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63 lines
2.0 KiB
Python
63 lines
2.0 KiB
Python
import os
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import random
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import sys
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import rabin_miller as rabinMiller, cryptomath_module as cryptoMath
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min_primitive_root = 3
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def main():
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print('Making key files...')
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makeKeyFiles('elgamal', 2048)
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print('Key files generation successful')
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# I have written my code naively same as definition of primitive root
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# however every time I run this program, memory exceeded...
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# so I used 4.80 Algorithm in Handbook of Applied Cryptography(CRC Press, ISBN : 0-8493-8523-7, October 1996)
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# and it seems to run nicely!
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def primitiveRoot(p_val):
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print("Generating primitive root of p")
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while True:
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g = random.randrange(3,p_val)
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if pow(g, 2, p_val) == 1:
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continue
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if pow(g, p_val, p_val) == 1:
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continue
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return g
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def generateKey(keySize):
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print('Generating prime p...')
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p = rabinMiller.generateLargePrime(keySize) # select large prime number.
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e_1 = primitiveRoot(p) # one primitive root on modulo p.
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d = random.randrange(3, p) # private_key -> have to be greater than 2 for safety.
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e_2 = cryptoMath.findModInverse(pow(e_1, d, p), p)
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publicKey = (keySize, e_1, e_2, p)
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privateKey = (keySize, d)
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return publicKey, privateKey
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def makeKeyFiles(name, keySize):
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if os.path.exists('%s_pubkey.txt' % name) or os.path.exists('%s_privkey.txt' % name):
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print('\nWARNING:')
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print('"%s_pubkey.txt" or "%s_privkey.txt" already exists. \n'
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'Use a different name or delete these files and re-run this program.' %
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(name, name))
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sys.exit()
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publicKey, privateKey = generateKey(keySize)
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print('\nWriting public key to file %s_pubkey.txt...' % name)
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with open('%s_pubkey.txt' % name, 'w') as fo:
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fo.write('%d,%d,%d,%d' % (publicKey[0], publicKey[1], publicKey[2], publicKey[3]))
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print('Writing private key to file %s_privkey.txt...' % name)
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with open('%s_privkey.txt' % name, 'w') as fo:
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fo.write('%d,%d' % (privateKey[0], privateKey[1]))
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if __name__ == '__main__':
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main()
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