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Diffstat (limited to 'static/freebsd/man3/SSL_CTX_set_client_cert_cb.3')
| -rw-r--r-- | static/freebsd/man3/SSL_CTX_set_client_cert_cb.3 | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/static/freebsd/man3/SSL_CTX_set_client_cert_cb.3 b/static/freebsd/man3/SSL_CTX_set_client_cert_cb.3 new file mode 100644 index 00000000..e1c3aa96 --- /dev/null +++ b/static/freebsd/man3/SSL_CTX_set_client_cert_cb.3 @@ -0,0 +1,165 @@ +.\" -*- mode: troff; coding: utf-8 -*- +.\" Automatically generated by Pod::Man v6.0.2 (Pod::Simple 3.45) +.\" +.\" Standard preamble: +.\" ======================================================================== +.de Sp \" Vertical space (when we can't use .PP) +.if t .sp .5v +.if n .sp +.. +.de Vb \" Begin verbatim text +.ft CW +.nf +.ne \\$1 +.. +.de Ve \" End verbatim text +.ft R +.fi +.. +.\" \*(C` and \*(C' are quotes in nroff, nothing in troff, for use with C<>. +.ie n \{\ +. ds C` "" +. ds C' "" +'br\} +.el\{\ +. ds C` +. ds C' +'br\} +.\" +.\" Escape single quotes in literal strings from groff's Unicode transform. +.ie \n(.g .ds Aq \(aq +.el .ds Aq ' +.\" +.\" If the F register is >0, we'll generate index entries on stderr for +.\" 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. +.\" +.\" Avoid warning from groff about undefined register 'F'. +.de IX +.. +.nr rF 0 +.if \n(.g .if rF .nr rF 1 +.if (\n(rF:(\n(.g==0)) \{\ +. if \nF \{\ +. de IX +. tm Index:\\$1\t\\n%\t"\\$2" +.. +. if !\nF==2 \{\ +. nr % 0 +. nr F 2 +. \} +. \} +.\} +.rr rF +.\" +.\" Required to disable full justification in groff 1.23.0. +.if n .ds AD l +.\" ======================================================================== +.\" +.IX Title "SSL_CTX_SET_CLIENT_CERT_CB 3ossl" +.TH SSL_CTX_SET_CLIENT_CERT_CB 3ossl 2026-04-07 3.5.6 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_client_cert_cb, SSL_CTX_get_client_cert_cb \- handle client certificate callback function +.SH SYNOPSIS +.IX Header "SYNOPSIS" +.Vb 1 +\& #include <openssl/ssl.h> +\& +\& void SSL_CTX_set_client_cert_cb(SSL_CTX *ctx, +\& int (*client_cert_cb)(SSL *ssl, X509 **x509, +\& EVP_PKEY **pkey)); +\& int (*SSL_CTX_get_client_cert_cb(SSL_CTX *ctx))(SSL *ssl, X509 **x509, +\& EVP_PKEY **pkey); +.Ve +.SH DESCRIPTION +.IX Header "DESCRIPTION" +\&\fBSSL_CTX_set_client_cert_cb()\fR sets the \fIclient_cert_cb\fR callback, that is +called when a client certificate is requested by a server and no certificate +was yet set for the SSL object. +.PP +When \fIclient_cert_cb\fR is NULL, no callback function is used. +.PP +\&\fBSSL_CTX_get_client_cert_cb()\fR returns a pointer to the currently set callback +function. +.PP +\&\fIclient_cert_cb\fR is the application defined callback. If it wants to +set a certificate, a certificate/private key combination must be set +using the \fIx509\fR and \fIpkey\fR arguments and "1" must be returned. The +certificate will be installed into \fIssl\fR, see the NOTES and BUGS sections. +If no certificate should be set, "0" has to be returned and no certificate +will be sent. A negative return value will suspend the handshake and the +handshake function will return immediately. \fBSSL_get_error\fR\|(3) +will return SSL_ERROR_WANT_X509_LOOKUP to indicate, that the handshake was +suspended. The next call to the handshake function will again lead to the call +of \fIclient_cert_cb\fR. It is the job of the \fIclient_cert_cb\fR to store information +about the state of the last call, if required to continue. +.SH NOTES +.IX Header "NOTES" +During a handshake (or renegotiation) a server may request a certificate +from the client. A client certificate must only be sent, when the server +did send the request. +.PP +When a certificate was set using the +\&\fBSSL_CTX_use_certificate\fR\|(3) family of functions, +it will be sent to the server. The TLS standard requires that only a +certificate is sent, if it matches the list of acceptable CAs sent by the +server. This constraint is violated by the default behavior of the OpenSSL +library. Using the callback function it is possible to implement a proper +selection routine or to allow a user interaction to choose the certificate to +be sent. +.PP +If a callback function is defined and no certificate was yet defined for the +SSL object, the callback function will be called. +If the callback function returns a certificate, the OpenSSL library +will try to load the private key and certificate data into the SSL +object using the \fBSSL_use_certificate()\fR and \fBSSL_use_private_key()\fR functions. +Thus it will permanently install the certificate and key for this SSL +object. It will not be reset by calling \fBSSL_clear\fR\|(3). +If the callback returns no certificate, the OpenSSL library will not send +a certificate. +.SH "RETURN VALUES" +.IX Header "RETURN VALUES" +\&\fBSSL_CTX_get_client_cert_cb()\fR returns function pointer of \fIclient_cert_cb\fR or +NULL if the callback is not set. +.SH BUGS +.IX Header "BUGS" +The \fIclient_cert_cb\fR cannot return a complete certificate chain, it can +only return one client certificate. If the chain only has a length of 2, +the root CA certificate may be omitted according to the TLS standard and +thus a standard conforming answer can be sent to the server. For a +longer chain, the client must send the complete chain (with the option +to leave out the root CA certificate). This can only be accomplished by +either adding the intermediate CA certificates into the trusted +certificate store for the SSL_CTX object (resulting in having to add +CA certificates that otherwise maybe would not be trusted), or by adding +the chain certificates using the +\&\fBSSL_CTX_add_extra_chain_cert\fR\|(3) +function, which is only available for the SSL_CTX object as a whole and that +therefore probably can only apply for one client certificate, making +the concept of the callback function (to allow the choice from several +certificates) questionable. +.PP +Once the SSL object has been used in conjunction with the callback function, +the certificate will be set for the SSL object and will not be cleared +even when \fBSSL_clear\fR\|(3) is being called. It is therefore +mandatory to destroy the SSL object using \fBSSL_free\fR\|(3) +and create a new one to return to the previous state. +.SH "SEE ALSO" +.IX Header "SEE ALSO" +\&\fBssl\fR\|(7), \fBSSL_CTX_use_certificate\fR\|(3), +\&\fBSSL_CTX_add_extra_chain_cert\fR\|(3), +\&\fBSSL_get_client_CA_list\fR\|(3), +\&\fBSSL_clear\fR\|(3), \fBSSL_free\fR\|(3) +.SH COPYRIGHT +.IX Header "COPYRIGHT" +Copyright 2002\-2020 The OpenSSL Project Authors. All Rights Reserved. +.PP +Licensed under the Apache License 2.0 (the "License"). You may not use +this file except in compliance with the License. You can obtain a copy +in the file LICENSE in the source distribution or at +<https://www.openssl.org/source/license.html>. |