/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.net.http;
/**
* HttpAuthHeader: a class to store HTTP authentication-header parameters.
* For more information, see: RFC 2617: HTTP Authentication.
*
* {@hide}
*/
public class HttpAuthHeader {
/**
* Possible HTTP-authentication header tokens to search for:
*/
public final static String BASIC_TOKEN = "Basic";
public final static String DIGEST_TOKEN = "Digest";
private final static String REALM_TOKEN = "realm";
private final static String NONCE_TOKEN = "nonce";
private final static String STALE_TOKEN = "stale";
private final static String OPAQUE_TOKEN = "opaque";
private final static String QOP_TOKEN = "qop";
private final static String ALGORITHM_TOKEN = "algorithm";
/**
* An authentication scheme. We currently support two different schemes:
* HttpAuthHeader.BASIC - basic, and
* HttpAuthHeader.DIGEST - digest (algorithm=MD5, QOP="auth").
*/
private int mScheme;
public static final int UNKNOWN = 0;
public static final int BASIC = 1;
public static final int DIGEST = 2;
/**
* A flag, indicating that the previous request from the client was
* rejected because the nonce value was stale. If stale is TRUE
* (case-insensitive), the client may wish to simply retry the request
* with a new encrypted response, without reprompting the user for a
* new username and password.
*/
private boolean mStale;
/**
* A string to be displayed to users so they know which username and
* password to use.
*/
private String mRealm;
/**
* A server-specified data string which should be uniquely generated
* each time a 401 response is made.
*/
private String mNonce;
/**
* A string of data, specified by the server, which should be returned
* by the client unchanged in the Authorization header of subsequent
* requests with URIs in the same protection space.
*/
private String mOpaque;
/**
* This directive is optional, but is made so only for backward
* compatibility with RFC 2069 [6]; it SHOULD be used by all
* implementations compliant with this version of the Digest scheme.
* If present, it is a quoted string of one or more tokens indicating
* the "quality of protection" values supported by the server. The
* value "auth" indicates authentication; the value "auth-int"
* indicates authentication with integrity protection.
*/
private String mQop;
/**
* 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".
*/
private String mAlgorithm;
/**
* Is this authentication request a proxy authentication request?
*/
private boolean mIsProxy;
/**
* Username string we get from the user.
*/
private String mUsername;
/**
* Password string we get from the user.
*/
private String mPassword;
/**
* Creates a new HTTP-authentication header object from the
* input header string.
* The header string is assumed to contain parameters of at
* most one authentication-scheme (ensured by the caller).
*/
public HttpAuthHeader(String header) {
if (header != null) {
parseHeader(header);
}
}
/**
* @return True iff this is a proxy authentication header.
*/
public boolean isProxy() {
return mIsProxy;
}
/**
* Marks this header as a proxy authentication header.
*/
public void setProxy() {
mIsProxy = true;
}
/**
* @return The username string.
*/
public String getUsername() {
return mUsername;
}
/**
* Sets the username string.
*/
public void setUsername(String username) {
mUsername = username;
}
/**
* @return The password string.
*/
public String getPassword() {
return mPassword;
}
/**
* Sets the password string.
*/
public void setPassword(String password) {
mPassword = password;
}
/**
* @return True iff this is the BASIC-authentication request.
*/
public boolean isBasic () {
return mScheme == BASIC;
}
/**
* @return True iff this is the DIGEST-authentication request.
*/
public boolean isDigest() {
return mScheme == DIGEST;
}
/**
* @return The authentication scheme requested. We currently
* support two schemes:
* HttpAuthHeader.BASIC - basic, and
* HttpAuthHeader.DIGEST - digest (algorithm=MD5, QOP="auth").
*/
public int getScheme() {
return mScheme;
}
/**
* @return True if indicating that the previous request from
* the client was rejected because the nonce value was stale.
*/
public boolean getStale() {
return mStale;
}
/**
* @return The realm value or null if there is none.
*/
public String getRealm() {
return mRealm;
}
/**
* @return The nonce value or null if there is none.
*/
public String getNonce() {
return mNonce;
}
/**
* @return The opaque value or null if there is none.
*/
public String getOpaque() {
return mOpaque;
}
/**
* @return The QOP ("quality-of_protection") value or null if
* there is none. The QOP value is always lower-case.
*/
public String getQop() {
return mQop;
}
/**
* @return The name of the algorithm used or null if there is
* none. By default, MD5 is used.
