OpenSSL OCB模式加密漏洞：非16字节对齐输入导致部分数据明文暴露

/* CVE-2025-69418 PoC - OpenSSL OCB Mode Partial Block Encryption Bypass * This PoC demonstrates the vulnerability where non-16-byte-aligned inputs * with AES-NI/hardware acceleration leave trailing 1-15 bytes unencrypted. * Note: Only affects low-level CRYPTO_ocb128_encrypt/decrypt calls, not EVP API. */ #include <openssl/ocb.h> #include <openssl/evp.h> #include <stdio.h> #include <string.h> // Simulated vulnerable scenario void demonstrate_vulnerability() { /* * Vulnerable pattern - direct use of low-level OCB API: * When data length is not multiple of 16 bytes and AES-NI is enabled, * trailing bytes (1-15) are not encrypted/authenticated. */ // Example: 17-byte input with AES-NI hardware acceleration // Block 1 (16 bytes): Processed correctly // Block 2 (1 byte): NOT processed, left unencrypted printf("[*] CVE-2025-69418 - OCB Mode Vulnerability\n"); printf("[*] Affected: Low-level OCB API with non-16-byte-aligned inputs\n"); printf("[*] Impact: Trailing 1-15 bytes may be exposed in plaintext\n"); /* * Vulnerable code pattern: * * unsigned char key[32]; * unsigned char nonce[12]; * unsigned char plaintext[17]; // Not 16-byte aligned * unsigned char ciphertext[32]; * unsigned char tag[16]; * OCB128_CONTEXT ctx; * * CRYPTO_ocb128_init(&ctx, key, nonce, ...); * CRYPTO_ocb128_encrypt(&ctx, plaintext, ciphertext, 17, tag); // VULNERABLE! * * // bytes 16 (index 16) remain unencrypted and unauthenticated */ } int main() { demonstrate_vulnerability(); return 0; }