From 82b7f378b6907ab315a6e50322d2a0a8794a0aa9 Mon Sep 17 00:00:00 2001
From: bentley <>
Date: Sun, 12 Oct 2014 09:33:04 +0000
Subject: Convert libssl manpages from pod to mdoc(7).

libcrypto has not been started yet.

ok schwarze@ miod@
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 src/lib/libssl/doc/SSL_CTX_set_options.3 | 384 +++++++++++++++++++++++++++++++
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 create mode 100644 src/lib/libssl/doc/SSL_CTX_set_options.3

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diff --git a/src/lib/libssl/doc/SSL_CTX_set_options.3 b/src/lib/libssl/doc/SSL_CTX_set_options.3
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@@ -0,0 +1,384 @@
+.Dd $Mdocdate: October 12 2014 $
+.Dt SSL_CTX_SET_OPTIONS 3
+.Os
+.Sh NAME
+.Nm SSL_CTX_set_options ,
+.Nm SSL_set_options ,
+.Nm SSL_CTX_clear_options ,
+.Nm SSL_clear_options ,
+.Nm SSL_CTX_get_options ,
+.Nm SSL_get_options ,
+.Nm SSL_get_secure_renegotiation_support
+.Nd manipulate SSL options
+.Sh SYNOPSIS
+.In openssl/ssl.h
+.Ft long
+.Fn SSL_CTX_set_options "SSL_CTX *ctx" "long options"
+.Ft long
+.Fn SSL_set_options "SSL *ssl" "long options"
+.Ft long
+.Fn SSL_CTX_clear_options "SSL_CTX *ctx" "long options"
+.Ft long
+.Fn SSL_clear_options "SSL *ssl" "long options"
+.Ft long
+.Fn SSL_CTX_get_options "SSL_CTX *ctx"
+.Ft long
+.Fn SSL_get_options "SSL *ssl"
+.Ft long
+.Fn SSL_get_secure_renegotiation_support "SSL *ssl"
+.Sh DESCRIPTION
+Note: all these functions are implemented using macros.
+.Pp
+.Fn SSL_CTX_set_options
+adds the options set via bitmask in
+.Fa options
+to
+.Fa ctx .
+Options already set before are not cleared!
+.Pp
+.Fn SSL_set_options
+adds the options set via bitmask in
+.Fa options
+to
+.Fa ssl .
+Options already set before are not cleared!
+.Pp
+.Fn SSL_CTX_clear_options
+clears the options set via bitmask in
+.Fa options
+to
+.Fa ctx .
+.Pp
+.Fn SSL_clear_options
+clears the options set via bitmask in
+.Fa options
+to
+.Fa ssl .
+.Pp
+.Fn SSL_CTX_get_options
+returns the options set for
+.Fa ctx .
+.Pp
+.Fn SSL_get_options
+returns the options set for
+.Fa ssl .
+.Pp
+.Fn SSL_get_secure_renegotiation_support
+indicates whether the peer supports secure renegotiation.
+.Sh NOTES
+The behaviour of the SSL library can be changed by setting several options.
+The options are coded as bitmasks and can be combined by a bitwise OR
+operation (|).
+.Pp
+.Fn SSL_CTX_set_options
+and
+.Fn SSL_set_options
+affect the (external) protocol behaviour of the SSL library.
+The (internal) behaviour of the API can be changed by using the similar
+.Xr SSL_CTX_set_mode 3
+and
+.Xr SSL_set_mode 3
+functions.
+.Pp
+During a handshake, the option settings of the SSL object are used.
+When a new SSL object is created from a context using
+.Xr SSL_new 3 ,
+the current option setting is copied.
+Changes to
+.Fa ctx
+do not affect already created
+.Vt SSL
+objects.
+.Fn SSL_clear
+does not affect the settings.
+.Pp
+The following
+.Em bug workaround
+options are available:
+.Bl -tag -width Ds
+.It Dv SSL_OP_MICROSOFT_SESS_ID_BUG
+.Lk www.microsoft.com
+\(en when talking SSLv2, if session-id reuse is performed,
+the session-id passed back in the server-finished message is different from the
+one decided upon.
