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<A NAME="MessageDigest(java.lang.String)"><!-- --></A><H3>
MessageDigest</H3>
<PRE>
protected <B>MessageDigest</B>(<A HREF="../../java/lang/String.html">String</A>&nbsp;algorithm)</PRE>
<DL>
<DD>Creates a message digest with the specified algorithm name.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>algorithm</CODE> - the standard name of the digest algorithm. 
 See Appendix A in the <a href=
 "../../../guide/security/CryptoSpec.html#AppA">
 Java Cryptography Architecture API Specification &amp; Reference </a> 
 for information about standard algorithm names.</DL>
</DD>
</DL>

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<A NAME="getInstance(java.lang.String)"><!-- --></A><H3>
getInstance</H3>
<PRE>
public static <A HREF="../../java/security/MessageDigest.html">MessageDigest</A> <B>getInstance</B>(<A HREF="../../java/lang/String.html">String</A>&nbsp;algorithm)
                                 throws <A HREF="../../java/security/NoSuchAlgorithmException.html">NoSuchAlgorithmException</A></PRE>
<DL>
<DD>Generates a MessageDigest object that implements the specified digest
 algorithm. If the default provider package
 provides an implementation of the requested digest algorithm,
 an instance of MessageDigest containing that implementation is returned.
 If the algorithm is not available in the default 
 package, other packages are searched.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>algorithm</CODE> - the name of the algorithm requested. 
 See Appendix A in the <a href=
 "../../../guide/security/CryptoSpec.html#AppA">
 Java Cryptography Architecture API Specification &amp; Reference </a> 
 for information about standard algorithm names.<DT><B>Returns:</B><DD>a Message Digest object implementing the specified
 algorithm.<DT><B>Throws:</B><DD><CODE><A HREF="../../java/security/NoSuchAlgorithmException.html">NoSuchAlgorithmException</A></CODE> - if the algorithm is
 not available in the caller's environment.</DL>
</DD>
</DL>
<HR>

<A NAME="getInstance(java.lang.String, java.lang.String)"><!-- --></A><H3>
getInstance</H3>
<PRE>
public static <A HREF="../../java/security/MessageDigest.html">MessageDigest</A> <B>getInstance</B>(<A HREF="../../java/lang/String.html">String</A>&nbsp;algorithm,
                                        <A HREF="../../java/lang/String.html">String</A>&nbsp;provider)
                                 throws <A HREF="../../java/security/NoSuchAlgorithmException.html">NoSuchAlgorithmException</A>,
                                        <A HREF="../../java/security/NoSuchProviderException.html">NoSuchProviderException</A></PRE>
<DL>
<DD>Generates a MessageDigest object implementing the specified
 algorithm, as supplied from the specified provider, if such an 
 algorithm is available from the provider.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>algorithm</CODE> - the name of the algorithm requested. 
 See Appendix A in the <a href=
 "../../../guide/security/CryptoSpec.html#AppA">
 Java Cryptography Architecture API Specification &amp; Reference </a> 
 for information about standard algorithm names.<DD><CODE>provider</CODE> - the name of the provider.<DT><B>Returns:</B><DD>a Message Digest object implementing the specified
 algorithm.<DT><B>Throws:</B><DD><CODE><A HREF="../../java/security/NoSuchAlgorithmException.html">NoSuchAlgorithmException</A></CODE> - if the algorithm is
 not available in the package supplied by the requested
 provider.<DD><CODE><A HREF="../../java/security/NoSuchProviderException.html">NoSuchProviderException</A></CODE> - if the provider is not
 available in the environment.<DT><B>See Also: </B><DD><A HREF="../../java/security/Provider.html"><CODE>Provider</CODE></A></DL>
</DD>
</DL>
<HR>

<A NAME="getProvider()"><!-- --></A><H3>
getProvider</H3>
<PRE>
public final <A HREF="../../java/security/Provider.html">Provider</A> <B>getProvider</B>()</PRE>
<DL>
<DD>Returns the provider of this message digest object.<DD><DL>
<DT><B>Returns:</B><DD>the provider of this message digest object</DL>
</DD>
</DL>
<HR>

<A NAME="update(byte)"><!-- --></A><H3>
update</H3>
<PRE>
public void <B>update</B>(byte&nbsp;input)</PRE>
<DL>
<DD>Updates the digest using the specified byte.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>input</CODE> - the byte with which to update the digest.</DL>
</DD>
</DL>
<HR>

<A NAME="update(byte[], int, int)"><!-- --></A><H3>
update</H3>
<PRE>
public void <B>update</B>(byte[]&nbsp;input,
                   int&nbsp;offset,
                   int&nbsp;len)</PRE>
<DL>
<DD>Updates the digest using the specified array of bytes, starting
 at the specified offset.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>input</CODE> - the array of bytes.<DD><CODE>offset</CODE> - the offset to start from in the array of bytes.<DD><CODE>len</CODE> - the number of bytes to use, starting at 
 <code>offset</code>.</DL>
</DD>
</DL>
<HR>

<A NAME="update(byte[])"><!-- --></A><H3>
update</H3>
<PRE>
public void <B>update</B>(byte[]&nbsp;input)</PRE>
<DL>
<DD>Updates the digest using the specified array of bytes.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>input</CODE> - the array of bytes.</DL>
</DD>
</DL>
<HR>

<A NAME="digest()"><!-- --></A><H3>
digest</H3>
<PRE>
public byte[] <B>digest</B>()</PRE>
<DL>
<DD>Completes the hash computation by performing final operations
 such as padding. The digest is reset after this call is made.<DD><DL>
<DT><B>Returns:</B><DD>the array of bytes for the resulting hash value.</DL>
</DD>
</DL>
<HR>

