/** Deletes an entry from the key table. */
void deleteEntry() {
PrincipalName pname = null;
try {
pname = new PrincipalName(principal);
if (pname.getRealm() == null) {
pname.setRealm(Config.getInstance().getDefaultRealm());
}
String answer;
BufferedReader cis = new BufferedReader(new InputStreamReader(System.in));
System.out.print(
"Are you sure you want to "
+ " delete service key for "
+ pname.toString()
+ " in "
+ table.tabName()
+ "?(Y/N) :");
System.out.flush();
answer = cis.readLine();
if (answer.equalsIgnoreCase("Y") || answer.equalsIgnoreCase("Yes")) ;
else {
// no error, the user did not want to delete the entry
System.exit(0);
}
} catch (KrbException e) {
System.err.println("Error occured while deleting the entry. " + "Deletion failed.");
e.printStackTrace();
System.exit(-1);
} catch (IOException e) {
System.err.println("Error occured while deleting the entry. " + " Deletion failed.");
e.printStackTrace();
System.exit(-1);
}
// admin.deleteEntry(pname);
table.deleteEntry(pname);
try {
table.save();
} catch (IOException e) {
System.err.println("Error occurs while saving the keytab." + "Deletion fails.");
e.printStackTrace();
System.exit(-1);
}
System.out.println("Done!");
}
/**
* Adds a service key to key table. If the specified key table does not exist, the program will
* automatically generate a new key table.
*/
void addEntry() {
PrincipalName pname = null;
try {
pname = new PrincipalName(principal);
if (pname.getRealm() == null) {
pname.setRealm(Config.getInstance().getDefaultRealm());
}
} catch (KrbException e) {
System.err.println("Failed to add " + principal + " to keytab.");
e.printStackTrace();
System.exit(-1);
}
if (password == null) {
try {
BufferedReader cis = new BufferedReader(new InputStreamReader(System.in));
System.out.print("Password for " + pname.toString() + ":");
System.out.flush();
password = new StringBuffer().append(cis.readLine());
} catch (IOException e) {
System.err.println("Failed to read the password.");
e.printStackTrace();
System.exit(-1);
}
}
try {
// admin.addEntry(pname, password);
table.addEntry(pname, password);
// admin.save();
table.save();
System.out.println("Done!");
System.out.println("Service key for " + principal + " is saved in " + table.tabName());
} catch (KrbCryptoException e) {
System.err.println("Failed to add " + principal + " to keytab.");
e.printStackTrace();
System.exit(-1);
} catch (IOException e) {
System.err.println("Failed to save new entry.");
e.printStackTrace();
System.exit(-1);
}
}
/**
* Encrypts the data using DES in CBC mode.
*
* @param data the buffer for plain text.
* @param key the key to encrypt the data.
* @param ivec initialization vector.
* @return buffer for encrypted data.
* @modified by Yanni Zhang, Feb 24 00.
*/
public byte[] encrypt(byte[] data, byte[] key, byte[] ivec, int usage) throws KrbCryptoException {
/*
* To meet export control requirements, double check that the
* key being used is no longer than 64 bits.
*
* Note that from a protocol point of view, an
* algorithm that is not DES will be rejected before this
* point. Also, a DES key that is not 64 bits will be
* rejected by a good implementations of JCE.
*/
if (key.length > 8) throw new KrbCryptoException("Invalid DES Key!");
int new_size = data.length + confounderSize() + checksumSize();
byte[] new_data;
byte pad;
/*Data padding: using Kerberos 5 GSS-API mechanism (1.2.2.3), Jun 1996.
*Before encryption, plaintext data is padded to the next higest multiple of blocksize.
*by appending between 1 and 8 bytes, the value of each such byte being the total number
*of pad bytes. For example, if new_size = 10, blockSize is 8, we should pad 2 bytes,
*and the value of each byte is 2.
*If plaintext data is a multiple of blocksize, we pad a 8 bytes of 8.
