iota_verifier_latest/
id_leak_verifier.rs

1// Copyright (c) Mysten Labs, Inc.
2// Modifications Copyright (c) 2024 IOTA Stiftung
3// SPDX-License-Identifier: Apache-2.0
4
5//! Objects whose struct type has key ability represent IOTA objects.
6//! They have unique IDs that should never be reused. This verifier makes
7//! sure that the id field of IOTA objects never get leaked.
8//! Unpack is the only bytecode that could extract the id field out of
9//! an IOTA object. From there, we track the flow of the value and make
10//! sure it can never get leaked outside of the function. There are four
11//! ways it can happen:
12//! 1. Returned
13//! 2. Written into a mutable reference
14//! 3. Added to a vector
15//! 4. Passed to a function cal::;
16use std::{collections::BTreeMap, error::Error, num::NonZeroU64};
17
18use iota_types::{
19    GENESIS_BRIDGE_ADDRESS, IOTA_FRAMEWORK_ADDRESS, IOTA_SYSTEM_ADDRESS,
20    error::{ExecutionError, VMMVerifierErrorSubStatusCode},
21};
22use move_abstract_stack::AbstractStack;
23use move_binary_format::{
24    errors::PartialVMError,
25    file_format::{
26        Bytecode, CodeOffset, CompiledModule, FunctionDefinitionIndex, FunctionHandle, LocalIndex,
27        StructDefinition, StructFieldInformation,
28    },
29};
30use move_bytecode_verifier::absint::{
31    AbstractDomain, FunctionContext, JoinResult, TransferFunctions, analyze_function,
32};
33use move_bytecode_verifier_meter::{Meter, Scope};
34use move_core_types::{
35    account_address::AccountAddress, ident_str, identifier::IdentStr, vm_status::StatusCode,
36};
37
38use crate::{check_for_verifier_timeout, to_verification_timeout_error, verification_failure};
39
40pub(crate) const JOIN_BASE_COST: u128 = 10;
41pub(crate) const JOIN_PER_LOCAL_COST: u128 = 5;
42pub(crate) const STEP_BASE_COST: u128 = 15;
43
44#[derive(Clone, Copy, Debug, Eq, PartialEq)]
45enum AbstractValue {
46    Fresh,
47    Other,
48}
49
50type FunctionIdent<'a> = (&'a AccountAddress, &'a IdentStr, &'a IdentStr);
51const OBJECT_NEW: FunctionIdent = (
52    &IOTA_FRAMEWORK_ADDRESS,
53    ident_str!("object"),
54    ident_str!("new"),
55);
56const OBJECT_NEW_UID_FROM_HASH: FunctionIdent = (
57    &IOTA_FRAMEWORK_ADDRESS,
58    ident_str!("object"),
59    ident_str!("new_uid_from_hash"),
60);
61const TS_NEW_OBJECT: FunctionIdent = (
62    &IOTA_FRAMEWORK_ADDRESS,
63    ident_str!("test_scenario"),
64    ident_str!("new_object"),
65);
66const IOTA_SYSTEM_CREATE: FunctionIdent = (
67    &IOTA_SYSTEM_ADDRESS,
68    ident_str!("iota_system"),
69    ident_str!("create"),
70);
71const IOTA_CLOCK_CREATE: FunctionIdent = (
72    &IOTA_FRAMEWORK_ADDRESS,
73    ident_str!("clock"),
74    ident_str!("create"),
75);
76// Kept for bytecode snapshot compatibility (snapshots v1-v24 still contain
77// authenticator_state::create which uses a special UID).
