Deprecate and no-op SSL_set_state.

Yes, OpenSSL lets you randomly change its internal state. This is used
as part of server-side renegotiation. Server-side renegotiation is gone.

BUG=429450

Change-Id: Ic1b013705734357acf64e8bf89a051b2b7521c64
Reviewed-on: https://boringssl-review.googlesource.com/4828
Reviewed-by: Adam Langley <agl@google.com>

include/openssl/ssl.h

diff --git a/include/openssl/ssl.h b/include/openssl/ssl.h
index aee6e18..0af4599 100644
--- a/include/openssl/ssl.h
+++ b/include/openssl/ssl.h
@@ -2099,7 +2099,6 @@
 OPENSSL_EXPORT void (*SSL_get_info_callback(const SSL *ssl))(const SSL *ssl,
                                                              int type, int val);
 OPENSSL_EXPORT int SSL_state(const SSL *ssl);
-OPENSSL_EXPORT void SSL_set_state(SSL *ssl, int state);
 
 OPENSSL_EXPORT void SSL_set_verify_result(SSL *ssl, long v);
 OPENSSL_EXPORT long SSL_get_verify_result(const SSL *ssl);
@@ -2404,6 +2403,9 @@
 /* SSL_renegotiate put an error on the error queue and returns zero. */
 OPENSSL_EXPORT int SSL_renegotiate(SSL *ssl);
 
+/* SSL_set_state does nothing. */
+OPENSSL_EXPORT void SSL_set_state(SSL *ssl, int state);
+
 
 /* Android compatibility section.
  *

ssl/ssl_lib.c

diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
index cca4dd1..c3997a9 100644
--- a/ssl/ssl_lib.c
+++ b/ssl/ssl_lib.c
@@ -2322,7 +2322,7 @@
 
 int SSL_state(const SSL *ssl) { return ssl->state; }
 
-void SSL_set_state(SSL *ssl, int state) { ssl->state = state; }
+void SSL_set_state(SSL *ssl, int state) { }
 
 void SSL_set_verify_result(SSL *ssl, long arg) { ssl->verify_result = arg; }