<A NAME="digest(byte[], int, int)"><!-- --></A><H3>
digest</H3>
<PRE>
public int <B>digest</B>(byte[]&nbsp;buf,
                  int&nbsp;offset,
                  int&nbsp;len)
           throws <A HREF="../../java/security/DigestException.html">DigestException</A></PRE>
<DL>
<DD>Completes the hash computation by performing final operations
 such as padding. The digest is reset after this call is made.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>buf</CODE> - output buffer for the computed digest<DD><CODE>offset</CODE> - offset into the output buffer to begin storing the digest<DD><CODE>len</CODE> - number of bytes within buf allotted for the digest<DT><B>Returns:</B><DD>the number of bytes placed into <code>buf</code><DT><B>Throws:</B><DD><CODE><A HREF="../../java/security/DigestException.html">DigestException</A></CODE> - if an error occurs.</DL>
</DD>
</DL>
<HR>

<A NAME="digest(byte[])"><!-- --></A><H3>
digest</H3>
<PRE>
public byte[] <B>digest</B>(byte[]&nbsp;input)</PRE>
<DL>
<DD>Performs a final update on the digest using the specified array 
 of bytes, then completes the digest computation. That is, this
 method first calls <A HREF="../../java/security/MessageDigest.html#update(byte[])"><CODE>update(input)</CODE></A>,
 passing the <i>input</i> array to the <code>update</code> method,
 then calls <A HREF="../../java/security/MessageDigest.html#digest()"><CODE>digest()</CODE></A>.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>input</CODE> - the input to be updated before the digest is
 completed.<DT><B>Returns:</B><DD>the array of bytes for the resulting hash value.</DL>
</DD>
</DL>
<HR>

<A NAME="toString()"><!-- --></A><H3>
toString</H3>
<PRE>
public <A HREF="../../java/lang/String.html">String</A> <B>toString</B>()</PRE>
<DL>
<DD>Returns a string representation of this message digest object.<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../java/lang/Object.html#toString()">toString</A></CODE> in class <CODE><A HREF="../../java/lang/Object.html">Object</A></CODE></DL>
</DD>
<DD>Following copied from class: <CODE>java.lang.Object</CODE></DD>
<DD><DL>
<DT><B>Returns:</B><DD>a string representation of the object.</DL>
</DD>
</DL>
<HR>

<A NAME="isEqual(byte[], byte[])"><!-- --></A><H3>
isEqual</H3>
<PRE>
public static boolean <B>isEqual</B>(byte[]&nbsp;digesta,
                              byte[]&nbsp;digestb)</PRE>
<DL>
<DD>Compares two digests for equality. Does a simple byte compare.<DD><DL>
<DT><B>Parameters:</B><DD><CODE>digesta</CODE> - one of the digests to compare.<DD><CODE>digestb</CODE> - the other digest to compare.<DT><B>Returns:</B><DD>true if the digests are equal, false otherwise.</DL>
</DD>
</DL>
<HR>

<A NAME="reset()"><!-- --></A><H3>
reset</H3>
<PRE>
public void <B>reset</B>()</PRE>
<DL>
<DD>Resets the digest for further use.</DL>
<HR>

<A NAME="getAlgorithm()"><!-- --></A><H3>
getAlgorithm</H3>
<PRE>
public final <A HREF="../../java/lang/String.html">String</A> <B>getAlgorithm</B>()</PRE>
<DL>
<DD>Returns a string that identifies the algorithm, independent of
 implementation details. The name should be a standard
 Java Security name (such as "SHA", "MD5", and so on). 
 See Appendix A in the <a href=
 "../../../guide/security/CryptoSpec.html#AppA">
 Java Cryptography Architecture API Specification &amp; Reference </a> 
 for information about standard algorithm names.<DD><DL>
<DT><B>Returns:</B><DD>the name of the algorithm</DL>
</DD>
</DL>
<HR>

<A NAME="getDigestLength()"><!-- --></A><H3>
getDigestLength</H3>
<PRE>
public final int <B>getDigestLength</B>()</PRE>
<DL>
<DD>Returns the length of the digest in bytes, or 0 if this operation is
 not supported by the provider and the implementation is not cloneable.<DD><DL>
<DT><B>Returns:</B><DD>the digest length in bytes, or 0 if this operation is not
 supported by the provider and the implementation is not cloneable.<DT><B>Since: </B><DD>1.2</DD>
</DL>
</DD>
</DL>
<HR>

<A NAME="clone()"><!-- --></A><H3>
clone</H3>
<PRE>
public <A HREF="../../java/lang/Object.html">Object</A> <B>clone</B>()
             throws <A HREF="../../java/lang/CloneNotSupportedException.html">CloneNotSupportedException</A></PRE>
<DL>
<DD>Returns a clone if the implementation is cloneable.<DD><DL>
<DT><B>Overrides:</B><DD><CODE><A HREF="../../java/security/MessageDigestSpi.html#clone()">clone</A></CODE> in class <CODE><A HREF="../../java/security/MessageDigestSpi.html">MessageDigestSpi</A></CODE></DL>
</DD>
<DD><DL>
<DT><B>Returns:</B><DD>a clone if the implementation is cloneable.<DT><B>Throws:</B><DD><CODE><A HREF="../../java/lang/CloneNotSupportedException.html">CloneNotSupportedException</A></CODE> - if this is called on an
 implementation that does not support <code>Cloneable</code>.</DL>
</DD>
</DL>
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