[UTXO-BUG] MED-3: Float precision loss in transfer endpoint — systematic rounding errors#2072
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ArokyaMatthew wants to merge 1 commit intoScottcjn:mainfrom
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…tic rounding errors int(amount_rtc * UNIT) uses float multiplication which truncates: int(0.1 * 100_000_000) = 9_999_999 instead of 10_000_000 Over thousands of transactions, the lost nanoRTC accumulates as implicit fee absorbed by miners. Fix: use Decimal(str(amount_rtc)) * UNIT for exact conversion. Test added: - test_transfer_float_precision (transfers 0.1 RTC, verifies exact 10_000_000 nanoRTC) All 16 endpoint tests pass. Bounty: #2819 (Medium, 50 RTC)
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Important fix! Float precision issues can cause significant problems in financial systems. |
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Vulnerability Class
Medium — Fee calculation exploit (50 RTC bounty)
The Bug
The transfer endpoint converts RTC amounts using float multiplication:
Floating-point imprecision means:
python
Fix
Use Decimal for exact conversion:
python
from decimal import Decimal
amount_nrtc = int(Decimal(str(amount_rtc)) * UNIT)
Test Added
test_transfer_float_precision — transfers 0.1 RTC and asserts recipient gets exactly 10,000,000 nanoRTC
All 16 endpoint tests pass.
Files Changed
node/utxo_endpoints.py — 2 lines changed + Decimal import
node/test_utxo_endpoints.py — 1 test added
Ref: Bounty #2819
MY WALLET IS aroky-x86-miner