X-Git-Url: https://www.bearssl.org/gitweb//home/git/?p=BearSSL;a=blobdiff_plain;f=inc%2Fbearssl_ssl.h;h=ad807ab9acbfe6e86104d6a69bbb008a2e4708fe;hp=2ac9e258a79b1ed2053dccaa189d770f095ac033;hb=ea95d8264c6aefe742a9c3f4f9d834b188566a29;hpb=968da0f646a43c69a2517a240c9963ff513981b3

diff --git a/inc/bearssl_ssl.h b/inc/bearssl_ssl.h
index 2ac9e25..ad807ab 100644
--- a/inc/bearssl_ssl.h
+++ b/inc/bearssl_ssl.h
@@ -2075,6 +2075,41 @@ void br_ssl_engine_close(br_ssl_engine_context *cc);
  */
 int br_ssl_engine_renegotiate(br_ssl_engine_context *cc);
 
+/**
+ * \brief Export key material from a connected SSL engine (RFC 5705).
+ *
+ * This calls compute a secret key of arbitrary length from the master
+ * secret of a connected SSL engine. If the provided context is not
+ * currently in "application data" state (initial handshake is not
+ * finished, another handshake is ongoing, or the connection failed or
+ * was closed), then this function returns 0. Otherwise, a secret key of
+ * length `len` bytes is computed and written in the buffer pointed to
+ * by `dst`, and 1 is returned.
+ *
+ * The computed key follows the specification described in RFC 5705.
+ * That RFC includes two key computations, with and without a "context
+ * value". If `context` is `NULL`, then the variant without context is
+ * used; otherwise, the `context_len` bytes located at the address
+ * pointed to by `context` are used in the computation. Note that it
+ * is possible to have a "with context" key with a context length of
+ * zero bytes, by setting `context` to a non-`NULL` value but
+ * `context_len` to 0.
+ *
+ * When context bytes are used, the context length MUST NOT exceed
+ * 65535 bytes.
+ *
+ * \param cc            SSL engine context.
+ * \param dst           destination buffer for exported key.
+ * \param len           exported key length (in bytes).
+ * \param label         disambiguation label.
+ * \param context       context value (or `NULL`).
+ * \param context_len   context length (in bytes).
+ * \return  1 on success, 0 on error.
+ */
+int br_ssl_key_export(br_ssl_engine_context *cc,
+	void *dst, size_t len, const char *label,
+	const void *context, size_t context_len);
+
 /*
  * Pre-declaration for the SSL client context.
  */