CVE-2026-4599 jsrsasign密钥恢复漏洞

// Conceptual PoC demonstrating the logic flaw in range checking // This simulates the vulnerable behavior where out-of-range values are accepted. const BigInteger = require('jsrsasign').BigInteger; function vulnerableGetRandom(max) { let candidate; let attempts = 0; do { // Simulate random byte generation candidate = new BigInteger(max.bitLength(), new SecureRandom()); attempts++; // VULNERABLE: Incomplete comparison logic // The actual bug allowed candidates that were technically out of bounds // due to missing checks on specific factors or incorrect comparison logic. // The fix ensures compareTo is strictly less than max. } while (candidate.compareTo(max) >= 0 && attempts < 1000); // Simplified return candidate; } // Note: A full exploit would require collecting many signatures to perform lattice reduction. // This code illustrates the source of the bias in the random number generation.