*/
public String getAlgorithm() {
return mAlgorithm;
}
/**
* @return True iff the authentication scheme requested by the
* server is supported; currently supported schemes:
* BASIC,
* DIGEST (only algorithm="md5", no qop or qop="auth).
*/
public boolean isSupportedScheme() {
// it is a good idea to enforce non-null realms!
if (mRealm != null) {
if (mScheme == BASIC) {
return true;
} else {
if (mScheme == DIGEST) {
return
mAlgorithm.equals("md5") &&
(mQop == null || mQop.equals("auth"));
}
}
}
return false;
}
/**
* Parses the header scheme name and then scheme parameters if
* the scheme is supported.
*/
private void parseHeader(String header) {
if (HttpLog.LOGV) {
HttpLog.v("HttpAuthHeader.parseHeader(): header: " + header);
}
if (header != null) {
String parameters = parseScheme(header);
if (parameters != null) {
// if we have a supported scheme
if (mScheme != UNKNOWN) {
parseParameters(parameters);
}
}
}
}
/**
* Parses the authentication scheme name. If we have a Digest
* scheme, sets the algorithm value to the default of MD5.
* @return The authentication scheme parameters string to be
* parsed later (if the scheme is supported) or null if failed
* to parse the scheme (the header value is null?).
*/
private String parseScheme(String header) {
if (header != null) {
int i = header.indexOf(' ');
if (i >= 0) {
String scheme = header.substring(0, i).trim();
if (scheme.equalsIgnoreCase(DIGEST_TOKEN)) {
mScheme = DIGEST;
// md5 is the default algorithm!!!
mAlgorithm = "md5";
} else {
if (scheme.equalsIgnoreCase(BASIC_TOKEN)) {
mScheme = BASIC;
}
}
return header.substring(i + 1);
}
}
return null;
}
/**
* Parses a comma-separated list of authentification scheme
* parameters.
*/
private void parseParameters(String parameters) {
if (HttpLog.LOGV) {
HttpLog.v("HttpAuthHeader.parseParameters():" +
" parameters: " + parameters);
}
if (parameters != null) {
int i;
do {
i = parameters.indexOf(',');
if (i < 0) {
// have only one parameter
parseParameter(parameters);
} else {
parseParameter(parameters.substring(0, i));
parameters = parameters.substring(i + 1);
}
} while (i >= 0);
}
}
/**
* Parses a single authentication scheme parameter. The parameter
* string is expected to follow the format: PARAMETER=VALUE.
*/
private void parseParameter(String parameter) {
if (parameter != null) {
// here, we are looking for the 1st occurence of '=' only!!!
int i = parameter.indexOf('=');
if (i >= 0) {
String token = parameter.substring(0, i).trim();
String value =
trimDoubleQuotesIfAny(parameter.substring(i + 1).trim());
if (HttpLog.LOGV) {
HttpLog.v("HttpAuthHeader.parseParameter():" +
" token: " + token +
" value: " + value);
}
if (token.equalsIgnoreCase(REALM_TOKEN)) {
mRealm = value;
} else {
if (mScheme == DIGEST) {
parseParameter(token, value);
}
}
}
}
}
/**
* If the token is a known parameter name, parses and initializes
* the token value.
*/
private void parseParameter(String token, String value) {
if (token != null && value != null) {
if (token.equalsIgnoreCase(NONCE_TOKEN)) {
mNonce = value;
return;
}
if (token.equalsIgnoreCase(STALE_TOKEN)) {
parseStale(value);
return;
}
if (token.equalsIgnoreCase(OPAQUE_TOKEN)) {
mOpaque = value;
return;
}
if (token.equalsIgnoreCase(QOP_TOKEN)) {
mQop = value.toLowerCase();
return;
}
if (token.equalsIgnoreCase(ALGORITHM_TOKEN)) {
mAlgorithm = value.toLowerCase();
return;
}
}
}
/**
* Parses and initializes the 'stale' paramer value. Any value
* different from case-insensitive "true" is considered "false".
*/
private void parseStale(String value) {
if (value != null) {
if (value.equalsIgnoreCase("true")) {
mStale = true;
}
}
}
/**
* Trims double-quotes around a parameter value if there are any.
* @return The string value without the outermost pair of double-
* quotes or null if the original value is null.
*/
static private String trimDoubleQuotesIfAny(String value) {
if (value != null) {
int len = value.length();
if (len > 2 &&
value.charAt(0) == '\"' && value.charAt(len - 1) == '\"') {
return value.substring(1, len - 1);
}
}
return value;
}
}
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