I am writing a C++ application using Openssl library to sign the outgoing messages and verify it on the other end. Everything works perfectly but still there is a strange point which I would like to discuss it and your help would be really appreciated in that case. I noticed that using private keys with the same length (256) still the ECDSA signature size is different sometimes. For example once it is 70 Bytes and next time is 72 Bytes using another key but with the same size. As far as I know the ECDSA_sig structure uses some sorta padding for the ASN.1 encoding purposes but I am not sure if it leads to different signature sizes or I have to investigate my code for a problem (Which I don't believe that is the case since the sign/verification process of my application has been tested successfully.)
Do you have any idea why the size of ECDSA_sig structure is different sometimes even though I am using the same private key length? Regards /Nasser -- View this message in context: http://openssl.6102.n7.nabble.com/Concerning-the-ECDSA-sig-size-tp46553.html Sent from the OpenSSL - User mailing list archive at Nabble.com. ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List openssl-users@openssl.org Automated List Manager majord...@openssl.org