*/
if (new_size % blockSize() == 0) {
new_data = new byte[new_size + blockSize()];
pad = (byte) 8;
} else {
new_data = new byte[new_size + blockSize() - new_size % blockSize()];
pad = (byte) (blockSize() - new_size % blockSize());
}
for (int i = new_size; i < new_data.length; i++) {
new_data[i] = pad;
}
byte[] conf = Confounder.bytes(confounderSize());
System.arraycopy(conf, 0, new_data, 0, confounderSize());
System.arraycopy(data, 0, new_data, startOfData(), data.length);
byte[] cksum = calculateChecksum(new_data, new_data.length);
System.arraycopy(cksum, 0, new_data, startOfChecksum(), checksumSize());
byte[] cipher = new byte[new_data.length];
Des.cbc_encrypt(new_data, cipher, key, ivec, true);
return cipher;
}
/**
* The main program that can be invoked at command line. <br>
* Usage: ktab <options> <br>
* available options to Ktab:
*
* <ul>
* <li><b>-l</b> list the keytab name and entries
* <li><b>-a</b> <<i>principal name</i>> (<<i>password</i>>) add an entry to the
* keytab. The entry is added only to the keytab. No changes are made to the Kerberos
* database.
* <li><b>-d</b> <<i>principal name</i>> delete an entry from the keytab The entry is
* deleted only from the keytab. No changes are made to the Kerberos database.
* <li><b>-k</b> <<i>keytab name</i> > specify keytab name and path with prefix FILE:
* <li><b>-help</b> display instructions.
*/
public static void main(String[] args) {
Ktab ktab = new Ktab();
if ((args.length == 1) && (args[0].equalsIgnoreCase("-help"))) {
ktab.printHelp();
System.exit(0);
} else if ((args == null) || (args.length == 0)) {
ktab.action = 'l';
} else {
ktab.processArgs(args);
}
try {
if (ktab.name == null) {
// ktab.admin = new KeyTabAdmin(); // use the default keytab.
ktab.table = KeyTab.getInstance();
if (ktab.table == null) {
if (ktab.action == 'a') {
ktab.table = KeyTab.create();
} else {
System.out.println("No default key table exists.");
System.exit(-1);
}
}
} else {
if ((ktab.action != 'a') && !(new File(ktab.name)).exists()) {
System.out.println("Key table " + ktab.name + " does not exist.");
System.exit(-1);
} else {
ktab.table = KeyTab.getInstance(ktab.name);
}
if (ktab.table == null) {
ktab.table = KeyTab.create(ktab.name);
}
}
} catch (RealmException e) {
System.err.println("Error loading key table.");
System.exit(-1);
} catch (IOException e) {
System.err.println("Error loading key table.");
System.exit(-1);
}
switch (ktab.action) {
case 'l':
ktab.listKt();
break;
case 'a':
ktab.addEntry();
break;
case 'd':
ktab.deleteEntry();
break;
default:
ktab.printHelp();
System.exit(-1);
}
}
/** Parses the command line arguments. */
void processArgs(String[] args) {
Character arg = null;
for (int i = 0; i < args.length; i++) {
if ((args[i].length() == 2) && (args[i].startsWith("-"))) {
arg = new Character(args[i].charAt(1));
} else {
printHelp();
System.exit(-1);
}
switch (arg.charValue()) {
case 'l':
case 'L':
action = 'l'; // list keytab location, name and entries
break;
case 'a':
case 'A':
action = 'a'; // add a new entry to keytab.
i++;
if ((i < args.length) && (!args[i].startsWith("-"))) {
principal = args[i];
} else {
System.out.println("Please specify the principal name" + " after -a option.");
printHelp();
System.exit(-1);
}
if ((i + 1 < args.length) && (!args[i + 1].startsWith("-"))) {
password = new StringBuffer().append(args[i + 1]);
i++;
} else {
password = null; // prompt user for password later.
}
break;
case 'd':
case 'D':
action = 'd'; // delete an entry.
i++;
if ((i < args.length) && (!args[i].startsWith("-"))) {
principal = args[i];
} else {
System.out.println(
"Please specify the principal"
+ "name of the entry you want to "
+ " delete after -d option.");
printHelp();
System.exit(-1);
}
break;
case 'k':
case 'K':
i++;
if ((i < args.length) && (!args[i].startsWith("-"))) {
if (args[i].length() >= 5 && args[i].substring(0, 5).equalsIgnoreCase("FILE:")) {
name = args[i].substring(5);
} else name = args[i];
} else {
System.out.println(
"Please specify the keytab " + "file name and location " + "after -k option");
printHelp();
System.exit(-1);
}
break;
default:
printHelp();
System.exit(-1);
}
}
}