Code archives/Algorithms/MD5 Digest

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MD5 Digest by Craig Kiesau
(Posted 25 years ago)
This is an MD5 algorithm, converted from some C code with some help/ideas from a Javascript source. I've written it so you should be able to use it as an include file without too much risk of function/variable clashing.

Any improvements, bugs, etc. let me know.

Update 30/3/2002 - Found out NOT was ~, so removed the pNot function. 
;Derived from the RSA Data Security, Inc. MD5 Message-Digest Algorithm

;This array needs to be here for Blitz
Dim MD5_x(0)

;Test it out    
blah$ = Input$("Enter a string to MD5: ")
Print MD5$(blah$)

;The main MD5 function
Function MD5$(sMessage$)

    ;Pads the String as per the MD5 standard
    nblk = ((Len(sMessage$) + 8) Shr 6) + 1  ;number of 16-word blocks
 
	Dim MD5_x(nblk * 16 - 1)
    ;Zero pad the string
    For i = 0 To nblk * 16 - 1
      MD5_x(i) = 0
    Next 
    ;Convert to array of "words"
    For i = 0 To (Len(sMessage$) - 1)
      MD5_x((i Shr 2)) = MD5_x((i Shr 2)) Or (Asc(Mid(sMessage$, (i + 1), 1)) Shl ((i Mod 4) * 8))
    Next 
    MD5_x((i Shr 2)) = MD5_x((i Shr 2)) Or (128 Shl (((i) Mod 4) * 8))
    MD5_x(nblk * 16 - 2) = Len(sMessage$) * 8
    
	;Set initial values
    MD5_a = 1732584193 ;&H67452301
    MD5_b = -271733879 ;&HEFCDAB89
    MD5_c = -1732584194 ;&H98BADCFE
    MD5_d = 271733878 ;&H10325476

	;Loop through the words
    For k = 0 To (nblk * 16 - 1) Step 16
        MD5_AA = MD5_a
        MD5_BB = MD5_b
        MD5_CC = MD5_c
        MD5_DD = MD5_d
    ;Round 1
        MD5_a = MD5_FF(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 0), 7, -680876936) ;&HD76AA478
        MD5_d = MD5_FF(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 1), 12, -389564586) ;&HE8C7B756
        MD5_c = MD5_FF(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 2), 17, 606105819 );&H242070DB
        MD5_b = MD5_FF(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 3), 22, -1044525330) ;&HC1BDCEEE
        MD5_a = MD5_FF(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 4), 7, -176418897) ;&HF57C0FAF
        MD5_d = MD5_FF(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 5), 12, 1200080426 );&H4787C62A
        MD5_c = MD5_FF(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 6), 17, -1473231341) ;&HA8304613
        MD5_b = MD5_FF(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 7), 22, -45705983) ;&HFD469501
        MD5_a = MD5_FF(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 8), 7, 1770035416) ;&H698098D8
        MD5_d = MD5_FF(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 9), 12, -1958414417 );&H8B44F7AF
        MD5_c = MD5_FF(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 10), 17, -42063 );&HFFFF5BB1
        MD5_b = MD5_FF(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 11), 22, -1990404162) ;&H895CD7BE
        MD5_a = MD5_FF(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 12), 7, 1804603682) ;&H6B901122
        MD5_d = MD5_FF(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 13), 12, -40341101) ;&HFD987193
        MD5_c = MD5_FF(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 14), 17, -1502002290) ;&HA679438E
        MD5_b = MD5_FF(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 15), 22, 1236535329) ;&H49B40821
    ;Round 2
        MD5_a = MD5_GG(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 1), 5, -165796510) ;&HF61E2562
        MD5_d = MD5_GG(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 6), 9, -1069501632) ;&HC040B340
        MD5_c = MD5_GG(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 11), 14, 643717713) ;&H265E5A51
        MD5_b = MD5_GG(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 0), 20, -373897302) ;&HE9B6C7AA
        MD5_a = MD5_GG(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 5), 5, -701558691) ;&HD62F105D
        MD5_d = MD5_GG(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 10), 9, 38016083) ;&H2441453
        MD5_c = MD5_GG(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 15), 14, -660478335) ;&HD8A1E681
        MD5_b = MD5_GG(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 4), 20, -405537848) ;&HE7D3FBC8
        MD5_a = MD5_GG(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 9), 5, 568446438) ;&H21E1CDE6
        MD5_d = MD5_GG(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 14), 9, -1019803690) ;&HC33707D6
        MD5_c = MD5_GG(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 3), 14, -187363961) ;&HF4D50D87
        MD5_b = MD5_GG(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 8), 20, 1163531501) ;&H455A14ED
        MD5_a = MD5_GG(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 13), 5, -1444681467) ;&HA9E3E905
        MD5_d = MD5_GG(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 2), 9, -51403784) ;&HFCEFA3F8
        MD5_c = MD5_GG(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 7), 14, 1735328473) ;&H676F02D9
        MD5_b = MD5_GG(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 12), 20, -1926607734) ;&H8D2A4C8A
    ;Round 3
        MD5_a =  MD5_HH(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 5), 4, -378558) ;&HFFFA3942
        MD5_d =  MD5_HH(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 8), 11, -2022574463) ;&H8771F681
        MD5_c = MD5_HH(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 11), 16, 1839030562) ;&H6D9D6122
        MD5_b = MD5_HH(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 14), 23, -35309556) ;&HFDE5380C
        MD5_a =  MD5_HH(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 1), 4, -1530992060) ;&HA4BEEA44
        MD5_d = MD5_HH(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 4), 11, 1272893353) ;&H4BDECFA9
        MD5_c = MD5_HH(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 7), 16, -155497632) ;&HF6BB4B60
        MD5_b = MD5_HH(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 10), 23, -1094730640) ;&HBEBFBC70
        MD5_a = MD5_HH(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 13), 4, 681279174) ;&H289B7EC6
        MD5_d = MD5_HH(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 0), 11, -358537222) ;&HEAA127FA
        MD5_c = MD5_HH(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 3), 16, -722521979) ;&HD4EF3085
        MD5_b = MD5_HH(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 6), 23, 76029189) ;&H4881D05
        MD5_a = MD5_HH(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 9), 4, -640364487) ;&HD9D4D039
        MD5_d = MD5_HH(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 12), 11, -421815835) ;&HE6DB99E5
        MD5_c = MD5_HH(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 15), 16, 530742520) ;&H1FA27CF8
        MD5_b = MD5_HH(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 2), 23, -995338651) ;&HC4AC5665
    ;Round 4
        MD5_a = MD5_II(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 0), 6, -198630844) ;&HF4292244
        MD5_d = MD5_II(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 7), 10, 1126891415) ;&H432AFF97
        MD5_c = MD5_II(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 14), 15, -1416354905) ;&HAB9423A7
        MD5_b = MD5_II(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 5), 21, -57434055) ;&HFC93A039
        MD5_a = MD5_II(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 12), 6, 1700485571) ;&H655B59C3
        MD5_d = MD5_II(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 3), 10, -1894986606) ;&H8F0CCC92
        MD5_c = MD5_II(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 10), 15, -1051523) ;&HFFEFF47D
        MD5_b = MD5_II(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 1), 21, -2054922799) ;&H85845DD1
        MD5_a = MD5_II(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 8), 6, 1873313359) ;&H6FA87E4F
        MD5_d = MD5_II(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 15), 10, -30611744) ;&HFE2CE6E0
        MD5_c = MD5_II(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 6), 15, -1560198380 );&HA3014314
        MD5_b = MD5_II(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 13), 21, 1309151649) ;&H4E0811A1      
        MD5_a = MD5_II(MD5_a, MD5_b, MD5_c, MD5_d, MD5_x(k + 4), 6, -145523070) ;&HF7537E82
        MD5_d = MD5_II(MD5_d, MD5_a, MD5_b, MD5_c, MD5_x(k + 11), 10, -1120210379) ;&HBD3AF235
        MD5_c = MD5_II(MD5_c, MD5_d, MD5_a, MD5_b, MD5_x(k + 2), 15, 718787259) ;&H2AD7D2BB
        MD5_b = MD5_II(MD5_b, MD5_c, MD5_d, MD5_a, MD5_x(k + 9), 21, -343485551) ;&HEB86D391

