feat: Added MD5 hashing algorithm (TheAlgorithms#1519)

* feat: Added MD5 hashing algorithm * Added wiki link * Remove spam? * Fix extend towards end * Return Uint32Array in MD5 function * Preprocess function now works on uint arrays * chunkify U32Array instead of string * Remove all string related functions * Replace typed arrays with named variables * Fix "Replace typed arrays with named variables" * Return Uint8 Array in MD5 function The MD5 function now returns a uint8 array with the correct endianness. * Add tests * Fix docstrings * Introduce hexMD5 function * Change test string * Format test file

Author: ManpreetXSingh

Hashes/MD5.js

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+// Module that replicates the MD5 Cryptographic Hash
+// function in Javascript.
+
+// main variables
+constS=[
+7,12,17,22,7,12,17,22,7,12,17,22,7,12,17,22,5,9,14,20,5,
+9,14,20,5,9,14,20,5,9,14,20,4,11,16,23,4,11,16,23,4,11,
+16,23,4,11,16,23,6,10,15,21,6,10,15,21,6,10,15,21,6,10,15,
+21
+]
+
+constK=[
+0xd76aa478,0xe8c7b756,0x242070db,0xc1bdceee,0xf57c0faf,0x4787c62a,
+0xa8304613,0xfd469501,0x698098d8,0x8b44f7af,0xffff5bb1,0x895cd7be,
+0x6b901122,0xfd987193,0xa679438e,0x49b40821,0xf61e2562,0xc040b340,
+0x265e5a51,0xe9b6c7aa,0xd62f105d,0x02441453,0xd8a1e681,0xe7d3fbc8,
+0x21e1cde6,0xc33707d6,0xf4d50d87,0x455a14ed,0xa9e3e905,0xfcefa3f8,
+0x676f02d9,0x8d2a4c8a,0xfffa3942,0x8771f681,0x6d9d6122,0xfde5380c,
+0xa4beea44,0x4bdecfa9,0xf6bb4b60,0xbebfbc70,0x289b7ec6,0xeaa127fa,
+0xd4ef3085,0x04881d05,0xd9d4d039,0xe6db99e5,0x1fa27cf8,0xc4ac5665,
+0xf4292244,0x432aff97,0xab9423a7,0xfc93a039,0x655b59c3,0x8f0ccc92,
+0xffeff47d,0x85845dd1,0x6fa87e4f,0xfe2ce6e0,0xa3014314,0x4e0811a1,
+0xf7537e82,0xbd3af235,0x2ad7d2bb,0xeb86d391
+]
+
+/**
+ * Separates an array into equal sized chunks
+ *
+ * @param{Array|string} array - array or string to separate into chunks
+ * @param{number} size - number of elements wanted in each chunk
+ * @return{Array} - array of original array split into chunks
+ *
+ * @example
+ * chunkify("this is a test", 2)
+ */
+functionchunkify(array,size){
+constchunks=[]
+for(leti=0;i<array.length;i+=size){
+chunks.push(array.slice(i,i+size))
+}
+returnchunks
+}
+
+/**
+ * Rotates the bits to the left
+ *
+ * @param{number} bits - 32 bit number
+ * @param{number} turns - number of rotations to make
+ * @return{number} - number after bits rotation
+ *
+ * @example
+ * rotateLeft(0b1011, 3); // 0b1011000
+ */
+functionrotateLeft(bits,turns){
+return(bits<<turns)|(bits>>>(32-turns))
+}
+
+/**
+ * Converts Uint8Array to Uint32Array
+ *
+ * @param{Uint8Array} u8Array Uint8Array to convert
+ * @returns{Uint32Array} - Required Uint32Array
+ */
+functionu8ToU32(u8Array){
+constuint32Array=newUint32Array(u8Array.length/4)
+
+for(leti=0;i<u8Array.length;i+=4){
+uint32Array[i/4]=
+(u8Array[i]|
+(u8Array[i+1]<<8)|
+(u8Array[i+2]<<16)|
+(u8Array[i+3]<<24))>>>
+0
+}
+
+returnuint32Array
+}
+
+/**
+ * Converts Uint32Array to Uint8Array
+ *
+ * @param{Uint32Array} u32Array Uint32Array to convert
+ * @returns{Uint8Array} - Required Uint8Array
+ */
+functionu32ToU8(u32Array){
+constuint8Array=newUint8Array(u32Array.length*4)
+
+for(leti=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
+}
+
+returnuint8Array
+}
+
+/**
+ * Adds padding to the end of the given array
+ *
+ * @param{Uint8Array} u8Array Array to pad
+ * @param{number} size Resulting size of the array
+ */
+functionpadEnd(u8Array,size){
+constresult=newUint8Array(size)
+result.set(u8Array)
+result.fill(0,u8Array.length)
+
+returnresult
+}
+
+/**
+ * Pre-processes message to feed the algorithm loop
+ *
+ * @param{Uint8Array} message - message to pre-process
+ * @return{Uint32Array} - processed message
+ */
+functionpreProcess(message){
+// Extend message by adding '0'
+//
+// message.length + 1 is for adding '1' bit
+// 56 - (length % 64) is for padding with '0's
+// 8 is for appending 64 bit message length
+letm=padEnd(
+message,
+message.length+1+(56-((message.length+1)%64))+8
+)
+
+// Add '1' bit at the end of the message
+m[message.length]=1<<7
+
+// convert message to 32 bit uint array
+m=u8ToU32(m)
+
+// Append the length of the message to the end
+// (ml / 0x100000000) | 0 is equivalent to (ml >> 32) & 0xffffffff) in other languages
+letml=message.length*8
+m[m.length-2]=ml&0xffffffff
+m[m.length-1]=(ml/0x100000000)|0
+
+returnm
+}
+
+/**
+ * Hashes message using MD5 Cryptographic Hash Function
+ *
+ * @see
+ * For more info: https://en.wikipedia.org/wiki/MD5
+ *
+ * @param{Uint8Array} message - message to hash
+ * @return{Uint8Array} - message digest (hash value)
+ */
+functionMD5(message){
+// Initialize variables:
+let[a0,b0,c0,d0]=[
+0x67452301>>>0,
+0xefcdab89>>>0,
+0x98badcfe>>>0,
+0x10325476>>>0
+]
+
+// pre-process message and split into 512 bit chunks
+constwords=Array.from(preProcess(message))
+constchunks=chunkify(words,16)
+
+chunks.forEach(function(chunk,_){
+// initialize variables for this chunk
+let[A,B,C,D]=[a0,b0,c0,d0]
+
+for(leti=0;i<64;i++){
+let[F,g]=[0,0]
+
+if(i<=15){
+F=(B&C)|(~B&D)
+g=i
+}elseif(i<=31){
+F=(D&B)|(~D&C)
+g=(5*i+1)%16
+}elseif(i<=47){
+F=B^C^D
+g=(3*i+5)%16
+}else{
+F=C^(B|~D)
+g=(7*i)%16
+}
+
+F=(F+A+K[i]+chunk[g])>>>0
+A=D
+D=C
+C=B
+B=((B+rotateLeft(F,S[i]))&0xffffffff)>>>0
+}
+
+// add values for this chunk to main hash variables (unsigned)
+a0=(a0+A)>>>0
+b0=(b0+B)>>>0
+c0=(c0+C)>>>0
+d0=(d0+D)>>>0
+})
+
+returnu32ToU8([a0,b0,c0,d0])
+}
+
+// export MD5 function
+export{MD5}

