I have three text values that I am encrypting and then writing to a file. Later I want to read the values back (in another script) and decrypt them.
I've successfully encrypted the values:
cenc = rsa.encrypt(client_name.encode('utf8'), publicKey)
denc = rsa.encrypt(expiry_date.encode('utf8'), publicKey)
fenc = rsa.encrypt(features.encode('utf8'), publicKey)
and written to a binary file:
licensefh = open("license.sfb", "wb")
licensefh.write(cenc)
licensefh.write(denc)
licensefh.write(fenc)
licensefh.close()
The three values cenc, denc and fenc are all of different lengths so when I read the file back:
licensefh = open("license.sfb", "rb")
encMessage = licensefh.read()
encMessage contains the entire file and I don't know how to get the three values back again.
I've tried using a separator between the values:
SEP = bytes(chr(0x02).encode('utf8'))
...
licensefh.write(cenc)
licensefh.write(SEP)
...
and then using encMessage.partition(SEP) or encMessage.split(SEP) but the data invariably contains the SEP value in it somewhere (I've tried a few different characters) so that didn't work.
I tried getting the length of the bytes objects cenc, denc and fenc, but this returned 256 for each value even though the contents of the variables are all different lengths.
My question is this. How do I write these three variable length values to a binary file and then separate them when I read them back again?
Here's an example of the 3 binary values:
b'tX\x10Fo\x89\x10~\x83Pok\xd1\xfb\xbe\x0e<a\xe5\x11md:\xe6\x84@\xfa\xf8\xe5\xeb\xf8\xdc{\xc0Z\xa0\xc0^\xc1\xd9\x820\xec\xec\xb0R\x99/\xa2l\x88\xa9\xa6g\xa3\x01m\xf9\x7f\x91\xb9\xe1\x80\xccs|\xb7_\xa9Fp\x11yvG\xdc\x02d\x8aK2\x92t\x0e\x1f\xca\x19\xbb&\xaf{\xc0y>\t|\x86\xab\x16.\xa5kZ"\xab6\xaaV\xf4w\x7f\xc5q\x07\xef\xa9\xa5\xa3\xf3 6\xdb\x03\x19S\xbd\x81\xf9\xc8\xc5\x90\x1e\x19\x86\xa4q\xe3?i\xc4\xac\t\xd5=3C\x9b#\xc3IuAN,\xeat\xc6\x96VFL\x1eFWZ\xa4\xd73\x92P@\x1d\xb9\x12\x15\xc9\xd4~\x8aWm^\xb8\x8b\x9d\x88\n)\xeb#\xe3\x93\xb1\\\xd6^\xe0\xce\xa2(\x05\xf5\xe6\x8b\xd1\x15\xd8v\xf0\xae\x90\xd8?\x01\r\x00\xf4\xa5\xadM|%\x98\xa9SR\xc6\xd0K\x9e&\xc3\xe0M\x81\x87\xdea\xcc\xd5\x9c\xcd\xfd1l\x1f\xb9?\xed\xd1\x95\xbc\x11\x85U9'
b'l\xd3S\xcc\x03\x9a\xf2\xfdr\xca\xbbA\x06\xfb\xd8\xbbWi\xdc\xb1\xf6&\x97T\x81Kl\r\x86\x9b\x95?\x94}\x8a\xd3\xa1V\x81\xd3]*B\x1f\x96`\xa3\xd1\xf2|B\x84?\xa0\ns\xb7\xcf\x18Y\x87\xcfR\x87!\x14\x81!\xf7\xf2\xe5x|=O\xe3\xba2\xf2!\x93\x0fT7\x0c~4\xa3\xe5\xb7\xf9wy\xb5\x12FM\x96\xd9\xfd\xedn\x9c\xacw\x1b\xc2\x17+\xb6\x05`\x10\xf8\xe4\x01\xde\xc7\xa2\xa0\x80\xd8\x15\xb1+<s\xc7\x19\x9c\x14\xb0\x1a"\x10\xbb\x0f\xe1\x05\x93\xd2?xX\xd9\x93\x8an\x8d\xcd\xbd!c\xd0,\xa45\xbai\xe3\xccx\x08\xaa,\xd1\xe5\'t\x91\xb8\xf2n$\x0c\xf9-\xb4\xc2\x07\x81\xe1\xe7\x8e\xb3\x98\x11\xf3\xa6\xd9wz\x9a3\xc9\x9c?z\xd8\xaa\x08}\xa2\x9c[\xf2\x9d\xe4\xcdb\xddl\xceV\x7f\xf1\x81\xb3\x88\x1e\x9c5?k\x0f\xc9\x86\x86&\xedV.\xa7\x8d\x13&V\xad\xca\xe5\x93\xfe\xa5\x94\xbc\xf5\xd1{Cl\xc0\x030\x92\x03\xc9'
b'#\xbdd7\xe9\xa0{\t\xb9\x87B\x9e\xf9\x97P^\xf3V\xb6\x93\x1f(J\x0b\xa3\xbf\xd8\x04\x86T\xa4\xca\xf3\xe8%\xddC\x11\xdb5\xff,\xf7\x13\xd7\xd2\xbc\xf3\x893\x83\xdcmJ\xc8p\xdf\x07V\x7fb\xeb\xa9\x8b\x0f\xca\xf9\x05\xfc\xdfS\x94b\x90\xcd\xfcn?/]\x11\xaf\xe606\xfb\\U59\xa0>\xbd\xd8\x1c\xa8\xca\x83\xf4C\x95v7\xc6\xe00\xe4,d_/\x83\xa0\xb9mO\x0e\xc4\x97J\x15\xf0\xca-\xa0\xafT\xe4\x82\x03\n\x14:\xa1\xdcL\x98\x9d,1\xfa\x10\xf4\xfd\xa0\x0b\xc7\x13!\xf7\xdb/\xda\x1a\x9df\x1cQ\xc0\x99H\x08\xa0c\x8f9/4\xc4\x05\xc6\x9eM\x8e\xe5V\xf8D\xc3\xfd\xad4\x94A\xb9[\x80\xb9\xcf\xe6\xd9\xb3M2\xd9N\xfbA\x18\x84/W\x9b\x92\xfe\xbb\xd6C\x85\xa3\xc6\xd2T\xd0\xb2\xb9\xf7R\xb4(s\xda\xbcX,9w\x17\x1c\xfb|\xa0\x87\xba\xca6>y\xba\\L4wc\x94\xe7$Y\x89\x07\x9b\xfe\x9b?{\x85'