IDC资讯中心
md5加密算法在vb中的实现
option explicit
dim w1 as string, w2 as string, w3 as string, w4 as string
function md5f(byval tempstr as string, byval w as string, byval x as s
tring, byval y as string, byval z as string, byval xin as string, byva
l qdata as string, byval rots as integer)
md5f = bigmod32add(rotleft(bigmod32add(bigmod32add(w, tempstr), bi
gmod32add(xin, qdata)), rots), x)
end function
sub md5f1(w as string, byval x as string, byval y as string, byval z a
s string, byval xin as string, byval qdata as string, byval rots as in
teger)
dim tempstr as string
tempstr = bigxor(z, bigand(x, bigxor(y, z)))
w = md5f(tempstr, w, x, y, z, xin, qdata, rots)
end sub
sub md5f2(w as string, byval x as string, byval y as string, byval z a
s string, byval xin as string, byval qdata as string, byval rots as in
teger)
dim tempstr as string
tempstr = bigxor(y, bigand(z, bigxor(x, y)))
w = md5f(tempstr, w, x, y, z, xin, qdata, rots)
end sub
sub md5f3(w as string, byval x as string, byval y as string, byval z a
s string, byval xin as string, byval qdata as string, byval rots as in
teger)
dim tempstr as string
tempstr = bigxor(x, bigxor(y, z))
w = md5f(tempstr, w, x, y, z, xin, qdata, rots)
end sub
sub md5f4(w as string, byval x as string, byval y as string, byval z a
s string, byval xin as string, byval qdata as string, byval rots as in
teger)
dim tempstr as string
tempstr = bigxor(y, bigor(x, bignot(z)))
w = md5f(tempstr, w, x, y, z, xin, qdata, rots)
end sub
function md5_calc(byval hashthis as string) as string
redim buf(0 to 3) as string
redim xin(0 to 15) as string
dim tempnum as integer, tempnum2 as integer, loopit as integer, loopou
ter as integer, loopinner as integer
dim a as string, b as string, c as string, d as string
add padding
tempnum = 8 * len(hashthis)
hashthis = hashthis + chr$(128) add binary 10000000
tempnum2 = 56 – len(hashthis) mod 64
if tempnum2 < 0 then
tempnum2 = 64 + tempnum2
end if
hashthis = hashthis + string$(tempnum2, chr$(0))
for loopit = 1 to 8
hashthis = hashthis + chr$(tempnum mod 256)
tempnum = tempnum – tempnum mod 256
tempnum = tempnum / 256
next loopit
set magic numbers
buf(0) = "67452301"
buf(1) = "efcdab89"
buf(2) = "98badcfe"
buf(3) = "10325476"
for each 512 bit section
for loopouter = 0 to len(hashthis) / 64 – 1
a = buf(0)
b = buf(1)
c = buf(2)
d = buf(3)
get the 512 bits
for loopit = 0 to 15
xin(loopit) = ""
for loopinner = 1 to 4
xin(loopit) = hex$(asc(mid$(hashthis, 64 * loopouter +
4 * loopit + loopinner, 1))) + xin(loopit)
if len(xin(loopit)) mod 2 then xin(loopit) = "0" + xin
(loopit)
next loopinner
next loopit
round 1
md5f1 a, b, c, d, xin(0), "d76aa478", 7
md5f1 d, a, b, c, xin(1), "e8c7b756", 12
md5f1 c, d, a, b, xin(2), "242070db", 17
md5f1 b, c, d, a, xin(3), "c1bdceee", 22
md5f1 a, b, c, d, xin(4), "f57c0faf", 7
md5f1 d, a, b, c, xin(5), "4787c62a", 12
md5f1 c, d, a, b, xin(6), "a8304613", 17
md5f1 b, c, d, a, xin(7), "fd469501", 22
md5f1 a, b, c, d, xin(8), "698098d8", 7
md5f1 d, a, b, c, xin(9), "8b44f7af", 12
md5f1 c, d, a, b, xin(10), "ffff5bb1", 17
md5f1 b, c, d, a, xin(11), "895cd7be", 22
