org.jboss.security.auth.spi
Class RFC2617Digest

java.lang.Object
  org.jboss.security.auth.spi.RFC2617Digest

All Implemented Interfaces:

DigestCallback

public class RFC2617Digest
extends Object
implements DigestCallback

An implementation of the DigestCallback that support the http digest auth as described in RFC2617 (http://www.ietf.org/rfc/rfc2617.txt). 3.2.2.1 Request-Digest If the "qop" value is "auth" or "auth-int": request-digest = <"> < KD ( H(A1), unq(nonce-value) ":" nc-value ":" unq(cnonce-value) ":" unq(qop-value) ":" H(A2) ) <"> If the "qop" directive is not present (this construction is for compatibility with RFC 2069): request-digest = <"> < KD ( H(A1), unq(nonce-value) ":" H(A2) ) > <"> See below for the definitions for A1 and A2. 3.2.2.2 A1 If the "algorithm" directive's value is "MD5" or is unspecified, then A1 is: A1 = unq(username-value) ":" unq(realm-value) ":" passwd where passwd = < user's password > If the "algorithm" directive's value is "MD5-sess", then A1 is calculated only once - on the first request by the client following receipt of a WWW-Authenticate challenge from the server. It uses the server nonce from that challenge, and the first client nonce value to construct A1 as follows: A1 = H( unq(username-value) ":" unq(realm-value) ":" passwd ) ":" unq(nonce-value) ":" unq(cnonce-value) This creates a 'session key' for the authentication of subsequent requests and responses which is different for each "authentication session", thus limiting the amount of material hashed with any one key. (Note: see further discussion of the authentication session in section 3.3.) Because the server need only use the hash of the user credentials in order to create the A1 value, this construction could be used in conjunction with a third party authentication service so that the web server would not need the actual password value. The specification of such a protocol is beyond the scope of this specification. 3.2.2.3 A2 If the "qop" directive's value is "auth" or is unspecified, then A2 is: A2 = Method ":" digest-uri-value If the "qop" value is "auth-int", then A2 is: A2 = Method ":" digest-uri-value ":" H(entity-body) 3.2.2.4 Directive values and quoted-string Note that the value of many of the directives, such as "username- value", are defined as a "quoted-string". However, the "unq" notation indicates that surrounding quotation marks are removed in forming the string A1. Thus if the Authorization header includes the fields username="Mufasa", realm=myhost@testrealm.com and the user Mufasa has password "Circle Of Life" then H(A1) would be H(Mufasa:myhost@testrealm.com:Circle Of Life) with no quotation marks in the digested string. No white space is allowed in any of the strings to which the digest function H() is applied unless that white space exists in the quoted strings or entity body whose contents make up the string to be digested. For example, the string A1 illustrated above must be Mufasa:myhost@testrealm.com:Circle Of Life with no white space on either side of the colons, but with the white space between the words used in the password value. Likewise, the other strings digested by H() must not have white space on either side of the colons which delimit their fields unless that white space was in the quoted strings or entity body being digested. Also note that if integrity protection is applied (qop=auth-int), the H(entity-body) is the hash of the entity body, not the message body - it is computed before any transfer encoding is applied by the sender and after it has been removed by the recipient. Note that this includes multipart boundaries and embedded headers in each part of any multipart content-type.

Version:

$Revision: 57203 $

Author:

Scott.Stark@jboss.org

Field Summary

static String	A2HASH An explicit A2 digest
static String	ALGORITHM A string indicating a pair of algorithms used to produce the digest and a checksum.
static String	AUTH_PARAM This directive allows for future extensions.
static String	CNONCE This MUST be specified if a qop directive is sent (see above), and MUST NOT be specified if the server did not send a qop directive in the WWW-Authenticate header field.
static String	DIGEST_URI The URI from Request-URI of the Request-Line; duplicated here because proxies are allowed to change the Request-Line in transit.
static String	METHOD The http method type
static String	NONCE A server-specified data string which MUST be different each time a digest-challenge is sent as part of initial authentication.
static String	NONCE_COUNT This MUST be specified if a qop directive is sent (see above), and MUST NOT be specified if the server did not send a qop directive in the WWW-Authenticate header field.
static String	QOP Indicates what "quality of protection" the client has applied to the message.
static String	REALM String which can enable users to know which username and password to use, in case they might have different ones for different servers.
static String	USERNAME The user's name in the specified realm.

Constructor Summary

RFC2617Digest()

Method Summary

String	getInfoDigest(MessageDigest digest)
void	init(Map options) Pass through access to the login module options.
static void	main(String[] args) Compute the
void	postDigest(MessageDigest digest) Post-hash callout afer the password has been added to allow for content after the password has been added.
void	preDigest(MessageDigest digest) Pre-hash callout to allow for content before the password.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

REALM

public static final String REALM

String which can enable users to know which username and password to use, in case they might have different ones for different servers.

