java source code of WiFi

package com.android.utils.wificonnecter;

/*
 * Wifi Connecter
 * 
 * Copyright (c) 20101 Kevin Yuan ([email protected])
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 * 
 **/ 


import java.util.Comparator;
import java.util.List;

import android.net.wifi.ScanResult;
import android.net.wifi.WifiConfiguration;
import android.net.wifi.WifiConfiguration.AuthAlgorithm;
import android.net.wifi.WifiConfiguration.GroupCipher;
import android.net.wifi.WifiConfiguration.KeyMgmt;
import android.net.wifi.WifiConfiguration.PairwiseCipher;
import android.net.wifi.WifiConfiguration.Protocol;
import android.net.wifi.WifiManager;
import android.text.TextUtils;
import android.util.Log;

public class WiFi {
	
	// Constants used for different security types
	public static final String WPA2 = "WPA2";
	public static final String WPA = "WPA";
	public static final String WEP = "WEP";
	public static final String OPEN = "Open";
    // For EAP Enterprise fields
    public static final String WPA_EAP = "WPA-EAP";
    public static final String IEEE8021X = "IEEE8021X";

    public static final String[] EAP_METHOD = { "PEAP", "TLS", "TTLS" };
    
    public static final int WEP_PASSWORD_AUTO = 0;
    public static final int WEP_PASSWORD_ASCII = 1;
    public static final int WEP_PASSWORD_HEX = 2;
    
	private static final String TAG = "Wifi Connecter";
	
	/**
	 * Change the password of an existing configured network and connect to it
	 * @param wifiMgr
	 * @param config
	 * @param newPassword
	 * @return
	 */
	public static boolean changePasswordAndConnect( final WifiManager wifiMgr, final WifiConfiguration config, final String newPassword, final int numOpenNetworksKept) {
		setupSecurity(config, getWifiConfigurationSecurity(config), newPassword);
		final int networkId = wifiMgr.updateNetwork(config);
		if(networkId == -1) {
			// Update failed.
			return false;
		}
        //确定
		return connectToConfiguredNetwork(wifiMgr, config, true);
	}
	
	/**
	 * Configure a network, and connect to it.
	 * @param wifiMgr
	 * @param scanResult
	 * @param password Password for secure network or is ignored.
	 * @return
	 */
	public static boolean connectToNewNetwork(final WifiManager wifiMgr, final ScanResult scanResult, final String password) {
        //1.获取wifi加密方式（WEP, WPA, WPA2, WPA_EAP, IEEE8021X）
		final String security = getScanResultSecurity(scanResult);
		
		if(security.equals(OPEN)) {
			final int numOpenNetworksKept = 10;
			checkForExcessOpenNetworkAndSave(wifiMgr, numOpenNetworksKept);
		}
		
		WifiConfiguration config = new WifiConfiguration();
		config.SSID = StringUtils.convertToQuotedString(scanResult.SSID);
		config.BSSID = scanResult.BSSID;
		setupSecurity(config, security, password);
		
		int id = wifiMgr.addNetwork(config);
		if(id == -1) {
			return false;
		}
		
		if(!wifiMgr.saveConfiguration()) {
			return false;
		}
		
		config = getWifiConfiguration(wifiMgr, config, security);
		if(config == null) {
			return false;
		}
		
		return connectToConfiguredNetwork(wifiMgr, config, true);
	}
	
	/**
	 * Connect to a configured network.
	 * @param wifiManager
	 * @param config
	 * @param numOpenNetworksKept Settings.Secure.WIFI_NUM_OPEN_NETWORKS_KEPT
	 * @return
	 */
	public static boolean connectToConfiguredNetwork( final WifiManager wifiMgr, WifiConfiguration config, boolean reassociate) {
		final String security = getWifiConfigurationSecurity(config);
		
		int oldPri = config.priority;
		// Make it the highest priority.
		int newPri = getMaxPriority(wifiMgr) + 1;
		if(newPri > MAX_PRIORITY) {
			newPri = shiftPriorityAndSave(wifiMgr);
			config = getWifiConfiguration(wifiMgr, config, security);
			if(config == null) {
				return false;
			}
		}
		
		// Set highest priority to this configured network
		config.priority = newPri;
		int networkId = wifiMgr.updateNetwork(config);
		if(networkId == -1) {
			return false;
		}
		
		// Do not disable others
		if(!wifiMgr.enableNetwork(networkId, false)) {
			config.priority = oldPri;
			return false;
		}
		
		if(!wifiMgr.saveConfiguration()) {
			config.priority = oldPri;
			return false;
		}
		
		// We have to retrieve the WifiConfiguration after save.
		config = getWifiConfiguration(wifiMgr, config, security);
		if(config == null) {
			return false;
		}
		
		// Disable others, but do not save.
		// Just to force the WifiManager to connect to it.
		if(!wifiMgr.enableNetwork(config.networkId, true)) {
			return false;
		}
		
		final boolean connect = reassociate ? wifiMgr.reassociate() : wifiMgr.reconnect();
		if(!connect) {
			return false;
		}
		
		return true;
	}
	
	private static void sortByPriority(final List<WifiConfiguration> configurations) {
		java.util.Collections.sort(configurations, new Comparator<WifiConfiguration>() {

