imports system
imports system.io
imports system.security
imports system.security.cryptography
imports system.text
module encrypt
private const ssecretkey as string = "password"
public sub main()
encryptfile("c:/temp/test.txt", _
"c:/temp/encrypted.txt", _
ssecretkey)
decryptfile("c:/temp/encrypted.txt", _
"c:/temp/decrypted.txt", _
ssecretkey)
end sub
sub encryptfile(byval sinputfilename as string, _
byval soutputfilename as string, _
byval skey as string)
dim fsinput as new filestream(sinputfilename, _
filemode.open, fileaccess.read)
dim fsencrypted as new filestream(soutputfilename, _
filemode.create, fileaccess.write)
dim des as new descryptoserviceprovider()
'為des算法設置安全碼.
'必須是64位,8個字節
des.key = asciiencoding.ascii.getbytes(skey)
des.iv = asciiencoding.ascii.getbytes(skey)
'創建des加密碼實例
dim desencrypt as icryptotransform = des.createencryptor()
'
dim cryptostream as new cryptostream(fsencrypted, _
desencrypt, _
cryptostreammode.write)
'讀取文件到數組
dim bytearrayinput(fsinput.length - 1) as byte
fsinput.read(bytearrayinput, 0, bytearrayinput.length)
'寫到加密文件中
cryptostream.write(bytearrayinput, 0, bytearrayinput.length)
cryptostream.close()
end sub
sub decryptfile(byval sinputfilename as string, _
byval soutputfilename as string, _
byval skey as string)
dim des as new descryptoserviceprovider()
des.key() = asciiencoding.ascii.getbytes(skey)
des.iv = asciiencoding.ascii.getbytes(skey)
'讀取加密文件
dim fsread as new filestream(sinputfilename, filemode.open, fileaccess.read)
'
dim desdecrypt as icryptotransform = des.createdecryptor()
'
dim cryptostreamdecr as new cryptostream(fsread, desdecrypt, cryptostreammode.read)
'輸出到解密文件
dim fsdecrypted as new streamwriter(soutputfilename)
fsdecrypted.write(new streamreader(cryptostreamdecr).readtoend)
fsdecrypted.flush()
fsdecrypted.close()
end sub
end module
