Add Blowfish encryption support in libavutil

Signed-off-by: Martin Storsjö <martin@martin.st>

1 files changed, 76 insertions, 0 deletions

diff --git a/libavutil/blowfish.h b/libavutil/blowfish.h
new file mode 100644
index 0000000000..8c29536cfe
--- /dev/null
+++ b/libavutil/blowfish.h
@@ -0,0 +1,76 @@
+/*
+ * Blowfish algorithm
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVUTIL_BLOWFISH_H
+#define AVUTIL_BLOWFISH_H
+
+#include <stdint.h>
+
+/**
+ * @defgroup lavu_blowfish Blowfish
+ * @ingroup lavu_crypto
+ * @{
+ */
+
+#define AV_BF_ROUNDS 16
+
+typedef struct AVBlowfish {
+    uint32_t p[AV_BF_ROUNDS + 2];
+    uint32_t s[4][256];
+} AVBlowfish;
+
+/**
+ * Initialize an AVBlowfish context.
+ *
+ * @param ctx an AVBlowfish context
+ * @param key a key
+ * @param key_len length of the key
+ */
+void av_blowfish_init(struct AVBlowfish *ctx, const uint8_t *key, int key_len);
+
+/**
+ * Encrypt or decrypt a buffer using a previously initialized context.
+ *
+ * @param ctx an AVBlowfish context
+ * @param xl left four bytes halves of input to be encrypted
+ * @param xr right four bytes halves of input to be encrypted
+ * @param decrypt 0 for encryption, 1 for decryption
+ */
+void av_blowfish_crypt_ecb(struct AVBlowfish *ctx, uint32_t *xl, uint32_t *xr,
+                           int decrypt);
+
+/**
+ * Encrypt or decrypt a buffer using a previously initialized context.
+ *
+ * @param ctx an AVBlowfish 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 ECB will be used
+ * @param decrypt 0 for encryption, 1 for decryption
+ */
+void av_blowfish_crypt(struct AVBlowfish *ctx, uint8_t *dst, const uint8_t *src,
+                       int count, uint8_t *iv, int decrypt);
+
+/**
+ * @}
+ */
+
+#endif /* AVUTIL_BLOWFISH_H */