1 files changed, 130 insertions, 0 deletions
diff --git a/deps/openssl/openssl/doc/man3/SSL_CTX_set_client_hello_cb.pod b/deps/openssl/openssl/doc/man3/SSL_CTX_set_client_hello_cb.pod
new file mode 100644
index 0000000000..6824b5b8d1
--- /dev/null
+++ b/deps/openssl/openssl/doc/man3/SSL_CTX_set_client_hello_cb.pod
@@ -0,0 +1,130 @@
+=pod
+
+=head1 NAME
+
+SSL_CTX_set_client_hello_cb, SSL_client_hello_cb_fn, SSL_client_hello_isv2, SSL_client_hello_get0_legacy_version, SSL_client_hello_get0_random, SSL_client_hello_get0_session_id, SSL_client_hello_get0_ciphers, SSL_client_hello_get0_compression_methods, SSL_client_hello_get1_extensions_present, SSL_client_hello_get0_ext - callback functions for early server-side ClientHello processing
+
+=head1 SYNOPSIS
+
+ typedef int (*SSL_client_hello_cb_fn)(SSL *s, int *al, void *arg);
+ void SSL_CTX_set_client_hello_cb(SSL_CTX *c, SSL_client_hello_cb_fn *f,
+                                  void *arg);
+ int SSL_client_hello_isv2(SSL *s);
+ unsigned int SSL_client_hello_get0_legacy_version(SSL *s);
+ size_t SSL_client_hello_get0_random(SSL *s, const unsigned char **out);
+ size_t SSL_client_hello_get0_session_id(SSL *s, const unsigned char **out);
+ size_t SSL_client_hello_get0_ciphers(SSL *s, const unsigned char **out);
+ size_t SSL_client_hello_get0_compression_methods(SSL *s,
+                                                  const unsigned char **out);
+ int SSL_client_hello_get1_extensions_present(SSL *s, int **out,
+                                              size_t *outlen);
+ int SSL_client_hello_get0_ext(SSL *s, int type, const unsigned char **out,
+                               size_t *outlen);
+
+=head1 DESCRIPTION
+
+SSL_CTX_set_client_hello_cb() sets the callback function, which is automatically
+called during the early stages of ClientHello processing on the server.
+The argument supplied when setting the callback is passed back to the
+callback at runtime.  A callback that returns failure (0) will cause the
+connection to terminate, and callbacks returning failure should indicate
+what alert value is to be sent in the B<al> parameter.  A callback may
+also return a negative value to suspend the handshake, and the handshake
+function will return immediately.  L<SSL_get_error(3)> will return
+SSL_ERROR_WANT_CLIENT_HELLO_CB to indicate that the handshake was suspended.
+It is the job of the ClientHello callback to store information about the state
+of the last call if needed to continue.  On the next call into the handshake
+function, the ClientHello callback will be called again, and, if it returns
+success, normal handshake processing will continue from that point.
+
+SSL_client_hello_isv2() indicates whether the ClientHello was carried in a
+SSLv2 record and is in the SSLv2 format.  The SSLv2 format has substantial
+differences from the normal SSLv3 format, including using three bytes per
+cipher suite, and not allowing extensions.  Additionally, the SSLv2 format
+'challenge' field is exposed via SSL_client_hello_get0_random(), padded to
+SSL3_RANDOM_SIZE bytes with zeros if needed.  For SSLv2 format ClientHellos,
+SSL_client_hello_get0_compression_methods() returns a dummy list that only includes
+the null compression method, since the SSLv2 format does not include a
+mechanism by which to negotiate compression.
+
+SSL_client_hello_get0_random(), SSL_client_hello_get0_session_id(),
+SSL_client_hello_get0_ciphers(), and
+SSL_client_hello_get0_compression_methods() provide access to the corresponding
+ClientHello fields, returning the field length and optionally setting an out
+pointer to the octets of that field.
+
+Similarly, SSL_client_hello_get0_ext() provides access to individual extensions
+from the ClientHello on a per-extension basis.  For the provided wire
+protocol extension type value, the extension value and length are returned
+in the output parameters (if present).
+
+SSL_client_hello_get1_extensions_present() can be used prior to
+SSL_client_hello_get0_ext(), to determine which extensions are present in the
+ClientHello before querying for them.  The B<out> and B<outlen> parameters are
+both required, and on success the caller must release the storage allocated for
+B<*out> using OPENSSL_free().  The contents of B<*out> is an array of integers
+holding the numerical value of the TLS extension types in the order they appear
+in the ClientHello.  B<*outlen> contains the number of elements in the array.
+
+=head1 NOTES
+
+The ClientHello callback provides a vast window of possibilities for application
+code to affect the TLS handshake.  A primary use of the callback is to
+allow the server to examine the server name indication extension provided
+by the client in order to select an appropriate certificate to present,
+and make other configuration adjustments relevant to that server name
+and its configuration.  Such configuration changes can include swapping out
+the associated SSL_CTX pointer, modifying the server's list of permitted TLS
+versions, changing the server's cipher list in response to the client's
+cipher list, etc.
+
+It is also recommended that applications utilize a ClientHello callback and
+not use a servername callback, in order to avoid unexpected behavior that
+occurs due to the relative order of processing between things like session
+resumption and the historical servername callback.
+
+The SSL_client_hello_* family of functions may only be called from code executing
+within a ClientHello callback.
+
+=head1 RETURN VALUES
+
+The application's supplied ClientHello callback returns
+SSL_CLIENT_HELLO_SUCCESS on success, SSL_CLIENT_HELLO_ERROR on failure, and
+SSL_CLIENT_HELLO_RETRY to suspend processing.
+
+SSL_client_hello_isv2() returns 1 for SSLv2-format ClientHellos and 0 otherwise.
+
+SSL_client_hello_get0_random(), SSL_client_hello_get0_session_id(),
+SSL_client_hello_get0_ciphers(), and
+SSL_client_hello_get0_compression_methods() return the length of the
+corresponding ClientHello fields.  If zero is returned, the output pointer
+should not be assumed to be valid.
+
+SSL_client_hello_get0_ext() returns 1 if the extension of type 'type' is present, and
+0 otherwise.
+
+SSL_client_hello_get1_extensions_present() returns 1 on success and 0 on failure.
+
+=head1 SEE ALSO
+
+L<ssl(7)>, L<SSL_CTX_set_tlsext_servername_callback(3)>,
+L<SSL_bytes_to_cipher_list>
+
+=head1 HISTORY
+
+The SSL ClientHello callback, SSL_client_hello_isv2(),
+SSL_client_hello_get0_random(), SSL_client_hello_get0_session_id(),
+SSL_client_hello_get0_ciphers(), SSL_client_hello_get0_compression_methods(),
+SSL_client_hello_get0_ext(), and SSL_client_hello_get1_extensions_present()
+were added in OpenSSL 1.1.1.
+
+=head1 COPYRIGHT
+
+Copyright 2017 The OpenSSL Project Authors. All Rights Reserved.
+
+Licensed under the OpenSSL license (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
+L<https://www.openssl.org/source/license.html>.
+
+=cut