MPC/Threshold Cryptography Audit | Holonym

Summary

100% of all REPORTED Findings have been addressed

About this report

Assessment Type

Advisory Assessment

Date of Engagement

August 26th, 2024 - September 20th, 2024

Source Code

decentralization

Assessed Commit ID

518213f

Severity Breakdown

0Risk Accepted
14Not Applicable
13Solved
27All Findings

Critical4
- 4Solved
High1
- 1Solved
Medium5
- 3Solved
- 2N/A
Low12
- 8N/A
- 4Solved
Informational5
- 4N/A
- 1Solved

Introduction#

Holonym engaged Halborn to perform a security assessment of their Rust codebase from September 2, 2024, to September 27, 2024. The assessment focused on the specific crates listed in the provided GitHub repository and included relevant commit hashes. More details can be found in the Scope section of this report.

Assessment Summary#

The Halborn team was allocated four weeks for the engagement and assigned a full-time security engineer to assess the security of the crates and the overall codebase. The security engineer is an expert in blockchain and smart contract security, with advanced skills in penetration testing and smart contract auditing, as well as extensive knowledge of various blockchain protocols.

The purpose of this assessment is to:

Ensure that codebase functions operate as intended
Identify potential security issues within codebase

Test Approach and Methodology#

Halborn Performed a combination of the manual view of the code and automated security testing to balance efficiency, timeliness, practicality, and accuracy regarding the scope of the codebase assessment. While manual testing is recommended to uncover flaws in logic, process, and implementation, automated testing techniques. They can quickly identify items that do not follow security best practices. The following phases and associated tools were used throughout the term of the assessment:

Research on the architecture, purpose, and usage of the Human network.
Manual code reading and walkthroughs to gain an understanding of the overall design and potential vulnerabilities.
Manual assessment of critical Rust variables and functions to identify arithmetic-related vulnerabilities.
Testing for race conditions and thread safety in the Rust actor framework.
Audit of the DKG (Distributed Key Generation) cryptographic protocol to ensure robustness against potential attacks.
Review of libp2p configuration and security to validate network communication integrity.
Security testing of cryptographic primitives to ensure they meet industry standards.
Scanning Rust files for vulnerabilities using Cargo Audit, identifying outdated dependencies and known security issues.
Checking for unsafe code usage with Cargo Geiger to minimize risks associated with unsafe Rust features.
Analysis of node communication and message integrity to mitigate risks from malicious nodes.
Review of error handling and logging practices to ensure sensitive information is not exposed.
Testing for denial-of-service vulnerabilities and resilience against resource exhaustion attacks.

Risk Methodology#

Every vulnerability and issue observed by Halborn is ranked based on two sets of Metrics and a Severity Coefficient. This system is inspired by the industry standard Common Vulnerability Scoring System.

The two Metric sets are: Exploitability and Impact. Exploitability captures the ease and technical means by which vulnerabilities can be exploited and Impact describes the consequences of a successful exploit.

The Severity Coefficients is designed to further refine the accuracy of the ranking with two factors: Reversibility and Scope. These capture the impact of the vulnerability on the environment as well as the number of users and smart contracts affected.

The final score is a value between 0-10 rounded up to 1 decimal place and 10 corresponding to the highest security risk. This provides an objective and accurate rating of the severity of security vulnerabilities in smart contracts.

The system is designed to assist in identifying and prioritizing vulnerabilities based on their level of risk to address the most critical issues in a timely manner.

4.1 EXPLOITABILITY

Attack Origin (AO):

Captures whether the attack requires compromising a specific account.

Attack Cost (AC):

Captures the cost of exploiting the vulnerability incurred by the attacker relative to sending a single transaction on the relevant blockchain. Includes but is not limited to financial and computational cost.

Attack Complexity (AX):

Describes the conditions beyond the attacker’s control that must exist in order to exploit the vulnerability. Includes but is not limited to macro situation, available third-party liquidity and regulatory challenges.

Metrics:

EXPLOITABILITY METRIC ( $m_e$ )	METRIC VALUE	NUMERICAL VALUE
Attack Origin (AO)	Arbitrary (AO:A)	1
Attack Origin (AO)	Specific (AO:S)	0.2
Attack Cost (AC)	Low (AC:L)	1
	Medium (AC:M)	0.67
	High (AC:H)	0.33
Attack Complexity (AX)	Low (AX:L)	1
	Medium (AX:M)	0.67
	High (AX:H)	0.33

Exploitability

E

is calculated using the following formula:

$E = \prod m_e$

4.2 IMPACT

Confidentiality (C):

Measures the impact to the confidentiality of the information resources managed by the contract due to a successfully exploited vulnerability. Confidentiality refers to limiting access to authorized users only.