78const IOTA_AUTHENTICATOR_STATE_CREATE: FunctionIdent = (
79    &IOTA_FRAMEWORK_ADDRESS,
80    ident_str!("authenticator_state"),
81    ident_str!("create"),
82);
83const IOTA_RANDOMNESS_STATE_CREATE: FunctionIdent = (
84    &IOTA_FRAMEWORK_ADDRESS,
85    ident_str!("random"),
86    ident_str!("create"),
87);
88const IOTA_DENY_LIST_CREATE: FunctionIdent = (
89    &IOTA_FRAMEWORK_ADDRESS,
90    ident_str!("deny_list"),
91    ident_str!("create"),
92);
93const IOTA_TRANSACTION_DENY_RULES_CREATE: FunctionIdent = (
94    &IOTA_FRAMEWORK_ADDRESS,
95    ident_str!("transaction_deny_rules"),
96    ident_str!("create"),
97);
98
99const IOTA_BRIDGE_CREATE: FunctionIdent = (
100    &GENESIS_BRIDGE_ADDRESS,
101    ident_str!("bridge"),
102    ident_str!("create"),
103);
104const FRESH_ID_FUNCTIONS: &[FunctionIdent] = &[OBJECT_NEW, OBJECT_NEW_UID_FROM_HASH, TS_NEW_OBJECT];
105const FUNCTIONS_TO_SKIP: &[FunctionIdent] = &[
106    IOTA_SYSTEM_CREATE,
107    IOTA_CLOCK_CREATE,
108    IOTA_AUTHENTICATOR_STATE_CREATE,
109    IOTA_RANDOMNESS_STATE_CREATE,
110    IOTA_DENY_LIST_CREATE,
111    IOTA_TRANSACTION_DENY_RULES_CREATE,
112    IOTA_BRIDGE_CREATE,
113];
114
115impl AbstractValue {
116    pub fn join(&self, value: &AbstractValue) -> AbstractValue {
117        if self == value {
118            *value
119        } else {
120            AbstractValue::Other
121        }
122    }
123}
124
125pub fn verify_module(
126    module: &CompiledModule,
127    meter: &mut (impl Meter + ?Sized),
128) -> Result<(), ExecutionError> {
129    verify_id_leak(module, meter)
130}
131
132fn verify_id_leak(
133    module: &CompiledModule,
134    meter: &mut (impl Meter + ?Sized),
135) -> Result<(), ExecutionError> {
136    for (index, func_def) in module.function_defs.iter().enumerate() {
137        let code = match func_def.code.as_ref() {
138            Some(code) => code,
139            None => continue,
140        };
141        let handle = module.function_handle_at(func_def.function);
142        let function_context =
143            FunctionContext::new(module, FunctionDefinitionIndex(index as u16), code, handle);
144        let initial_state = AbstractState::new(&function_context);
145        let mut verifier = IDLeakAnalysis::new(module, &function_context);
146        let function_to_verify = verifier.cur_function();
147        if FUNCTIONS_TO_SKIP.contains(&function_to_verify) {
148            continue;
149        }
150        analyze_function(&function_context, meter, &mut verifier, initial_state).map_err(
151            |err| {
152                // Handle verification timeout specially
153                if check_for_verifier_timeout(&err.major_status()) {
154                    to_verification_timeout_error(err.to_string())
155                } else if let Some(message) = err.source().as_ref() {
156                    let function_name =
157                        module.identifier_at(module.function_handle_at(func_def.function).name);
158                    let module_name = module.self_id();
159                    verification_failure(format!(
160                        "{message} Found in {module_name}::{function_name}"
161                    ))
162                } else {
163                    verification_failure(err.to_string())
164                }
165            },
166        )?;
167    }
168
169    Ok(())
170}
171
172#[derive(Clone, Debug, PartialEq, Eq)]
173pub(crate) struct AbstractState {
174    locals: BTreeMap<LocalIndex, AbstractValue>,
175}
176
177impl AbstractState {
178    /// create a new abstract state
179    pub fn new(function_context: &FunctionContext) -> Self {
180        let mut state = AbstractState {
181            locals: BTreeMap::new(),
182        };
183
184        for param_idx in 0..function_context.parameters().len() {
185            state
186                .locals
187                .insert(param_idx as LocalIndex, AbstractValue::Other);
188        }
189
190        state
191    }
192}
193
194impl AbstractDomain for AbstractState {
195    /// attempts to join state to self and returns the result
196    fn join(
197        &mut self,
198        state: &AbstractState,
