_size_felts,
         )
         .map_err(HintError::Memory)?;

src/hint_processor/builtin_hint_processor/dict_hint_utils.rs

@@ -138,7 +138,7 @@ pub fn dict_write(
     let tracker = dict.get_tracker_mut(dict_ptr)?;
     //dict_ptr is a pointer to a struct, with the ordered fields (key, prev_value, new_value),
     //dict_ptr.prev_value will be equal to dict_ptr + 1
-    let dict_ptr_prev_value = dict_ptr + 1_i32;
+    let dict_ptr_prev_value = (dict_ptr + 1_i32)?;
     //Tracker set to track next dictionary entry
     tracker.current_ptr.offset += DICT_ACCESS_SIZE;
     //Get previous value

src/hint_processor/builtin_hint_processor/find_element_hint.rs

@@ -36,7 +36,7 @@ pub fn find_element(
     if let Some(find_element_index_value) = find_element_index {
         let find_element_index_usize = felt_to_usize(&find_element_index_value)?;
         let found_key = vm
-            .get_integer(array_start + (elm_size * find_element_index_usize))
+            .get_integer((array_start + (elm_size * find_element_index_usize))?)
             .map_err(|_| HintError::KeyNotFound)?;
 
         if found_key.as_ref() != key.as_ref() {
@@ -68,7 +68,7 @@ pub fn find_element(
 
         for i in 0..n_elms_iter {
             let iter_key = vm
-                .get_integer(array_start + (elm_size * i as usize))
+                .get_integer((array_start + (elm_size * i as usize))?)
                 .map_err(|_| HintError::KeyNotFound)?;
 
             if iter_key.as_ref() == key.as_ref() {

src/hint_processor/builtin_hint_processor/keccak_utils.rs

@@ -144,7 +144,7 @@ pub fn unsafe_keccak_finalize(
         offset: keccak_state_ptr.offset + 1,
     })?;
 
-    let n_elems = end_ptr.sub(&start_ptr)?;
+    let n_elems = (end_ptr - start_ptr)?;
 
     let mut keccak_input = Vec::new();
     let range = vm.get_integer_range(start_ptr, n_elems)?;

src/hint_processor/builtin_hint_processor/math_utils.rs

@@ -120,10 +120,10 @@ pub fn assert_le_felt(
     let (q_0, r_0) = (lengths_and_indices[0].0).div_mod_floor(prime_over_3_high);
     let (q_1, r_1) = (lengths_and_indices[1].0).div_mod_floor(prime_over_2_high);
 
-    vm.insert_value(range_check_ptr + 1_i32, q_0)?;
+    vm.insert_value((range_check_ptr + 1_i32)?, q_0)?;
     vm.insert_value(range_check_ptr, r_0)?;
-    vm.insert_value(range_check_ptr + 3_i32, q_1)?;
-    vm.insert_value(range_check_ptr + 2_i32, r_1)?;
+    vm.insert_value((range_check_ptr + 3_i32)?, q_1)?;
+    vm.insert_value((range_check_ptr + 2_i32)?, r_1)?;
     Ok(())
 }
 

src/hint_processor/builtin_hint_processor/pow_utils.rs

@@ -22,7 +22,9 @@ pub fn pow(
     ap_tracking: &ApTracking,
 ) -> Result<(), HintError> {
     let prev_locs_exp = vm
-        .get_integer(get_relocatable_from_var_name("prev_locs", vm, ids_data, ap_tracking)? + 4_i32)
+        .get_integer(
+            (get_relocatable_from_var_name("prev_locs", vm, ids_data, ap_tracking)? + 4_i32)?,
+        )
         .map_err(|_| {
             HintError::IdentifierHasNoMember("prev_locs".to_string(), "exp".to_string())
         })?;