+.It Dv SSL_OP_NETSCAPE_CHALLENGE_BUG
+Netscape-Commerce/1.12, when talking SSLv2, accepts a 32 byte challenge but
+then appears to only use 16 bytes when generating the encryption keys.
+Using 16 bytes is ok but it should be ok to use 32.
+According to the SSLv3 spec, one should use 32 bytes for the challenge when
+operating in SSLv2/v3 compatibility mode, but as mentioned above, this breaks
+this server so 16 bytes is the way to go.
+.It Dv SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG
+As of OpenSSL 0.9.8q and 1.0.0c, this option has no effect.
+.It Dv SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG
+\&...
+.It Dv SSL_OP_MICROSOFT_BIG_SSLV3_BUFFER
+\&...
+.It Dv SSL_OP_SAFARI_ECDHE_ECDSA_BUG
+Don't prefer ECDHE-ECDSA ciphers when the client appears to be Safari on OS X.
+OS X 10.8..10.8.3 has broken support for ECDHE-ECDSA ciphers.
+.It Dv SSL_OP_SSLEAY_080_CLIENT_DH_BUG
+\&...
+.It Dv SSL_OP_TLS_D5_BUG
+\&...
+.It Dv SSL_OP_TLS_BLOCK_PADDING_BUG
+\&...
+.It Dv SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS
+Disables a countermeasure against a SSL 3.0/TLS 1.0 protocol vulnerability
+affecting CBC ciphers, which cannot be handled by some broken SSL
+implementations.
+This option has no effect for connections using other ciphers.
+.It Dv SSL_OP_TLSEXT_PADDING
+Adds a padding extension to ensure the ClientHello size is never between 256
+and 511 bytes in length.
+This is needed as a workaround for some implementations.
+.It Dv SSL_OP_ALL
+All of the above bug workarounds.
+.El
+.Pp
+It is usually safe to use
+.Dv SSL_OP_ALL
+to enable the bug workaround options if compatibility with somewhat broken
+implementations is desired.
+.Pp
+The following
+.Em modifying
+options are available:
+.Bl -tag -width Ds
+.It Dv SSL_OP_TLS_ROLLBACK_BUG
+Disable version rollback attack detection.
+.Pp
+During the client key exchange, the client must send the same information
+about acceptable SSL/TLS protocol levels as during the first hello.
+Some clients violate this rule by adapting to the server's answer.
+(Example: the client sends a SSLv2 hello and accepts up to SSLv3.1=TLSv1,
+the server only understands up to SSLv3.
+In this case the client must still use the same SSLv3.1=TLSv1 announcement.
+Some clients step down to SSLv3 with respect to the server's answer and violate
+the version rollback protection.)
+.It Dv SSL_OP_SINGLE_DH_USE
+Always create a new key when using temporary/ephemeral DH parameters
+(see
+.Xr SSL_CTX_set_tmp_dh_callback 3 ) .
+This option must be used to prevent small subgroup attacks, when the DH
+parameters were not generated using
+.Dq strong
+primes (e.g., when using DSA-parameters, see
+.Xr dhparam 1 ) .
+If
+.Dq strong
+primes were used, it is not strictly necessary to generate a new DH key during
+each handshake but it is also recommended.
+.Dv SSL_OP_SINGLE_DH_USE
+should therefore be enabled whenever temporary/ephemeral DH parameters are used.
+.It SSL_OP_EPHEMERAL_RSA
+Always use ephemeral (temporary) RSA key when doing RSA operations (see
+.Xr SSL_CTX_set_tmp_rsa_callback 3 ) .
+According to the specifications, this is only done when a RSA key can only be
+used for signature operations (namely under export ciphers with restricted RSA
+keylength).
+By setting this option, ephemeral RSA keys are always used.
+This option breaks compatibility with the SSL/TLS specifications and may lead
+to interoperability problems with clients and should therefore never be used.
