passkey.html
来自「java类库详细讲解」· HTML 代码 · 共 219 行
HTML
219 行
<HTML>
<HEAD>
<META http-equiv="Content-Type" content="text/html; charset=UTF-8">
<TITLE>Encrypting with DES Using a Pass Phrase
(Java Developers Almanac Example)
</TITLE>
<META CONTENT="Patrick Chan" NAME="AUTHOR">
<META CONTENT="Code Examples from The Java Developers Almanac 1.4" NAME="DESCRIPTION">
<META CONTENT="Addison-Wesley/Patrick Chan" NAME="OWNER">
<META CONTENT="3/20/02" NAME="revision">
<STYLE TYPE="text/css">
<!-- BODY CODE {font-family: Courier, Monospace; font-size: 11pt} TABLE, BODY {font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 10pt} PRE {font-family: Courier, Monospace; font-size: 10pt} H3 {font-family: Verdana, Arial, Helvetica, sans-serif; font-size: 11pt} A.eglink {text-decoration: none} A:hover.eglink {text-decoration: underline} -->
</STYLE>
</HEAD>
<BODY>
<TABLE CELLSPACING="0" CELLPADDING="0" BORDER="0">
<TR>
<TD rowspan="3"><A HREF="/?l=ex"><IMG BORDER="0" ALIGN="BOTTOM" HSPACE="10" SRC="/egs/almanac14a.jpg"></A></TD><TD VALIGN="top"><font face="Times" size="6"><b>The Java Developers Almanac 1.4</b></font>
<br>
Order this book from <a href="/cgi-bin/scripts/redirect.pl?l=ex&url=http://www.amazon.com/exec/obidos/ASIN/0201752808/xeo">Amazon</a>.
</TD>
</TR>
<TR>
<TD align="right" valign="bottom">
<FORM method="get" action="/cgi-bin/search/find.pl">
<INPUT size="25" name="words" type="text"><INPUT value="Search" type="submit">
</FORM>
</TD>
</TR>
</TABLE>
<HR color="#6666cc">
<DIV ALIGN="LEFT">
<A HREF="/">Home</A>
>
<A HREF="../index.html">List of Packages</A>
>
<B><A HREF="../javax.crypto/pkg.html">javax.crypto</A></B><font color="#666666" SIZE="-2">
[14 examples]
</font>
>
<B><A HREF="../javax.crypto/pkg.html#Encrypting%20and%20Decrypting">Encrypting and Decrypting</A></B><font color="#666666" SIZE="-2">
[6 examples]
</font>
</DIV><P>
<h3>
e464.
Encrypting with DES Using a Pass Phrase</h3>
This example demonstrates how to use a pass phrase (a string password
of multiple words) for encryption.
<pre>
public class DesEncrypter {
Cipher ecipher;
Cipher dcipher;
// 8-byte Salt
byte[] salt = {
(byte)<font color="#0066ff"><i>0xA9</i></font>, (byte)<font color="#0066ff"><i>0x9B</i></font>, (byte)<font color="#0066ff"><i>0xC8</i></font>, (byte)<font color="#0066ff"><i>0x32</i></font>,
(byte)<font color="#0066ff"><i>0x56</i></font>, (byte)<font color="#0066ff"><i>0x35</i></font>, (byte)<font color="#0066ff"><i>0xE3</i></font>, (byte)<font color="#0066ff"><i>0x03</i></font>
};
// Iteration count
int iterationCount = <font color="#0066ff"><i>19</i></font>;
DesEncrypter(String passPhrase) {
try {
// Create the key
KeySpec keySpec = new PBEKeySpec(passPhrase.toCharArray(), salt, iterationCount);
SecretKey key = SecretKeyFactory.getInstance(
"PBEWithMD5AndDES").generateSecret(keySpec);
ecipher = Cipher.getInstance(key.getAlgorithm());
dcipher = Cipher.getInstance(key.getAlgorithm());
// Prepare the parameter to the ciphers
AlgorithmParameterSpec paramSpec = new PBEParameterSpec(salt, iterationCount);
// Create the ciphers
ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
} catch (java.security.InvalidAlgorithmParameterException e) {
} catch (java.security.spec.InvalidKeySpecException e) {
} catch (javax.crypto.NoSuchPaddingException e) {
} catch (java.security.NoSuchAlgorithmException e) {
} catch (java.security.InvalidKeyException e) {
}
}
public String encrypt(String str) {
try {
// Encode the string into bytes using utf-8
byte[] utf8 = str.getBytes("UTF8");
// Encrypt
byte[] enc = ecipher.doFinal(utf8);
// Encode bytes to base64 to get a string
return new sun.misc.BASE64Encoder().encode(enc);
} catch (javax.crypto.BadPaddingException e) {
} catch (IllegalBlockSizeException e) {
} catch (UnsupportedEncodingException e) {
} catch (java.io.IOException e) {
}
return null;
}
public String decrypt(String str) {
try {
// Decode base64 to get bytes
byte[] dec = new sun.misc.BASE64Decoder().decodeBuffer(str);
// Decrypt
byte[] utf8 = dcipher.doFinal(dec);
// Decode using utf-8
return new String(utf8, "UTF8");
} catch (javax.crypto.BadPaddingException e) {
} catch (IllegalBlockSizeException e) {
} catch (UnsupportedEncodingException e) {
} catch (java.io.IOException e) {
}
return null;
}
}
</pre>
<pre>
// Here is an example that uses the class
try {
// Create encrypter/decrypter class
DesEncrypter encrypter = new DesEncrypter(<font color="#0066ff"><i>"My Pass Phrase!"</i></font>);
// Encrypt
String encrypted = encrypter.encrypt(<font color="#0066ff"><i>"Don't tell anybody!"</i></font>);
// Decrypt
String decrypted = encrypter.decrypt(encrypted);
} catch (Exception e) {
}
</pre>
<P><table width="600" CELLSPACING="0" CELLPADDING="2" BORDER="0">
<tr>
<td bgcolor="#6666cc" align="center"><font color="#ffffff">
Related Examples
</font></td>
</tr>
</table>
e461. <a class="eglink" href="ListCipher.html?l=rel">
Listing All Available Encryption and Decryption Algorithms
</a>
<br>
e462. <a class="eglink" href="DesString.html?l=rel">
Encrypting a String with DES
</a>
<br>
e463. <a class="eglink" href="DesFile.html?l=rel">
Encrypting a File or Stream with DES
</a>
<br>
e465. <a class="eglink" href="MakeDes.html?l=rel">
Converting a 56-bit Value to a DES Key
</a>
<br>
e466. <a class="eglink" href="EncryptObject.html?l=rel">
Encrypting an Object with DES
</a>
<br>
<table width="600" CELLSPACING="0" CELLPADDING="2" BORDER="0">
<tr>
<td align="left">
<br>
See also:
<a class="eglink" href="/egs/javax.crypto/pkg.html?l=rel#Key%20Agreement">
Key Agreement
</a>
<a class="eglink" href="/egs/javax.crypto/pkg.html?l=rel#MAC">
MAC
</a>
<a class="eglink" href="/egs/javax.crypto/pkg.html?l=rel#Symmetric%20Keys">
Symmetric Keys
</a>
</td>
</tr>
</table>
<br>
<br>
<FONT FACE="Verdana, Arial, Helvetica, sans-serif" SIZE="0">
© 2002 Addison-Wesley.
</FONT>
</BODY>
</HTML>
⌨️ 快捷键说明
复制代码Ctrl + C
搜索代码Ctrl + F
全屏模式F11
增大字号Ctrl + =
减小字号Ctrl + -
显示快捷键?