1 files changed, 162 insertions, 0 deletions
diff --git a/src/libstrongswan/crypto/aead.c b/src/libstrongswan/crypto/aead.c
new file mode 100644
index 000000000..51cb05909
--- /dev/null
+++ b/src/libstrongswan/crypto/aead.c
@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2010 Martin Willi
+ * Copyright (C) 2010 revosec AG
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program 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 General Public License
+ * for more details.
+ */
+
+#include "aead.h"
+
+#include <debug.h>
+
+typedef struct private_aead_t private_aead_t;
+
+/**
+ * Private data of an aead_t object.
+ */
+struct private_aead_t {
+
+	/**
+	 * Public aead_t interface.
+	 */
+	aead_t public;
+
+	/**
+	 * traditional crypter
+	 */
+	crypter_t *crypter;
+
+	/**
+	 * draditional signer
+	 */
+	signer_t *signer;
+};
+
+METHOD(aead_t, encrypt, void,
+	private_aead_t *this, chunk_t plain, chunk_t assoc, chunk_t iv,
+	chunk_t *encrypted)
+{
+	chunk_t encr, sig;
+
+	this->signer->get_signature(this->signer, assoc, NULL);
+	this->signer->get_signature(this->signer, iv, NULL);
+
+	if (encrypted)
+	{
+		this->crypter->encrypt(this->crypter, plain, iv, &encr);
+		this->signer->allocate_signature(this->signer, encr, &sig);
+		*encrypted = chunk_cat("cmm", iv, encr, sig);
+	}
+	else
+	{
+		this->crypter->encrypt(this->crypter, plain, iv, NULL);
+		this->signer->get_signature(this->signer, plain, plain.ptr + plain.len);
+	}
+}
+
+METHOD(aead_t, decrypt, bool,
+	private_aead_t *this, chunk_t encrypted, chunk_t assoc, chunk_t iv,
+	chunk_t *plain)
+{
+	chunk_t sig;
+	size_t bs;
+
+	bs = this->crypter->get_block_size(this->crypter);
+	sig.len = this->signer->get_block_size(this->signer);
+	if (sig.len > encrypted.len || (encrypted.len - sig.len) % bs)
+	{
+		DBG1(DBG_LIB, "invalid encrypted data length %d with block size %d",
+			encrypted.len - sig.len, bs);
+		return FALSE;
+	}
+	chunk_split(encrypted, "mm", encrypted.len - sig.len,
+				&encrypted, sig.len, &sig);
+
+	this->signer->get_signature(this->signer, assoc, NULL);
+	this->signer->get_signature(this->signer, iv, NULL);
+	if (!this->signer->verify_signature(this->signer, encrypted, sig))
+	{
+		DBG1(DBG_LIB, "MAC verification failed");
+		return FALSE;
+	}
+	this->crypter->decrypt(this->crypter, encrypted, iv, plain);
+	return TRUE;
+}
+
+METHOD(aead_t, get_block_size, size_t,
+	private_aead_t *this)
+{
+	return this->crypter->get_block_size(this->crypter);
+}
+
+METHOD(aead_t, get_icv_size, size_t,
+	private_aead_t *this)
+{
+	return this->signer->get_block_size(this->signer);
+}
+
+METHOD(aead_t, get_iv_size, size_t,
+	private_aead_t *this)
+{
+	return this->crypter->get_iv_size(this->crypter);
+}
+
+METHOD(aead_t, get_key_size, size_t,
+	private_aead_t *this)
+{
+	return this->crypter->get_key_size(this->crypter) +
+			this->signer->get_key_size(this->signer);
+}
+
+METHOD(aead_t, set_key, void,
+	private_aead_t *this, chunk_t key)
+{
+	chunk_t sig, enc;
+
+	chunk_split(key, "mm", this->signer->get_key_size(this->signer), &sig,
+				this->crypter->get_key_size(this->crypter), &enc);
+
+	this->signer->set_key(this->signer, sig);
+	this->crypter->set_key(this->crypter, enc);
+}
+
+METHOD(aead_t, destroy, void,
+	private_aead_t *this)
+{
+	this->crypter->destroy(this->crypter);
+	this->signer->destroy(this->signer);
+	free(this);
+}
+
+/**
+ * See header
+ */
+aead_t *aead_create(crypter_t *crypter, signer_t *signer)
+{
+	private_aead_t *this;
+
+	INIT(this,
+		.public = {
+			.encrypt = _encrypt,
+			.decrypt = _decrypt,
+			.get_block_size = _get_block_size,
+			.get_icv_size = _get_icv_size,
+			.get_iv_size = _get_iv_size,
+			.get_key_size = _get_key_size,
+			.set_key = _set_key,
+			.destroy = _destroy,
+		},
+		.crypter = crypter,
+		.signer = signer,
+	);
+
+	return &this->public;
+}