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🏷 Cryptography 4 patterns

Topic: Cryptography

All Java patterns related to Cryptography — java.evolved

PEM encoding/decoding

Old String pem = "-----BEGIN CERTIFICATE-----\n" + Base64.getMimeEncoder() .encodeToString( cert.getEncoded()) + "\n-----END CERTIFICATE-----";

Modern // Encode to PEM String pem = PEMEncoder.of() .encodeToString(cert); // Decode from PEM var cert = PEMDecoder.of() .decode(pemString);

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JDK 25+ learn more →

Key Derivation Functions

Old SecretKeyFactory factory = SecretKeyFactory.getInstance( "PBKDF2WithHmacSHA256"); KeySpec spec = new PBEKeySpec( password, salt, 10000, 256); SecretKey key = factory.generateSecret(spec);

Modern var kdf = KDF.getInstance("HKDF-SHA256"); SecretKey key = kdf.deriveKey( "AES", KDF.HKDFParameterSpec .ofExtract() .addIKM(inputKey) .addSalt(salt) .thenExpand(info, 32) .build() );

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JDK 25+ learn more →

Strong random generation

Old // Default algorithm — may not be // the strongest available SecureRandom random = new SecureRandom(); byte[] bytes = new byte[32]; random.nextBytes(bytes);

Modern // Platform's strongest algorithm SecureRandom random = SecureRandom.getInstanceStrong(); byte[] bytes = new byte[32]; random.nextBytes(bytes);

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JDK 9+ learn more →

TLS 1.3 by default

Old SSLContext ctx = SSLContext.getInstance("TLSv1.2"); ctx.init(null, trustManagers, null); SSLSocketFactory factory = ctx.getSocketFactory(); // Must specify protocol version

Modern // TLS 1.3 is the default! var client = HttpClient.newBuilder() .sslContext(SSLContext.getDefault()) .build(); // Already using TLS 1.3

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JDK 11+ learn more →