Re: encryption

[Amardeep Singh <amardeeptalwar@yahoo.com>]

I use the base64 encryption for the small encryption
type method. 
Here is the sample of the code that may be useful to
you.
-----------
public class Base64
{
    public static String encode(byte[] raw) {
        StringBuffer encoded = new StringBuffer();

        for (int i = 0; i < raw.length; i += 3) {
            encoded.append(encodeBlock(raw, i));
        }
        return encoded.toString();
    }
  
    protected static char[] encodeBlock(byte[] raw,
int offset) {
        int block = 0;
        int slack = raw.length - offset - 1;
        int end = (slack >= 2) ? 2 : slack;

        for (int i = 0; i <= end; i++) {
            byte b = raw[offset + i];
            int neuter = (b < 0) ? b + 256 : b;

            block += neuter << (8 * (2 - i));
        }
        char[] base64 = new char[4];

        for (int i = 0; i < 4; i++) {
            int sixbit = (block >>> (6 * (3 - i))) &
0x3f;

            base64[i] = getChar(sixbit);
        }
        if (slack < 1) base64[2] = '=';
        if (slack < 2) base64[3] = '=';
        return base64;
    }
  
    protected static char getChar(int sixBit) {
        if (sixBit >= 0 && sixBit <= 25)
            return (char) ('A' + sixBit);
        if (sixBit >= 26 && sixBit <= 51)
            return (char) ('a' + (sixBit - 26));
        if (sixBit >= 52 && sixBit <= 61)
            return (char) ('0' + (sixBit - 52));
        if (sixBit == 62) return '+';
        if (sixBit == 63) return '/';
        return '?';
    }
  
    public static byte[] decode(String base64) {
        int pad = 0;

        for (int i = base64.length() - 1;
base64.charAt(i) == '='; i--)
            pad++;
        int length = base64.length() * 6 / 8 - pad;
        byte[] raw = new byte[length];
        int rawIndex = 0;

        for (int i = 0; i < base64.length(); i += 4) {
            int block = (getValue(base64.charAt(i)) <<
18)
                + (getValue(base64.charAt(i + 1)) <<
12)
                + (getValue(base64.charAt(i + 2)) <<
6)
                + (getValue(base64.charAt(i + 3)));
		  
            for (int j = 0; j < 3 && rawIndex + j <
raw.length; j++)
                raw[rawIndex + j] = (byte) ((block >>
(8 * (2 - j))) & 0xff);
            rawIndex += 3;
        }
        return raw;
    }
  
    protected static int getValue(char c) {
        if (c >= 'A' && c <= 'Z') return c - 'A';
        if (c >= 'a' && c <= 'z') return c - 'a' + 26;
        if (c >= '0' && c <= '9') return c - '0' + 52;
        if (c == '+') return 62;
        if (c == '/') return 63;
        if (c == '=') return 0;
        return -1;
    }
}



--- Wade Steele <wsteele3@csc.com> wrote:
> I have some code to generate a Key.  What I need to
> do is store this key
> into a database so that I can retrieve it at a later
> time to decrypt a
> string.  What is the easiest way of handling this? 
> It would be nice if
> there was a way of converting it to a different
> format, that could be
> persisted, retrieved again, and converted back to a
> Key.
> 
> Any help would be great.  Possibly a BLOB?  I
> haven't a clue.
> 
> Thanks,
> 
> Wade
> 
> 


=====

Amardeep Singh 

678 642 8898 (C)


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