Dear squid developers and users, after upgrading our squid 2.7 setup to squid 3.3.8 we experience problems with a custom Java applet connecting to a HTTPS server. Both squid 2.7 and squid 3.3.8 are installed on the same machine and use the same configuration except the 'http_port' directive. (squid 3.3.8 uses a copy of the squid 2.7 config file with configuration options adapted to the new squid 3.x syntax where necessary). With squid 2.7 *all* HTTP CONNECT requests from the applet (the applet issues a bunch of HTTPS requests to a single server) work just fine. With squid 3.3.8 however, the applet issues a couple of HTTPS requests and then hangs. Switching the Java proxy settings to the squid 2.7 port and starting the applet again solves the problem. The only apparent difference between squid 2.7 and squid 3.3.8 from clients perspective seems to be HTTP/1.0 vs. HTTP/1.1 in the proxy requests: connect using squid 2.7: CONNECT some.host.name:443 HTTP/1.1 User-Agent: Java/1.7.0_17 Host: some.host.name Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2 Proxy-Connection: keep-alive HTTP/1.0 200 Connection established connect using squid 3.3.8: CONNECT some.host.name:443 HTTP/1.1 User-Agent: Java/1.7.0_17 Host: some.host.name Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2 Proxy-Connection: keep-alive HTTP/1.1 200 Connection established Looking at the packet dumps taken from the client and internet facing NICs on the proxy there are no (at least according to my limited knowledge) apparent errors. So my question would be if there were any changes between the listed squid versions in handling HTTP CONNECT requests that might cause the above mentioned issue. Of course I will supply the packet dumps and complete configuration if needed. squid 2.7 -v: Squid Cache: Version 2.7.STABLE7 configure options: '--prefix=/usr' '--exec_prefix=/usr' '--bindir=/usr/sbin' '--sbindir=/usr/sbin' '--libexecdir=/usr/lib/squid' '--sysconfdir=/etc/squid' '--localstatedir=/var/spool/squid' '--datadir=/usr/share/squid' '--enable-async-io' '--with-pthreads' '--enable-storeio=ufs,aufs,coss,diskd,null' '--enable-linux-netfilter' '--enable-arp-acl' '--enable-epoll' '--enable-removal-policies=lru,heap' '--enable-snmp' '--enable-delay-pools' '--enable-htcp' '--enable-cache-digests' '--enable-underscores' '--enable-referer-log' '--enable-useragent-log' '--enable-auth=basic,digest,ntlm,negotiate' '--enable-negotiate-auth-helpers=squid_kerb_auth' '--enable-carp' '--enable-follow-x-forwarded-for' '--with-large-files' '--with-maxfd=65536' 'i386-debian-linux' 'build_alias=i386-debian-linux' 'host_alias=i386-debian-linux' 'target_alias=i386-debian-linux' 'CFLAGS=-Wall -g -O2' 'LDFLAGS=-Wl,-Bsymbolic-functions' 'CPPFLAGS=' squid 3.3.8 -v: Squid Cache: Version 3.3.8 configure options: '--build=i486-linux-gnu' '--prefix=/usr' '--includedir=${prefix}/include' '--mandir=${prefix}/share/man' '--infodir=${prefix}/share/info' '--sysconfdir=/etc' '--localstatedir=/var' '--libexecdir=${prefix}/lib/squid3' '--disable-maintainer-mode' '--disable-dependency-tracking' '--disable-silent-rules' '--srcdir=.' '--datadir=/usr/share/squid3' '--sysconfdir=/etc/squid3' '--mandir=/usr/share/man' '--enable-inline' '--enable-async-io=8' '--enable-storeio=ufs,aufs,diskd,rock' '--enable-removal-policies=lru,heap' '--enable-delay-pools' '--enable-cache-digests' '--enable-underscores' '--enable-icap-client' '--enable-follow-x-forwarded-for' '--enable-auth-basic=DB,fake,getpwnam,LDAP,MSNT,MSNT-multi-domain,NCSA,NIS,PAM,POP3,RADIUS,SASL,SMB' '--enable-auth-digest=file,LDAP' '--enable-auth-negotiate=kerberos,wrapper' '--enable-auth-ntlm=fake,smb_lm' '--enable-external-acl-helpers=file_userip,kerberos_ldap_group,LDAP_group,session,SQL_session,unix_group,wbinfo_group' '--enable-url-rewrite-helpers=fake' '--enable-eui' '--enable-esi' '--enable-zph-qos' '--disable-translation' '--with-swapdir=/var/spool/squid3' '--with-logdir=/var/log/squid3' '--with-pidfile=/var/run/squid3.pid' '--with-filedescriptors=65536' '--with-large-files' '--with-default-user=proxy' '--enable-epoll' '--enable-linux-netfilter' 'build_alias=i486-linux-gnu' 'CFLAGS=-g -O2 -g -Wall -O2' 'LDFLAGS=-Wl,-Bsymbolic-functions' 'CPPFLAGS=' 'CXXFLAGS=-g -O2 -g -Wall -O2' --enable-ltdl-convenience # uname -a Linux proxymgmt02 2.6.32-47-generic-pae #109-Ubuntu SMP Tue May 7 02:19:47 UTC 2013 i686 GNU/Linux Best regards, Robert