in reply to Re^2: convert hexadecimal value to encrypted string
in thread convert hexadecimal value to encrypted string

You'll need to send the data back to the encryption server and have it decrypt it.
  • Comment on Re^3: convert hexadecimal value to encrypted string

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Re^4: convert hexadecimal value to encrypted string
by linuxfan (Beadle) on Dec 11, 2004 at 03:08 UTC
    That is what I am trying to do. In order to send the data back to the encryption server, I need to read it from the database first, create a request and then send it to the server.

    The problem I am seeing right now is that the data I have extracted from the database is in Hex format like the string I posted earlier (639D879F224CA2A1BA73CC4884DBD362) and the server does not recognize this as a valid cipher text (sending a request with this string results in error). That is the reason I wish to convert the hex string to a "string format" using pack/unpack so that I can send the "correct" ciphertext to the server. IMHO, a conversion of the hex number to a regular string should work.

    Thanks!

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      Aha. I see. When I tried to pack your string I noticed that perl thought that it was being given unicode data and treated it accordingly. Instead of plain pack "H*", $str, try do { use bytes; pack "H*", $str }. See bytes for more on forcing perl to not try to interpret it as unicode.

      Oh further drat. when I wrote that I saw things like \323 and thought "aha! a value over 255, obviously unicode." Unfortunately for me, that was an octal number and this whole digression on unicode is entirely unrelated. So, show us the value produced by the encryption server and the value fetched from the database. As-is, there isn't anything that you're doing wrong.

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        Here's how the database stores the encrypted string:

        639D879F224CA2A1BA73CC4884DBD362

        I know the plaintext string that corresponds to the above cipher text. It is

        8235

        I can send an encrypt request to the server with the above string, and obtain the encrypted data. Since it contains unprintable characters, I am giving you the Base64 encoded the value of the encrypted string. You can obtain the encrypted string by simply running 

         perl -MMIME::Base64 -e 'print decode_base64($str) . "\n";'

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        to get the encrypted string.

        The Base 64 encoded string of the encrypted string is

        vY+TqCu5/Wdg6O+ilDqHVQ==

        As mentioned earlier I want to verify that the encryption/decryption process works ok. So the hex string at the beginning of this post should be equal to the Base64 decoded string vY+TqCu5/Wdg6O+ilDqHVQ==

        Thanks a lot for your time!

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