Control; forwarded -1 https://gitlab.com/gnutls/gnutls/issues/259
On 2017-08-24 Thomas Klute <thomas2.kl...@uni-dortmund.de> wrote: > Package: libgnutls30 > Version: 3.5.14-3 > Severity: normal > If the %SAFE_RENEGOTIATION flag is enabled in the priorities string of > a GnuTLS server, Client Hellos from OpenSSL clients attempting session > resumption are rejected with a "safe renegotiation failed" error, even > though the client does support safe renegotiation. Note that the > handshake works as expected if the session cache entry or ticket has > expired (without resumption, of course), so the bug only affects > otherwise successful resumption. > I have initially observed this bug using mod_gnutls (package > libapache2-mod-gnutls), but it is fully reproducible using only the > GnuTLS and OpenSSL command line tools. The logs below have been > produced by running a gnutls-serv server and connecting using openssl > s_client and gnutls-cli (separated by three pings for clarity in > client logs and packet capture), both set to immediately disconnect > and resume after the initial handshake. The GnuTLS client can resume > the TLS session as expected, while the OpenSSL client is rejected. > Commands to reproduce: > (server)$ gnutls-serv --priority="NORMAL:%SAFE_RENEGOTIATION" > --x509keyfile=server/secret.key --x509certfile=server/x509-chain.pem -p 4433 > (OpenSSL client)$ openssl s_client -connect localhost:4433 -reconnect > (GnuTLS client)$ gnutls-cli -p 4433 --x509cafile=authority/x509.pem > --resume localhost > A packet capture taken during this process shows a difference in how > GnuTLS and OpenSSL signal safe renegotiation support in the Client > Hello: GnuTLS sends the renegotiation_info extension, OpenSSL includes > the TLS_EMPTY_RENEGOTIATION_INFO_SCSV in the list of cipher suites. > According to RFC 5746 both are equally valid for both full and > session-resumption handshakes, but the GnuTLS server appears to ignore > the SCSV during session resumption. [...] Hello, thank you, I have forwarded the issue upstream after verifying that it still applies to 3.6.0. cu Andreas -- `What a good friend you are to him, Dr. Maturin. His other friends are so grateful to you.' `I sew his ears on from time to time, sure'