src/hint_processor/builtin_hint_processor/secp/bigint_utils.rs

@@ -33,10 +33,10 @@ impl BigInt3<'_> {
             d0: vm.get_integer(addr).map_err(|_| {
                 HintError::IdentifierHasNoMember(name.to_string(), "d0".to_string())
             })?,
-            d1: vm.get_integer(addr + 1).map_err(|_| {
+            d1: vm.get_integer((addr + 1)?).map_err(|_| {
                 HintError::IdentifierHasNoMember(name.to_string(), "d1".to_string())
             })?,
-            d2: vm.get_integer(addr + 2).map_err(|_| {
+            d2: vm.get_integer((addr + 2)?).map_err(|_| {
                 HintError::IdentifierHasNoMember(name.to_string(), "d2".to_string())
             })?,
         })
@@ -91,7 +91,7 @@ pub fn bigint_to_uint256(
 ) -> Result<(), HintError> {
     let x_struct = get_relocatable_from_var_name("x", vm, ids_data, ap_tracking)?;
     let d0 = vm.get_integer(x_struct)?;
-    let d1 = vm.get_integer(x_struct + 1_i32)?;
+    let d1 = vm.get_integer((x_struct + 1_i32)?)?;
     let d0 = d0.as_ref();
     let d1 = d1.as_ref();
     let base_86 = constants

src/hint_processor/builtin_hint_processor/secp/ec_utils.rs

@@ -40,7 +40,7 @@ impl EcPoint<'_> {
         let point_addr = get_relocatable_from_var_name(name, vm, ids_data, ap_tracking)?;
         Ok(EcPoint {
             x: BigInt3::from_base_addr(point_addr, &format!("{}.x", name), vm)?,
-            y: BigInt3::from_base_addr(point_addr + 3, &format!("{}.y", name), vm)?,
+            y: BigInt3::from_base_addr((point_addr + 3)?, &format!("{}.y", name), vm)?,
         })
     }
 }
@@ -71,7 +71,7 @@ pub fn ec_negate(
             .to_bigint();
 
     //ids.point
-    let point_y = get_relocatable_from_var_name("point", vm, ids_data, ap_tracking)? + 3i32;
+    let point_y = (get_relocatable_from_var_name("point", vm, ids_data, ap_tracking)? + 3i32)?;
     let y_bigint3 = BigInt3::from_base_addr(point_y, "point.y", vm)?;
     let y = pack(y_bigint3);
     let value = (-y).mod_floor(&secp_p);

src/hint_processor/builtin_hint_processor/set.rs

@@ -46,11 +46,11 @@ pub fn set_add(
         ));
     }
 
-    let range_limit = set_end_ptr.sub(&set_ptr)?;
+    let range_limit = (set_end_ptr - set_ptr)?;
 
     for i in (0..range_limit).step_by(elm_size) {
         let set_iter = vm
-            .get_range(&MaybeRelocatable::from(set_ptr + i), elm_size)
+            .get_range(&MaybeRelocatable::from((set_ptr + i)?), elm_size)
             .map_err(VirtualMachineError::Memory)?;
 
         if set_iter == elm {

src/hint_processor/builtin_hint_processor/sha256_utils.rs

@@ -56,7 +56,7 @@ pub fn sha256_main(
     let mut message: Vec<u8> = Vec::with_capacity(4 * SHA256_INPUT_CHUNK_SIZE_FELTS);
 
     for i in 0..SHA256_INPUT_CHUNK_SIZE_FELTS {
-        let input_element = vm.get_integer(input_ptr + i)?;
+        let input_element = vm.get_integer((input_ptr + i)?)?;
         let bytes = felt_to_u32(input_element.as_ref())?.to_be_bytes();
         message.extend(bytes);
     }

src/hint_processor/builtin_hint_processor/squash_dict_utils.rs

@@ -141,7 +141,7 @@ pub fn squash_dict_inner_continue_loop(
     };
     //loop_temps.delta_minus1 = loop_temps + 3 as it is the fourth field of the struct
     //Insert loop_temps.delta_minus1 into memory
-    let should_continue_addr = loop_temps_addr + 3_i32;
+    let should_continue_addr = (loop_temps_addr + 3_i32)?;
     vm.insert_value(should_continue_addr, should_continue)
         .map_err(HintError::Memory)
 }
@@ -265,7 +265,7 @@ pub fn squash_dict(
     //A map from key to the list of indices accessing it.
     let mut access_indices = HashMap::<Felt, Vec<Felt>>::new();
     for i in 0..n_accesses_usize {
-        let key_addr = address + DICT_ACCESS_SIZE * i;
+        let key_addr = (address + DICT_ACCESS_SIZE * i)?;
         let key = vm
             .get_integer(key_addr)
             .map_err(|_| MemoryError::ExpectedInteger(key_addr))?;

