[EXT-SEC-AUDIT] Architecturally insecure type declarations

[pro-wh]

Issue transferred from an external security audit report.

Severity: Medium
Type: Data Validation
Target: go/staking/api/commission.go
Difficulty: High
Finding ID: TOB-OL-108

Description

Int is set based on the architecture on a specific machine. MaxRateSteps and
MaxBoundSteps could be converted incorrectly between 32-bit and 64-bit machine
architectures.

Figure TOB-OL-108.1: shows https://github.com/oasislabs/oasis-core/blob/f3dec8e8bc17d0bae64b636bddc9a3100abc6866/go/staking/api/commission.go#L15-L20

Exploit Scenario

A 64-bit machine sets MaxBoundSteps to a value greater than the maximum value of a
32-bit architecture int ( 2,147,483,647) . MaxBoundSteps is read on a 32-bit machine and the
value is not what was originally set.

Recommendation

Convert to an architecture independent type (e.g. int32 , int64 ) for any int that could be a
large value.