Merge GH #803 Add botan_ffi_supports_version func

3 files changed, 18 insertions, 0 deletions

diff --git a/src/lib/ffi/ffi.cpp b/src/lib/ffi/ffi.cpp
index 4727c0763..5c4cba4e7 100644
--- a/src/lib/ffi/ffi.cpp
+++ b/src/lib/ffi/ffi.cpp
@@ -208,6 +208,17 @@ uint32_t botan_ffi_api_version()
    return BOTAN_HAS_FFI;
    }
 
+int botan_ffi_supports_api(uint32_t api_version)
+   {
+   /*
+   * In the future if multiple versions are supported, this
+   * function would accept any of them.
+   */
+   if(api_version == BOTAN_HAS_FFI)
+      return 0;
+   return -1;
+   }
+
 const char* botan_version_string()
    {
    return Botan::version_cstr();
diff --git a/src/lib/ffi/ffi.h b/src/lib/ffi/ffi.h
index ed1b55a56..3378e0dcd 100644
--- a/src/lib/ffi/ffi.h
+++ b/src/lib/ffi/ffi.h
@@ -66,6 +66,12 @@ how to provide the cleanest API for such users would be most welcome.
 */
 BOTAN_DLL uint32_t botan_ffi_api_version();
 
+/*
+* Return 0 (ok) if the version given is one this library supports.
+* botan_ffi_supports_api(botan_ffi_api_version()) will always return 0.
+*/
+BOTAN_DLL int botan_ffi_supports_api(uint32_t api_version);
+
 BOTAN_DLL const char* botan_version_string();
 BOTAN_DLL uint32_t botan_version_major();
 BOTAN_DLL uint32_t botan_version_minor();
diff --git a/src/tests/test_ffi.cpp b/src/tests/test_ffi.cpp
index dd066e248..243583e8f 100644
--- a/src/tests/test_ffi.cpp
+++ b/src/tests/test_ffi.cpp
@@ -42,6 +42,7 @@ class FFI_Unit_Tests : public Test
          result.test_is_eq("Patch version", botan_version_patch(), Botan::version_patch());
          result.test_is_eq("Botan version", botan_version_string(), Botan::version_cstr());
          result.test_is_eq("Botan version datestamp", botan_version_datestamp(), Botan::version_datestamp());
+         result.test_is_eq("FFI supports its own version", botan_ffi_supports_api(botan_ffi_api_version()), 0);
 
          const std::vector<uint8_t> mem1 = { 0xFF, 0xAA, 0xFF };
          const std::vector<uint8_t> mem2 = mem1;