create GenericTokenService

in jwt module

Author: biancodavide3

jwt/src/main/java/com/biancodavide3/jwt/GenericTokenService.java

@@ -0,0 +1,74 @@
+package com.biancodavide3.jwt;
+
+import io.jsonwebtoken.Claims;
+import io.jsonwebtoken.Jwts;
+import io.jsonwebtoken.SignatureAlgorithm;
+import io.jsonwebtoken.io.Decoders;
+import io.jsonwebtoken.security.Keys;
+import org.springframework.stereotype.Service;
+
+import java.security.Key;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Function;
+
+@Service
+public class GenericTokenService {
+
+ // todo make this come from vault
+ private String secretKey;
+
+ // creation
+
+ protected String generateToken(
+ String subject,
+ int expiration,
+ Map<String, Object> extraClaims
+ ) {
+ return Jwts
+ .builder()
+ .setClaims(extraClaims)
+ .setSubject(subject)
+ .setIssuedAt(new Date(System.currentTimeMillis()))
+ .setExpiration(new Date(System.currentTimeMillis() + hoursToMillis(expiration)))
+ .signWith(signingKey(), SignatureAlgorithm.HS256)
+ .compact();
+ }
+
+ protected String generateToken(String subject, int expiration) {
+ return generateToken(subject, expiration, new HashMap<>());
+ }
+
+ private long hoursToMillis(int expiration) {
+ return expiration * 60L * 60L * 1000L;
+ }
+
+ private Key signingKey() {
+ byte[] bytes = Decoders.BASE64.decode(secretKey);
+ return Keys.hmacShaKeyFor(bytes);
+ }
+
+ // validation
+
+ protected <T> T extractClaim(String token, Function<Claims, T> claimsResolver) {
+ Claims claims = Jwts
+ .parserBuilder()
+ .setSigningKey(signingKey())
+ .build()
+ .parseClaimsJws(token)
+ .getBody();
+ return claimsResolver.apply(claims);
+ }
+
+ protected boolean isTokenValid(String token, String subject) {
+ String extractedSubject = extractClaim(token, Claims::getSubject);
+ return extractedSubject.equals(subject) && !isTokenExpired(token);
+ }
+
+ private boolean isTokenExpired(String token) {
+ Date extractedDate = extractClaim(token, Claims::getExpiration);
+ return extractedDate.before(new Date());
+ }
+
+}