+Ciphers with EDH (ephemeral Diffie-Hellman) key exchange should be used instead.
+.It Dv SSL_OP_CIPHER_SERVER_PREFERENCE
+When choosing a cipher, use the server's preferences instead of the client
+preferences.
+When not set, the SSL server will always follow the client's preferences.
+When set, the SSLv3/TLSv1 server will choose following its own preferences.
+Because of the different protocol, for SSLv2 the server will send its list of
+preferences to the client and the client chooses.
+.It Dv SSL_OP_NETSCAPE_CA_DN_BUG
+If we accept a netscape connection, demand a client cert, have a
+non-self-signed CA which does not have its CA in netscape, and the browser has
+a cert, it will crash/hang.
+Works for 3.x and 4.xbeta
+.It Dv SSL_OP_NETSCAPE_DEMO_CIPHER_CHANGE_BUG
+\&...
+.It Dv SSL_OP_NO_SSLv2
+As of
+.Ox 5.6 ,
+this option has no effect as SSLv2 support has been removed.
+In previous versions it disabled use of the SSLv2 protocol.
+.It Dv SSL_OP_NO_SSLv3
+Do not use the SSLv3 protocol.
+.It Dv SSL_OP_NO_TLSv1
+Do not use the TLSv1.0 protocol.
+.It Dv SSL_OP_NO_TLSv1_1
+Do not use the TLSv1.1 protocol.
+.It Dv SSL_OP_NO_TLSv1_2
+Do not use the TLSv1.2 protocol.
+.It Dv SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
+When performing renegotiation as a server, always start a new session (i.e.,
+session resumption requests are only accepted in the initial handshake).
+This option is not needed for clients.
+.It Dv SSL_OP_NO_TICKET
+Normally clients and servers will, where possible, transparently make use of
+RFC4507bis tickets for stateless session resumption.
+.Pp
+If this option is set this functionality is disabled and tickets will not be
+used by clients or servers.
+.It Dv SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
+As of
+.Ox 5.6 ,
+this option has no effect.
+In previous versions it allowed legacy insecure renegotiation between OpenSSL
+and unpatched clients or servers.
+See the
+.Sx SECURE RENEGOTIATION
+section for more details.
+.It Dv SSL_OP_LEGACY_SERVER_CONNECT
+Allow legacy insecure renegotiation between OpenSSL and unpatched servers
+.Em only :
+this option is currently set by default.
+See the
+.Sx SECURE RENEGOTIATION
+section for more details.
+.El
+.Sh SECURE RENEGOTIATION
+OpenSSL 0.9.8m and later always attempts to use secure renegotiation as
+described in RFC5746.
+This counters the prefix attack described in CVE-2009-3555 and elsewhere.
+.Pp
+The deprecated and highly broken SSLv2 protocol does not support renegotiation
+at all; its use is
+.Em strongly
+discouraged.
+.Pp
+This attack has far-reaching consequences which application writers should be
+aware of.
+In the description below an implementation supporting secure renegotiation is
+referred to as
+.Dq patched .
+A server not supporting secure
+renegotiation is referred to as
+.Dq unpatched .
+.Pp
+The following sections describe the operations permitted by OpenSSL's secure
+renegotiation implementation.
+.Ss Patched client and server
+Connections and renegotiation are always permitted by OpenSSL implementations.
+.Ss Unpatched client and patched OpenSSL server
+The initial connection succeeds but client renegotiation is denied by the
+server with a
+.Em no_renegotiation
+warning alert if TLS v1.0 is used or a fatal
+.Em handshake_failure
+alert in SSL v3.0.
+.Pp
+If the patched OpenSSL server attempts to renegotiate a fatal
+.Em handshake_failure
+alert is sent.
+This is because the server code may be unaware of the unpatched nature of the
+client.
+.Pp
+.Em N.B.:
+a bug in OpenSSL clients earlier than 0.9.8m (all of which are unpatched) will
+result in the connection hanging if it receives a
+.Em no_renegotiation
+alert.
+OpenSSL versions 0.9.8m and later will regard a
+.Em no_renegotiation
+alert as fatal and respond with a fatal
+.Em handshake_failure
+alert.
+This is because the OpenSSL API currently has no provision to indicate to an
+application that a renegotiation attempt was refused.
+.Ss Patched OpenSSL client and unpatched server
+If the option
+.Dv SSL_OP_LEGACY_SERVER_CONNECT
+is set then initial connections and renegotiation between patched OpenSSL
+clients and unpatched servers succeeds.
+If neither option is set then initial connections to unpatched servers will
+fail.
+.Pp
+The option
+.Dv SSL_OP_LEGACY_SERVER_CONNECT
+is currently set by default even though it has security implications:
+otherwise it would be impossible to connect to unpatched servers (i.e., all of
+them initially) and this is clearly not acceptable.
+Renegotiation is permitted because this does not add any additional security
+issues: during an attack clients do not see any renegotiations anyway.
+.Pp
+As more servers become patched the option
+.Dv SSL_OP_LEGACY_SERVER_CONNECT
+will
+.Em not
+be set by default in a future version of OpenSSL.
+.Pp
+OpenSSL client applications wishing to ensure they can connect to unpatched
+servers should always
+.Em set
+.Dv SSL_OP_LEGACY_SERVER_CONNECT
+.Pp
+OpenSSL client applications that want to ensure they can
+.Em not
+connect to unpatched servers (and thus avoid any security issues) should always
+.Em clear
+.Dv SSL_OP_LEGACY_SERVER_CONNECT
+using
+.Fn SSL_CTX_clear_options
+or
+.Fn SSL_clear_options .
+.Sh RETURN VALUES
+.Fn SSL_CTX_set_options
+and
+.Fn SSL_set_options
+return the new options bitmask after adding
+.Fa options .
+.Pp
+.Fn SSL_CTX_clear_options
+and
+.Fn SSL_clear_options
+return the new options bitmask after clearing
+.Fa options .
+.Pp
+.Fn SSL_CTX_get_options
+and
+.Fn SSL_get_options
+return the current bitmask.
+.Pp
+.Fn SSL_get_secure_renegotiation_support
+returns 1 is the peer supports secure renegotiation and 0 if it does not.
+.Sh SEE ALSO
+.Xr dhparam 1 ,
+.Xr ssl 3 ,
+.Xr SSL_clear 3 ,
+.Xr SSL_CTX_set_tmp_dh_callback 3 ,
+.Xr SSL_CTX_set_tmp_rsa_callback 3 ,
+.Xr SSL_new 3
+.Sh HISTORY
+.Dv SSL_OP_CIPHER_SERVER_PREFERENCE
+and
+.Dv SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION
+have been added in
+OpenSSL 0.9.7.
+.Pp
+.Dv SSL_OP_TLS_ROLLBACK_BUG
+has been added in OpenSSL 0.9.6 and was automatically enabled with
+.Dv SSL_OP_ALL .
+As of 0.9.7, it is no longer included in
+.Dv SSL_OP_ALL
+and must be explicitly set.
+.Pp
+.Dv SSL_OP_DONT_INSERT_EMPTY_FRAGMENTS
+has been added in OpenSSL 0.9.6e.
+Versions up to OpenSSL 0.9.6c do not include the countermeasure that can be
+disabled with this option (in OpenSSL 0.9.6d, it was always enabled).
+.Pp
+.Fn SSL_CTX_clear_options
+and
+.Fn SSL_clear_options
+were first added in OpenSSL 0.9.8m.
+.Pp
+.Dv SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION ,
+.Dv SSL_OP_LEGACY_SERVER_CONNECT
+and the function
+.Fn SSL_get_secure_renegotiation_support
+were first added in OpenSSL 0.9.8m.
+.Pp
+.Dv SSL_OP_NO_SSLv2
+and
+.Dv SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION
+were changed to have no effect in
+.Ox 5.6 .
-- 
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