Fix botan_privkey_create if the desired algorithm was not available in build

If DSA was disabled, caused memory corruption/crashes due to combination of
uninitialized object and the tests not checking return values as carefully
as they should.

3 files changed, 47 insertions, 9 deletions

diff --git a/src/lib/ffi/ffi.cpp b/src/lib/ffi/ffi.cpp
index f067db75b..390afae81 100644
--- a/src/lib/ffi/ffi.cpp
+++ b/src/lib/ffi/ffi.cpp
@@ -980,20 +980,31 @@ int botan_privkey_create(botan_privkey_t* key_obj,
    {
    try
       {
-      if(key_obj == nullptr || rng_obj == nullptr)
-         return -1;
+      if(key_obj == nullptr)
+         return BOTAN_FFI_ERROR_NULL_POINTER;
+
+      *key_obj = nullptr;
+      if(rng_obj == nullptr)
+         return BOTAN_FFI_ERROR_NULL_POINTER;
+
       if(algo_name == nullptr)
          algo_name = "RSA";
       if(algo_params == nullptr)
          algo_params = "";
 
-      *key_obj = nullptr;
-
       Botan::RandomNumberGenerator& rng = safe_get(rng_obj);
       std::unique_ptr<Botan::Private_Key> key(
          Botan::create_private_key(algo_name, rng, algo_params));
-      *key_obj = new botan_privkey_struct(key.release());
-      return 0;
+
+      if(key)
+         {
+         *key_obj = new botan_privkey_struct(key.release());
+         return 0;
+         }
+      else
+         {
+         return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
+         }
       }
    catch(std::exception& e)
       {
@@ -1215,6 +1226,10 @@ int botan_privkey_load_dsa(botan_privkey_t* key,
       }
    return -1;
 #else
+   BOTAN_UNUSED(p);
+   BOTAN_UNUSED(q);
+   BOTAN_UNUSED(g);
+   BOTAN_UNUSED(x);
    return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
 #endif
    }
@@ -1238,6 +1253,10 @@ int botan_pubkey_load_dsa(botan_pubkey_t* key,
 
    return -1;
 #else
+   BOTAN_UNUSED(p);
+   BOTAN_UNUSED(q);
+   BOTAN_UNUSED(g);
+   BOTAN_UNUSED(y);
    return BOTAN_FFI_ERROR_NOT_IMPLEMENTED;
 #endif
    }
@@ -1365,7 +1384,7 @@ int botan_pubkey_get_field(botan_mp_t output,
                            botan_pubkey_t key,
                            const char* field_name_cstr)
    {
-   if(field_name_cstr == NULL)
+   if(field_name_cstr == nullptr)
       return BOTAN_FFI_ERROR_NULL_POINTER;
 
    const std::string field_name(field_name_cstr);
@@ -1379,7 +1398,7 @@ int botan_privkey_get_field(botan_mp_t output,
                                       botan_privkey_t key,
                                       const char* field_name_cstr)
    {
-   if(field_name_cstr == NULL)
+   if(field_name_cstr == nullptr)
       return BOTAN_FFI_ERROR_NULL_POINTER;
 
    const std::string field_name(field_name_cstr);
diff --git a/src/tests/test_ffi.cpp b/src/tests/test_ffi.cpp
index abc069c97..c196cf5c4 100644
--- a/src/tests/test_ffi.cpp
+++ b/src/tests/test_ffi.cpp
@@ -387,11 +387,26 @@ class FFI_Unit_Tests : public Test
 
          std::vector<Test::Result> results;
          results.push_back(ffi_test_mp(rng));
+
+#if defined(BOTAN_HAS_RSA)
          results.push_back(ffi_test_rsa(rng));
+#endif
+
+#if defined(BOTAN_HAS_DSA)
          results.push_back(ffi_test_dsa(rng));
+#endif
+
+#if defined(BOTAN_HAS_ECDSA)
          results.push_back(ffi_test_ecdsa(rng));
+#endif
+
+#if defined(BOTAN_HAS_ECDH)
          results.push_back(ffi_test_ecdh(rng));
+#endif
+
+#if defined(BOTAN_HAS_MCELIECE)
          results.push_back(ffi_test_mceliece(rng));
+#endif
 
          TEST_FFI_OK(botan_rng_destroy, (rng));
 
@@ -629,6 +644,7 @@ class FFI_Unit_Tests : public Test
          Test::Result result("FFI RSA");
 
          botan_privkey_t priv;
+
          if(TEST_FFI_OK(botan_privkey_create_rsa, (&priv, rng, 1024)))
             {
             TEST_FFI_OK(botan_privkey_check_key, (priv, rng, 0));
@@ -754,6 +770,7 @@ class FFI_Unit_Tests : public Test
          Test::Result result("FFI DSA");
 
          botan_privkey_t priv;
+
          if(TEST_FFI_OK(botan_privkey_create, (&priv, "DSA", "dsa/jce/1024", rng)))
             {
             TEST_FFI_OK(botan_privkey_check_key, (priv, rng, 0));
@@ -863,7 +880,7 @@ class FFI_Unit_Tests : public Test
          if(TEST_FFI_OK(botan_privkey_create_ecdsa, (&priv, rng, "secp384r1")))
             {
             botan_pubkey_t pub;
-            TEST_FFI_OK(botan_privkey_export_pubkey, (&pub, priv));
+            REQUIRE_FFI_OK(botan_privkey_export_pubkey, (&pub, priv));
 
             ffi_test_pubkey_export(result, pub, priv, rng);
 
diff --git a/src/tests/unit_tls.cpp b/src/tests/unit_tls.cpp
index 77aebce93..28152e624 100644
--- a/src/tests/unit_tls.cpp
+++ b/src/tests/unit_tls.cpp
@@ -132,6 +132,8 @@ class Credentials_Manager_Test : public Botan::Credentials_Manager
                   chain.push_back(*m_dsa_ca);
                   break;
                   }
+#else
+               BOTAN_UNUSED(context);
 #endif
                }
             }