Only print FFI exceptions to stdout if an env var is set

So debugging is possible but default is silent.

2 files changed, 7 insertions, 1 deletions

diff --git a/src/lib/ffi/ffi.cpp b/src/lib/ffi/ffi.cpp
index 74c576631..48b9cf803 100644
--- a/src/lib/ffi/ffi.cpp
+++ b/src/lib/ffi/ffi.cpp
@@ -16,7 +16,10 @@ namespace Botan_FFI {
 
 int ffi_error_exception_thrown(const char* func_name, const char* exn, int rc)
    {
-   fprintf(stderr, "in %s exception '%s' returning %d\n", func_name, exn, rc);
+   if(std::getenv("BOTAN_FFI_PRINT_EXCEPTIONS"))
+      {
+      std::fprintf(stderr, "in %s exception '%s' returning %d\n", func_name, exn, rc);
+      }
    return rc;
    }
 
diff --git a/src/tests/test_ffi.cpp b/src/tests/test_ffi.cpp
index de80f3e3b..8f3639ad4 100644
--- a/src/tests/test_ffi.cpp
+++ b/src/tests/test_ffi.cpp
@@ -868,6 +868,9 @@ class FFI_Unit_Tests final : public Test
 
             TEST_FFI_OK(botan_block_cipher_clear, (cipher));
 
+            TEST_FFI_RC(BOTAN_FFI_ERROR_KEY_NOT_SET, botan_block_cipher_encrypt_blocks, (cipher, nullptr, nullptr, 0));
+            TEST_FFI_RC(BOTAN_FFI_ERROR_KEY_NOT_SET, botan_block_cipher_decrypt_blocks, (cipher, nullptr, nullptr, 0));
+
             TEST_FFI_RC(16, botan_block_cipher_block_size, (cipher));
 
             size_t min_keylen = 0, max_keylen = 0, mod_keylen = 0;