Sha256 > Main (#1)

* Update SHA256Advanced.java

ByteFromHex function

* OH MY GOD

45 mins of coding. my brain hurts lol. its likely i will move sha256 to its own package inside of hash as Digest and several other classes will be included in it so instead of plopping them inside of misc i think ill use a standalone package. thanks for reading my rant

* several sha components

finally made sha256 standalone package, added classes:
HMAC
HKDF (placeholder for now)
Hex
Digest too but i did that last night

* desc

maybe it done

* Update README.md

* COMPLETION!

XACrypto\SHA256 is officially finished in its entirety. I might still make more modifications tho lol

* Update XACrypto.java

yippie! i made a dumb mistake

* bug fix

TWO. GOD. DAMN. CHARACTERS. completely messed up the end hash. i used 0 instead of i inside a for loop. i want to die :)

* remove tests + update README + good riddance garbage messagedigest sha256

yip

src/de/caydenno1/xacrypto/hash/sha256/Digest.java

@@ -0,0 +1,97 @@
+package de.caydenno1.xacrypto.hash.sha256;
+
+import de.caydenno1.xacrypto.misc.Constants;
+import de.caydenno1.xacrypto.misc.XACryptoException;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.StandardCharsets;
+import java.util.Arrays;
+
+import static de.caydenno1.xacrypto.hash.sha256.SHA256.Word2Byte;
+import static de.caydenno1.xacrypto.hash.sha256.SHA256.compress;
+
+public final class Digest {
+    private final int[] s = Constants.SHA256_H.clone();
+    private final byte[] buf = new byte[64];
+    private int bufLen = 0;
+    private long total = 0L;
+
+    public Digest(){};
+
+    public Digest upd(byte[] d) throws XACryptoException {
+        return upd(d, 0, d.length);
+    }
+
+    /**
+     * i have never used javadoc before ;-; just using google for javadoc format lol
+     * @param d data
+     * @param o Offset
+     * @param l count
+     * @return {@code this} end data after modification
+     */
+    public Digest upd(byte[] d, int o, int l) throws XACryptoException {
+        if(o<0||l<0||o+l>d.length) throw new XACryptoException("take a look at your code :)");
+        total += l;
+        if (bufLen > 0) {
+            int fil = Math.min(64 - bufLen, l);
+            System.arraycopy(d,o,buf,bufLen,fil);
+            bufLen += fil;o+=fil;l-=fil;
+            if (bufLen == 64) { compress(s, buf, 0); bufLen=0; }
+        }
+
+        while(l >= 64){
+            compress(s,d,o);
+            o += 64;
+            l -= 64;
+        };
+        // save whats remaining i suppose..
+        if (l>0) {
+            System.arraycopy(d, o, buf, 0, l);
+            bufLen = l;
+        };
+        return this; // we returned "this" !1
+    }
+    public Digest upd(String text) throws XACryptoException { return upd(text.getBytes(StandardCharsets.UTF_8) );};
+
+    public Digest upd(ByteBuffer buf) throws XACryptoException {
+        if (buf.hasArray()) { return upd(buf.array(), buf.arrayOffset() + buf.position(), buf.remaining()); }
+        byte[] temp = new byte[buf.remaining()];
+        buf.get(temp);
+        return upd(temp);
+    };
+
+    @SuppressWarnings("ConstantValue")
+    public byte[] digest() {
+        byte[] t = new byte[bufLen];
+        System.arraycopy(buf,0,t,0,bufLen);
+        long bit = total * 8L;
+        int pad = 64 - (int)((bufLen+1+8) % 64)%64;
+        if (pad<0) pad += 64;
+        int total = bufLen + 1 + pad + 8;
+
+        byte[] last = new byte[total];
+        System.arraycopy(t, 0, last, 0, bufLen);
+        last[bufLen] = (byte) 0x80;
+        for (int i = 7; i >= 0; i--) {
+            last[total - 8 + i] = (byte) (bit & 0xff);
+            bit >>>= 8;
+        }
+
+        int[] sa = s.clone();
+        for (int off = 0; off < last.length; off += 64) { compress(sa, last, off); }
+        byte[] o = Word2Byte(sa);
+        reset();
+        return o;
+    }
+
+    public void reset() {
+        System.arraycopy(Constants.SHA256_H, 0, s, 0, 8);
+        Arrays.fill(buf, (byte) 0);
+        bufLen = 0;
+        total = 0L;
+    }
+
+    public long get() {
+        return total;
+    }
+}