[crypto] Allow cms_decrypt() to be called on unregistered images

Signed-off-by: Michael Brown <mcb30@ipxe.org>

diff --git a/src/crypto/cms.c b/src/crypto/cms.c
index 3a5debfcf82918514ac7c0e3e6479034515708f9..6c8217c0fcab1e7708b8cc896fece5287b90ac70 100644 (file)
--- a/src/crypto/cms.c
+++ b/src/crypto/cms.c
@@ -1101,13 +1101,15 @@ int cms_decrypt ( struct cms_message *cms, struct image *image,
        /* Duplicate cipher context for potential reencryption on error */
        memcpy ( ctxdup, ctx, cipher->ctxsize );
 
-       /* Temporarily unregister image */
-       image_get ( image );
-       unregister_image ( image );
-
        /* Clear trusted flag before modifying image */
        image_untrust ( image );
 
+       /* Temporarily unregister image, if applicable */
+       if ( original_flags & IMAGE_REGISTERED ) {
+               image_get ( image );
+               unregister_image ( image );
+       }
+
        /* Decrypt one block at a time */
        offset = 0;
        remaining = image->len;
@@ -1167,10 +1169,12 @@ int cms_decrypt ( struct cms_message *cms, struct image *image,
        copy_to_user ( image->data, ( offset - frag_len ), tmp, frag_len );
        image->len -= pad_len;
 
-       /* Clear image type and re-register image */
+       /* Clear image type and re-register image, if applicable */
        image->type = NULL;
-       register_image ( image );
-       image_put ( image );
+       if ( original_flags & IMAGE_REGISTERED ) {
+               register_image ( image );
+               image_put ( image );
+       }
 
        /* Free temporary working space */
        free ( tmp );
@@ -1191,9 +1195,11 @@ int cms_decrypt ( struct cms_message *cms, struct image *image,
                cipher_encrypt ( cipher, ctxdup, tmp, tmp, CMS_DECRYPT_BLKSZ );
                copy_to_user ( image->data, offset, tmp, CMS_DECRYPT_BLKSZ );
        }
+       if ( original_flags & IMAGE_REGISTERED ) {
+               register_image ( image ); /* Cannot fail on re-registration */
+               image_put ( image );
+       }
        image->flags = original_flags;
-       register_image ( image ); /* Cannot fail on re-registration */
-       image_put ( image );
  err_cipher:
        free ( tmp );
  err_alloc: