Fix the Windows fuzzer build

OPENSSL_WINDOWS doesn't *quite* imply that crypto/rand_extra/windows.c
is used, thanks to fuzzer mode.

The sea of ifdefs here is becoming quite a mess, so I've added
OPENSSL_RAND_* resolve the dispatch in one place. Perhaps later we
should also we can also simplify this by just including
CRYPTO_init_sysrand and CRYPTO_sysrand_if_available in all the C files.
But that'll be easier to do when Trusty's RNG is moved in tree.

While I'm here, fold some of the ifdefs in windows.c together.

Change-Id: Ic9c21c5c943a409ebb1d77f27daea1eeb9422e9d
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/61085
Auto-Submit: David Benjamin <davidben@google.com>
Reviewed-by: Bob Beck <bbe@google.com>
Commit-Queue: Bob Beck <bbe@google.com>

crypto/fipsmodule/rand/internal.h

@@ -26,9 +26,16 @@ extern "C" {
 #endif
 
 
-#if !defined(OPENSSL_WINDOWS) && !defined(OPENSSL_FUCHSIA) && \
-    !defined(BORINGSSL_UNSAFE_DETERMINISTIC_MODE) && !defined(OPENSSL_TRUSTY)
-#define OPENSSL_URANDOM
+#if defined(BORINGSSL_UNSAFE_DETERMINISTIC_MODE)
+#define OPENSSL_RAND_DETERMINISTIC
+#elif defined(OPENSSL_FUCHSIA)
+#define OPENSSL_RAND_FUCHSIA
+#elif defined(OPENSSL_TRUSTY)
+// Trusty's PRNG file is, for now, maintained outside the tree.
+#elif defined(OPENSSL_WINDOWS)
+#define OPENSSL_RAND_WINDOWS
+#else
+#define OPENSSL_RAND_URANDOM
 #endif
 
 // RAND_bytes_with_additional_data samples from the RNG after mixing 32 bytes
@@ -70,15 +77,15 @@ void CRYPTO_sysrand(uint8_t *buf, size_t len);
 // depending on the vendor's configuration.
 void CRYPTO_sysrand_for_seed(uint8_t *buf, size_t len);
 
-#if defined(OPENSSL_URANDOM) || defined(OPENSSL_WINDOWS)
+#if defined(OPENSSL_RAND_URANDOM) || defined(OPENSSL_RAND_WINDOWS)
 // CRYPTO_init_sysrand initializes long-lived resources needed to draw entropy
 // from the operating system.
 void CRYPTO_init_sysrand(void);
 #else
 OPENSSL_INLINE void CRYPTO_init_sysrand(void) {}
-#endif  // defined(OPENSSL_URANDOM) || defined(OPENSSL_WINDOWS)
+#endif  // defined(OPENSSL_RAND_URANDOM) || defined(OPENSSL_RAND_WINDOWS)
 
-#if defined(OPENSSL_URANDOM)
+#if defined(OPENSSL_RAND_URANDOM)
 // CRYPTO_sysrand_if_available fills |len| bytes at |buf| with entropy from the
 // operating system, or early /dev/urandom data, and returns 1, _if_ the entropy
 // pool is initialized or if getrandom() is not available and not in FIPS mode.
@@ -90,7 +97,7 @@ OPENSSL_INLINE int CRYPTO_sysrand_if_available(uint8_t *buf, size_t len) {
   CRYPTO_sysrand(buf, len);
   return 1;
 }
-#endif  // defined(OPENSSL_URANDOM)
+#endif  // defined(OPENSSL_RAND_URANDOM)
 
 // rand_fork_unsafe_buffering_enabled returns whether fork-unsafe buffering has
 // been enabled via |RAND_enable_fork_unsafe_buffering|.

crypto/fipsmodule/rand/urandom.c

@@ -20,7 +20,7 @@
 
 #include "internal.h"
 
-#if defined(OPENSSL_URANDOM)
+#if defined(OPENSSL_RAND_URANDOM)
 
 #include <assert.h>
 #include <errno.h>
@@ -352,4 +352,4 @@ int CRYPTO_sysrand_if_available(uint8_t *out, size_t requested) {
   }
 }
 
-#endif  // OPENSSL_URANDOM
+#endif  // OPENSSL_RAND_URANDOM

crypto/fipsmodule/rand/urandom_test.cc

@@ -22,9 +22,9 @@
 #include "getrandom_fillin.h"
 #include "internal.h"
 
-#if (defined(OPENSSL_X86_64) || defined(OPENSSL_AARCH64)) && \
-    !defined(BORINGSSL_SHARED_LIBRARY) &&                    \
-    defined(OPENSSL_URANDOM) && defined(USE_NR_getrandom)
+#if (defined(OPENSSL_X86_64) || defined(OPENSSL_AARCH64)) &&               \
+    !defined(BORINGSSL_SHARED_LIBRARY) && defined(OPENSSL_RAND_URANDOM) && \
+    defined(USE_NR_getrandom)
 
 #include <elf.h>
 #include <linux/random.h>

crypto/rand_extra/deterministic.c

@@ -14,14 +14,15 @@
 
 #include <openssl/rand.h>
 
-#if defined(BORINGSSL_UNSAFE_DETERMINISTIC_MODE)
+#include "../fipsmodule/rand/internal.h"
+
+#if defined(OPENSSL_RAND_DETERMINISTIC)
 