Integrity (I):

Measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of data stored and/or processed on-chain. Integrity impact directly affecting Deposit or Yield records is excluded.

Availability (A):

Measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability. This metric refers to smart contract features and functionality, not state. Availability impact directly affecting Deposit or Yield is excluded.

Deposit (D):

Measures the impact to the deposits made to the contract by either users or owners.

Yield (Y):

Measures the impact to the yield generated by the contract for either users or owners.

Metrics:

IMPACT METRIC ( $m_I$ )	METRIC VALUE	NUMERICAL VALUE
Confidentiality (C)	None (C:N)	0
	Low (C:L)	0.25
	Medium (C:M)	0.5
	High (C:H)	0.75
	Critical (C:C)	1
Integrity (I)	None (I:N)	0
	Low (I:L)	0.25
	Medium (I:M)	0.5
	High (I:H)	0.75
	Critical (I:C)	1
Availability (A)	None (A:N)	0
	Low (A:L)	0.25
	Medium (A:M)	0.5
	High (A:H)	0.75
	Critical (A:C)	1
Deposit (D)	None (D:N)	0
	Low (D:L)	0.25
	Medium (D:M)	0.5
	High (D:H)	0.75
	Critical (D:C)	1
Yield (Y)	None (Y:N)	0
	Low (Y:L)	0.25
	Medium (Y:M)	0.5
	High (Y:H)	0.75
	Critical (Y:C)	1

Impact

I

is calculated using the following formula:

$I = max(m_I) + \frac{\sum{m_I} - max(m_I)}{4}$

4.3 SEVERITY COEFFICIENT

Reversibility (R):

Describes the share of the exploited vulnerability effects that can be reversed. For upgradeable contracts, assume the contract private key is available.

Scope (S):

Captures whether a vulnerability in one vulnerable contract impacts resources in other contracts.

Metrics:

SEVERITY COEFFICIENT ( $C$ )	COEFFICIENT VALUE	NUMERICAL VALUE
Reversibility ( $r$ )	None (R:N)	1
	Partial (R:P)	0.5
	Full (R:F)	0.25
Scope ( $s$ )	Changed (S:C)	1.25
Scope ( $s$ )	Unchanged (S:U)	1

Severity Coefficient

C

is obtained by the following product:

$C = rs$

The Vulnerability Severity Score

S

is obtained by:

$S = min(10, EIC * 10)$

The score is rounded up to 1 decimal places.

Critical	High	Medium	Low	Informational
9 - 10	7 - 8.9	4.5 - 6.9	2 - 4.4	0 - 1.9

Scope#

(a) Repository:decentralization

(b) Assessed Commit ID:518213f810ba743bf5d16c601859fc3b12fb729b

33 files

actors / src

6 files

actor_manager.rs

rust

app_state_actor.rs

rust

dkg_engine_actor.rs

rust

election_actor.rs

rust

gossip_engine_actor.rs

rust

lib.rs

rust

cryptography / src

13 files

curve.rs

rust

dkg.rs

rust

empty.rs

rust

github.com/holonym-foundation/decentralization/blob/main-net-alpha_v1/mishti/crates/actors/src/gossip_engine_actor.rs#L402C72-L402C73~L414 75df6a4f13ba4c9a549559d5064d498fb3e19579 github.com/holonym-foundation/decentralization/blob/fix-audit/mishti/crates/cryptography/src/polynomial.rs 64e8c4be799e8d7d279430454777bf74d652f3f0 github.com/holonym-foundation/decentralization/blob/main-net-alpha_v1/mishti/crates/actors/src/dkg_engine_actor.rs#L1440~L1443 github.com/holonym-foundation/decentralization/blob/fix-audit/mishti/crates/cryptography/src/polynomial.rs#L40_L53

Out-of-Scope: New features/implementations after the remediation commit IDs.

