Merge branch '61-edits' and MichaelSims-master

src/main/java/io/jsonwebtoken/JwtParser.java

@@ -131,11 +131,21 @@ public interface JwtParser {
      * The parser uses a {@link DefaultClock DefaultClock} instance by default.
      *
      * @param clock a {@code Clock} object to return the timestamp to use when validating the parsed JWT.
-     * @return the builder instance for method chaining.
+     * @return the parser for method chaining.
      * @since 0.7.0
      */
     JwtParser setClock(Clock clock);
 
+    /**
+     * Sets the amount of clock skew in seconds to tolerate when verifying the local time against the {@code exp}
+     * and {@code nbf} claims.
+     *
+     * @param seconds the number of seconds to tolerate for clock skew when verifying {@code exp} or {@code nbf} claims.
+     * @return the parser for method chaining.
+     * @since 0.7.0
+     */
+    JwtParser setAllowedClockSkewSeconds(long seconds);
+
     /**
      * Sets the signing key used to verify any discovered JWS digital signature.  If the specified JWT string is not
      * a JWS (no signature), this key is not used.

src/main/java/io/jsonwebtoken/impl/DefaultJwtParser.java

@@ -57,6 +57,7 @@ public class DefaultJwtParser implements JwtParser {
 
     //don't need millis since JWT date fields are only second granularity:
     private static final String ISO_8601_FORMAT = "yyyy-MM-dd'T'HH:mm:ss'Z'";
+    private static final int MILLISECONDS_PER_SECOND = 1000;
 
     private ObjectMapper objectMapper = new ObjectMapper();
 
@@ -72,52 +73,47 @@ public class DefaultJwtParser implements JwtParser {
 
     private Clock clock = DefaultClock.INSTANCE;
 
+    private long allowedClockSkewMillis = 0;
+
     @Override
     public JwtParser requireIssuedAt(Date issuedAt) {
         expectedClaims.setIssuedAt(issuedAt);
-
         return this;
     }
 
     @Override
     public JwtParser requireIssuer(String issuer) {
         expectedClaims.setIssuer(issuer);
-
         return this;
     }
 
     @Override
     public JwtParser requireAudience(String audience) {
         expectedClaims.setAudience(audience);
-
         return this;
     }
 
     @Override
     public JwtParser requireSubject(String subject) {
         expectedClaims.setSubject(subject);
-
         return this;
     }
 
     @Override
     public JwtParser requireId(String id) {
         expectedClaims.setId(id);
-
         return this;
     }
 
     @Override
     public JwtParser requireExpiration(Date expiration) {
         expectedClaims.setExpiration(expiration);
-
         return this;
     }
 
     @Override
     public JwtParser requireNotBefore(Date notBefore) {
         expectedClaims.setNotBefore(notBefore);
-
         return this;
     }
 
@@ -126,7 +122,6 @@ public class DefaultJwtParser implements JwtParser {
         Assert.hasText(claimName, "claim name cannot be null or empty.");
         Assert.notNull(value, "The value cannot be null for claim name: " + claimName);
         expectedClaims.put(claimName, value);
-
         return this;
     }
 
@@ -137,6 +132,12 @@ public class DefaultJwtParser implements JwtParser {
         return this;
     }
 
+    @Override
+    public JwtParser setAllowedClockSkewSeconds(long seconds) {
+        this.allowedClockSkewMillis = Math.max(0, seconds * MILLISECONDS_PER_SECOND);
+        return this;
+    }
+
     @Override
     public JwtParser setSigningKey(byte[] key) {
         Assert.notEmpty(key, "signing key cannot be null or empty.");
@@ -354,24 +355,33 @@ public class DefaultJwtParser implements JwtParser {
             }
         }
 
+        final boolean allowSkew = this.allowedClockSkewMillis > 0;
+
         //since 0.3:
         if (claims != null) {
 
             SimpleDateFormat sdf;
 
             final Date now = this.clock.now();
+            long nowTime = now.getTime();
 
             //https://tools.ietf.org/html/draft-ietf-oauth-json-web-token-30#section-4.1.4
             //token MUST NOT be accepted on or after any specified exp time:
             Date exp = claims.getExpiration();
             if (exp != null) {
 
-                if (now.equals(exp) || now.after(exp)) {
+                long maxTime = nowTime - this.allowedClockSkewMillis;
+                Date max = allowSkew ? new Date(maxTime) : now;
+                if (max.after(exp)) {
                     sdf = new SimpleDateFormat(ISO_8601_FORMAT);
                     String expVal = sdf.format(exp);
                     String nowVal = sdf.format(now);
 
