我正在使用python学习如何使用RSA和SHA加密消息。我已经编写了RSA代码，并且正确地将SHA代码实现到程序中，以便我的消息首先使用RSA加密，然后使用SHA进行哈希处理。看看，让我知道你的想法。感谢。
# RSA Cipher
# http://inventwithpython.com/hacking (BSD Licensed)
import sys, os
import hashlib
# IMPORTANT: The block size MUST be less than or equal to the key size!
# (Note: The block size is in bytes, the key size is in bits. There
# are 8 bits in 1 byte.)
DEFAULT_BLOCK_SIZE = 128 # 128 bytes
BYTE_SIZE = 256 # One byte has 256 different values.
def main():
# Runs a test that encrypts a message to a file or decrypts a message
# from a file.
filename = 'encrypted_file.txt' # the file to write to/read from
eord = "encrypt or decrypt?"
mode = (input(eord)) # set to 'encrypt' or 'decrypt'
secure = 'Please enter public key'
ath = eval(input(secure))
if mode == 'encrypt':
if ath == 615:
message = input('What is your message?')
pubKeyFilename = 'al_sweigart_pubkey.txt'
print('Encrypting and writing to %s...' % (filename))
encryptedText = encryptAndWriteToFile(filename, pubKeyFilename, message)
mystring = filename
# Assumes the default UTF-8
hash_object = hashlib.md5(mystring.encode())
print('Encrypted text:')
print(encryptedText)
else:
print('incorrect public key try again')
elif mode == 'decrypt':
privKeyFilename = 'al_sweigart_privkey.txt'
print('Reading from %s and decrypting...' % (filename))
decryptedText = readFromFileAndDecrypt(filename, privKeyFilename)
print('Decrypted text:')
print(decryptedText)
def getBlocksFromText(message, blockSize=DEFAULT_BLOCK_SIZE):
# Converts a string message to a list of block integers. Each integer
# represents 128 (or whatever blockSize is set to) string characters.
messageBytes = message.encode('ascii') # convert the string to bytes
blockInts = []
for blockStart in range(0, len(messageBytes), blockSize):
# Calculate the block integer for this block of text
blockInt = 0
for i in range(blockStart, min(blockStart + blockSize, len(messageBytes))):
blockInt += messageBytes[i] * (BYTE_SIZE ** (i % blockSize))
blockInts.append(blockInt)
return blockInts
def getTextFromBlocks(blockInts, messageLength, blockSize=DEFAULT_BLOCK_SIZE):
# Converts a list of block integers to the original message string.
# The original message length is needed to properly convert the last
# block integer.
message = []
for blockInt in blockInts:
blockMessage = []
for i in range(blockSize - 1, -1, -1):
if len(message) + i < messageLength:
# Decode the message string for the 128 (or whatever
# blockSize is set to) characters from this block integer.
asciiNumber = blockInt // (BYTE_SIZE ** i)
blockInt = blockInt % (BYTE_SIZE ** i)
blockMessage.insert(0, chr(asciiNumber))
message.extend(blockMessage)
return ''.join(message)
def encryptMessage(message, key, blockSize=DEFAULT_BLOCK_SIZE):
# Converts the message string into a list of block integers, and then
# encrypts each block integer. Pass the PUBLIC key to encrypt.
encryptedBlocks = []
n, e = key
for block in getBlocksFromText(message, blockSize):
# ciphertext = plaintext ^ e mod n
encryptedBlocks.append(pow(block, e, n))
return encryptedBlocks
def decryptMessage(encryptedBlocks, messageLength, key, blockSize=DEFAULT_BLOCK_SIZE):
# Decrypts a list of encrypted block ints into the original message
# string. The original message length is required to properly decrypt
# the last block. Be sure to pass the PRIVATE key to decrypt.
decryptedBlocks = []
n, d = key
for block in encryptedBlocks:
# plaintext = ciphertext ^ d mod n
decryptedBlocks.append(pow(block, d, n))
return getTextFromBlocks(decryptedBlocks, messageLength, blockSize)
def readKeyFile(keyFilename):
# Given the filename of a file that contains a public or private key,
# return the key as a (n,e) or (n,d) tuple value.
fo = open(keyFilename)
content = fo.read()
fo.close()
keySize, n, EorD = content.split(',')
return (int(keySize), int(n), int(EorD))
def encryptAndWriteToFile(messageFilename, keyFilename, message, blockSize=DEFAULT_BLOCK_SIZE):
# Using a key from a key file, encrypt the message and save it to a
# file. Returns the encrypted message string.
keySize, n, e = readKeyFile(keyFilename)
# Check that key size is greater than block size.
if keySize < blockSize * 8: # * 8 to convert bytes to bits
sys.exit('ERROR: Block size is %s bits and key size is %s bits. The RSA cipher requires the block size to be equal to or greater than the key size. Either decrease the block size or use different keys.' % (blockSize * 8, keySize))
# Encrypt the message
encryptedBlocks = encryptMessage(message, (n, e), blockSize)
# Convert the large int values to one string value.
for i in range(len(encryptedBlocks)):
encryptedBlocks[i] = str(encryptedBlocks[i])
encryptedContent = ','.join(encryptedBlocks)
# Write out the encrypted string to the output file.
encryptedContent = '%s_%s_%s' % (len(message), blockSize, encryptedContent)
fo = open(messageFilename, 'w')
fo.write(encryptedContent)
fo.close()
# Also return the encrypted string.
return encryptedContent
def readFromFileAndDecrypt(messageFilename, keyFilename):
# Using a key from a key file, read an encrypted message from a file
# and then decrypt it. Returns the decrypted message string.
keySize, n, d = readKeyFile(keyFilename)
# Read in the message length and the encrypted message from the file.
fo = open(messageFilename)
content = fo.read()
messageLength, blockSize, encryptedMessage = content.split('_')
messageLength = int(messageLength)
blockSize = int(blockSize)
# Check that key size is greater than block size.
if keySize < blockSize * 8: # * 8 to convert bytes to bits
sys.exit('ERROR: Block size is %s bits and key size is %s bits. The RSA cipher requires the block size to be equal to or greater than the key size. Did you specify the correct key file and encrypted file?' % (blockSize * 8, keySize))
# Convert the encrypted message into large int values.
encryptedBlocks = []
for block in encryptedMessage.split(','):
encryptedBlocks.append(int(block))
# Decrypt the large int values.
return decryptMessage(encryptedBlocks, messageLength, (n, d), blockSize)
# If rsaCipher.py is run (instead of imported as a module) call
# the main() function.
if __name__ == '__main__':
main()