X-Git-Url: https://gitweb.dragonflybsd.org/dragonfly.git/blobdiff_plain/1c1178bcf271a69e11dab32a6d5c93d9648928b8..64511c1e53c1648834778735b5d45fd725439206:/secure/lib/libssl/man/SSL_CTX_set_options.3

diff --git a/secure/lib/libssl/man/SSL_CTX_set_options.3 b/secure/lib/libssl/man/SSL_CTX_set_options.3
index dde2aa2299..5bdf42dab2 100644
--- a/secure/lib/libssl/man/SSL_CTX_set_options.3
+++ b/secure/lib/libssl/man/SSL_CTX_set_options.3
@@ -1,15 +1,7 @@
-.\" Automatically generated by Pod::Man 2.16 (Pod::Simple 3.05)
+.\" Automatically generated by Pod::Man 2.23 (Pod::Simple 3.14)
 .\"
 .\" Standard preamble:
 .\" ========================================================================
-.de Sh \" Subsection heading
-.br
-.if t .Sp
-.ne 5
-.PP
-\fB\\$1\fR
-.PP
-..
 .de Sp \" Vertical space (when we can't use .PP)
 .if t .sp .5v
 .if n .sp
@@ -53,7 +45,7 @@
 .el       .ds Aq '
 .\"
 .\" If the F register is turned on, we'll generate index entries on stderr for
-.\" titles (.TH), headers (.SH), subsections (.Sh), items (.Ip), and index
+.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
 .\" entries marked with X<> in POD.  Of course, you'll have to process the
 .\" output yourself in some meaningful fashion.
 .ie \nF \{\
@@ -132,13 +124,13 @@
 .\" ========================================================================
 .\"
 .IX Title "SSL_CTX_set_options 3"
-.TH SSL_CTX_set_options 3 "2009-04-11" "0.9.8k" "OpenSSL"
+.TH SSL_CTX_set_options 3 "2011-02-08" "1.0.0d" "OpenSSL"
 .\" For nroff, turn off justification.  Always turn off hyphenation; it makes
 .\" way too many mistakes in technical documents.
 .if n .ad l
 .nh
 .SH "NAME"
-SSL_CTX_set_options, SSL_set_options, SSL_CTX_get_options, SSL_get_options \- manipulate SSL engine options
+SSL_CTX_set_options, SSL_set_options, SSL_CTX_clear_options, SSL_clear_options, SSL_CTX_get_options, SSL_get_options, SSL_get_secure_renegotiation_support \- manipulate SSL options
 .SH "SYNOPSIS"
 .IX Header "SYNOPSIS"
 .Vb 1
@@ -147,25 +139,40 @@ SSL_CTX_set_options, SSL_set_options, SSL_CTX_get_options, SSL_get_options \- ma
 \& long SSL_CTX_set_options(SSL_CTX *ctx, long options);
 \& long SSL_set_options(SSL *ssl, long options);
 \&
+\& long SSL_CTX_clear_options(SSL_CTX *ctx, long options);
+\& long SSL_clear_options(SSL *ssl, long options);
+\&
 \& long SSL_CTX_get_options(SSL_CTX *ctx);
 \& long SSL_get_options(SSL *ssl);
+\&
+\& long SSL_get_secure_renegotiation_support(SSL *ssl);
 .Ve
 .SH "DESCRIPTION"
 .IX Header "DESCRIPTION"
+Note: all these functions are implemented using macros.
+.PP
 \&\fISSL_CTX_set_options()\fR adds the options set via bitmask in \fBoptions\fR to \fBctx\fR.
 Options already set before are not cleared!
 .PP
 \&\fISSL_set_options()\fR adds the options set via bitmask in \fBoptions\fR to \fBssl\fR.
 Options already set before are not cleared!
 .PP
+\&\fISSL_CTX_clear_options()\fR clears the options set via bitmask in \fBoptions\fR
+to \fBctx\fR.
+.PP
+\&\fISSL_clear_options()\fR clears the options set via bitmask in \fBoptions\fR to \fBssl\fR.
+.PP
 \&\fISSL_CTX_get_options()\fR returns the options set for \fBctx\fR.
