[v3 PATCH 2/5] bcrypt: Implement BCryptDecrypt for AES GCM mode.

[Alistair Leslie-Hughes]

From: Michael Müller

Signed-off-by: Alistair Leslie-Hughes 
---
 dlls/bcrypt/bcrypt_main.c  | 28 +++++++++++++++++++++++-----
 dlls/bcrypt/tests/bcrypt.c |  8 ++++----
 2 files changed, 27 insertions(+), 9 deletions(-)

diff --git a/dlls/bcrypt/bcrypt_main.c b/dlls/bcrypt/bcrypt_main.c
index 96695532b5..573cd374a4 100644
--- a/dlls/bcrypt/bcrypt_main.c
+++ b/dlls/bcrypt/bcrypt_main.c
@@ -1361,17 +1361,35 @@ NTSTATUS WINAPI BCryptDecrypt( BCRYPT_KEY_HANDLE handle, UCHAR *input, ULONG inp
            padding, iv, iv_len, output, output_len, ret_len, flags );

if (!key || key->hdr.magic != MAGIC_KEY) return STATUS_INVALID_HANDLE;
-    if (padding)
-    {
-        FIXME( "padding info not implemented\n" );
-        return STATUS_NOT_IMPLEMENTED;
-    }
     if (flags & ~BCRYPT_BLOCK_PADDING)
     {
         FIXME( "flags %08x not supported\n", flags );
         return STATUS_NOT_IMPLEMENTED;
     }

+    if (key->mode == MODE_ID_GCM)
+    {
+        BCRYPT_AUTHENTICATED_CIPHER_MODE_INFO *auth_info = padding;
+
+        if (!auth_info) return STATUS_INVALID_PARAMETER;
+        if (!auth_info->pbNonce) return STATUS_INVALID_PARAMETER;
+        if (!auth_info->pbTag) return STATUS_INVALID_PARAMETER;
+        if (auth_info->cbTag < 12 || auth_info->cbTag > 16) return STATUS_INVALID_PARAMETER;
+
+        if ((status = key_set_params( key, auth_info->pbNonce, auth_info->cbNonce )))
+            return status;
+
+        *ret_len = input_len;
+        if (flags & BCRYPT_BLOCK_PADDING) return STATUS_INVALID_PARAMETER;
+        if (!output) return STATUS_SUCCESS;
+        if (output_len < *ret_len) return STATUS_BUFFER_TOO_SMALL;
+
+        if ((status = key_decrypt( key, input, input_len, output, output_len )))
+            return status;
+
+        return STATUS_SUCCESS;
+    }
+
     if ((status = key_set_params( key, iv, iv_len ))) return status;

*ret_len = input_len;
diff --git a/dlls/bcrypt/tests/bcrypt.c b/dlls/bcrypt/tests/bcrypt.c
index 1875fb3f89..e3cbc87db4 100644
--- a/dlls/bcrypt/tests/bcrypt.c
+++ b/dlls/bcrypt/tests/bcrypt.c
@@ -969,16 +969,16 @@ static void test_BCryptDecrypt(void)
     memcpy(ivbuf, iv, sizeof(iv));
     memset(plaintext, 0, sizeof(plaintext));
     ret = pBCryptDecrypt(key, ciphertext4, 32, &auth_info, ivbuf, 16, plaintext, 32, &size, 0);
-    todo_wine ok(ret == STATUS_SUCCESS, "got %08x\n", ret);
-    todo_wine ok(size == 32, "got %u\n", size);
-    todo_wine ok(!memcmp(plaintext, expected3, sizeof(expected3)), "wrong data\n");
+    ok(ret == STATUS_SUCCESS, "got %08x\n", ret);
+    ok(size == 32, "got %u\n", size);
+    ok(!memcmp(plaintext, expected3, sizeof(expected3)), "wrong data\n");

/* test with wrong tag */
     memcpy(ivbuf, iv, sizeof(iv));
     auth_info.pbTag = iv; /* wrong tag */
     ret = pBCryptDecrypt(key, ciphertext4, 32, &auth_info, ivbuf, 16, plaintext, 32, &size, 0);
     todo_wine ok(ret == STATUS_AUTH_TAG_MISMATCH, "got %08x\n", ret);
-    todo_wine ok(size == 32, "got %u\n", size);
+    ok(size == 32, "got %u\n", size);

ret = pBCryptDestroyKey(key);
     ok(ret == STATUS_SUCCESS, "got %08x\n", ret);