Support Android's "baremetal" target
This corresponds to the libcrypto_baremetal build target in Android,
which is an embedded-style platform that uses a subset of the bionic
libc. It will also, eventually, use getentropy for its PRNG.
As part of this, generalize the OPENSSL_TRUSTY exclusion for file BIOs
to OPENSSL_NO_FILESYSTEM. Upstream OpenSSL uses OPENSSL_NO_STDIO, but
that excludes all of FILE entirely. We already require FILE in quite a
few places (urandom.c, self_test.c) for writing to stderr, and FILE is
part of C standard library. So, let's tentatively say that we require
you have FILE and stderr.
Instead, OPENSSL_NO_FILESYSTEM is saying you don't have fopen. You're
still required to have the three std{in,out,err} FILEs, and given a
FILE, you need to allow the standard operations on it. (Possibly in
forms that always fail.)
To keep us honest, whenever a function is excluded, I've dropped it from
the header too, and followed callers up the chain. I have not attempted
to make the tests work when these are excluded. Later CLs in this series
will do the same for NO_SOCK and NO_POSIX_IO. This was a little tedious,
but not too bad.
(I assume we'll end up changing our minds on this a lot. For now, let's
try this.)
I haven't yet restored OPENSSL_RAND_TRUSTY or removed the OPENSSL_TRUSTY
ifdef on file.c. Having a separate CL makes it a bit easier to revert if
something goes wrong.
This depends on
https://android-review.googlesource.com/c/platform/bionic/+/2659335,
which fixes the header bionic uses for getentropy.
Bug: 629, b:291102972
Change-Id: Idd839cd3fa4253128de54bd1be7da261dbcdeb7c
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/61726
Auto-Submit: David Benjamin <davidben@google.com>
Reviewed-by: Bob Beck <bbe@google.com>
Commit-Queue: Bob Beck <bbe@google.com>
diff --git a/include/openssl/target.h b/include/openssl/target.h
index 92eaf75..f830c14 100644
--- a/include/openssl/target.h
+++ b/include/openssl/target.h
@@ -70,10 +70,13 @@
#define OPENSSL_WINDOWS
#endif
-// Trusty isn't Linux but currently defines __linux__. As a workaround, we
-// exclude it here.
+// Trusty and Android baremetal aren't't Linux but currently define __linux__.
+// As a workaround, we exclude them here.
+//
// TODO(b/169780122): Remove this workaround once Trusty no longer defines it.
-#if defined(__linux__) && !defined(__TRUSTY__)
+// TODO(b/291101350): Remove this workaround once Android baremetal no longer
+// defines it.
+#if defined(__linux__) && !defined(__TRUSTY__) && !defined(ANDROID_BAREMETAL)
#define OPENSSL_LINUX
#endif
@@ -88,6 +91,7 @@
// platforms must introduce their own defines.
#if defined(__TRUSTY__)
#define OPENSSL_TRUSTY
+#define OPENSSL_NO_FILESYSTEM
#define OPENSSL_NO_POSIX_IO
#define OPENSSL_NO_SOCK
#define OPENSSL_NO_THREADS_CORRUPT_MEMORY_AND_LEAK_SECRETS_IF_THREADED
@@ -97,6 +101,17 @@
// other platform is not supported. Other embedded platforms must introduce
// their own defines.
#if defined(OPENSSL_NANOLIBC)
+#define OPENSSL_NO_FILESYSTEM
+#define OPENSSL_NO_POSIX_IO
+#define OPENSSL_NO_SOCK
+#define OPENSSL_NO_THREADS_CORRUPT_MEMORY_AND_LEAK_SECRETS_IF_THREADED
+#endif
+
+// Android baremetal is an embedded target that uses a subset of bionic.
+// Defining this on any other platform is not supported. Other embedded
+// platforms must introduce their own defines.
+#if defined(ANDROID_BAREMETAL)
+#define OPENSSL_NO_FILESYSTEM
#define OPENSSL_NO_POSIX_IO
#define OPENSSL_NO_SOCK
#define OPENSSL_NO_THREADS_CORRUPT_MEMORY_AND_LEAK_SECRETS_IF_THREADED