 #include <string.h>
 
 #include <openssl/chacha.h>
 
 #include "../internal.h"
-#include "../fipsmodule/rand/internal.h"
 
 
 // g_num_calls is the number of calls to |CRYPTO_sysrand| that have occurred.
@@ -53,4 +54,4 @@ void CRYPTO_sysrand_for_seed(uint8_t *out, size_t requested) {
   CRYPTO_sysrand(out, requested);
 }
 
-#endif  // BORINGSSL_UNSAFE_DETERMINISTIC_MODE
+#endif  // OPENSSL_RAND_DETERMINISTIC

crypto/rand_extra/fuchsia.c

@@ -14,15 +14,15 @@
 
 #include <openssl/rand.h>
 
-#if defined(OPENSSL_FUCHSIA) && !defined(BORINGSSL_UNSAFE_DETERMINISTIC_MODE)
+#include "../fipsmodule/rand/internal.h"
+
+#if defined(OPENSSL_RAND_FUCHSIA)
 
 #include <limits.h>
 #include <stdlib.h>
 
 #include <zircon/syscalls.h>
 
-#include "../fipsmodule/rand/internal.h"
-
 void CRYPTO_sysrand(uint8_t *out, size_t requested) {
   zx_cprng_draw(out, requested);
 }
@@ -31,4 +31,4 @@ void CRYPTO_sysrand_for_seed(uint8_t *out, size_t requested) {
   CRYPTO_sysrand(out, requested);
 }
 
-#endif  // OPENSSL_FUCHSIA && !BORINGSSL_UNSAFE_DETERMINISTIC_MODE
+#endif  // OPENSSL_RAND_FUCHSIA

crypto/rand_extra/windows.c

@@ -14,7 +14,9 @@
 
 #include <openssl/rand.h>
 
-#if defined(OPENSSL_WINDOWS) && !defined(BORINGSSL_UNSAFE_DETERMINISTIC_MODE)
+#include "../fipsmodule/rand/internal.h"
+
+#if defined(OPENSSL_RAND_WINDOWS)
 
 #include <limits.h>
 #include <stdlib.h>
@@ -31,12 +33,29 @@ OPENSSL_MSVC_PRAGMA(comment(lib, "bcrypt.lib"))
 
 OPENSSL_MSVC_PRAGMA(warning(pop))
 
-#include "../fipsmodule/rand/internal.h"
-
 #if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP) && \
     !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
+
 void CRYPTO_init_sysrand(void) {}
+
+void CRYPTO_sysrand(uint8_t *out, size_t requested) {
+  while (requested > 0) {
+    ULONG output_bytes_this_pass = ULONG_MAX;
+    if (requested < output_bytes_this_pass) {
+      output_bytes_this_pass = (ULONG)requested;
+    }
+    if (!BCRYPT_SUCCESS(BCryptGenRandom(
+            /*hAlgorithm=*/NULL, out, output_bytes_this_pass,
+            BCRYPT_USE_SYSTEM_PREFERRED_RNG))) {
+      abort();
+    }
+    requested -= output_bytes_this_pass;
+    out += output_bytes_this_pass;
+  }
+}
+
 #else
+
 // See: https://learn.microsoft.com/en-us/windows/win32/seccng/processprng
 typedef BOOL (WINAPI *ProcessPrngFunction)(PBYTE pbData, SIZE_T cbData);
 static ProcessPrngFunction g_processprng_fn = NULL;
@@ -56,26 +75,8 @@ void CRYPTO_init_sysrand(void) {
   static CRYPTO_once_t once = CRYPTO_ONCE_INIT;
   CRYPTO_once(&once, init_processprng);
 }
-#endif  // WINAPI_PARTITION_APP && !WINAPI_PARTITION_DESKTOP
 
 void CRYPTO_sysrand(uint8_t *out, size_t requested) {
-#if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_APP) && \
-    !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
-  while (requested > 0) {
-    ULONG output_bytes_this_pass = ULONG_MAX;
-    if (requested < output_bytes_this_pass) {
-      output_bytes_this_pass = (ULONG)requested;
-    }
-    if (!BCRYPT_SUCCESS(BCryptGenRandom(
-            /*hAlgorithm=*/NULL, out, output_bytes_this_pass,
-            BCRYPT_USE_SYSTEM_PREFERRED_RNG))) {
-      abort();
-    }
-    requested -= output_bytes_this_pass;
-    out += output_bytes_this_pass;
-  }
-  return;
-#else
   CRYPTO_init_sysrand();
   // On non-UWP configurations, use ProcessPrng instead of BCryptGenRandom
   // to avoid accessing resources that may be unavailable inside the
@@ -83,11 +84,12 @@ void CRYPTO_sysrand(uint8_t *out, size_t requested) {
   if (!g_processprng_fn(out, requested)) {
     abort();
   }
-#endif  // WINAPI_PARTITION_APP && !WINAPI_PARTITION_DESKTOP
 }
 
+#endif  // WINAPI_PARTITION_APP && !WINAPI_PARTITION_DESKTOP
+
 void CRYPTO_sysrand_for_seed(uint8_t *out, size_t requested) {
   CRYPTO_sysrand(out, requested);
 }
 
-#endif  // OPENSSL_WINDOWS && !BORINGSSL_UNSAFE_DETERMINISTIC_MODE
+#endif  // OPENSSL_RAND_WINDOWS