On Wed, Nov 09, 2005, Antonio Ruiz Martnez wrote: > > The question is that I have received a PKCS#1 that claims to be > compliant with PKCS#1 v2.1. With the openssl, with rsautl, I'm getting > an error telling me that the object is too long.... > Then I have decrypted the information received and I have seen that its > length it is 20 bytes, that is, a sha-1 digest. In PKCS#1 v1.5, it is > not possible because we have to used the DigestInfo structure and that > it is the reason because I'm getting the error with rsautl. > Then, I have been reading the PKCS#1 v2.1 standard and the funtions > RSASSA-PSS and RSASSA-PKCS1-V1_5 have and encoding function but RSASP1, > RSAVP1 not. After reading it I'm not sure it is possible to put directly > the hash and openssl is not fully compliant or I don't understand very > well the standard. >
Well there is support for PSS and OAEP from PKCS#1 v2.1 but it isn't fully integrated into the API. I'm assuming you've used the -verify option to rsautl and no other options to change padding mode. If it uses PSS and/or OAEP then you wouln't get that error instead you'd get a padding check failure. What I suspect you have is a non-standard PKCS#1 v1.5 which doesn't use the expected DigestInfo but uses the raw digest instead. If you want to confirm this you can use the -raw option and -hexdump. If it has loads of 0XFF characters that will show its PKCS#1 v1.5. Steve. -- Dr Stephen N. Henson. Email, S/MIME and PGP keys: see homepage OpenSSL project core developer and freelance consultant. Funding needed! Details on homepage. Homepage: http://www.drh-consultancy.demon.co.uk ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List openssl-users@openssl.org Automated List Manager [EMAIL PROTECTED]