md5f1 a, b, c, d, xin(12), "6b901122", 7
md5f1 d, a, b, c, xin(13), "fd987193", 12
md5f1 c, d, a, b, xin(14), "a679438e", 17
md5f1 b, c, d, a, xin(15), "49b40821", 22
round 2
md5f2 a, b, c, d, xin(1), "f61e2562", 5
md5f2 d, a, b, c, xin(6), "c040b340", 9
md5f2 c, d, a, b, xin(11), "265e5a51", 14
md5f2 b, c, d, a, xin(0), "e9b6c7aa", 20
md5f2 a, b, c, d, xin(5), "d62f105d", 5
md5f2 d, a, b, c, xin(10), "02441453", 9
md5f2 c, d, a, b, xin(15), "d8a1e681", 14
md5f2 b, c, d, a, xin(4), "e7d3fbc8", 20
md5f2 a, b, c, d, xin(9), "21e1cde6", 5
md5f2 d, a, b, c, xin(14), "c33707d6", 9
md5f2 c, d, a, b, xin(3), "f4d50d87", 14
md5f2 b, c, d, a, xin(8), "455a14ed", 20
md5f2 a, b, c, d, xin(13), "a9e3e905", 5
md5f2 d, a, b, c, xin(2), "fcefa3f8", 9
md5f2 c, d, a, b, xin(7), "676f02d9", 14
md5f2 b, c, d, a, xin(12), "8d2a4c8a", 20
round 3
md5f3 a, b, c, d, xin(5), "fffa3942", 4
md5f3 d, a, b, c, xin(8), "8771f681", 11
md5f3 c, d, a, b, xin(11), "6d9d6122", 16
md5f3 b, c, d, a, xin(14), "fde5380c", 23
md5f3 a, b, c, d, xin(1), "a4beea44", 4
md5f3 d, a, b, c, xin(4), "4bdecfa9", 11
md5f3 c, d, a, b, xin(7), "f6bb4b60", 16
md5f3 b, c, d, a, xin(10), "bebfbc70", 23
md5f3 a, b, c, d, xin(13), "289b7ec6", 4
md5f3 d, a, b, c, xin(0), "e27fa", 11
md5f3 c, d, a, b, xin(3), "d4ef3085", 16
md5f3 b, c, d, a, xin(6), "04881d05", 23
md5f3 a, b, c, d, xin(9), "d9d4d039", 4
md5f3 d, a, b, c, xin(12), "e6db99e5", 11
md5f3 c, d, a, b, xin(15), "1fa27cf8", 16
md5f3 b, c, d, a, xin(2), "c4ac5665", 23
round 4
md5f4 a, b, c, d, xin(0), "f4292244", 6
md5f4 d, a, b, c, xin(7), "432aff97", 10
md5f4 c, d, a, b, xin(14), "ab9423a7", 15
md5f4 b, c, d, a, xin(5), "fc93a039", 21
md5f4 a, b, c, d, xin(12), "655b59c3", 6
md5f4 d, a, b, c, xin(3), "8f0ccc92", 10
md5f4 c, d, a, b, xin(10), "ffeff47d", 15
md5f4 b, c, d, a, xin(1), "85845dd1", 21
md5f4 a, b, c, d, xin(8), "6fa87e4f", 6
md5f4 d, a, b, c, xin(15), "fe2ce6e0", 10
md5f4 c, d, a, b, xin(6), "a3014314", 15
md5f4 b, c, d, a, xin(13), "4e0811a1", 21
md5f4 a, b, c, d, xin(4), "f7537e82", 6
md5f4 d, a, b, c, xin(11), "bd3af235", 10
md5f4 c, d, a, b, xin(2), "2ad7d2bb", 15
md5f4 b, c, d, a, xin(9), "eb86d391", 21
buf(0) = bigadd(buf(0), a)
buf(1) = bigadd(buf(1), b)
buf(2) = bigadd(buf(2), c)
buf(3) = bigadd(buf(3), d)
next loopouter
extract md5hash
hashthis = ""
for loopit = 0 to 3
for loopinner = 3 to 0 step -1
hashthis = hashthis + chr(val("&h" + mid$(buf(loopit), 1 +
2 * loopinner, 2)))
next loopinner
next loopit
and return it
md5_calc = hashthis
end function
function bigmod32add(byval value1 as string, byval value2 as string) a
s string
bigmod32add = right$(bigadd(value1, value2), 8)
end function
public function bigadd(byval value1 as string, byval value2 as string)
as string
dim valueans as string
dim loopit as integer, tempnum as integer
tempnum = len(value1) – len(value2)
if tempnum < 0 then
value1 = space$(abs(tempnum)) + value1
elseif tempnum > 0 then
value2 = space$(abs(tempnum)) + value2
end if
tempnum = 0
for loopit = len(value1) to 1 step -1
tempnum = tempnum + val("&h" + mid$(value1, loopit, 1)) + val(