Assessment Summary & Findings Overview#

#	Title	Severity	Score	Status
HAL-01	Unrestricted Growth of PubkeyShares HashMap Can Lead to Out-of-Memory (OOM)	Critical	10.0	Solved03/08/2025
HAL-02	Message::ForwardMulRequest Potential DDoS	Critical	10.0	Solved06/04/2025
HAL-03	Inadequate Validation of Messages in DKG Protocol	Critical	10.0	Solved03/08/2025
HAL-04	Deadlock in DKG	Critical	10.0	Solved03/08/2025
HAL-05	Lack of Validation for Threshold Parameters in update_threshold Function	High	7.5	Solved02/13/2025
HAL-06	Incorrect Threshold Check for Multiplication Verification in process_verification Function	Medium	5.0	Solved03/08/2025
HAL-07	Incomplete Election State Update and Lack of Error Handling in conduct_election Function	Medium	5.0	Not Applicable03/08/2025
HAL-08	Panic in Polynomial Generation from Seed	Medium	5.0	Solved06/11/2025
HAL-09	Out-of-Bounds Access Due to Empty Vectors	Medium	5.0	Not Applicable03/08/2025
HAL-10	Missing t,n Validation in Network Initialization	Medium	5.0	Solved03/08/2025
HAL-11	Non-Constant Time Cryptographic Operations In PointTrait	Low	2.5	Not Applicable03/08/2025
HAL-12	Missing Error Handling for encode() in process_verification Function	Low	2.5	Not Applicable03/08/2025
HAL-13	Lack of I/O Lock for File Operations in StoreKeyShares Handling	Low	2.5	Not Applicable03/08/2025
HAL-14	Missing Synchronization for Shared State in ElectionEngineState	Low	2.5	Not Applicable03/08/2025
HAL-15	Insecure RNG for Polynomial Coefficients	Low	2.5	Not Applicable03/08/2025
HAL-16	Sensitive Data Exposure Through Logging of Seed Value	Low	2.5	Solved10/10/2024
HAL-17	Misconfigurations in gossip Initialization	Low	2.5	Solved03/08/2025
HAL-18	Lack of Peer Blacklisting in Gossipsub Engine	Low	2.5	Solved03/08/2025
HAL-19	Unchecked Return Values in Request and Subscription Handlers	Low	2.5	Not Applicable03/08/2025
HAL-20	Insufficient Error Handling in handle_store_reshared_received_pubshare	Low	2.5	Solved06/04/2025
HAL-21	Missing Update of Total Nodes in add_node Function	Low	2.5	Not Applicable03/08/2025
HAL-22	Multiple Overflows in Polynomial Operations	Low	2.5	Not Applicable03/08/2025
HAL-23	Invalid Threshold Calculation in calculate_threshold Function	Informational	—	Not Applicable03/08/2025
HAL-24	Function Naming and State Update Issue in check_election_status	Informational	—	Not Applicable03/08/2025
HAL-25	Missing Degree Constraints in Polynomial Creation Function	Informational	—	Solved06/01/2025
HAL-26	Insecure Fallback to Local Random Number Generation	Informational	—	Not Applicable03/08/2025
HAL-27	Use of Non-Cryptographically Secure Random Number Generators in dkg nodes	Informational	—	Not Applicable03/08/2025

Findings & Tech Details#

HAL-01Solved

Unrestricted Growth of PubkeyShares HashMap Can Lead to Out-of-Memory (OOM)

Critical

10.0AO:A/AC:L/AX:L/R:N/S:U/C:N/A:C/I:N/D:N/Y:NAO:A/AC:L/AX:L/R:N/S:U/C:N/A:C/I:N/D:N/Y:N

Description

Recommendation

Remediation Comment

HAL-02Solved

Message::ForwardMulRequest Potential DDoS

Critical

10.0AO:A/AC:L/AX:L/R:N/S:U/C:N/A:C/I:N/D:N/Y:NAO:A/AC:L/AX:L/R:N/S:U/C:N/A:C/I:N/D:N/Y:N

Description

Recommendation

Remediation Comment

Addressed in:

Remediation Comment

Addressed in:

Recommendation

Remediation Comment

Addressed in:

Remediation Comment

Addressed in:

Remediation Comment

Addressed in:

github.com/holonym-foundation/decentralization/blob/main-net-alpha_v1/mishti/crates/actors/src/dkg_engine_actor.rs#L1440~L1443

HAL-21Not Applicable

Missing Update of Total Nodes in add_node Function

Low

2.5AO:A/AC:L/AX:L/R:N/S:U/C:N/A:N/I:L/D:N/Y:NAO:A/AC:L/AX:L/R:N/S:U/C:N/A:N/I:L/D:N/Y:N

Description

Insecure Fallback to Local Random Number Generation

Informational

Description

Recommendation

Remediation Comment

HAL-27Not Applicable

Use of Non-Cryptographically Secure Random Number Generators in dkg nodes

Informational

Description

Recommendation

Remediation Comment

8. Automated Testing#

Disclaimer#

Halborn strongly recommends conducting a follow-up assessment of the project either within six months or immediately following any material changes to the codebase, whichever comes first. This approach is crucial for maintaining the project’s integrity and addressing potential vulnerabilities introduced by code modifications.