Hashes/tests/MD5.test.js

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+import{MD5}from'../MD5'
+
+/**
+ * Returns the MD5 hash of the given message as a hexadecimal string
+ *
+ * @param{Uint8Array} message - message to hash
+ * @return{string} - hash as a hexadecimal string
+ */
+functionhexMD5(message){
+returnArray.from(MD5(message),(byte)=>
+byte.toString(16).padStart(2,'0')
+).join('')
+}
+
+describe('Testing MD5 function',()=>{
+it('should return the correct hash for "The quick brown fox jumps over the lazy dog"',()=>{
+constinput=newTextEncoder().encode(
+'The quick brown fox jumps over the lazy dog'
+)
+consthash=hexMD5(input)
+
+expect(hash).toBe('9e107d9d372bb6826bd81d3542a419d6')
+})
+
+it('should return the correct hash for "JavaScript!"',()=>{
+constinput=newTextEncoder().encode('JavaScript!')
+consthash=hexMD5(input)
+
+expect(hash).toBe('209eddd6b61af0643907a8e069a08fb8')
+})
+
+it('should correctly hash an empty string',()=>{
+constinput=newTextEncoder().encode('')
+consthash=hexMD5(input)
+
+expect(hash).toBe('d41d8cd98f00b204e9800998ecf8427e')
+})
+})