feat: Added MD5 hashing algorithm

Hashes/MD5.js

@@ -76,6 +76,25 @@ function u8ToU32(u8Array) {
   return uint32Array
 }
 
+/**
+ * Converts Uint32Array to Uint8Array
+ *
+ * @param {Uint32Array} u32Array Uint32Array to convert
+ * @returns {Uint8Array} - Required Uint8Array
+ */
+function u32ToU8(u32Array) {
+  const uint8Array = new Uint8Array(u32Array.length * 4)
+
+  for (let i = 0; i < u32Array.length; i++) {
+    uint8Array[i * 4] = u32Array[i] & 0xff
+    uint8Array[i * 4 + 1] = (u32Array[i] >> 8) & 0xff
+    uint8Array[i * 4 + 2] = (u32Array[i] >> 16) & 0xff
+    uint8Array[i * 4 + 3] = (u32Array[i] >> 24) & 0xff
+  }
+
+  return uint8Array
+}
+
 /**
  * Adds padding to the end of the given array
  *
@@ -129,11 +148,16 @@ function preProcess(message) {
  * For more info: https://en.wikipedia.org/wiki/MD5
  *
  * @param {Uint8Array} message - message to hash
- * @return {Uint32Array} - message digest (hash value)
+ * @return {Uint8Array} - message digest (hash value)
  */
 function MD5(message) {
   // Initialize variables:
-  let [a0, b0, c0, d0] = [0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476]
+  let [a0, b0, c0, d0] = [
+    0x67452301 >>> 0,
+    0xefcdab89 >>> 0,
+    0x98badcfe >>> 0,
+    0x10325476 >>> 0
+  ]
 
   // pre-process message and split into 512 bit chunks
   const words = Array.from(preProcess(message))
@@ -160,21 +184,21 @@ function MD5(message) {
         g = (7 * i) % 16
       }
 
-      F = F + A + K[i] + chunk[g]
+      F = (F + A + K[i] + chunk[g]) >>> 0
       A = D
       D = C
       C = B
-      B = (B + (rotateLeft(F, S[i]) % 0xFFFFFFFF)) >>> 0
+      B = ((B + rotateLeft(F, S[i])) & 0xffffffff) >>> 0
     }
 
     // add values for this chunk to main hash variables (unsigned)
-    a0 = a0 + A
-    b0 = b0 + B
-    c0 = c0 + C
-    d0 = d0 + D
+    a0 = (a0 + A) >>> 0
+    b0 = (b0 + B) >>> 0
+    c0 = (c0 + C) >>> 0
+    d0 = (d0 + D) >>> 0
   })
 
-  return [a0, b0, c0, d0]
+  return u32ToU8([a0, b0, c0, d0])
 }
 
 // export MD5 function

Hashes/tests/MD5.test.js

@@ -0,0 +1,37 @@
+import { MD5 } from '../MD5'
+
+describe('Testing MD5 function', () => {
+  it('should return the correct hash for "The quick brown fox jumps over the lazy dog"', () => {
+    const input = new TextEncoder().encode(
+      'The quick brown fox jumps over the lazy dog'
+    )
+
+    const hash = Array.from(MD5(input), (byte) =>
+      byte.toString(16).padStart(2, '0')
+    ).join('')
+
+    expect(hash).toBe('9e107d9d372bb6826bd81d3542a419d6')
+  })
+
+  it('should return the correct hash for "The quick brown fox jumps over the lazy dog."', () => {
+    const input = new TextEncoder().encode(
+      'The quick brown fox jumps over the lazy dog.'
+    )
+
+    const hash = Array.from(MD5(input), (byte) =>
+      byte.toString(16).padStart(2, '0')
+    ).join('')
+
+    expect(hash).toBe('e4d909c290d0fb1ca068ffaddf22cbd0')
+  })
+
+  it('should correctly hash an empty string', () => {
+    const input = new TextEncoder().encode('')
+
+    const hash = Array.from(MD5(input), (byte) =>
+      byte.toString(16).padStart(2, '0')
+    ).join('')
+
+    expect(hash).toBe('d41d8cd98f00b204e9800998ecf8427e')
+  })
+})