Add some documentation for SSL_get_shared_ciphers()

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6115)

2 files changed, 19 insertions, 2 deletions

diff --git a/doc/ssl/SSL_get_ciphers.pod b/doc/ssl/SSL_get_ciphers.pod
index aecadd9138..7697d27917 100644
--- a/doc/ssl/SSL_get_ciphers.pod
+++ b/doc/ssl/SSL_get_ciphers.pod
@@ -2,7 +2,10 @@
 
 =head1 NAME
 
-SSL_get_ciphers, SSL_get_cipher_list - get list of available SSL_CIPHERs
+SSL_get_ciphers,
+SSL_get_cipher_list,
+SSL_get_shared_ciphers
+- get list of available SSL_CIPHERs
 
 =head1 SYNOPSIS
 
@@ -10,6 +13,7 @@ SSL_get_ciphers, SSL_get_cipher_list - get list of available SSL_CIPHERs
 
  STACK_OF(SSL_CIPHER) *SSL_get_ciphers(const SSL *ssl);
  const char *SSL_get_cipher_list(const SSL *ssl, int priority);
+ char *SSL_get_shared_ciphers(const SSL *s, char *buf, int size);
 
 =head1 DESCRIPTION
 
@@ -22,6 +26,19 @@ listed for B<ssl> with B<priority>. If B<ssl> is NULL, no ciphers are
 available, or there are less ciphers than B<priority> available, NULL
 is returned.
 
+SSL_get_shared_ciphers() creates a colon separated and NUL terminated list of
+SSL_CIPHER names that are available in both the client and the server. B<buf> is
+the buffer that should be populated with the list of names and B<size> is the
+size of that buffer. A pointer to B<buf> is returned on success or NULL on
+error. If the supplied buffer is not large enough to contain the complete list
+of names then a truncated list of names will be returned. Note that just because
+a ciphersuite is available (i.e. it is configured in the cipher list) and shared
+by both the client and the server it does not mean that it is enabled (for
+example some ciphers may not be usable by a server if there is not a suitable
+certificate configured). This function will return available shared ciphersuites
+whether or not they are enabled. This is a server side function only and must
+only be called after the completion of the initial handshake.
+
 =head1 NOTES
 
 The details of the ciphers obtained by SSL_get_ciphers() can be obtained using
diff --git a/doc/ssl/ssl.pod b/doc/ssl/ssl.pod
index 70cca178a2..5408d61b31 100644
--- a/doc/ssl/ssl.pod
+++ b/doc/ssl/ssl.pod
@@ -572,7 +572,7 @@ connection defined in the B<SSL> structure.
 
 =item SSL_SESSION *B<SSL_get_session>(const SSL *ssl);
 
-=item char *B<SSL_get_shared_ciphers>(const SSL *ssl, char *buf, int len);
+=item char *B<SSL_get_shared_ciphers>(const SSL *ssl, char *buf, int size);
 
 =item int B<SSL_get_shutdown>(const SSL *ssl);