On Fri May 16 09:22:55 2014, [email protected] wrote: > Hi, > > The man page for the smime utility documents this about the symmetric > cipher selection: > > If not specified 40 bit RC2 is used. Only used with -encrypt. > > This policy is implemented at line 545 of apps/smime.c as of openssl-1.0.1g. > > This algorithmic default is unreasonable today.
Agreed. This was unchanged from the days of "export grade encryption" when RC2-40 was all that could be guaranteed. > > I would suggest changing the default to aes-256-cbc (to minimize > compatibility problems) and asking somebody knowledgeable to look > at what smime is doing with IVs and MACs to ensure that it's sane. > (I'm sure there are safer block cipher modes than CBC; they just might > be more controversial as defaults for backwards compatibility with > older OpenSSLs.) > The S/MIME utility uses S/MIME v2 (PKCS#7) which are both rather ancient and S/MIME v3 (CMS) is preferred. CBC mode is all that is supported for S/MIME. Traditionally there were two algorithms supported for S/MIME v2 40 bit RC2 and triple DES. For maximum compatibility I'll change the default to triple DES. Steve. -- Dr Stephen N. Henson. OpenSSL project core developer. Commercial tech support now available see: http://www.openssl.org ______________________________________________________________________ OpenSSL Project http://www.openssl.org Development Mailing List [email protected] Automated List Manager [email protected]