199        meter: &mut (impl Meter + ?Sized),
200    ) -> Result<JoinResult, PartialVMError> {
201        meter.add(Scope::Function, JOIN_BASE_COST)?;
202        meter.add_items(Scope::Function, JOIN_PER_LOCAL_COST, state.locals.len())?;
203        let mut changed = false;
204        for (local, value) in &state.locals {
205            let old_value = *self.locals.get(local).unwrap_or(&AbstractValue::Other);
206            let new_value = value.join(&old_value);
207            changed |= new_value != old_value;
208            self.locals.insert(*local, new_value);
209        }
210        if changed {
211            Ok(JoinResult::Changed)
212        } else {
213            Ok(JoinResult::Unchanged)
214        }
215    }
216}
217
218struct IDLeakAnalysis<'a> {
219    binary_view: &'a CompiledModule,
220    function_context: &'a FunctionContext<'a>,
221    stack: AbstractStack<AbstractValue>,
222}
223
224impl<'a> IDLeakAnalysis<'a> {
225    fn new(binary_view: &'a CompiledModule, function_context: &'a FunctionContext<'a>) -> Self {
226        Self {
227            binary_view,
228            function_context,
229            stack: AbstractStack::new(),
230        }
231    }
232
233    fn stack_popn(&mut self, n: u64) -> Result<(), PartialVMError> {
234        let Some(n) = NonZeroU64::new(n) else {
235            return Ok(());
236        };
237        self.stack.pop_any_n(n).map_err(|e| {
238            PartialVMError::new(StatusCode::VERIFIER_INVARIANT_VIOLATION)
239                .with_message(format!("Unexpected stack error on pop_n: {e}"))
240        })
241    }
242
243    fn stack_push(&mut self, val: AbstractValue) -> Result<(), PartialVMError> {
244        self.stack.push(val).map_err(|e| {
245            PartialVMError::new(StatusCode::VERIFIER_INVARIANT_VIOLATION)
246                .with_message(format!("Unexpected stack error on push: {e}"))
247        })
248    }
249
250    fn stack_pushn(&mut self, n: u64, val: AbstractValue) -> Result<(), PartialVMError> {
251        self.stack.push_n(val, n).map_err(|e| {
252            PartialVMError::new(StatusCode::VERIFIER_INVARIANT_VIOLATION)
253                .with_message(format!("Unexpected stack error on push_n: {e}"))
254        })
255    }
256
257    fn resolve_function(&self, function_handle: &FunctionHandle) -> FunctionIdent<'a> {
258        let m = self.binary_view.module_handle_at(function_handle.module);
259        let address = self.binary_view.address_identifier_at(m.address);
260        let module = self.binary_view.identifier_at(m.name);
261        let function = self.binary_view.identifier_at(function_handle.name);
262        (address, module, function)
263    }
264
265    fn cur_function(&self) -> FunctionIdent<'a> {
266        let fdef = self
267            .binary_view
268            .function_def_at(self.function_context.index().unwrap());
269        let handle = self.binary_view.function_handle_at(fdef.function);
270        self.resolve_function(handle)
271    }
272}
273
274impl TransferFunctions for IDLeakAnalysis<'_> {
275    type State = AbstractState;
276
277    fn execute(
278        &mut self,
279        state: &mut Self::State,
280        bytecode: &Bytecode,
281        index: CodeOffset,
282        (_first_index, last_index): (u16, u16),
283        meter: &mut (impl Meter + ?Sized),
284    ) -> Result<(), PartialVMError> {
285        execute_inner(self, state, bytecode, index, meter)?;
286        // invariant: the stack should be empty at the end of the block
287        // If it is not, something is wrong with the implementation, so throw an
288        // invariant violation
289        if index == last_index && !self.stack.is_empty() {
290            let msg = "Invalid stack transitions. Non-zero stack size at the end of the block"
291                .to_string();
292            debug_assert!(false, "{msg}",);
293            return Err(
294                PartialVMError::new(StatusCode::VERIFIER_INVARIANT_VIOLATION).with_message(msg),
295            );
296        }
297        Ok(())
298    }
299}
300
301fn call(
302    verifier: &mut IDLeakAnalysis,
303    function_handle: &FunctionHandle,