			@Override
			public int compare(WifiConfiguration object1,
					WifiConfiguration object2) {
				return object1.priority - object2.priority;
			}
		});
	}
	
	/**
	 * Ensure no more than numOpenNetworksKept open networks in configuration list.
	 * @param wifiMgr
	 * @param numOpenNetworksKept
	 * @return Operation succeed or not.
	 */
	private static boolean checkForExcessOpenNetworkAndSave(final WifiManager wifiMgr, final int numOpenNetworksKept) {
		final List<WifiConfiguration> configurations = wifiMgr.getConfiguredNetworks();
		sortByPriority(configurations);
		
		boolean modified = false;
		int tempCount = 0;
		for(int i = configurations.size() - 1; i >= 0; i--) {
			final WifiConfiguration config = configurations.get(i);
			if(getWifiConfigurationSecurity(config).equals(OPEN)) {
				tempCount++;
				if(tempCount >= numOpenNetworksKept) {
					modified = true;
					wifiMgr.removeNetwork(config.networkId);
				}
			}
		}
		if(modified) {
			return wifiMgr.saveConfiguration();
		}
		
		return true;
	}
	
	private static final int MAX_PRIORITY = 99999;
	
	private static int shiftPriorityAndSave(final WifiManager wifiMgr) {
		final List<WifiConfiguration> configurations = wifiMgr.getConfiguredNetworks();
		sortByPriority(configurations);
		final int size = configurations.size();
		for(int i = 0; i < size; i++) {
			final WifiConfiguration config = configurations.get(i);
			config.priority = i;
			wifiMgr.updateNetwork(config);
		}
		wifiMgr.saveConfiguration();
		return size;
	}

	private static int getMaxPriority(final WifiManager wifiManager) {
		final List<WifiConfiguration> configurations = wifiManager.getConfiguredNetworks();
		int pri = 0;
		for(final WifiConfiguration config : configurations) {
			if(config.priority > pri) {
				pri = config.priority;
			}
		}
		return pri;
	}

	public static WifiConfiguration getWifiConfiguration(final WifiManager wifiMgr,
                                                         final ScanResult hotsopt, String hotspotSecurity) {
		final String ssid = StringUtils.convertToQuotedString(hotsopt.SSID);
		if(ssid.length() == 0) {
			return null;
		}
		
		final String bssid = hotsopt.BSSID;
		if(bssid == null) {
			return null;
		}
		
		if(hotspotSecurity == null) {
			hotspotSecurity = getScanResultSecurity(hotsopt);
		}
		
		final List<WifiConfiguration> configurations = wifiMgr.getConfiguredNetworks();

		for(final WifiConfiguration config : configurations) {
			if(config.SSID == null || !ssid.equals(config.SSID)) {
				continue;
			}
			if(config.BSSID == null || bssid.equals(config.BSSID)) {
				final String configSecurity = getWifiConfigurationSecurity(config);
				if(hotspotSecurity.equals(configSecurity)) {
					return config;
				}
			}
		}
		return null;
	}
	
	public static WifiConfiguration getWifiConfiguration(final WifiManager wifiMgr,
                                                         final WifiConfiguration configToFind, String security) {
		final String ssid = configToFind.SSID;
		if(ssid.length() == 0) {
			return null;
		}
		
		final String bssid = configToFind.BSSID;

		
		if(security == null) {
			security = getWifiConfigurationSecurity(configToFind);
		}
		
		final List<WifiConfiguration> configurations = wifiMgr.getConfiguredNetworks();

		for(final WifiConfiguration config : configurations) {
			if(config.SSID == null || !ssid.equals(config.SSID)) {
				continue;
			}
			if(config.BSSID == null || bssid == null || bssid.equals(config.BSSID)) {
				final String configSecurity = getWifiConfigurationSecurity(config);
				if(security.equals(configSecurity)) {
					return config;
				}
			}
		}
		return null;
	}
	
	/**
     * @return The security of a given {@link WifiConfiguration}.
     */
    static public String getWifiConfigurationSecurity(WifiConfiguration wifiConfig) {

        if (wifiConfig.allowedKeyManagement.get(KeyMgmt.NONE)) {
            // If we never set group ciphers, wpa_supplicant puts all of them.
            // For open, we don't set group ciphers.
            // For WEP, we specifically only set WEP40 and WEP104, so CCMP
            // and TKIP should not be there.
            if (!wifiConfig.allowedGroupCiphers.get(GroupCipher.CCMP)
                    && (wifiConfig.allowedGroupCiphers.get(GroupCipher.WEP40)
                            || wifiConfig.allowedGroupCiphers.get(GroupCipher.WEP104))) {
                return WEP;
            } else {
                return OPEN;
            }
        } else if (wifiConfig.allowedProtocols.get(Protocol.RSN)) {
            return WPA2;
        } else if (wifiConfig.allowedKeyManagement.get(KeyMgmt.WPA_EAP)) {
            return WPA_EAP;
        } else if (wifiConfig.allowedKeyManagement.get(KeyMgmt.IEEE8021X)) {
            return IEEE8021X;
        } else if (wifiConfig.allowedProtocols.get(Protocol.WPA)) {
            return WPA;
        } else {
            Log.w(TAG, "Unknown security type from WifiConfiguration, falling back on open.");
            return OPEN;
        }
    }
	