"&h" + mid$(value2, loopit, 1))
valueans = hex$(tempnum mod 16) + valueans
tempnum = int(tempnum / 16)
next loopit
if tempnum <> 0 then
valueans = hex$(tempnum) + valueans
end if
bigadd = right(valueans, 8)
end function
public function rotleft(byval value1 as string, byval rots as integer)
as string
dim tempstr as string
dim loopit as integer, loopinner as integer
dim tempnum as integer
rots = rots mod 32
if rots = 0 then
rotleft = value1
exit function
end if
value1 = right$(value1, 8)
tempstr = string$(8 – len(value1), "0") + value1
value1 = ""
convert to binary
for loopit = 1 to 8
tempnum = val("&h" + mid$(tempstr, loopit, 1))
for loopinner = 3 to 0 step -1
if tempnum and 2 ^ loopinner then
value1 = value1 + "1"
else
value1 = value1 + "0"
end if
next loopinner
next loopit
tempstr = mid$(value1, rots + 1) + left$(value1, rots)
and convert back to hex
value1 = ""
for loopit = 0 to 7
tempnum = 0
for loopinner = 0 to 3
if val(mid$(tempstr, 4 * loopit + loopinner + 1, 1)) then
tempnum = tempnum + 2 ^ (3 – loopinner)
end if
next loopinner
value1 = value1 + hex$(tempnum)
next loopit
rotleft = right(value1, 8)
end function
function bigand(byval value1 as string, byval value2 as string) as str
ing
dim valueans as string
dim loopit as integer, tempnum as integer
tempnum = len(value1) – len(value2)
if tempnum < 0 then
value2 = mid$(value2, abs(tempnum) + 1)
elseif tempnum > 0 then
value1 = mid$(value1, tempnum + 1)
end if
for loopit = 1 to len(value1)
valueans = valueans + hex$(val("&h" + mid$(value1, loopit, 1))
and val("&h" + mid$(value2, loopit, 1)))
next loopit
bigand = valueans
end function
function bignot(byval value1 as string) as string
dim valueans as string
dim loopit as integer
value1 = right$(value1, 8)
value1 = string$(8 – len(value1), "0") + value1
for loopit = 1 to 8
valueans = valueans + hex$(15 xor val("&h" + mid$(value1, loop
it, 1)))
next loopit
bignot = valueans
end function
function bigor(byval value1 as string, byval value2 as string) as stri
ng
dim valueans as string
dim loopit as integer, tempnum as integer
tempnum = len(value1) – len(value2)
if tempnum < 0 then
valueans = left$(value2, abs(tempnum))
value2 = mid$(value2, abs(tempnum) + 1)
elseif tempnum > 0 then
valueans = left$(value1, abs(tempnum))
value1 = mid$(value1, tempnum + 1)
end if
for loopit = 1 to len(value1)
valueans = valueans + hex$(val("&h" + mid$(value1, loopit, 1))
or val("&h" + mid$(value2, loopit, 1)))
next loopit
bigor = valueans
end function
function bigxor(byval value1 as string, byval value2 as string) as str
ing
dim valueans as string
dim loopit as integer, tempnum as integer
tempnum = len(value1) – len(value2)
if tempnum < 0 then
valueans = left$(value2, abs(tempnum))
value2 = mid$(value2, abs(tempnum) + 1)
elseif tempnum > 0 then
valueans = left$(value1, abs(tempnum))
value1 = mid$(value1, tempnum + 1)
end if
for loopit = 1 to len(value1)
valueans = valueans + hex$(val("&h" + mid$(value1, loopit, 1))
xor val("&h" + mid$(value2, loopit, 1)))
next loopit
bigxor = right(valueans, 8)
end function
to be continue…
