Stop treating ECDH as experimental

.travis.yml

@@ -33,7 +33,7 @@ env:
     - CFLAGS=-O0 CTIMETEST=no
     - ECMULTGENPRECISION=2
     - ECMULTGENPRECISION=8
-    - RUN_VALGRIND=yes BIGNUM=no ASM=x86_64 EXPERIMENTAL=yes ECDH=yes  RECOVERY=yes EXTRAFLAGS="--disable-openssl-tests" BUILD=
+    - RUN_VALGRIND=yes BIGNUM=no ASM=x86_64 ECDH=yes  RECOVERY=yes EXTRAFLAGS="--disable-openssl-tests" BUILD=
 matrix:
   fast_finish: true
   include:
@@ -81,7 +81,7 @@ matrix:
             - libc6-dbg:i386
     # S390x build (big endian system)
     - compiler: gcc
-      env: HOST=s390x-unknown-linux-gnu ECDH=yes RECOVERY=yes EXPERIMENTAL=yes CTIMETEST=
+      env: HOST=s390x-unknown-linux-gnu ECDH=yes RECOVERY=yes CTIMETEST=
       arch: s390x
 
 # We use this to install macOS dependencies instead of the built in `homebrew` plugin,

README.md

@@ -16,7 +16,7 @@ Features:
 * Very efficient implementation.
 * Suitable for embedded systems.
 * Optional module for public key recovery.
-* Optional module for ECDH key exchange (experimental).
+* Optional module for ECDH key exchange.
 
 Experimental features have not received enough scrutiny to satisfy the standard of quality of this library but are made available for testing and review by the community. The APIs of these features should not be considered stable.
 

configure.ac

@@ -122,7 +122,7 @@ AC_ARG_ENABLE(ecmult_static_precomputation,
     [use_ecmult_static_precomputation=auto])
 
 AC_ARG_ENABLE(module_ecdh,
-    AS_HELP_STRING([--enable-module-ecdh],[enable ECDH shared secret computation (experimental)]),
+    AS_HELP_STRING([--enable-module-ecdh],[enable ECDH shared secret computation]),
     [enable_module_ecdh=$enableval],
     [enable_module_ecdh=no])
 
@@ -458,14 +458,10 @@ if test x"$enable_experimental" = x"yes"; then
   AC_MSG_NOTICE([******])
   AC_MSG_NOTICE([WARNING: experimental build])
   AC_MSG_NOTICE([Experimental features do not have stable APIs or properties, and may not be safe for production use.])
-  AC_MSG_NOTICE([Building ECDH module: $enable_module_ecdh])
   AC_MSG_NOTICE([Building extrakeys module: $enable_module_extrakeys])
   AC_MSG_NOTICE([Building schnorrsig module: $enable_module_schnorrsig])
   AC_MSG_NOTICE([******])
 else
-  if test x"$enable_module_ecdh" = x"yes"; then
-    AC_MSG_ERROR([ECDH module is experimental. Use --enable-experimental to allow.])
-  fi
   if test x"$enable_module_extrakeys" = x"yes"; then
     AC_MSG_ERROR([extrakeys module is experimental. Use --enable-experimental to allow.])
   fi