1 files changed, 90 insertions, 0 deletions
diff --git a/lib/crypto_backend/cipher_generic.c b/lib/crypto_backend/cipher_generic.c
new file mode 100644
index 0000000..bce36e0
--- /dev/null
+++ b/lib/crypto_backend/cipher_generic.c
@@ -0,0 +1,90 @@
+/*
+ * Linux kernel cipher generic utilities
+ *
+ * Copyright (C) 2018-2021 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2018-2021 Milan Broz
+ *
+ * This file is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This file is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this file; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <string.h>
+#include <stdbool.h>
+#include <errno.h>
+#include "crypto_backend.h"
+
+struct cipher_alg {
+	const char *name;
+	const char *mode;
+	int blocksize;
+	bool wrapped_key;
+};
+
+/* FIXME: Getting block size should be dynamic from cipher backend. */
+static const struct cipher_alg cipher_algs[] = {
+	{ "cipher_null", NULL, 16, false },
+	{ "aes",         NULL, 16, false },
+	{ "serpent",     NULL, 16, false },
+	{ "twofish",     NULL, 16, false },
+	{ "anubis",      NULL, 16, false },
+	{ "blowfish",    NULL,  8, false },
+	{ "camellia",    NULL, 16, false },
+	{ "cast5",       NULL,  8, false },
+	{ "cast6",       NULL, 16, false },
+	{ "des",         NULL,  8, false },
+	{ "des3_ede",    NULL,  8, false },
+	{ "khazad",      NULL,  8, false },
+	{ "seed",        NULL, 16, false },
+	{ "tea",         NULL,  8, false },
+	{ "xtea",        NULL,  8, false },
+	{ "paes",        NULL, 16,  true }, /* protected AES, s390 wrapped key scheme */
+	{ "xchacha12,aes", "adiantum", 32, false },
+	{ "xchacha20,aes", "adiantum", 32, false },
+	{ "sm4",         NULL, 16, false },
+	{ NULL,          NULL,  0, false }
+};
+
+static const struct cipher_alg *_get_alg(const char *name, const char *mode)
+{
+	int i = 0;
+
+	while (name && cipher_algs[i].name) {
+		if (!strcasecmp(name, cipher_algs[i].name))
+			if (!mode || !cipher_algs[i].mode ||
+			    !strncasecmp(mode, cipher_algs[i].mode, strlen(cipher_algs[i].mode)))
+				return &cipher_algs[i];
+		i++;
+	}
+	return NULL;
+}
+
+int crypt_cipher_ivsize(const char *name, const char *mode)
+{
+	const struct cipher_alg *ca = _get_alg(name, mode);
+
+	if (!ca)
+		return -EINVAL;
+
+	if (mode && !strcasecmp(mode, "ecb"))
+		return 0;
+
+	return ca->blocksize;
+}
+
+int crypt_cipher_wrapped_key(const char *name, const char *mode)
+{
+	const struct cipher_alg *ca = _get_alg(name, mode);
+
+	return ca ? (int)ca->wrapped_key : 0;
+}