 .PP
 \&\fISSL_get_options()\fR returns the options set for \fBssl\fR.
+.PP
+\&\fISSL_get_secure_renegotiation_support()\fR indicates whether the peer supports
+secure renegotiation.
 .SH "NOTES"
 .IX Header "NOTES"
 The behaviour of the \s-1SSL\s0 library can be changed by setting several options.
 The options are coded as bitmasks and can be combined by a logical \fBor\fR
-operation (|). Options can only be added but can never be reset.
+operation (|).
 .PP
 \&\fISSL_CTX_set_options()\fR and \fISSL_set_options()\fR affect the (external)
 protocol behaviour of the \s-1SSL\s0 library. The (internal) behaviour of
@@ -193,18 +200,7 @@ when operating in SSLv2/v3 compatibility mode, but as mentioned above,
 this breaks this server so 16 bytes is the way to go.
 .IP "\s-1SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG\s0" 4
 .IX Item "SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG"
-ssl3.netscape.com:443, first a connection is established with \s-1RC4\-MD5\s0.
-If it is then resumed, we end up using \s-1DES\-CBC3\-SHA\s0.  It should be
-\&\s-1RC4\-MD5\s0 according to 7.6.1.3, 'cipher_suite'.
-.Sp
-Netscape\-Enterprise/2.01 (https://merchant.netscape.com) has this bug.
-It only really shows up when connecting via SSLv2/v3 then reconnecting
-via SSLv3. The cipher list changes....
-.Sp
-\&\s-1NEW\s0 \s-1INFORMATION\s0.  Try connecting with a cipher list of just
-\&\s-1DES\-CBC\-SHA:RC4\-MD5\s0.  For some weird reason, each new connection uses
-\&\s-1RC4\-MD5\s0, but a re-connect tries to use DES-CBC-SHA.  So netscape, when
-doing a re-connect, always takes the first cipher in the cipher list.
+As of OpenSSL 0.9.8q and 1.0.0c, this option has no effect.
 .IP "\s-1SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG\s0" 4
 .IX Item "SSL_OP_SSLREF2_REUSE_CERT_TYPE_BUG"
 \&...
@@ -305,21 +301,106 @@ Do not use the TLSv1 protocol.
 .IX Item "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.
+handshake). This option is not needed for clients.
 .IP "\s-1SSL_OP_NO_TICKET\s0" 4
 .IX Item "SSL_OP_NO_TICKET"
 Normally clients and servers will, where possible, transparently make use
-of RFC4507bis tickets for stateless session resumption if extension support
-is explicitly set when OpenSSL is compiled.
+of RFC4507bis tickets for stateless session resumption.
 .Sp
 If this option is set this functionality is disabled and tickets will
 not be used by clients or servers.
+.IP "\s-1SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION\s0" 4
+.IX Item "SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION"
+Allow legacy insecure renegotiation between OpenSSL and unpatched clients or
+servers. See the \fB\s-1SECURE\s0 \s-1RENEGOTIATION\s0\fR section for more details.
+.IP "\s-1SSL_OP_LEGACY_SERVER_CONNECT\s0" 4
+.IX Item "SSL_OP_LEGACY_SERVER_CONNECT"
+Allow legacy insecure renegotiation between OpenSSL and unpatched servers
+\&\fBonly\fR: this option is currently set by default. See the
+\&\fB\s-1SECURE\s0 \s-1RENEGOTIATION\s0\fR section for more details.
+.SH "SECURE RENEGOTIATION"
+.IX Header "SECURE RENEGOTIATION"
+OpenSSL 0.9.8m and later always attempts to use secure renegotiation as
+described in \s-1RFC5746\s0. This counters the prefix attack described in
+\&\s-1CVE\-2009\-3555\s0 and elsewhere.
+.PP
+The deprecated and highly broken SSLv2 protocol does not support
+renegotiation at all: its use is \fBstrongly\fR 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 \fIpatched\fR. A server not supporting secure
+renegotiation is referred to as \fIunpatched\fR.
+.PP
+The following sections describe the operations permitted by OpenSSL's secure
+renegotiation implementation.
+.SS "Patched client and server"
+.IX Subsection "Patched client and server"
+Connections and renegotiation are always permitted by OpenSSL implementations.
+.SS "Unpatched client and patched OpenSSL server"
+.IX Subsection "Unpatched client and patched OpenSSL server"
+The initial connection suceeds but client renegotiation is denied by the
+server with a \fBno_renegotiation\fR warning alert if \s-1TLS\s0 v1.0 is used or a fatal
+\&\fBhandshake_failure\fR alert in \s-1SSL\s0 v3.0.
+.PP
+If the patched OpenSSL server attempts to renegotiate a fatal
+\&\fBhandshake_failure\fR alert is sent. This is because the server code may be
+unaware of the unpatched nature of the client.
+.PP
+If the option \fB\s-1SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION\s0\fR is set then
+renegotiation \fBalways\fR succeeds.
+.PP
+\&\fB\s-1NB:\s0\fR 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
+\&\fBno_renegotiation\fR alert. OpenSSL versions 0.9.8m and later will regard
+a \fBno_renegotiation\fR alert as fatal and respond with a fatal
+\&\fBhandshake_failure\fR alert. This is because the OpenSSL \s-1API\s0 currently has
+no provision to indicate to an application that a renegotiation attempt
+was refused.
+.SS "Patched OpenSSL client and unpatched server."
+.IX Subsection "Patched OpenSSL client and unpatched server."
+If the option \fB\s-1SSL_OP_LEGACY_SERVER_CONNECT\s0\fR or
+\&\fB\s-1SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION\s0\fR 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 \fB\s-1SSL_OP_LEGACY_SERVER_CONNECT\s0\fR 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 \fB\s-1SSL_OP_LEGACY_SERVER_CONNECT\s0\fR will
+\&\fBnot\fR 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 \fBset\fR \fB\s-1SSL_OP_LEGACY_SERVER_CONNECT\s0\fR
+.PP
+OpenSSL client applications that want to ensure they can \fBnot\fR connect to
+unpatched servers (and thus avoid any security issues) should always \fBclear\fR
+\&\fB\s-1SSL_OP_LEGACY_SERVER_CONNECT\s0\fR using \fISSL_CTX_clear_options()\fR or
+\&\fISSL_clear_options()\fR.
+.PP
+The difference between the \fB\s-1SSL_OP_LEGACY_SERVER_CONNECT\s0\fR and
+\&\fB\s-1SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION\s0\fR options is that
+\&\fB\s-1SSL_OP_LEGACY_SERVER_CONNECT\s0\fR enables initial connections and secure
+renegotiation between OpenSSL clients and unpatched servers \fBonly\fR, while
+\&\fB\s-1SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION\s0\fR allows initial connections
+and renegotiation between OpenSSL and unpatched clients or servers.
 .SH "RETURN VALUES"
 .IX Header "RETURN VALUES"
 \&\fISSL_CTX_set_options()\fR and \fISSL_set_options()\fR return the new options bitmask
 after adding \fBoptions\fR.
 .PP
+\&\fISSL_CTX_clear_options()\fR and \fISSL_clear_options()\fR return the new options bitmask
+after clearing \fBoptions\fR.
+.PP
 \&\fISSL_CTX_get_options()\fR and \fISSL_get_options()\fR return the current bitmask.
+.PP
+\&\fISSL_get_secure_renegotiation_support()\fR returns 1 is the peer supports
+secure renegotiation and 0 if it does not.
 .SH "SEE ALSO"
 .IX Header "SEE ALSO"
 \&\fIssl\fR\|(3), \fISSL_new\fR\|(3), \fISSL_clear\fR\|(3),
@@ -340,3 +421,10 @@ and must be explicitly set.
 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
+\&\fISSL_CTX_clear_options()\fR and \fISSL_clear_options()\fR were first added in OpenSSL
+0.9.8m.
+.PP
+\&\fB\s-1SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION\s0\fR, \fB\s-1SSL_OP_LEGACY_SERVER_CONNECT\s0\fR
+and the function \fISSL_get_secure_renegotiation_support()\fR were first added in
+OpenSSL 0.9.8m.