openssl sha1 message digest not matching with NIST vector input? When I call openssl sha1 from the command line

 echo "00" | xxd -r -p | openssl dgst -sha1


the output I am receive is

(stdin)= 5ba93c9db0cff93f52b521d7420e43f6eda2784f


But the NIST Vector output is:

 MD = da39a3ee5e6b4b0d3255bfef95601890afd80709


Can anyone please explain this?
You read the testvector incorrectly.

I assume you are referring to the following part of the file SHA1ShortMsg.rsp of the FIPS 180-4 vectors: 

[L = 20]

Len = 0 
Msg = 00 
MD = da39a3ee5e6b4b0d3255bfef95601890afd80709


This test vector has length 0, so the specified hash is for an empty message and not for a single zero byte. This openssl command shows the correct result.


  $ echo -n ""|openssl dgst -sha1
  (stdin)= da39a3ee5e6b4b0d3255bfef95601890afd80709