        MD5_a = MD5_a + MD5_AA
        MD5_b = MD5_b + MD5_BB
        MD5_c = MD5_c + MD5_CC
        MD5_d = MD5_d + MD5_DD
    Next
    
    Return Lower(WordToHex$(MD5_a) + WordToHex$(MD5_b) + WordToHex$(MD5_c) + WordToHex$(MD5_d))
End Function

Function MD5_F(x, y, z)
	Return (x And y) Or (~(x) And z)
End Function

Function MD5_G(x, y, z)
    Return (x And z) Or (y And (~(z)))
End Function

Function MD5_H(x, y, z)
    Return (x Xor y Xor z)
End Function

Function MD5_I(x, y, z)
    Return (y Xor (x Or (~(z))))
End Function

Function MD5_FF(a, b, c, d, x, s, ac)
    a = (a + ((MD5_F(b, c, d)+ x)+ ac))
    a = RotateLeft(a, s)
    Return a + b
End Function

Function MD5_GG(a, b, c, d, x, s, ac)
    a = (a + ((MD5_G(b, c, d) + x) + ac))
    a = RotateLeft(a, s)
    Return a + b
End Function

Function MD5_HH(a, b, c, d, x, s, ac)
    a = (a + ((MD5_H(b, c, d) + x) + ac))
    a = RotateLeft(a, s)
    Return a + b
End Function

Function MD5_II(a, b, c, d, x, s, ac)
    a = (a + ((MD5_I(b, c, d) + x) + ac))
    a = RotateLeft(a, s)
    Return a + b
End Function

Function RotateLeft(lValue, iShiftBits)
    Return (lValue Shl iShiftBits) Or (lValue Shr (32 - iShiftBits))
End Function

Function WordToHex$(lValue)
    For lCount = 0 To 3
        lByte = (lValue Shr lCount * 8) And 255
        ToHex$ = ToHex$ + Right("0" + Hex$(lByte), 2)
    Next
	Return ToHex$
End Function