    /**
     * Fill in the security fields of WifiConfiguration config.
     * @param config The object to fill.
     * @param security If is OPEN, password is ignored.
     * @param password Password of the network if security is not OPEN.
     */
	static private void setupSecurity(WifiConfiguration config, String security, final String password) {
        config.allowedAuthAlgorithms.clear();
        config.allowedGroupCiphers.clear();
        config.allowedKeyManagement.clear();
        config.allowedPairwiseCiphers.clear();
        config.allowedProtocols.clear();
        
        if (TextUtils.isEmpty(security)) {
            security = OPEN;
            Log.w(TAG, "Empty security, assuming open");
        }
        
        if (security.equals(WEP)) {
        	 int wepPasswordType = WEP_PASSWORD_AUTO;
            // If password is empty, it should be left untouched
            if (!TextUtils.isEmpty(password)) {
				if (wepPasswordType == WEP_PASSWORD_AUTO) {
                    if (isHexWepKey(password)) {
                        config.wepKeys[0] = password;
                    } else {
                        config.wepKeys[0] = StringUtils.convertToQuotedString(password);
                    }
                } else {
                    config.wepKeys[0] = wepPasswordType == WEP_PASSWORD_ASCII
                            ? StringUtils.convertToQuotedString(password)
                            : password;
                }
            }
            
            config.wepTxKeyIndex = 0;
            
            config.allowedAuthAlgorithms.set(AuthAlgorithm.OPEN);
            config.allowedAuthAlgorithms.set(AuthAlgorithm.SHARED);

            config.allowedKeyManagement.set(KeyMgmt.NONE);
            
            config.allowedGroupCiphers.set(GroupCipher.WEP40);
            config.allowedGroupCiphers.set(GroupCipher.WEP104);
            
        } else if (security.equals(WPA) || security.equals(WPA2)){
            config.allowedGroupCiphers.set(GroupCipher.TKIP);
            config.allowedGroupCiphers.set(GroupCipher.CCMP);
            
            config.allowedKeyManagement.set(KeyMgmt.WPA_PSK);
            
            config.allowedPairwiseCiphers.set(PairwiseCipher.CCMP);
            config.allowedPairwiseCiphers.set(PairwiseCipher.TKIP);

            config.allowedProtocols.set(security.equals(WPA2) ? Protocol.RSN : Protocol.WPA);
            
            // If password is empty, it should be left untouched
            if (!TextUtils.isEmpty(password)) {
                if (password.length() == 64 && isHex(password)) {
                    // Goes unquoted as hex
                    config.preSharedKey = password;
                } else {
                    // Goes quoted as ASCII
                    config.preSharedKey = StringUtils.convertToQuotedString(password);
                }
            }
            
        } else if (security.equals(OPEN)) {
            config.allowedKeyManagement.set(KeyMgmt.NONE);
        } else if (security.equals(WPA_EAP) || security.equals(IEEE8021X)) {
            config.allowedGroupCiphers.set(GroupCipher.TKIP);
            config.allowedGroupCiphers.set(GroupCipher.CCMP);
            if (security.equals(WPA_EAP)) {
                config.allowedKeyManagement.set(KeyMgmt.WPA_EAP);
            } else {
                config.allowedKeyManagement.set(KeyMgmt.IEEE8021X);
            }
            if (!TextUtils.isEmpty(password)) {
                config.preSharedKey = StringUtils.convertToQuotedString(password);
            }
        }
    }
	
	private static boolean isHexWepKey(String wepKey) {
        final int len = wepKey.length();
        
        // WEP-40, WEP-104, and some vendors using 256-bit WEP (WEP-232?)
        if (len != 10 && len != 26 && len != 58) {
            return false;
        }
        
        return isHex(wepKey);
    }
    
    private static boolean isHex(String key) {
        for (int i = key.length() - 1; i >= 0; i--) {
            final char c = key.charAt(i);
            if (!(c >= '0' && c <= '9' || c >= 'A' && c <= 'F' || c >= 'a' && c <= 'f')) {
                return false;
            }
        }
        
        return true;
    }

    static final String[] SECURITY_MODES = { WEP, WPA, WPA2, WPA_EAP, IEEE8021X };
	
	/**
     * @return The security of a given {@link ScanResult}.
     */
    public static String getScanResultSecurity(ScanResult scanResult) {
        final String cap = scanResult.capabilities;
        for (int i = SECURITY_MODES.length - 1; i >= 0; i--) {
            if (cap.contains(SECURITY_MODES[i])) {
                return SECURITY_MODES[i];
            }
        }
        
        return OPEN;
    }
}