Verifying and Getting the contents of a P7S signed SMIME file

P7S Signatures are fairly common but it is really hard to find the OpenSSL one liner that just gets you the content. So rather than doing something evil with dd (the signature is 171 bytes and the header 3 bytes) lets do it properly with OpenSSL.
Verify and get the content of your signed file

openssl smime -verify -noverify -in file.p7s -inform DER -out file


Not hard at all