RTMPE protocol support

This adds two protocols, but one of them is an internal implementation
detail just used as an abstraction layer/generalization in the code. The
RTMPE protocol implementation uses ffrtmpcrypt:// as an alternative to the
tcp:// protocol. This allows moving most of the lower level logic out
from the higher level generic rtmp code.

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

1 files changed, 102 insertions, 0 deletions

diff --git a/libavformat/rtmpdh.h b/libavformat/rtmpdh.h
new file mode 100644
index 0000000000..5de8bde821
--- /dev/null
+++ b/libavformat/rtmpdh.h
@@ -0,0 +1,102 @@
+/*
+ * RTMP Diffie-Hellmann utilities
+ * Copyright (c) 2012 Samuel Pitoiset
+ *
+ * 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 AVFORMAT_RTMPDH_H
+#define AVFORMAT_RTMPDH_H
+
+#include "avformat.h"
+#include "config.h"
+
+#if CONFIG_NETTLE || CONFIG_GCRYPT
+#if CONFIG_NETTLE
+#include <gmp.h>
+#include <nettle/bignum.h>
+
+typedef mpz_ptr FFBigNum;
+#elif CONFIG_GCRYPT
+#include <gcrypt.h>
+
+typedef gcry_mpi_t FFBigNum;
+#endif
+
+typedef struct FF_DH {
+  FFBigNum p;
+  FFBigNum g;
+  FFBigNum pub_key;
+  FFBigNum priv_key;
+  long length;
+} FF_DH;
+
+#elif CONFIG_OPENSSL
+#include <openssl/bn.h>
+#include <openssl/dh.h>
+
+typedef BIGNUM *FFBigNum;
+typedef DH FF_DH;
+#endif
+
+/**
+ * Initialize a Diffie-Hellmann context.
+ *
+ * @param key_len length of the key
+ * @return a new Diffie-Hellmann context on success, NULL otherwise
+ */
+FF_DH *ff_dh_init(int key_len);
+
+/**
+ * Free a Diffie-Hellmann context.
+ *
+ * @param dh a Diffie-Hellmann context to free
+ */
+void ff_dh_free(FF_DH *dh);
+
+/**
+ * Generate a public key.
+ *
+ * @param dh a Diffie-Hellmann context
+ * @return zero on success, negative value otherwise
+ */
+int ff_dh_generate_public_key(FF_DH *dh);
+
+/**
+ * Write the public key into the given buffer.
+ *
+ * @param dh            a Diffie-Hellmann context, containing the public key to write
+ * @param pub_key       the buffer where the public key is written
+ * @param pub_key_len   the length of the buffer
+ * @return zero on success, negative value otherwise
+ */
+int ff_dh_write_public_key(FF_DH *dh, uint8_t *pub_key, int pub_key_len);
+
+/**
+ * Compute the shared secret key from the private FF_DH value and the
+ * other party's public value.
+ *
+ * @param dh            a Diffie-Hellmann context, containing the private key
+ * @param pub_key       the buffer containing the public key
+ * @param pub_key_len   the length of the buffer
+ * @param secret_key    the buffer where the secret key is written
+ * @return length of the shared secret key on success, negative value otherwise
+ */
+int ff_dh_compute_shared_secret_key(FF_DH *dh, const uint8_t *pub_key,
+                                    int pub_key_len, uint8_t *secret_key);
+
+#endif /* AVFORMAT_RTMPDH_H */