1樓：鵬凌三千
rem ****** rsa program
rem (c) w.buchanan
rem jan 2002
function check_prime(byval val as long) as boolean
dim primes
primes = array(1, 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397)
check_prime = false
for i = 0 to 78
if (val = primes(i)) then
prime = true
end if
next i
check_prime = prime
end function
function decrypt(byval c, byval n, byval d as long)
dim i, g, f as long
on error goto errorhandler
if (d mod 2 = 0) then
g = 1
else
g = c
end if
for i = 1 to d / 2
f = c * c mod n
g = f * g mod n
next i
decrypt = g
exit function
errorhandler:
select case err.number ' evaluate error number.
case 6
status.text = "calculation overflow, please select smaller values"
case else
status.text = "calculation error"
end select
end function
function getd(byval e as long, byval phi as long) as long
dim u(3) as long
dim v(3) as long
dim q, temp1, temp2, te*** as long
u(0) = 1
u(1) = 0
u(2) = phi
v(0) = 0
v(1) = 1
v(2) = e
while (v(2) <> 0)
q = int(u(2) / v(2))
temp1 = u(0) - q * v(0)
temp2 = u(1) - q * v(1)
te*** = u(2) - q * v(2)
u(0) = v(0)
u(1) = v(1)
u(2) = v(2)
v(0) = temp1
v(1) = temp2
v(2) = te***
wend
if (u(1) < 0) then
getd = (u(1) + phi)
else
getd = u(1)
end if
end function
function gete(byval phi as long) as long
dim great, e as long
great = 0
e = 2
while (great <> 1)
e = e + 1
great = get_common_denom(e, phi)
wend
gete = e
end function
function get_common_denom(byval e as long, byval phi as long)
dim great, temp, a as long
if (e > phi) then
while (e mod phi <> 0)
temp = e mod phi
e = phi
phi = temp
wend
great = phi
else
while (phi mod e <> 0)
a = phi mod e
phi = e
e = a
wend
great = e
end if
get_common_denom = great
end function
private sub show_primes()
status.text = "1"
no_primes = 1
for i = 2 to 400
prime = true
for j = 2 to (i / 2)
if ((i mod j) = 0) then
prime = false
end if
next j
if (prime = true) then
no_primes = no_primes + 1
status.text = status.text + ", " + str(i)
end if
next i
status.text = status.text + vbcrlf + "number of primes found:
" + str(no_primes)
end sub
private sub command1_click()
dim p, q, n, e, phi, d, m, c as long
p = text1.text
q = text2.text
if (check_prime(p) = false) then
status.text = "p is not a prime or is too large, please re-enter"
elseif (check_prime(q) = false) then
status.text = "q is not a prime or is too large, please re-enter"
else
n = p * q
text3.text = n
phi = (p - 1) * (q - 1)
e = gete((phi))
d = getd((e), (phi))
text4.text = phi
text5.text = d
text6.text = e
m = text7.text
c = (m ^ e) mod n
text8.text = c
m = decrypt(c, n, d)
text9.text = m
label12.caption = "decrypt key =<" + str(d) + "," + str(n) + ">"
label13.caption = "encrypt key =<" + str(e) + "," + str(n) + ">"
end if
end sub
private sub command2_click()
endend sub
private sub command3_click()
frmbrowser.show
end sub
private sub command4_click()
call show_primes
end sub
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