retitle 481132 libgnutls26: should use EDH only if server cert supports it kthxbye
On Wed, May 14, 2008 at 05:42:45PM +0200, Simon Josefsson wrote:
Hi! Thanks for the report. Unfortunately, I think your certificate is
incorrect, you'll need the digitalSignature Key Usage Bit as well.
RFC 2246 and 4346:
DHE_RSA RSA public key that can be used for
signing.
...
All certificate profiles and key and cryptographic formats are
defined by the IETF PKIX working group [PKIX]. When a key usage
extension is present, the digitalSignature bit MUST be set for the
key to be eligible for signing, as described above, and the
keyEncipherment bit MUST be present to allow encryption, as described
above. The keyAgreement bit must be set on Diffie-Hellman
certificates.
I've figured out what the problem is. If I don't disable kEDH in sendmail's config, it fails, but if I do disable it, it works. My IMAP server also has kEDH disabled, and so it also works. Apparently OpenSSL doesn't try to use kEDH, and so it doesn't fail. GnuTLS should implement the same behavior; if a certificate doesn't support digitalSignature, then GnuTLS shouldn't try to use it in that way. RSA key exchange is fine for what I need. -- brian m. carlson / brian with sandals: Houston, Texas, US +1 713 440 7475 | http://crustytoothpaste.ath.cx/~bmc | My opinion only troff on top of XML: http://crustytoothpaste.ath.cx/~bmc/code/thwack OpenPGP: RSA v4 4096b 88AC E9B2 9196 305B A994 7552 F1BA 225C 0223 B187
signature.asc
Description: Digital signature
