read note in readme

README.md

@@ -1,6 +1,7 @@
 A multi-purpose Cryptography library in Java. Working on it day by day, slowly. Someday this will be complete, today is not that day.
 
 ### Current objective: Hashing (SHA-0)
+### Note: SHA0 is so unused that I am unable to verify if mine works or not due to the lack of online SHA(ers).
 
 Use `setopt interactivecomments` (zsh only) to allow using `#` for comments if you see errors like `zsh: command not found: #`
 

src/de/caydenno1/xacrypto/XACrypto.java

@@ -1,7 +1,10 @@
 package de.caydenno1.xacrypto;
-
+import de.caydenno1.xacrypto.hash.sha.SHA0;
 public class XACrypto {
     private XACrypto() {}
 
-    static void main(String[] args) {}
+    static void main(String[] args) {
+        String res = SHA0.hash("tah");
+        System.out.println(res);
+    }
 }

src/de/caydenno1/xacrypto/hash/ROT.java

@@ -0,0 +1,10 @@
+package de.caydenno1.xacrypto.hash;
+
+public class ROT {
+    public static int ROTR(int x, int n){
+        return (x >>> n) | (x << (32 - n));
+    }
+    public static int ROTL(int x, int n){
+        return (x << n) | (x >>> (32 - n));
+    }
+}

src/de/caydenno1/xacrypto/hash/sha/SHA0.java

@@ -0,0 +1,116 @@
+package de.caydenno1.xacrypto.hash.sha;
+
+import de.caydenno1.xacrypto.misc.Constants;
+
+import java.nio.charset.StandardCharsets;
+
+public class SHA0 {
+    // we really only need one file. very simple code
+    public static byte[] hash(byte[] data){
+        System.out.println("Beware, SHA0 is deprecated and cryptographically broken. Use at your own risk.");
+        byte[] padded = pad(data);
+
+        int a0 = Constants.SHA0_H[0], a1 = Constants.SHA0_H[1], a2 = Constants.SHA0_H[2], a3 = Constants.SHA0_H[3], a4 = Constants.SHA0_H[4];
+
+        int[] w = new int[80];
+
+        for (int i = 0 ; i < padded.length ; i += 64) {
+
+            for (int j = 0 ; j < 16 ; j++) {
+                int o = i + j * 4;
+                w[j] = ((padded[o] & 0xff) << 24)
+                        | ((padded[o + 1] & 0xff) << 16)
+                        | ((padded[o + 2] & 0xff) << 8)
+                        | (padded[o + 3] & 0xff);
+            }
+
+            for (int t = 16; t < 80; t++) {
+                w[t] = w[t-3] ^ w[t-8] ^ w[t-14] ^ w[t-16];
+            }
+
+            int a = a0, b = a1, c = a2, d = a3, e = a4;
+
+            for (int t = 0 ; t < 80 ; t++) {
+                int f, k;
+
+                if (t < 20) {
+                    f = (b & c);
+                    k = Constants.SHA0_K[0];
+                } else if (t < 40) {
+                    f = b ^ c ^ d;
+                    k = Constants.SHA0_K[1];
+                } else if (t < 60) {
+                    f = (b & c) | (b & d) | (c & d);
+                    k = Constants.SHA0_K[2];
+                } else {
+                    f = b ^ c ^ d;
+                    k = Constants.SHA0_K[3];
+                }
+
+                int temp = de.caydenno1.xacrypto.hash.ROT.ROTL(a, 5);
+                temp += f;
+                temp += e;
+                temp += k;
+                temp += w[t];
+
+                e = d;
+                d = c;
+                c = de.caydenno1.xacrypto.hash.ROT.ROTL(b, 30);
+                b = a;
+                a = temp;
+            }
+
+            a0 += a;
+            a1 += b;
+            a2 += c;
+            a3 += d;
+            a4 += e;
+        }
+
+        return INT2BYTE(a0, a1, a2, a3, a4);
+    }
+
+    public static String hash(String data) {
+        byte[] result = hash(data.getBytes(StandardCharsets.UTF_8));
+        return hex(result);
+    }
+
+    public static String hex(byte[] data) {
+        StringBuilder builder = new StringBuilder();
+        for (byte b : data) builder.append(String.format("%02x", b));
+        return builder.toString();
+    }
+
+    private static byte[] pad(byte[] mesg) {
+        int len = mesg.length;
+        long bit = (long) len * 8;
+
+        int padL = (64 - ((len + 9) % 64)) % 64;
+        byte[] o = new byte[len+padL+9];
+
+        System.arraycopy(mesg,0,o,0,len);
+        o[len] = (byte) 0x80;
+        for (int i = 0; i < 8; i++) {
+            o[o.length - (i+1)] = (byte) (bit >>> (8*i));
+        }
+
+        return o;
+    }
+
+    private static byte[] INT2BYTE(int a,int b,int c,int d,int e) {
+        byte[] out = new byte[20];
+        write(a, out, 0);
+        write(b, out, 4);
+        write(c, out, 8);
+        write(d, out, 12);
+        write(e, out, 16);
+        return out;
+    }
+
+    private static void write(int v, byte[] o, int i) {
+        o[i  ] = (byte)(v >>> 24);
+        o[i+1] = (byte)(v >>> 16);
+        o[i+2] = (byte)(v >>>  8);
+        o[i+3] = (byte)(v       );
+    }
+}

