MD5 and ToHex Calculations

[lgrupido]

I am trying to talk to a secure online system. As part of the security, I need to produce a line of text as a security key. the key is composed of several data points. The points must be put through Md5 and then converted to hex.

But my information is not coming up the same as what the system is expecting.

I am using:

*to_hex(Md5(variablename))

As a test, I am just trying it with a value of 10. In interactive mode, we get:

? md5("10")
= "d3d9446802a44259755d38e6d163e820"

? *to_hex(md5("10"))
= "6433643934343638303261343432353937353564333865366431363365383230"

But the value I am supposed to be getting is:

d41d8cd98f00b204e9800998ecf8427e

I don't understand why I am getting a number with the to_hex command that does not look even remotely hexadecimal.

[Lenny Forziati]

Re: MD5 and ToHex Calculations

*to_hex() converts each character of the string to the hexadecimal value of that character. The output you are seeing is correct and matches the output from the conversion when done by the .Net Framework:

Encoding = new System::Text::ASCIIEncoding()
ba = Encoding.GetBytes(md5("10"))
hexString = System::BitConverter::ToString(ba)
?strtran(hexString,"-","")
= "6433643934343638303261343432353937353564333865366431363365383230"

Your string d41d8cd98f00b204e9800998ecf8427e looks like a different md5 value but I don't see how it is being calculated. Do you have more info on what is expected or some sample code to achieve it an any other language?

[lgrupido]

Re: MD5 and ToHex Calculations

I am trying to create what is called a tamper proof seal. The full definition from their documentation is below.

But they have a test form where you can type in any number and they will show you what the tps would look like. Right now, I am just trying to get a simple "10" to match.


This is their PHP example:

return bin2hex( md5($hashstr, true) );


## Notes on the TAMPER_PROOF_SEAL:
The TAMPER_PROOF_SEAL is an MD5 checksum of your SECRET KEY and a few transaction parameters. We use an
MD5 simply to avoid sending the SECRET KEY over the wire, and we include some of the transaction parameters
simply as a convenient source of "random" padding. The TAMPER_PROOF_SEAL is currently calculated as follows:

md5(SECRET KEY + ACCOUNT_ID + TRANS_TYPE + AMOUNT + MASTER_ID + NAME1 + PAYMENT_ACCOUNT)
where '+' indicates string concantenation and undefined fields are concantenated as '' (null string)

Your md5 function must return a hex-encoded md5 checksum. If you do not know your SECRET KEY, please contact
Bluepay support.

[lgrupido]

Re: MD5 and ToHex Calculations

As a further FYI: I am trying to integrate with the BLUEPAY API to process credit card transactions.

https://www.bluepay.com/developers/f...documentation/

[Davidk]

Re: MD5 and ToHex Calculations

Lenny is certainly the guy you want on this... but going to stick my nose in for just a sec. Their PHP example of md5 allows a second parameter "true" or "false". When true is set md5 returns binary.

[Lenny Forziati]

Re: MD5 and ToHex Calculations

Larry,

PHP's bintohex() function is for converting binary data into a hexidecimal string. There is no need for this step because Xbasic's md5() function is already giving you the hexidecimal string.

d3d9446802a44259755d38e6d163e820 is the correct md5 value for 10, which you can confirm any many online sources: https://www.google.com/webhp?sourcei...d5%20generator

Because of the "tamper proof seal", an md5 of just your 10 is not what's being used though and why the md5 values do not match.

[lgrupido]

Re: MD5 and ToHex Calculations

So what I think is happening - What I need to do is convert to Md5 as binary, and then convert the binary string to Hex, but Alpha is taking the Md5 straight to Hex, which is creating a hex value different from what Blue Pay is expecting.

[lgrupido]

Re: MD5 and ToHex Calculations

Scratch that last post - I see what you are saying and I think I can figure it out from here.

If not I will shout back.

I wasn't comparing apples to apples and I was using the test form wrong. I had help in misleading myself from BluePay tech support, but I think I see now.

I can just use the Alpha Md5 directly and it looks like it will give me the correct answer.

Thank you.