src/hint_processor/builtin_hint_processor/uint256_utils.rs

@@ -33,9 +33,9 @@ pub fn uint256_add(
     let a_relocatable = get_relocatable_from_var_name("a", vm, ids_data, ap_tracking)?;
     let b_relocatable = get_relocatable_from_var_name("b", vm, ids_data, ap_tracking)?;
     let a_low = vm.get_integer(a_relocatable)?;
-    let a_high = vm.get_integer(a_relocatable + 1_usize)?;
+    let a_high = vm.get_integer((a_relocatable + 1_usize)?)?;
     let b_low = vm.get_integer(b_relocatable)?;
-    let b_high = vm.get_integer(b_relocatable + 1_usize)?;
+    let b_high = vm.get_integer((b_relocatable + 1_usize)?)?;
     let a_low = a_low.as_ref();
     let a_high = a_high.as_ref();
     let b_low = b_low.as_ref();
@@ -105,7 +105,7 @@ pub fn uint256_sqrt(
     let n_addr = get_relocatable_from_var_name("n", vm, ids_data, ap_tracking)?;
     let root_addr = get_relocatable_from_var_name("root", vm, ids_data, ap_tracking)?;
     let n_low = vm.get_integer(n_addr)?;
-    let n_high = vm.get_integer(n_addr + 1_usize)?;
+    let n_high = vm.get_integer((n_addr + 1_usize)?)?;
     let n_low = n_low.as_ref();
     let n_high = n_high.as_ref();
 
@@ -127,7 +127,7 @@ pub fn uint256_sqrt(
         )));
     }
     vm.insert_value(root_addr, Felt::new(root))?;
-    vm.insert_value(root_addr + 1_i32, Felt::zero())
+    vm.insert_value((root_addr + 1_i32)?, Felt::zero())
         .map_err(HintError::Memory)
 }
 
@@ -141,7 +141,7 @@ pub fn uint256_signed_nn(
     ap_tracking: &ApTracking,
 ) -> Result<(), HintError> {
     let a_addr = get_relocatable_from_var_name("a", vm, ids_data, ap_tracking)?;
-    let a_high = vm.get_integer(a_addr + 1_usize)?;
+    let a_high = vm.get_integer((a_addr + 1_usize)?)?;
     //Main logic
     //memory[ap] = 1 if 0 <= (ids.a.high % PRIME) < 2 ** 127 else 0
     let result: Felt = if !a_high.is_negative() && a_high.as_ref() <= &Felt::new(i128::MAX) {
@@ -176,9 +176,9 @@ pub fn uint256_unsigned_div_rem(
     let remainder_addr = get_relocatable_from_var_name("remainder", vm, ids_data, ap_tracking)?;
 
     let a_low = vm.get_integer(a_addr)?;
-    let a_high = vm.get_integer(a_addr + 1_usize)?;
+    let a_high = vm.get_integer((a_addr + 1_usize)?)?;
     let div_low = vm.get_integer(div_addr)?;
-    let div_high = vm.get_integer(div_addr + 1_usize)?;
+    let div_high = vm.get_integer((div_addr + 1_usize)?)?;
     let a_low = a_low.as_ref();
     let a_high = a_high.as_ref();
     let div_low = div_low.as_ref();
@@ -208,11 +208,11 @@ pub fn uint256_unsigned_div_rem(
     //Insert ids.quotient.low
     vm.insert_value(quotient_addr, quotient_low)?;
     //Insert ids.quotient.high
-    vm.insert_value(quotient_addr + 1_i32, quotient_high)?;
+    vm.insert_value((quotient_addr + 1_i32)?, quotient_high)?;
     //Insert ids.remainder.low
     vm.insert_value(remainder_addr, remainder_low)?;
     //Insert ids.remainder.high
-    vm.insert_value(remainder_addr + 1_i32, remainder_high)?;
+    vm.insert_value((remainder_addr + 1_i32)?, remainder_high)?;
     Ok(())
 }
 

