Emscripten's getentropy does not enforce the 256-byte limit

Author: justsmth

crypto/rand_extra/getentropy_test.cc

@@ -54,12 +54,16 @@ TEST(GetEntropyTest, NotObviouslyBroken) {
   memcpy(buf3, buf1, sizeof(buf3));
   EXPECT_EQ(getentropy(buf1, sizeof(buf1)), 0);
   EXPECT_NE(Bytes(buf1), Bytes(buf3));
-  errno = 0;
-  uint8_t toobig[257];
   // getentropy should fail returning -1 and setting errno to EIO if you request
   // more than 256 bytes of entropy. macOS's man page says EIO but it actually
   // returns EINVAL, so we accept either.
+  // Note: Emscripten's getentropy implementation does not enforce the 256-byte
+  // limit, so we skip this check on WASM.
+#if !defined(OPENSSL_WASM)
+  errno = 0;
+  uint8_t toobig[257];
   EXPECT_EQ(getentropy(toobig, 257), -1);
   EXPECT_TRUE(errno == EIO || errno == EINVAL);
+#endif
 }
 #endif