Why is this an issue?
Strong cipher algorithms are cryptographic systems resistant to cryptanalysis, they
are not vulnerable to well-known attacks like brute force attacks for example.
A general recommendation is to only use cipher algorithms intensively tested and promoted by the cryptographic community.
More specifically for block cipher, it’s not recommended to use algorithm with a block size inferior than 128 bits.
Noncompliant code example
botan
#include <botan/cipher_mode.h>
Botan::Cipher_Mode::create("Blowfish/CBC/PKCS7", Botan::ENCRYPTION); // Noncompliant: Blowfish use a 64-bit block size makes it vulnerable to birthday attacks
Botan::Cipher_Mode::create("DES/CBC/PKCS7", Botan::ENCRYPTION); // Noncompliant: DES works with 56-bit keys allow attacks via exhaustive search
Botan::Cipher_Mode::create("3DES/CBC/PKCS7", Botan::ENCRYPTION); // Noncompliant: Triple DES is vulnerable to meet-in-the-middle attack
Botan::Cipher_Mode::create("DESX/CBC/PKCS7", Botan::ENCRYPTION); // Noncompliant: Triple DES is vulnerable to meet-in-the-middle attack
Botan::Cipher_Mode::create("CAST-128/CBC/PKCS7", Botan::ENCRYPTION); // Noncompliant: 64-bit size block cipher
Botan::Cipher_Mode::create("GOST-28147-89/CBC/PKCS7", Botan::ENCRYPTION); // Noncompliant: 64-bit size block cipher
Botan::Cipher_Mode::create("IDEA/CBC/PKCS7", Botan::ENCRYPTION); // Noncompliant: 64-bit size block cipher
Botan::Cipher_Mode::create("KASUMI/CBC/PKCS7", Botan::ENCRYPTION); // Noncompliant: 64-bit size block cipher
Botan::Cipher_Mode::create("MISTY1/CBC/PKCS7", Botan::ENCRYPTION); // Noncompliant: 64-bit size block cipher
Botan::Cipher_Mode::create("XTEA/CBC/PKCS7", Botan::ENCRYPTION); // Noncompliant: 64-bit size block cipher
Botan::Cipher_Mode::create("RC4", Botan::ENCRYPTION); // Noncompliant: has numerous design flaws which make it hard to use correctly
crypto++
#include <cryptopp/arc4.h>
#include <cryptopp/blowfish.h>
#include <cryptopp/cast.h>
#include <cryptopp/des.h>
#include <cryptopp/gost.h>
#include <cryptopp/idea.h>
#include <cryptopp/rc2.h>
#include <cryptopp/tea.h>
CryptoPP::ARC4::Encryption(key, sizeof(key)); // Noncompliant: RC4/ARC4 has numerous design flaws which make it hard to use correctly
CryptoPP::Blowfish::Encryption(key, sizeof(key)); // Noncompliant: 64-bit size block
CryptoPP::GOST::Encryption(key, sizeof(key)); // Noncompliant: 64-bit size block
CryptoPP::IDEA::Encryption(key, sizeof(key)); // Noncompliant: 64-bit size block
CryptoPP::XTEA::Encryption(key, sizeof(key)); // Noncompliant: 64-bit size block
CryptoPP::DES::Encryption(key, sizeof(key)); // Noncompliant: DES works with 56-bit keys allow attacks via exhaustive search
CryptoPP::DES_EDE2::Encryption(key, sizeof(key)); // Noncompliant: Triple DES is vulnerable to meet-in-the-middle attack
CryptoPP::DES_EDE3::Encryption(key, sizeof(key)); // Noncompliant: Triple DES is vulnerable to meet-in-the-middle attack
CryptoPP::DES_XEX3::Encryption(key, sizeof(key)); // Noncompliant: Triple DES is vulnerable to meet-in-the-middle attack
CryptoPP::RC2::Encryption(key, sizeof(key)); // Noncompliant: RC2 is vulnerable to a related-key attack
CryptoPP::RC2Encryption(key, sizeof(key)); // Noncompliant; alternative
CryptoPP::RC2Decryption(key, sizeof(key)); // Noncompliant; alternative
OpenSSL
#include <openssl/evp.h>
EVP_bf_cbc(); // Noncompliant: 64-bit size block
EVP_cast5_cbc(); // Noncompliant: 64-bit size block
EVP_des_cbc(); // Noncompliant: DES works with 56-bit keys allow attacks via exhaustive search
EVP_idea_cbc(); // Noncompliant: 64-bit size block
EVP_rc4(); // Noncompliant: has numerous design flaws which make it hard to use correctly
EVP_rc2_cbc(); // Noncompliant: RC2 is vulnerable to a related-key attack
Compliant solution
botan
#include <botan/cipher_mode.h>
Botan::Cipher_Mode::create("AES-256/GCM", Botan::ENCRYPTION); // Compliant: AES is a good default choice for symmetric encryption
crypto++
#include <cryptopp/aes.h>
CryptoPP::AES::Encryption(key, sizeof(key)); // Compliant: AES is a good default choice for symmetric encryption
OpenSSL
#include <openssl/evp.h>
EVP_aes_128_gcm() // Compliant: AES is a good default choice for symmetric encryption
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