src/hint_processor/builtin_hint_processor/usort.rs

@@ -48,7 +48,7 @@ pub fn usort_body(
     let mut positions_dict: HashMap<Felt, Vec<u64>> = HashMap::new();
     let mut output: Vec<Felt> = Vec::new();
     for i in 0..input_len_u64 {
-        let val = vm.get_integer(input_ptr + i as usize)?.into_owned();
+        let val = vm.get_integer((input_ptr + i as usize)?)?.into_owned();
         if let Err(output_index) = output.binary_search(&val) {
             output.insert(output_index, val.clone());
         }
@@ -65,11 +65,11 @@ pub fn usort_body(
     let output_len = output.len();
 
     for (i, sorted_element) in output.into_iter().enumerate() {
-        vm.insert_value(output_base + i, sorted_element)?;
+        vm.insert_value((output_base + i)?, sorted_element)?;
     }
 
     for (i, repetition_amount) in multiplicities.into_iter().enumerate() {
-        vm.insert_value(multiplicities_base + i, Felt::new(repetition_amount))?;
+        vm.insert_value((multiplicities_base + i)?, Felt::new(repetition_amount))?;
     }
 
     insert_value_from_var_name(

src/hint_processor/hint_processor_utils.rs

@@ -112,9 +112,9 @@ pub fn compute_addr_from_reference(
                 &hint_reference.offset2,
             )?;
 
-            Some(offset1 + value.get_int_ref()?.to_usize()?)
+            Some((offset1 + value.get_int_ref()?.to_usize()?).ok()?)
         }
-        OffsetValue::Value(value) => Some(offset1 + *value),
+        OffsetValue::Value(value) => Some((offset1 + *value).ok()?),
         _ => None,
     }
 }
@@ -129,7 +129,7 @@ fn apply_ap_tracking_correction(
         return None;
     }
     let ap_diff = hint_ap_tracking.offset - ref_ap_tracking.offset;
-    ap.sub_usize(ap_diff).ok()
+    (ap - ap_diff).ok()
 }
 
 //Tries to convert a Felt value to usize
@@ -168,9 +168,9 @@ fn get_offset_value_reference(
     }
 
     if *deref {
-        vm.get_maybe(&(base_addr + *offset))
+        vm.get_maybe(&(base_addr + *offset).ok()?)
     } else {
-        Some((base_addr + *offset).into())
+        Some((base_addr + *offset).ok()?.into())
     }
 }
 

src/types/errors/math_errors.rs

@@ -6,6 +6,7 @@ use crate::types::relocatable::{MaybeRelocatable, Relocatable};
 
 #[derive(Debug, Error, PartialEq)]
 pub enum MathError {
+    // Math functions
     #[error("Can't calculate the square root of negative number: {0})")]
     SqrtNegative(Felt),
     #[error("{0} is not divisible by {1}")]
@@ -28,7 +29,9 @@ pub enum MathError {
     #[error("Operation failed: {0} - {1}, offsets cant be negative")]
     RelocatableSubNegOffset(Relocatable, usize),
     #[error("Operation failed: {0} + {1}, maximum offset value exceeded")]
-    RelocatableAddOffsetExceeded(Relocatable, Felt),
+    RelocatableAddFeltOffsetExceeded(Relocatable, Felt),
+    #[error("Operation failed: {0} + {1}, maximum offset value exceeded")]
+    RelocatableAddUsizeOffsetExceeded(Relocatable, usize),
     #[error("Operation failed: {0} + {1}, cant add two relocatable values")]
     RelocatableAdd(Relocatable, Relocatable),
     #[error("Operation failed: {0} - {1}, cant substract two relocatable values with different segment indexes")]