See Also:

Constant Field Values

USERNAME

public static final String USERNAME

The user's name in the specified realm.

See Also:

Constant Field Values

DIGEST_URI

public static final String DIGEST_URI

The URI from Request-URI of the Request-Line; duplicated here because proxies are allowed to change the Request-Line in transit.

See Also:

Constant Field Values

NONCE

public static final String NONCE

A server-specified data string which MUST be different each time a digest-challenge is sent as part of initial authentication. It is recommended that this string be base64 or hexadecimal data. Note that since the string is passed as a quoted string, the double-quote character is not allowed unless escaped (see section 7.2). The contents of the nonce are implementation dependent. The security of the implementation depends on a good choice. It is RECOMMENDED that it contain at least 64 bits of entropy. The nonce is opaque to the client. This directive is required and MUST appear exactly once; if not present, or if multiple instances are present, the client should abort the authentication exchange.

See Also:

Constant Field Values

CNONCE

public static final String CNONCE

This MUST be specified if a qop directive is sent (see above), and MUST NOT be specified if the server did not send a qop directive in the WWW-Authenticate header field. The cnonce-value is an opaque quoted string value provided by the client and used by both client and server to avoid chosen plaintext attacks, to provide mutual authentication, and to provide some message integrity protection. See the descriptions below of the calculation of the response- digest and request-digest values.

See Also:

Constant Field Values

NONCE_COUNT

public static final String NONCE_COUNT

This MUST be specified if a qop directive is sent (see above), and MUST NOT be specified if the server did not send a qop directive in the WWW-Authenticate header field. The nc-value is the hexadecimal count of the number of requests (including the current request) that the client has sent with the nonce value in this request. For example, in the first request sent in response to a given nonce value, the client sends "nc=00000001". The purpose of this directive is to allow the server to detect request replays by maintaining its own copy of this count - if the same nc-value is seen twice, then the request is a replay. See the description below of the construction of the request-digest value.

See Also:

Constant Field Values

QOP

public static final String QOP

Indicates what "quality of protection" the client has applied to the message. If present, its value MUST be one of the alternatives the server indicated it supports in the WWW-Authenticate header. These values affect the computation of the request-digest. Note that this is a single token, not a quoted list of alternatives as in WWW- Authenticate. This directive is optional in order to preserve backward compatibility with a minimal implementation of RFC 2069 [6], but SHOULD be used if the server indicated that qop is supported by providing a qop directive in the WWW-Authenticate header field.

See Also:

Constant Field Values

ALGORITHM

public static final String ALGORITHM

A string indicating a pair of algorithms used to produce the digest and a checksum. If this is not present it is assumed to be "MD5". If the algorithm is not understood, the challenge should be ignored (and a different one used, if there is more than one). In this document the string obtained by applying the digest algorithm to the data "data" with secret "secret" will be denoted by KD(secret, data), and the string obtained by applying the checksum algorithm to the data "data" will be denoted H(data). The notation unq(X) means the value of the quoted-string X without the surrounding quotes.

See Also:

Constant Field Values

AUTH_PARAM

public static final String AUTH_PARAM

This directive allows for future extensions. Any unrecognized directive MUST be ignored.

See Also:

Constant Field Values

METHOD

public static final String METHOD

The http method type

See Also:

Constant Field Values

A2HASH

public static final String A2HASH

An explicit A2 digest

See Also:

Constant Field Values

Constructor Detail

RFC2617Digest

public RFC2617Digest()

Method Detail

init

public void init(Map options)

Description copied from interface: DigestCallback

Pass through access to the login module options. When coming from a login module this includes the following keys: javax.security.auth.login.name - for the username javax.security.auth.login.password - for the String password

Specified by:

init in interface DigestCallback

preDigest

public void preDigest(MessageDigest digest)

Description copied from interface: DigestCallback

Pre-hash callout to allow for content before the password. Any content should be added using the MessageDigest update methods.

Specified by:

preDigest in interface DigestCallback

Parameters:

digest - - the security digest being used for the one-way hash

postDigest

public void postDigest(MessageDigest digest)

Description copied from interface: DigestCallback

Post-hash callout afer the password has been added to allow for content after the password has been added. Any content should be added using the MessageDigest update methods.

Specified by:

postDigest in interface DigestCallback

Parameters:

digest - - the security digest being used for the one-way hash

getInfoDigest

public String getInfoDigest(MessageDigest digest)

main

public static void main(String[] args)
                 throws NoSuchAlgorithmException

Compute the

Parameters:

args -

Throws:

NoSuchAlgorithmException