remove @EAP_LDFLAGS@, no longer exists

[mech_eap.git] / libeap / src / crypto / aes-ctr.c

diff --git a/libeap/src/crypto/aes-ctr.c b/libeap/src/crypto/aes-ctr.c
new file mode 100644 (file)
index 0000000..468f877
--- /dev/null
+++ b/libeap/src/crypto/aes-ctr.c
@@ -0,0 +1,61 @@
+/*
+ * AES-128 CTR
+ *
+ * Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See README and COPYING for more details.
+ */
+
+#include "includes.h"
+
+#include "common.h"
+#include "aes.h"
+#include "aes_wrap.h"
+
+/**
+ * aes_128_ctr_encrypt - AES-128 CTR mode encryption
+ * @key: Key for encryption (16 bytes)
+ * @nonce: Nonce for counter mode (16 bytes)
+ * @data: Data to encrypt in-place
+ * @data_len: Length of data in bytes
+ * Returns: 0 on success, -1 on failure
+ */
+int aes_128_ctr_encrypt(const u8 *key, const u8 *nonce,
+                       u8 *data, size_t data_len)
+{
+       void *ctx;
+       size_t j, len, left = data_len;
+       int i;
+       u8 *pos = data;
+       u8 counter[AES_BLOCK_SIZE], buf[AES_BLOCK_SIZE];
+
+       ctx = aes_encrypt_init(key, 16);
+       if (ctx == NULL)
+               return -1;
+       os_memcpy(counter, nonce, AES_BLOCK_SIZE);
+
+       while (left > 0) {
+               aes_encrypt(ctx, counter, buf);
+
+               len = (left < AES_BLOCK_SIZE) ? left : AES_BLOCK_SIZE;
+               for (j = 0; j < len; j++)
+                       pos[j] ^= buf[j];
+               pos += len;
+               left -= len;
+
+               for (i = AES_BLOCK_SIZE - 1; i >= 0; i--) {
+                       counter[i]++;
+                       if (counter[i])
+                               break;
+               }
+       }
+       aes_encrypt_deinit(ctx);
+       return 0;
+}