Add visibility rules.

This change marks public symbols as dynamically exported. This means
that it becomes viable to build a shared library of libcrypto and libssl
with -fvisibility=hidden.

On Windows, one not only needs to mark functions for export in a
component, but also for import when using them from a different
component. Because of this we have to build with
|BORINGSSL_IMPLEMENTATION| defined when building the code. Other
components, when including our headers, won't have that defined and then
the |OPENSSL_EXPORT| tag becomes an import tag instead. See the #defines
in base.h

In the asm code, symbols are now hidden by default and those that need
to be exported are wrapped by a C function.

In order to support Chromium, a couple of libssl functions were moved to
ssl.h from ssl_locl.h: ssl_get_new_session and ssl_update_cache.

Change-Id: Ib4b76e2f1983ee066e7806c24721e8626d08a261
Reviewed-on: https://boringssl-review.googlesource.com/1350
Reviewed-by: Adam Langley <agl@google.com>

1 files changed, 7 insertions, 6 deletions

diff --git a/include/openssl/ecdh.h b/include/openssl/ecdh.h
index 48aa08d5..e97d7576 100644
--- a/include/openssl/ecdh.h
+++ b/include/openssl/ecdh.h
@@ -82,16 +82,17 @@ extern "C" {
  * return value. Otherwise, as many bytes of the shared key as will fit are
  * copied directly to, at most, |outlen| bytes at |out|. It returns the number
  * of bytes written to |out|, or -1 on error. */
-int ECDH_compute_key(void *out, size_t outlen, const EC_POINT *pub_key,
-                     EC_KEY *priv_key, void *(*KDF)(const void *in, size_t inlen,
-                                                void *out, size_t *outlen));
+OPENSSL_EXPORT int ECDH_compute_key(void *out, size_t outlen,
+                                    const EC_POINT *pub_key, EC_KEY *priv_key,
+                                    void *(*KDF)(const void *in, size_t inlen,
+                                                 void *out, size_t *outlen));
 
 /* ECDH_KDF_X9_62 writes |outlen| bytes to |out| using the KDF from X9.62
  * applied to |Z| and |sinfo| and using the hash |md|. It returns one on
  * success and zero otherwise. */
-int ECDH_KDF_X9_62(uint8_t *out, size_t outlen, const uint8_t *Z,
-                   size_t Zlen, const uint8_t *sinfo, size_t sinfolen,
-                   const EVP_MD *md);
+OPENSSL_EXPORT int ECDH_KDF_X9_62(uint8_t *out, size_t outlen, const uint8_t *Z,
+                                  size_t Zlen, const uint8_t *sinfo,
+                                  size_t sinfolen, const EVP_MD *md);
 
 
 #if defined(__cplusplus)