Add support for TEA (Tiny Encryption Algorithm)

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

1 files changed, 71 insertions, 0 deletions

diff --git a/libavutil/tea.h b/libavutil/tea.h
new file mode 100644
index 0000000000..dd929bdafd
--- /dev/null
+++ b/libavutil/tea.h
@@ -0,0 +1,71 @@
+/*
+ * A 32-bit implementation of the TEA algorithm
+ * Copyright (c) 2015 Vesselin Bontchev
+ *
+ * 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_TEA_H
+#define AVUTIL_TEA_H
+
+#include <stdint.h>
+
+/**
+ * @file
+ * @brief Public header for libavutil TEA algorithm
+ * @defgroup lavu_tea TEA
+ * @ingroup lavu_crypto
+ * @{
+ */
+
+extern const int av_tea_size;
+
+struct AVTEA;
+
+/**
+  * Allocate an AVTEA context
+  * To free the struct: av_free(ptr)
+  */
+struct AVTEA *av_tea_alloc(void);
+
+/**
+ * Initialize an AVTEA context.
+ *
+ * @param ctx an AVTEA context
+ * @param key a key of 16 bytes used for encryption/decryption
+ * @param rounds the number of rounds in TEA (64 is the "standard")
+ */
+void av_tea_init(struct AVTEA *ctx, const uint8_t key[16], int rounds);
+
+/**
+ * Encrypt or decrypt a buffer using a previously initialized context.
+ *
+ * @param ctx an AVTEA context
+ * @param dst destination array, can be equal to src
+ * @param src source array, can be equal to dst
+ * @param count number of 8 byte blocks
+ * @param iv initialization vector for CBC mode, if NULL then ECB will be used
+ * @param decrypt 0 for encryption, 1 for decryption
+ */
+void av_tea_crypt(struct AVTEA *ctx, uint8_t *dst, const uint8_t *src,
+                  int count, uint8_t *iv, int decrypt);
+
+/**
+ * @}
+ */
+
+#endif /* AVUTIL_TEA_H */