304) -> Result<(), PartialVMError> {
305    let parameters = verifier
306        .binary_view
307        .signature_at(function_handle.parameters);
308    verifier.stack_popn(parameters.len() as u64)?;
309
310    let return_ = verifier.binary_view.signature_at(function_handle.return_);
311    let function = verifier.resolve_function(function_handle);
312    if FRESH_ID_FUNCTIONS.contains(&function) {
313        if return_.0.len() != 1 {
314            debug_assert!(false, "{function:?} should have a single return value");
315            return Err(PartialVMError::new(StatusCode::UNKNOWN_VERIFICATION_ERROR)
316                .with_message("Should have a single return value".to_string())
317                .with_sub_status(
318                    VMMVerifierErrorSubStatusCode::MULTIPLE_RETURN_VALUES_NOT_ALLOWED as u64,
319                ));
320        }
321        verifier.stack_push(AbstractValue::Fresh)?;
322    } else {
323        verifier.stack_pushn(return_.0.len() as u64, AbstractValue::Other)?;
324    }
325    Ok(())
326}
327
328fn num_fields(struct_def: &StructDefinition) -> u64 {
329    match &struct_def.field_information {
330        StructFieldInformation::Native => 0,
331        StructFieldInformation::Declared(fields) => fields.len() as u64,
332    }
333}
334
335fn pack(
336    verifier: &mut IDLeakAnalysis,
337    struct_def: &StructDefinition,
338) -> Result<(), PartialVMError> {
339    // When packing, an object whose struct type has key ability must have the first
340    // field as "id". That fields must come from one of the functions that
341    // creates a new UID.
342    let handle = verifier
343        .binary_view
344        .datatype_handle_at(struct_def.struct_handle);
345    let num_fields = num_fields(struct_def);
346    verifier.stack_popn(num_fields - 1)?;
347    let last_value = verifier.stack.pop().unwrap();
348    if handle.abilities.has_key() && last_value != AbstractValue::Fresh {
349        let (cur_package, cur_module, cur_function) = verifier.cur_function();
350        let msg = format!(
351            "Invalid object creation in {cur_package}::{cur_module}::{cur_function}. \
352                Object created without a newly created UID. \
353                The UID must come directly from iota::{}::{}. \
354                Or for tests, it can come from iota::{}::{}",
355            OBJECT_NEW.1, OBJECT_NEW.2, TS_NEW_OBJECT.1, TS_NEW_OBJECT.2,
356        );
357
358        return Err(PartialVMError::new(StatusCode::UNKNOWN_VERIFICATION_ERROR)
359            .with_message(msg)
360            .with_sub_status(VMMVerifierErrorSubStatusCode::INVALID_OBJECT_CREATION as u64));
361    }
362    verifier.stack_push(AbstractValue::Other)?;
363    Ok(())
364}
365
366fn unpack(
367    verifier: &mut IDLeakAnalysis,
368    struct_def: &StructDefinition,
369) -> Result<(), PartialVMError> {
370    verifier.stack.pop().unwrap();
371    verifier.stack_pushn(num_fields(struct_def), AbstractValue::Other)
372}
373
374fn execute_inner(
375    verifier: &mut IDLeakAnalysis,
376    state: &mut AbstractState,
377    bytecode: &Bytecode,
378    _: CodeOffset,
379    meter: &mut (impl Meter + ?Sized),
380) -> Result<(), PartialVMError> {
381    meter.add(Scope::Function, STEP_BASE_COST)?;
382    // TODO: Better diagnostics with location
383    match bytecode {
384        Bytecode::Pop => {
385            verifier.stack.pop().unwrap();
386        }
387        Bytecode::CopyLoc(_local) => {
388            // cannot copy a UID
389            verifier.stack_push(AbstractValue::Other)?;
390        }
391        Bytecode::MoveLoc(local) => {
392            let value = state.locals.remove(local).unwrap();
393            verifier.stack_push(value)?;
394        }
395        Bytecode::StLoc(local) => {
396            let value = verifier.stack.pop().unwrap();
397            state.locals.insert(*local, value);
398        }
399
400        // Reference won't be ID.
401        Bytecode::FreezeRef
402        // ID doesn't have copy ability, hence ReadRef won't produce an ID.
403        | Bytecode::ReadRef
404        // Following are unary operators that don't apply to ID.