src/de/caydenno1/xacrypto/hash/sha256/SHA256.java

@@ -8,12 +8,12 @@ import java.util.concurrent.RecursiveTask;
 
 import static de.caydenno1.xacrypto.hash.sha256.Hex.hash;
 import static de.caydenno1.xacrypto.hash.sha256.Hex.doubleHash;
+import static de.caydenno1.xacrypto.hash.ROT.ROTR;
+
 public final class SHA256 {
     private SHA256(){}
 
-    private static int ROTR(int x, int n){
-        return (x >>> n) | (x << (32 - n));
-    }
+
     public static void compress(int[] h, byte[] b, int offline){
         int[] w = new int [64];
 
@@ -92,9 +92,7 @@ public final class SHA256 {
         if (a == null || b == null) return a == b;
         if (a.length != b.length) return false;
         int diff = 0;
-        for (int i = 0; i < a.length; i++) {
-            diff |= (a[i] ^ b[i]);
-        }
+        for (int i = 0; i < a.length; i++) diff |= (a[i] ^ b[i]);
         return diff == 0;
     }
 
@@ -181,14 +179,12 @@ public final class SHA256 {
     }
 
     static void xor(byte[] dest, byte[] src) {
-        for(int i=0;i<dest.length;i++)dest[i]^=src[i];
+        for (int i = 0 ; i < dest.length ; i++) dest[i]^=src[i];
     }
 
     public static byte[] ByteFromHex(String hex) {
         byte[] out = new byte[hex.length() / 2];
-        for (int i=0;i<out.length;i++) {
-            out[i] = (byte)((Character.digit(hex.charAt(i * 2),16) << 4)|Character.digit(hex.charAt(i * 2 + 1), 16));
-        }
+        for (int i = 0 ; i < out.length ; i++) out[i] = (byte)((Character.digit(hex.charAt(i * 2),16) << 4)|Character.digit(hex.charAt(i * 2 + 1), 16));
         return out;
     }
 }

src/de/caydenno1/xacrypto/misc/Constants.java

@@ -1,6 +1,15 @@
 package de.caydenno1.xacrypto.misc;
 
 public class Constants {
+    public static final int[] SHA1_K = {
+            0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6
+    };
+    public static final int[] SHA0_K = {
+            0x00000000,
+            0x5a827999,
+            0x6ed9eba1,
+            0x8f1bbcdc
+    };
     public static final int[] SHA256_K = {
             0x428a2f98,0x71374491,0xb5c0fbcf,0xe9b5dba5,0x3956c25b,
             0x59f111f1,0x923f82a4,0xab1c5ed5,0xd807aa98,0x12835b01,
@@ -22,5 +31,9 @@ public class Constants {
             0x510e527f,0x9b05688c,0x1f83d9ab,0x5be0cd19
     };
 
+    public static final int[] SHA0_H = {
+            0x67452301,0xEFCDAB89,0x98BADCFE,0x10325476,0xC3D2E1F0
+    };
+
     // (no longer a placeholder)
 }