# Verification ## Verifier ```java Verifier verifier(PublicKey publicKey, String algorithm); ``` Returns a verifier for the given private key and algorithm. ### Usage Example ```java KeyStore keystore = keystore("classpath:keystore.p12", "password".toCharArray(), "PKCS12"); PublicKey publicKey = publicKey(keystore, "alice"); Verifier verifier = verifier(publicKey, "SHA512withRSA"); byte[] signature = ...; boolean verified = verifier.verify("Hello".getBytes(UTF_8), signature); ``` ## Verifier by Key ```text VerifierByKey verifier(Map publicKeyMap, String algorithm) ``` Returns a verifier that allows choosing the public key at runtime from a map of preconfigured keys. ### Usage Example ```java KeyStore keystore = keystore("classpath:keystore.p12", "password".toCharArray(), "PKCS12"); PublicKey aKey = publicKey(keystore, "alice"); PublicKey bKey = publicKey(keystore, "bob"); Map keys = Map.of("alice", aKey, "bob", bKey); VerifierByKey verifier = verifier(keys, "SHA512withRSA"); byte[] aSignature = ...; // Alice's signature byte[] bSignature = ...; // Bob's signature boolean verified = verifier.verify("alice", "Hello Alice".getBytes(UTF_8), bSignature); boolean verified = verifier.verify("bob", "Hello Bob".getBytes(UTF_8), aSignature); ``` ## Encoding Verifier ```java EncodingVerifier verifier( PublicKey publicKey, String algorithm, Encoding encoding ); ``` Returns an encoding verifier for the given key, algorithm and encoding. Assumes using the default JCA provider and UTF-8 as the plaintext string character set encoding. ### Usage Example ```java KeyStore keystore = keystore("classpath:keystore.p12", "password".toCharArray(), "PKCS12"); PublicKey publicKey = publicKey(keystore, "alice"); EncodingVerifier verifier = verifier(publicKey, "SHA512withRSA", BASE64); String signature = ...; // base64 encoded signature boolean verified = verifier.verify("Hello", signature); ``` ## Encoding Verifier with Custom Character Set ```java EncodingVerifier verifier( PublicKey publicKey, String algorithm, Charset charset, Encoding encoding ); ``` Same as [encoding verifier](verify.md#encoding-verifier) but allows specifying a custom character set for the plaintext messages. ### Usage Example ```java KeyStore keystore = keystore("classpath:keystore.p12", "password".toCharArray(), "PKCS12"); PublicKey publicKey = publicKey(keystore, "alice"); EncodingVerifier verifier = verifier(publicKey, "SHA512withRSA", ISO_8859_1, BASE64); String signature = ...; // base64 encoded signature boolean verified = verifier.verify("Hello", signature); ```