--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lib/libavutil/hmac.h	Tue Dec 31 14:52:14 2013 +0000
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2012 Martin Storsjo
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVUTIL_HMAC_H
+#define AVUTIL_HMAC_H
+
+#include <stdint.h>
+
+/**
+ * @defgroup lavu_hmac HMAC
+ * @ingroup lavu_crypto
+ * @{
+ */
+
+enum AVHMACType {
+    AV_HMAC_MD5,
+    AV_HMAC_SHA1,
+};
+
+typedef struct AVHMAC AVHMAC;
+
+/**
+ * Allocate an AVHMAC context.
+ * @param type The hash function used for the HMAC.
+ */
+AVHMAC *av_hmac_alloc(enum AVHMACType type);
+
+/**
+ * Free an AVHMAC context.
+ * @param ctx The context to free, may be NULL
+ */
+void av_hmac_free(AVHMAC *ctx);
+
+/**
+ * Initialize an AVHMAC context with an authentication key.
+ * @param ctx    The HMAC context
+ * @param key    The authentication key
+ * @param keylen The length of the key, in bytes
+ */
+void av_hmac_init(AVHMAC *ctx, const uint8_t *key, unsigned int keylen);
+
+/**
+ * Hash data with the HMAC.
+ * @param ctx  The HMAC context
+ * @param data The data to hash
+ * @param len  The length of the data, in bytes
+ */
+void av_hmac_update(AVHMAC *ctx, const uint8_t *data, unsigned int len);
+
+/**
+ * Finish hashing and output the HMAC digest.
+ * @param ctx    The HMAC context
+ * @param out    The output buffer to write the digest into
+ * @param outlen The length of the out buffer, in bytes
+ * @return       The number of bytes written to out, or a negative error code.
+ */
+int av_hmac_final(AVHMAC *ctx, uint8_t *out, unsigned int outlen);
+
+/**
+ * Hash an array of data with a key.
+ * @param ctx    The HMAC context
+ * @param data   The data to hash
+ * @param len    The length of the data, in bytes
+ * @param key    The authentication key
+ * @param keylen The length of the key, in bytes
+ * @param out    The output buffer to write the digest into
+ * @param outlen The length of the out buffer, in bytes
+ * @return       The number of bytes written to out, or a negative error code.
+ */
+int av_hmac_calc(AVHMAC *ctx, const uint8_t *data, unsigned int len,
+                 const uint8_t *key, unsigned int keylen,
+                 uint8_t *out, unsigned int outlen);
+
+/**
+ * @}
+ */
+
+#endif /* AVUTIL_HMAC_H */