package gov.nist.javax.sip.clientauthutils; import gov.nist.core.StackLogger; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; /** * The class takes standard Http Authentication details and returns a response according to the * MD5 algorithm * * @author Emil Ivov */ public class MessageDigestAlgorithm { /** * Calculates an http authentication response in accordance with rfc2617. * <p> * * @param algorithm a string indicating a pair of algorithms (MD5 (default), or MD5-sess) used * to produce the digest and a checksum. * @param hashUserNameRealmPasswd MD5 hash of (username:realm:password) * @param nonce_value A server-specified data string provided in the challenge. * @param cnonce_value an optional client-chosen value whose purpose is to foil chosen * plaintext attacks. * @param method the SIP method of the request being challenged. * @param digest_uri_value the value of the "uri" directive on the Authorization header in the * request. * @param entity_body the entity-body * @param qop_value Indicates what "quality of protection" the client has applied to the * message. * @param nc_value the hexadecimal count of the number of requests (including the current * request) that the client has sent with the nonce value in this request. * @return a digest response as defined in rfc2617 * @throws NullPointerException in case of incorrectly null parameters. */ static String calculateResponse(String algorithm, String hashUserNameRealmPasswd, String nonce_value, String nc_value, String cnonce_value, String method, String digest_uri_value, String entity_body, String qop_value, StackLogger stackLogger) { if (stackLogger.isLoggingEnabled()) { stackLogger.logDebug("trying to authenticate using : " + algorithm + ", "+ hashUserNameRealmPasswd + ", " + nonce_value + ", " + nc_value + ", " + cnonce_value + ", " + method + ", " + digest_uri_value + ", " + entity_body + ", " + qop_value); } if (hashUserNameRealmPasswd == null || method == null || digest_uri_value == null || nonce_value == null) throw new NullPointerException( "Null parameter to MessageDigestAlgorithm.calculateResponse()"); // The following follows closely the algorithm for generating a response // digest as specified by rfc2617 if (cnonce_value == null || cnonce_value.length() == 0) throw new NullPointerException( "cnonce_value may not be absent for MD5-Sess algorithm."); String A2 = null; if (qop_value == null || qop_value.trim().length() == 0 || qop_value.trim().equalsIgnoreCase("auth")) { A2 = method + ":" + digest_uri_value; } else { if (entity_body == null) entity_body = ""; A2 = method + ":" + digest_uri_value + ":" + H(entity_body); } String request_digest = null; if (cnonce_value != null && qop_value != null && nc_value != null && (qop_value.equalsIgnoreCase("auth") || qop_value.equalsIgnoreCase("auth-int"))) { request_digest = KD(hashUserNameRealmPasswd, nonce_value + ":" + nc_value + ":" + cnonce_value + ":" + qop_value + ":" + H(A2)); } else { request_digest = KD(hashUserNameRealmPasswd, nonce_value + ":" + H(A2)); } return request_digest; } /** * Calculates an http authentication response in accordance with rfc2617. * <p> * * @param algorithm a string indicating a pair of algorithms (MD5 (default), or MD5-sess) used * to produce the digest and a checksum. * @param username_value username_value (see rfc2617) * @param realm_value A string that has been displayed to the user in order to determine the * context of the username and password to use. * @param passwd the password to encode in the challenge response. * @param nonce_value A server-specified data string provided in the challenge. * @param cnonce_value an optional client-chosen value whose purpose is to foil chosen * plaintext attacks. * @param method the SIP method of the request being challenged. * @param digest_uri_value the value of the "uri" directive on the Authorization header in the * request. * @param entity_body the entity-body * @param qop_value Indicates what "quality of protection" the client has applied to the * message. * @param nc_value the hexadecimal count of the number of requests (including the current * request) that the client has sent with the nonce value in this request. * @return a digest response as defined in rfc2617 * @throws NullPointerException in case of incorrectly null parameters. */ static String calculateResponse(String algorithm, String username_value, String realm_value, String passwd, String nonce_value, String nc_value, String cnonce_value, String method, String digest_uri_value, String entity_body, String qop_value, StackLogger stackLogger) { if (stackLogger.isLoggingEnabled()) { stackLogger.logDebug("trying to authenticate using : " + algorithm + ", " + username_value + ", " + realm_value + ", " + (passwd != null && passwd.trim().length() > 0) + ", " + nonce_value + ", " + nc_value + ", " + cnonce_value + ", " + method + ", " + digest_uri_value + ", " + entity_body + ", " + qop_value); } if (username_value == null || realm_value == null || passwd == null || method == null || digest_uri_value == null || nonce_value == null) throw new NullPointerException( "Null parameter to MessageDigestAlgorithm.calculateResponse()"); // The following follows closely the algorithm for generating a response // digest as specified by rfc2617 String A1 = null; if (algorithm == null || algorithm.trim().length() == 0 || algorithm.trim().equalsIgnoreCase("MD5")) { A1 = username_value + ":" + realm_value + ":" + passwd; } else { if (cnonce_value == null || cnonce_value.length() == 0) throw new NullPointerException( "cnonce_value may not be absent for MD5-Sess algorithm."); A1 = H(username_value + ":" + realm_value + ":" + passwd) + ":" + nonce_value + ":" + cnonce_value; } String A2 = null; if (qop_value == null || qop_value.trim().length() == 0 || qop_value.trim().equalsIgnoreCase("auth")) { A2 = method + ":" + digest_uri_value; } else { if (entity_body == null) entity_body = ""; A2 = method + ":" + digest_uri_value + ":" + H(entity_body); } String request_digest = null; if (cnonce_value != null && qop_value != null && nc_value != null && (qop_value.equalsIgnoreCase("auth") || qop_value.equalsIgnoreCase("auth-int"))) { request_digest = KD(H(A1), nonce_value + ":" + nc_value + ":" + cnonce_value + ":" + qop_value + ":" + H(A2)); } else { request_digest = KD(H(A1), nonce_value + ":" + H(A2)); } return request_digest; } /** * Defined in rfc 2617 as H(data) = MD5(data); * * @param data data * @return MD5(data) */ private static String H(String data) { try { MessageDigest digest = MessageDigest.getInstance("MD5"); return toHexString(digest.digest(data.getBytes())); } catch (NoSuchAlgorithmException ex) { // shouldn't happen throw new RuntimeException("Failed to instantiate an MD5 algorithm", ex); } } /** * Defined in rfc 2617 as KD(secret, data) = H(concat(secret, ":", data)) * * @param data data * @param secret secret * @return H(concat(secret, ":", data)); */ private static String KD(String secret, String data) { return H(secret + ":" + data); } // the following code was copied from the NIST-SIP instant // messenger (its author is Olivier Deruelle). Thanks for making it public! /** * to hex converter */ private static final char[] toHex = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; /** * Converts b[] to hex string. * * @param b the bte array to convert * @return a Hex representation of b. */ private static String toHexString(byte b[]) { int pos = 0; char[] c = new char[b.length * 2]; for (int i = 0; i < b.length; i++) { c[pos++] = toHex[(b[i] >> 4) & 0x0F]; c[pos++] = toHex[b[i] & 0x0f]; } return new String(c); } }