diff --git a/CMakeLists.txt b/CMakeLists.txt
index f85b4391..050ba974 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -31,8 +31,8 @@ if (NOT GO_EXECUTABLE)
 endif()
 
 if(CMAKE_COMPILER_IS_GNUCXX OR CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-  set(C_CXX_FLAGS "-Wall -Werror -Wformat=2 -Wsign-compare -Wmissing-field-initializers -ggdb -fvisibility=hidden")
-  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${C_CXX_FLAGS} -Wmissing-prototypes")
+  set(C_CXX_FLAGS "-Wall -Werror -Wformat=2 -Wsign-compare -Wmissing-field-initializers -Wwrite-strings -ggdb -fvisibility=hidden -fno-common")
+  set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${C_CXX_FLAGS} -Wmissing-prototypes -Wold-style-definition -Wstrict-prototypes")
   set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++11 ${C_CXX_FLAGS} -Wmissing-declarations")
 elseif(MSVC)
   set(MSVC_DISABLED_WARNINGS_LIST
diff --git a/util/BUILD b/util/BUILD
new file mode 100644
index 00000000..86bcc786
--- /dev/null
+++ b/util/BUILD
@@ -0,0 +1,128 @@
+# Copyright (c) 2016, Google Inc.
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+# SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+# OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+# CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
+
+licenses(["notice"])
+
+exports_files(["LICENSE"])
+
+load(
+    ":BUILD.generated.bzl",
+    "crypto_headers",
+    "crypto_internal_headers",
+    "crypto_sources",
+    "crypto_sources_linux_x86_64",
+    "crypto_sources_mac_x86_64",
+    "ssl_headers",
+    "ssl_internal_headers",
+    "ssl_sources",
+    "tool_sources",
+    "tool_headers",
+)
+
+config_setting(
+    name = "linux_x86_64",
+    values = {"cpu": "k8"},
+)
+
+config_setting(
+    name = "mac_x86_64",
+    values = {"cpu": "darwin"},
+)
+
+boringssl_copts = [
+    # Assembler option --noexecstack adds .note.GNU-stack to each object to
+    # ensure that binaries can be built with non-executable stack.
+    "-Wa,--noexecstack",
+
+    # This is needed on Linux systems (at least) to get rwlock in pthread.
+    "-D_XOPEN_SOURCE=700",
+
+    # Exported symbols are annotated specifically in header files. This option
+    # sets the default for all other symbols to be hidden. (Applies only to
+    # shared-library builds.)
+    "-fvisibility=hidden",
+
+    # This list of warnings should match those in the top-level CMakeLists.txt.
+    "-Wall",
+    "-Werror",
+    "-Wformat=2",
+    "-Wsign-compare",
+    "-Wmissing-field-initializers",
+    "-Wwrite-strings",
+    "-Wshadow",
+    "-fno-common",
+
+    # Modern build environments should be able to set this to use atomic
+    # operations for reference counting rather than locks. However, it's
+    # known not to work on some Android builds.
+    # "-DOPENSSL_C11_ATOMIC",
+] + select({
+    ":linux_x86_64": [],
+    ":mac_x86_64": [],
+    "//conditions:default": ["-DOPENSSL_NO_ASM"],
+})
+
+crypto_sources_asm = select({
+    ":linux_x86_64": crypto_sources_linux_x86_64,
+    ":mac_x86_64": crypto_sources_mac_x86_64,
+    "//conditions:default": [],
+})
+
+# For C targets only (not C++), compile with C11 support.
+boringssl_copts_c11 = boringssl_copts + [
+    "-std=c11",
+    "-Wmissing-prototypes",
+    "-Wold-style-definition",
+    "-Wstrict-prototypes",
+]
+
+# For C targets only (not C++), compile with C11 support.
+boringssl_copts_cxx = boringssl_copts + [
+    "-std=c++11",
+    "-Wmissing-declarations",
+]
+
+cc_library(
+    name = "crypto",
+    srcs = crypto_sources + crypto_internal_headers + crypto_sources_asm,
+    hdrs = crypto_headers,
+    copts = boringssl_copts_c11,
+    includes = ["src/include"],
+    linkopts = select({
+        ":mac_x86_64": [],
+        "//conditions:default": ["-lpthread"],
+    }),
+    visibility = ["//visibility:public"],
+)
+
+cc_library(
+    name = "ssl",
+    srcs = ssl_sources + ssl_internal_headers,
+    hdrs = ssl_headers,
+    copts = boringssl_copts_c11,
+    includes = ["src/include"],
+    visibility = ["//visibility:public"],
+    deps = [":crypto"],
+)
+
+cc_binary(
+    name = "bssl",
+    srcs = tool_sources + tool_headers + [
+        "src/crypto/test/scoped_types.h",
+        "src/ssl/test/scoped_types.h",
+    ],
+    copts = boringssl_copts_cxx,
+    visibility = ["//visibility:public"],
+    deps = [":ssl"],
+)