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);
}
}