405        | Bytecode::CastU8
406        | Bytecode::CastU16
407        | Bytecode::CastU32
408        | Bytecode::CastU64
409        | Bytecode::CastU128
410        | Bytecode::CastU256
411        | Bytecode::Not
412        | Bytecode::VecLen(_)
413        | Bytecode::VecPopBack(_) => {
414            verifier.stack.pop().unwrap();
415            verifier.stack_push(AbstractValue::Other)?;
416        }
417
418        // These bytecodes don't operate on any value.
419        Bytecode::Branch(_)
420        | Bytecode::Nop => {}
421
422        // These binary operators cannot produce ID as result.
423        Bytecode::Eq
424        | Bytecode::Neq
425        | Bytecode::Add
426        | Bytecode::Sub
427        | Bytecode::Mul
428        | Bytecode::Mod
429        | Bytecode::Div
430        | Bytecode::BitOr
431        | Bytecode::BitAnd
432        | Bytecode::Xor
433        | Bytecode::Shl
434        | Bytecode::Shr
435        | Bytecode::Or
436        | Bytecode::And
437        | Bytecode::Lt
438        | Bytecode::Gt
439        | Bytecode::Le
440        | Bytecode::Ge
441        | Bytecode::VecImmBorrow(_)
442        | Bytecode::VecMutBorrow(_) => {
443            verifier.stack.pop().unwrap();
444            verifier.stack.pop().unwrap();
445            verifier.stack_push(AbstractValue::Other)?;
446        }
447        Bytecode::WriteRef => {
448            verifier.stack.pop().unwrap();
449            verifier.stack.pop().unwrap();
450        }
451
452        // These bytecodes produce references, and hence cannot be ID.
453        Bytecode::MutBorrowLoc(_)
454        | Bytecode::ImmBorrowLoc(_) => verifier.stack_push(AbstractValue::Other)?,
455
456        | Bytecode::MutBorrowField(_)
457        | Bytecode::MutBorrowFieldGeneric(_)
458        | Bytecode::ImmBorrowField(_)
459        | Bytecode::ImmBorrowFieldGeneric(_) => {
460            verifier.stack.pop().unwrap();
461            verifier.stack_push(AbstractValue::Other)?;
462        }
463
464        // These bytecodes are not allowed, and will be
465        // flagged as error in a different verifier.
466        Bytecode::MoveFromDeprecated(_)
467                | Bytecode::MoveFromGenericDeprecated(_)
468                | Bytecode::MoveToDeprecated(_)
469                | Bytecode::MoveToGenericDeprecated(_)
470                | Bytecode::ImmBorrowGlobalDeprecated(_)
471                | Bytecode::MutBorrowGlobalDeprecated(_)
472                | Bytecode::ImmBorrowGlobalGenericDeprecated(_)
473                | Bytecode::MutBorrowGlobalGenericDeprecated(_)
474                | Bytecode::ExistsDeprecated(_)
475                | Bytecode::ExistsGenericDeprecated(_) => {
476            panic!("Should have been checked by global_storage_access_verifier.");
477        }
478
479        Bytecode::Call(idx) => {
480            let function_handle = verifier.binary_view.function_handle_at(*idx);
481            call(verifier, function_handle)?;
482        }
483        Bytecode::CallGeneric(idx) => {
484            let func_inst = verifier.binary_view.function_instantiation_at(*idx);
485            let function_handle = verifier.binary_view.function_handle_at(func_inst.handle);
486            call(verifier, function_handle)?;
487        }
488
489        Bytecode::Ret => {
490            verifier.stack_popn(verifier.function_context.return_().len() as u64)?
491        }
492
493        Bytecode::BrTrue(_) | Bytecode::BrFalse(_) | Bytecode::Abort => {
494            verifier.stack.pop().unwrap();
495        }
496
497        // These bytecodes produce constants, and hence cannot be ID.
