File	Doc	Category	Size	Date	Package
SHA.java	API Doc	phoneME MR2 API (J2ME)	6167	Wed May 02 18:00:24 BST 2007	com.sun.midp.crypto

SHA

• java.lang.Object
  • MessageDigest

Fields Summary
private int[]	state State needed for SHA hash.
private int[]	num State needed for SHA hash.
private int[]	count State needed for SHA hash.
private int[]	data State needed for SHA hash.

Constructors Summary
SHA() Create SHA digest object. // data block reset();

Methods Summary
public java.lang.Object	clone() Clones the MessageDigest object. return a clone of this object SHA cpy = new SHA(); System.arraycopy(this.state, 0, cpy.state, 0, this.state.length); System.arraycopy(this.num, 0, cpy.num, 0, this.num.length); System.arraycopy(this.count, 0, cpy.count, 0, this.count.length); System.arraycopy(this.data, 0, cpy.data, 0, this.data.length); return cpy;
public int	digest(byte[] buf, int offset, int len) Completes the hash computation by performing final operations such as padding. The digest is reset after this call is made. param buf output buffer for the computed digest param offset offset into the output buffer to begin storing the digest param len number of bytes within buf allotted for the digest return the number of bytes placed into buf exception DigestException if an error occurs. if (len < getDigestLength()) { throw new DigestException("Buffer too short."); } // check the parameters to prevent a VM crash int test = buf[offset] + buf[offset + getDigestLength() - 1]; nativeFinal(null, 0, 0, buf, offset, state, num, count, data); return getDigestLength();
public java.lang.String	getAlgorithm() Gets the message digest algorithm. return algorithm implemented by this MessageDigest object return "SHA-1";
public int	getDigestLength() Gets the length (in bytes) of the hash. return byte-length of the hash produced by this object return 20;
private static native void	nativeFinal(byte[] inBuf, int inOff, int inLen, byte[] outBuf, int outOff, int[] state, int[] num, int[] count, int[] data) Generates a hash of all/last input data. Completes and returns the hash compuatation after performing final operations such as padding. The MessageDigest object is reset after this call. param inBuf input buffer of data to be hashed param inOff offset within inBuf where input data begins param inLen length (in bytes) of data to be hashed param outBuf output buffer where the hash should be placed param outOff offset within outBuf where the resulting hash begins param state internal hash state param num internal hash state param count internal hash state param data internal hash state
private static native void	nativeUpdate(byte[] inBuf, int inOff, int inLen, int[] state, int[] num, int[] count, int[] data) Accumulates a hash of the input data. This method is useful when the input data to be hashed is not available in one byte array. param inBuf input buffer of data to be hashed param inOff offset within inBuf where input data begins param inLen length (in bytes) of data to be hashed param state internal hash state param num internal hash state param count internal hash state param data internal hash state
public void	reset() Resets the MessageDigest to the initial state for further use. // SHA1 initialization constants state[0] = 0x67452301; state[1] = 0xEFCDAB89; state[2] = 0x98BADCFE; state[3] = 0x10325476; state[4] = 0xC3D2E1F0; num[0] = 0; count[0] = count[1] = 0; for (int i = 0; i < data.length; i++) data[i] = 0;
public void	update(byte[] inBuf, int inOff, int inLen) Accumulates a hash of the input data. This method is useful when the input data to be hashed is not available in one byte array. param inBuf input buffer of data to be hashed param inOff offset within inBuf where input data begins param inLen length (in bytes) of data to be hashed see #doFinal(byte[], int, int, byte[], int) if (inLen == 0) { return; } // check parameters to avoid a VM crash int test = inBuf[inOff] + inBuf[inLen - 1] + inBuf[inOff + inLen - 1]; nativeUpdate(inBuf, inOff, inLen, state, num, count, data);