package com.nimbusds.jose;
import java.text.ParseException;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import net.minidev.json.JSONObject;
import com.nimbusds.jose.jwk.JWK;
import com.nimbusds.jose.util.Base64URL;
import com.nimbusds.jose.util.JSONObjectUtils;
import com.nimbusds.jose.util.X509CertChainUtils;
/**
* JSON Web Signature (JWS) header.
*
* <p>Supports all {@link #getRegisteredParameterNames registered header
* parameters} of the JWS specification:
*
* <ul>
* <li>alg
* <li>jku
* <li>jwk
* <li>x5u
* <li>x5t
* <li>x5c
* <li>kid
* <li>typ
* <li>cty
* <li>crit
* </ul>
*
* <p>The header may also carry {@link #setCustomParameters custom parameters};
* these will be serialised and parsed along the registered ones.
*
* <p>Example header of a JSON Web Signature (JWS) object using the
* {@link JWSAlgorithm#HS256 HMAC SHA-256 algorithm}:
*
* <pre>
* {
* "alg" : "HS256"
* }
* </pre>
*
* @author Vladimir Dzhuvinov
* @version $version$ (2013-10-07)
*/
public class JWSHeader extends CommonSEHeader implements ReadOnlyJWSHeader {
/**
* The registered parameter names.
*/
private static final Set<String> REGISTERED_PARAMETER_NAMES;
/**
* Initialises the registered parameter name set.
*/
static {
Set<String> p = new HashSet<String>();
p.add("alg");
p.add("jku");
p.add("jwk");
p.add("x5u");
p.add("x5t");
p.add("x5c");
p.add("kid");
p.add("typ");
p.add("cty");
p.add("crit");
REGISTERED_PARAMETER_NAMES = Collections.unmodifiableSet(p);
}
/**
* Creates a new JSON Web Signature (JWS) header.
*
* <p>Note: Use {@link PlainHeader} to create a header with algorithm
* {@link Algorithm#NONE none}.
*
* @param alg The JWS algorithm. Must not be "none" or {@code null}.
*/
public JWSHeader(final JWSAlgorithm alg) {
super(alg);
if (alg.getName().equals(Algorithm.NONE.getName())) {
throw new IllegalArgumentException("The JWS algorithm cannot be \"none\"");
}
}
/**
* Gets the registered parameter names for JWS headers.
*
* @return The registered parameter names, as an unmodifiable set.
*/
public static Set<String> getRegisteredParameterNames() {
return REGISTERED_PARAMETER_NAMES;
}
@Override
public JWSAlgorithm getAlgorithm() {
return (JWSAlgorithm)alg;
}
/**
* @throws IllegalArgumentException If the specified parameter name
* matches a registered parameter
* name.
*/
@Override
public void setCustomParameter(final String name, final Object value) {
if (getRegisteredParameterNames().contains(name)) {
throw new IllegalArgumentException("The parameter name \"" + name + "\" matches a registered name");
}
super.setCustomParameter(name, value);
}
@Override
public Set<String> getIncludedParameters() {
Set<String> includedParameters =
new HashSet<String>(getCustomParameters().keySet());
includedParameters.add("alg");
if (getType() != null) {
includedParameters.add("typ");
}
if (getContentType() != null) {
includedParameters.add("cty");
}
if (getCriticalHeaders() != null && ! getCriticalHeaders().isEmpty()) {
includedParameters.add("crit");
}
if (getJWKURL() != null) {
includedParameters.add("jku");
}
if (getJWK() != null) {
includedParameters.add("jwk");
}
if (getX509CertURL() != null) {
includedParameters.add("x5u");
}
if (getX509CertThumbprint() != null) {
includedParameters.add("x5t");
}
if (getX509CertChain() != null) {
includedParameters.add("x5c");
}
if (getKeyID() != null) {
includedParameters.add("kid");
}
return includedParameters;
}
/**
* Parses a JWS header from the specified JSON object.
*
* @param json The JSON object to parse. Must not be {@code null}.
*
* @return The JWS header.
*
* @throws ParseException If the specified JSON object doesn't
* represent a valid JWS header.
*/
public static JWSHeader parse(final JSONObject json)
throws ParseException {
// Get the "alg" parameter
Algorithm alg = Header.parseAlgorithm(json);
if (! (alg instanceof JWSAlgorithm)) {
throw new ParseException("The algorithm \"alg\" header parameter must be for signatures", 0);
}
// Create a minimal header
JWSHeader h = new JWSHeader((JWSAlgorithm)alg);
// Parse optional + custom parameters
for (final String name: json.keySet()) {
if (name.equals("alg")) {
continue; // Skip
} else if (name.equals("typ")) {
h.setType(new JOSEObjectType(JSONObjectUtils.getString(json, name)));
} else if (name.equals("cty")) {
h.setContentType(JSONObjectUtils.getString(json, name));
} else if (name.equals("crit")) {
h.setCriticalHeaders(new HashSet<String>(JSONObjectUtils.getStringList(json, name)));
} else if (name.equals("jku")) {
h.setJWKURL(JSONObjectUtils.getURL(json, name));
} else if (name.equals("jwk")) {
h.setJWK(JWK.parse(JSONObjectUtils.getJSONObject(json, name)));
} else if (name.equals("x5u")) {
h.setX509CertURL(JSONObjectUtils.getURL(json, name));
} else if (name.equals("x5t")) {
h.setX509CertThumbprint(new Base64URL(JSONObjectUtils.getString(json, name)));
} else if (name.equals("x5c")) {
h.setX509CertChain(X509CertChainUtils.parseX509CertChain(JSONObjectUtils.getJSONArray(json, name)));
} else if (name.equals("kid")) {
h.setKeyID(JSONObjectUtils.getString(json, name));
} else {
h.setCustomParameter(name, json.get(name));
}
}
return h;
}
/**
* Parses a JWS header from the specified JSON object string.
*
* @param s The JSON object string to parse. Must not be {@code null}.
*
* @return The JWS header.
*
* @throws ParseException If the specified JSON object string doesn't
* represent a valid JWS header.
*/
public static JWSHeader parse(final String s)
throws ParseException {
JSONObject jsonObject = JSONObjectUtils.parseJSONObject(s);
return parse(jsonObject);
}
/**
* Parses a JWS header from the specified Base64URL.
*
* @param base64URL The Base64URL to parse. Must not be {@code null}.
*
* @return The JWS header.
*
* @throws ParseException If the specified Base64URL doesn't represent
* a valid JWS header.
*/
public static JWSHeader parse(final Base64URL base64URL)
throws ParseException {
JWSHeader header = parse(base64URL.decodeToString());
header.setParsedBase64URL(base64URL);
return header;
}
}