-                    String msg = "JWT expired at " + expVal + ". Current time: " + nowVal;
+                    long differenceMillis = maxTime - exp.getTime();
+
+                    String msg = "JWT expired at " + expVal + ". Current time: " + nowVal + ", a difference of " +
+                        differenceMillis + " milliseconds.  Allowed clock skew: " +
+                        this.allowedClockSkewMillis + " milliseconds.";
                     throw new ExpiredJwtException(header, claims, msg);
                 }
             }
@@ -381,12 +391,19 @@ public class DefaultJwtParser implements JwtParser {
             Date nbf = claims.getNotBefore();
             if (nbf != null) {
 
-                if (now.before(nbf)) {
+                long minTime = nowTime + this.allowedClockSkewMillis;
+                Date min = allowSkew ? new Date(minTime) : now;
+                if (min.before(nbf)) {
                     sdf = new SimpleDateFormat(ISO_8601_FORMAT);
                     String nbfVal = sdf.format(nbf);
                     String nowVal = sdf.format(now);
 
-                    String msg = "JWT must not be accepted before " + nbfVal + ". Current time: " + nowVal;
+                    long differenceMillis = nbf.getTime() - minTime;
+
+                    String msg = "JWT must not be accepted before " + nbfVal + ". Current time: " + nowVal +
+                        ", a difference of " +
+                        differenceMillis + " milliseconds.  Allowed clock skew: " +
+                        this.allowedClockSkewMillis + " milliseconds.";
                     throw new PrematureJwtException(header, claims, msg);
                 }
             }

src/test/groovy/io/jsonwebtoken/JwtParserTest.groovy

@@ -176,8 +176,8 @@ class JwtParserTest {
         } catch (ExpiredJwtException e) {
             assertTrue e.getMessage().startsWith('JWT expired at ')
 
-            //https://github.com/jwtk/jjwt/issues/107 :
+            //https://github.com/jwtk/jjwt/issues/107 (the Z designator at the end of the timestamp):
-            assertTrue e.getMessage().endsWith('Z')
+            assertTrue e.getMessage().contains('Z, a difference of ')
         }
     }
 
@@ -194,8 +194,60 @@ class JwtParserTest {
         } catch (PrematureJwtException e) {
             assertTrue e.getMessage().startsWith('JWT must not be accepted before ')
 
-            //https://github.com/jwtk/jjwt/issues/107 :
+            //https://github.com/jwtk/jjwt/issues/107 (the Z designator at the end of the timestamp):
-            assertTrue e.getMessage().endsWith('Z')
+            assertTrue e.getMessage().contains('Z, a difference of ')
+        }
+    }
+
+    @Test
+    void testParseWithExpiredJwtWithinAllowedClockSkew() {
+        Date exp = new Date(System.currentTimeMillis() - 3000)
+
+        String subject = 'Joe'
+        String compact = Jwts.builder().setSubject(subject).setExpiration(exp).compact()
+
+        Jwt<Header,Claims> jwt = Jwts.parser().setAllowedClockSkewSeconds(10).parse(compact)
+
+        assertEquals jwt.getBody().getSubject(), subject
+    }
+
+    @Test
+    void testParseWithExpiredJwtNotWithinAllowedClockSkew() {
+        Date exp = new Date(System.currentTimeMillis() - 3000)
+
+        String compact = Jwts.builder().setSubject('Joe').setExpiration(exp).compact()
+
+        try {
+            Jwts.parser().setAllowedClockSkewSeconds(1).parse(compact)
+            fail()
+        } catch (ExpiredJwtException e) {
+            assertTrue e.getMessage().startsWith('JWT expired at ')
+        }
+    }
+
+    @Test
+    void testParseWithPrematureJwtWithinAllowedClockSkew() {
+        Date exp = new Date(System.currentTimeMillis() + 3000)
+
+        String subject = 'Joe'
+        String compact = Jwts.builder().setSubject(subject).setNotBefore(exp).compact()
+
+        Jwt<Header,Claims> jwt = Jwts.parser().setAllowedClockSkewSeconds(10).parse(compact)
+
+        assertEquals jwt.getBody().getSubject(), subject
+    }
+
+    @Test
+    void testParseWithPrematureJwtNotWithinAllowedClockSkew() {
+        Date exp = new Date(System.currentTimeMillis() + 3000)
+
+        String compact = Jwts.builder().setSubject('Joe').setNotBefore(exp).compact()
+
+        try {
+            Jwts.parser().setAllowedClockSkewSeconds(1).parse(compact)
+            fail()
+        } catch (PrematureJwtException e) {
+            assertTrue e.getMessage().startsWith('JWT must not be accepted before ')
         }
     }