On 18 Sep 1995, Jeff Weinstein wrote:
The implementation guide recommends using rc2-cbc 40-bit for content encryption when there is no way to determine the capabilities of the recipient. When you do know what the recipient can do, it recommends using RC2-CBC with a longer key or DES-CBC.
Hmm.... notice the use of a non public cipher as the base cipher.... what a shame.... A note for non-USA people, the next version of SSLeay will include the full fuctionality of RSAref/RSAeuro and I should soon have the PKCS-7 stuff finished in the next release after that. I've almost finished the documentation of the encryption/RSA type routines. The encryption/open/seal routines supporting any cipher that conforms with a specified Cipher API. It will be shipping with examples of des-ecb, des-cfb, des-cbc, des-ede2, des-ede3, idea-ecb, idea-cfb, idea-cbc and rc4-128. If people could send me the official Object identifiers for these ciphers, I'll be able to support them in PKCS-7, otherwise they will only be supported in PEM mode. eg, rc4 is '1 2 840 113549 3 4' but I don't even know what des in cbc mode is. I lack documentation. If any-one can email SMIME/PKCS-7 stuff that is encrypted/sealed, I'll be able to extract the object identifiers.
For key encryption support for RSA with key sizes of 512 to 1024 is required, and support for 2048 bit keys is recommended. A minimum key size of 768 bits is recommended for US users.
Again, SSLeay has no restrictions, 4096 bits anyone :-) eric (who is just lacking documentation :-( -- Eric Young | Signature removed since it was generating AARNet: eay@mincom.oz.au | more followups than the message contents :-)