498        Bytecode::LdTrue | Bytecode::LdFalse | Bytecode::LdU8(_) | Bytecode::LdU16(_)| Bytecode::LdU32(_)  | Bytecode::LdU64(_) | Bytecode::LdU128(_)| Bytecode::LdU256(_)  | Bytecode::LdConst(_) => {
499            verifier.stack_push(AbstractValue::Other)?;
500        }
501
502        Bytecode::Pack(idx) => {
503            let struct_def = verifier.binary_view.struct_def_at(*idx);
504            pack(verifier, struct_def)?;
505        }
506        Bytecode::PackGeneric(idx) => {
507            let struct_inst = verifier.binary_view.struct_instantiation_at(*idx);
508            let struct_def = verifier.binary_view.struct_def_at(struct_inst.def);
509            pack(verifier, struct_def)?;
510        }
511        Bytecode::Unpack(idx) => {
512            let struct_def = verifier.binary_view.struct_def_at(*idx);
513            unpack(verifier, struct_def)?;
514        }
515        Bytecode::UnpackGeneric(idx) => {
516            let struct_inst = verifier.binary_view.struct_instantiation_at(*idx);
517            let struct_def = verifier.binary_view.struct_def_at(struct_inst.def);
518            unpack(verifier, struct_def)?;
519        }
520
521        Bytecode::VecPack(_, num) => {
522            verifier.stack_popn(*num )?;
523            verifier.stack_push(AbstractValue::Other)?;
524        }
525
526        Bytecode::VecPushBack(_) => {
527            verifier.stack.pop().unwrap();
528            verifier.stack.pop().unwrap();
529        }
530
531        Bytecode::VecUnpack(_, num) => {
532            verifier.stack.pop().unwrap();
533            verifier.stack_pushn(*num, AbstractValue::Other)?;
534        }
535
536        Bytecode::VecSwap(_) => {
537            verifier.stack.pop().unwrap();
538            verifier.stack.pop().unwrap();
539            verifier.stack.pop().unwrap();
540        }
541        Bytecode::PackVariant(vidx) =>  {
542            let handle = verifier.binary_view.variant_handle_at(*vidx);
543            let variant = verifier.binary_view.variant_def_at(handle.enum_def, handle.variant);
544            let num_fields = variant.fields.len();
545            verifier.stack_popn(num_fields as u64)?;
546            verifier.stack_push(AbstractValue::Other)?;
547        }
548        Bytecode::PackVariantGeneric(vidx) =>  {
549            let handle = verifier.binary_view.variant_instantiation_handle_at(*vidx);
550            let enum_inst = verifier.binary_view.enum_instantiation_at(handle.enum_def);
551            let variant = verifier.binary_view.variant_def_at(enum_inst.def, handle.variant);
552            let num_fields = variant.fields.len();
553            verifier.stack_popn(num_fields as u64)?;
554            verifier.stack_push(AbstractValue::Other)?;
555        }
556        Bytecode::UnpackVariant(vidx)
557        | Bytecode::UnpackVariantImmRef(vidx)
558        | Bytecode::UnpackVariantMutRef(vidx) =>  {
559            let handle = verifier.binary_view.variant_handle_at(*vidx);
560            let variant = verifier.binary_view.variant_def_at(handle.enum_def, handle.variant);
561            let num_fields = variant.fields.len();
562            verifier.stack.pop().unwrap();
563            verifier.stack_pushn(num_fields as u64, AbstractValue::Other)?;
564        }
565        Bytecode::UnpackVariantGeneric(vidx)
566        | Bytecode::UnpackVariantGenericImmRef(vidx)
567        | Bytecode::UnpackVariantGenericMutRef(vidx) =>  {
568            let handle = verifier.binary_view.variant_instantiation_handle_at(*vidx);
569            let enum_inst = verifier.binary_view.enum_instantiation_at(handle.enum_def);
570            let variant = verifier.binary_view.variant_def_at(enum_inst.def, handle.variant);
571            let num_fields = variant.fields.len();
572            verifier.stack.pop().unwrap();
573            verifier.stack_pushn(num_fields as u64, AbstractValue::Other)?;
574        }
575        Bytecode::VariantSwitch(_) =>  {
576            verifier.stack.pop().unwrap();
577        }
578    };
579    Ok(())
580}
iota_verifier_latest/id_leak_verifier.rs

iota_verifier_latest/
id_leak_verifier.rs
