package org.springframework.security.web.authentication.preauth.x509;
import org.springframework.security.authentication.BadCredentialsException;
import org.springframework.security.core.SpringSecurityMessageSource;
import org.springframework.util.Assert;
import org.springframework.context.support.MessageSourceAccessor;
import org.springframework.context.MessageSource;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import java.security.cert.X509Certificate;
import java.util.regex.Pattern;
import java.util.regex.Matcher;
/**
* Obtains the principal from a certificate using a regular expression match against the Subject (as returned by a call
* to {@link X509Certificate#getSubjectDN()}).
* <p>
* The regular expression should contain a single group; for example the default expression "CN=(.*?)(?:,|$)" matches the
* common name field. So "CN=Jimi Hendrix, OU=..." will give a user name of "Jimi Hendrix".
* <p>
* The matches are case insensitive. So "emailAddress=(.?)," will match "EMAILADDRESS=jimi@hendrix.org, CN=..." giving a
* user name "jimi@hendrix.org"
*
* @author Luke Taylor
*/
public class SubjectDnX509PrincipalExtractor implements X509PrincipalExtractor {
//~ Instance fields ================================================================================================
protected final Log logger = LogFactory.getLog(getClass());
protected MessageSourceAccessor messages = SpringSecurityMessageSource.getAccessor();
private Pattern subjectDnPattern;
public SubjectDnX509PrincipalExtractor() {
setSubjectDnRegex("CN=(.*?)(?:,|$)");
}
public Object extractPrincipal(X509Certificate clientCert) {
//String subjectDN = clientCert.getSubjectX500Principal().getName();
String subjectDN = clientCert.getSubjectDN().getName();
logger.debug("Subject DN is '" + subjectDN + "'");
Matcher matcher = subjectDnPattern.matcher(subjectDN);
if (!matcher.find()) {
throw new BadCredentialsException(messages.getMessage("SubjectDnX509PrincipalExtractor.noMatching",
new Object[] {subjectDN}, "No matching pattern was found in subject DN: {0}"));
}
if (matcher.groupCount() != 1) {
throw new IllegalArgumentException("Regular expression must contain a single group ");
}
String username = matcher.group(1);
logger.debug("Extracted Principal name is '" + username + "'");
return username;
}
/**
* Sets the regular expression which will by used to extract the user name from the certificate's Subject
* DN.
* <p>
* It should contain a single group; for example the default expression "CN=(.*?)(?:,|$)" matches the common
* name field. So "CN=Jimi Hendrix, OU=..." will give a user name of "Jimi Hendrix".
* <p>
* The matches are case insensitive. So "emailAddress=(.?)," will match "EMAILADDRESS=jimi@hendrix.org,
* CN=..." giving a user name "jimi@hendrix.org"
*
* @param subjectDnRegex the regular expression to find in the subject
*/
public void setSubjectDnRegex(String subjectDnRegex) {
Assert.hasText(subjectDnRegex, "Regular expression may not be null or empty");
subjectDnPattern = Pattern.compile(subjectDnRegex, Pattern.CASE_INSENSITIVE);
}
public void setMessageSource(MessageSource messageSource) {
this.messages = new MessageSourceAccessor(messageSource);
}
}