Fix end-point shared secret for DTLS/SCTP

[openssl.git] / doc / man3 / SSL_CTX_set_mode.pod

diff --git a/doc/man3/SSL_CTX_set_mode.pod b/doc/man3/SSL_CTX_set_mode.pod
index 06e9a29cce5078788c7f2da84c3638225bfa55a4..a4997c96227781d15e6f1a6d94efaa71fe7152ed 100644 (file)
--- a/doc/man3/SSL_CTX_set_mode.pod
+++ b/doc/man3/SSL_CTX_set_mode.pod
@@ -121,6 +121,15 @@ Kernel TLS might not support all the features of OpenSSL. For instance,
 renegotiation, and setting the maximum fragment size is not possible as of
 Linux 4.20.
 
+=item SSL_MODE_DTLS_SCTP_LABEL_LENGTH_BUG
+
+Older versions of OpenSSL had a bug in the computation of the label length
+used for computing the endpoint-pair shared secret. The bug was that the
+terminating zero was included in the length of the label. Setting this option
+enables this behaviour to allow interoperability with such broken
+implementations. Please note that setting this option breaks interoperability
+with correct implementations. This option only applies to DTLS over SCTP.
+
 =back
 
 All modes are off by default except for SSL_MODE_AUTO_RETRY which is on by