md5 - Question of Vendor ID in RFC2408 (ISAKMP)

Question

I am reading the RFC2408(https://tools.ietf.org/html/rfc2408). I have a question about "Vendor ID section" at page 43(https://tools.ietf.org/html/rfc2408#page-43). The document says,

For instance: "Example Company IPsec. Version 97.1" (not including the quotes) has MD5 hash: 48544f9b1fe662af98b9b39e50c01a5a, when using MD5file.

But I use many md5 tools like 'md5sum' command or online tools, that they all got result "3245b3577c9e4f751675322f259ff016".

I tried the command on Linux:

echo -n "Example Company IPsec.  Version 97.1" | md5sum
3245b3577c9e4f751675322f259ff016  -

I got different result, I believe the RFC ducument would not be wrong, So I wonder where am I wrong, or do I miss some thing?

question from:https://stackoverflow.com/questions/65878387/question-of-vendor-id-in-rfc2408-isakmp

Answer 1

The MD5 hash is actually of the value:

Example Company IPsec. Version 97.1

That is, only one space separates IPsec. and Version and there is a newline character at the end.

So you get this with:

echo "Example Company IPsec. Version 97.1" | md5sum
48544f9b1fe662af98b9b39e50c01a5a  -

Please note two things:

1. While th vendor ID values must be unique, they are otherwise completely arbitrary. This is just an example of how one might be generated. So its correctness is not really relevant.
2. ISAKMP/IKEv1 has been obsolete for years, please refer to IKEv2 instead (RFC 7296).