Set SSL_OP_LEGACY_SERVER_CONNECT when peeking at servers #2354
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Our TLS Server Hello parser does not treat legacy servers specially, but
enabling legacy server support in OpenSSL allows OpenSSL to advance
enough in its Server Hello processing to provide our SslBump code with
the server certificate (that we then validate). Successful certificate
validation, in turn, may result in Squid splicing the connection, even
if OpenSSL detected other errors:
noteNegotiationError: hold TLS write on FD 15 despite
SQUID_TLS_ERR_CONNECT+TLS_LIB_ERR=2000068+TLS_IO_ERR=1
A spliced connection allows the TLS client to handle a legacy server the
way the client needs to handle it, without unwanted Squid meddling.
This PR was created with input and collaboration from The Measurement
Factory
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The earlier variation of these changes was tested in production. This master-based variation was lab-tested.
Eventually, we may decide to enable more TLS peeking workarounds here, but I think it is best to start with this minimal PR.
Ideally, we should probably remove OpenSSL as the peeking mechanism driver, so that Squid code can look at raw TLS server handshake bytes (something we already do!) without having to work around OpenSSL restrictions, but that is a much bigger long-term change (that may even become impossible as TLS protections advance).
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Any reason this is not also done for the "stare" mode? I would expect to see the same issues occuring for that. |
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Our TLS Server Hello parser does not treat legacy servers specially, but
enabling legacy server support in OpenSSL allows OpenSSL to advance
enough in its Server Hello processing to provide our SslBump code with
the server certificate (that we then validate). Successful certificate
validation, in turn, may result in Squid splicing the connection, even
if OpenSSL detected other errors:
noteNegotiationError: hold TLS write on FD 15 despite
SQUID_TLS_ERR_CONNECT+TLS_LIB_ERR=2000068+TLS_IO_ERR=1
A spliced connection allows the TLS client to handle a legacy server the
way the client needs to handle it, without unwanted Squid meddling.
This is a Measurement Factory project.
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Our TLS Server Hello parser does not treat legacy servers specially, but
enabling legacy server support in OpenSSL allows OpenSSL to advance
enough in its Server Hello processing to provide our SslBump code with
the server certificate (that we then validate). Successful certificate
validation, in turn, may result in Squid splicing the connection, even
if OpenSSL detected other errors:
noteNegotiationError: hold TLS write on FD 15 despite
SQUID_TLS_ERR_CONNECT+TLS_LIB_ERR=2000068+TLS_IO_ERR=1
A spliced connection allows the TLS client to handle a legacy server the
way the client needs to handle it, without unwanted Squid meddling.
This is a Measurement Factory project.
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…#2354) Our TLS Server Hello parser does not treat legacy servers specially, but enabling legacy server support in OpenSSL allows OpenSSL to advance enough in its Server Hello processing to provide our SslBump code with the server certificate (that we then validate). Successful certificate validation, in turn, may result in Squid splicing the connection, even if OpenSSL detected other errors: noteNegotiationError: hold TLS write on FD 15 despite SQUID_TLS_ERR_CONNECT+TLS_LIB_ERR=2000068+TLS_IO_ERR=1 A spliced connection allows the TLS client to handle a legacy server the way the client needs to handle it, without unwanted Squid meddling. This is a Measurement Factory project.
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Our TLS Server Hello parser does not treat legacy servers specially, but
enabling legacy server support in OpenSSL allows OpenSSL to advance
enough in its Server Hello processing to provide our SslBump code with
the server certificate (that we then validate). Successful certificate
validation, in turn, may result in Squid splicing the connection, even
if OpenSSL detected other errors:
noteNegotiationError: hold TLS write on FD 15 despite
SQUID_TLS_ERR_CONNECT+TLS_LIB_ERR=2000068+TLS_IO_ERR=1
A spliced connection allows the TLS client to handle a legacy server the
way the client needs to handle it, without unwanted Squid meddling.
This is a Measurement Factory project.
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Our TLS Server Hello parser does not treat legacy servers specially, but
enabling legacy server support in OpenSSL allows OpenSSL to advance
enough in its Server Hello processing to provide our SslBump code with
the server certificate (that we then validate). Successful certificate
validation, in turn, may result in Squid splicing the connection, even
if OpenSSL detected other errors:
A spliced connection allows the TLS client to handle a legacy server the
way the client needs to handle it, without unwanted Squid meddling.
This is a Measurement Factory project.