diff --git a/libavformat/Makefile b/libavformat/Makefile
index 5e029ed96bc89be2c4fcca8a24f76eab101ddbc2..e2e398212553eefcf8c598d7d4a5b00397111082 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -312,6 +312,7 @@ OBJS+= avio.o aviobuf.o
OBJS-$(CONFIG_APPLEHTTP_PROTOCOL) += applehttpproto.o
OBJS-$(CONFIG_CONCAT_PROTOCOL) += concat.o
+OBJS-$(CONFIG_CRYPTO_PROTOCOL) += crypto.o
OBJS-$(CONFIG_FILE_PROTOCOL) += file.o
OBJS-$(CONFIG_GOPHER_PROTOCOL) += gopher.o
OBJS-$(CONFIG_HTTP_PROTOCOL) += http.o httpauth.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 931947d60a965730b827deb29421d2f4b87450ab..f1c3d3b76811552f3646a311dbe6429997c727b1 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -235,6 +235,7 @@ void av_register_all(void)
/* protocols */
REGISTER_PROTOCOL (APPLEHTTP, applehttp);
REGISTER_PROTOCOL (CONCAT, concat);
+ REGISTER_PROTOCOL (CRYPTO, crypto);
REGISTER_PROTOCOL (FILE, file);
REGISTER_PROTOCOL (GOPHER, gopher);
REGISTER_PROTOCOL (HTTP, http);
diff --git a/libavformat/crypto.c b/libavformat/crypto.c
new file mode 100644
index 0000000000000000000000000000000000000000..ea6012ad09fc9eff5c542c954a5575f91435f3f2
--- /dev/null
+++ b/libavformat/crypto.c
@@ -0,0 +1,170 @@
+/*
+ * Decryption protocol handler
+ * Copyright (c) 2011 Martin Storsjo
+ *
+ * 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
+ */
+
+#include "avformat.h"
+#include "libavutil/aes.h"
+#include "libavutil/avstring.h"
+#include "libavutil/opt.h"
+#include "internal.h"
+#include "url.h"
+
+#define MAX_BUFFER_BLOCKS 150
+#define BLOCKSIZE 16
+
+typedef struct {
+ const AVClass *class;
+ URLContext *hd;
+ uint8_t inbuffer [BLOCKSIZE*MAX_BUFFER_BLOCKS],
+ outbuffer[BLOCKSIZE*MAX_BUFFER_BLOCKS];
+ uint8_t *outptr;
+ int indata, indata_used, outdata;
+ int eof;
+ uint8_t *key;
+ int keylen;
+ uint8_t *iv;
+ int ivlen;
+ struct AVAES *aes;
+} CryptoContext;
+
+#define OFFSET(x) offsetof(CryptoContext, x)
+static const AVOption options[] = {
+ {"key", "AES decryption key", OFFSET(key), FF_OPT_TYPE_BINARY },
+ {"iv", "AES decryption initialization vector", OFFSET(iv), FF_OPT_TYPE_BINARY },
+ { NULL }
+};
+
+static const AVClass crypto_class = {
+ "crypto", av_default_item_name, options, LIBAVUTIL_VERSION_INT
+};
+
+static int crypto_open(URLContext *h, const char *uri, int flags)
+{
+ const char *nested_url;
+ int ret;
+ CryptoContext *c = h->priv_data;
+
+ if (!av_strstart(uri, "crypto+", &nested_url) &&
+ !av_strstart(uri, "crypto:", &nested_url)) {
+ av_log(h, AV_LOG_ERROR, "Unsupported url %s\n", uri);
+ ret = AVERROR(EINVAL);
+ goto err;
+ }
+
+ if (c->keylen < BLOCKSIZE || c->ivlen < BLOCKSIZE) {
+ av_log(h, AV_LOG_ERROR, "Key or IV not set\n");
+ ret = AVERROR(EINVAL);
+ goto err;
+ }
+ if (flags & AVIO_FLAG_WRITE) {
+ av_log(h, AV_LOG_ERROR, "Only decryption is supported currently\n");
+ ret = AVERROR(ENOSYS);
+ goto err;
+ }
+ if ((ret = ffurl_open(&c->hd, nested_url, AVIO_FLAG_READ)) < 0) {
+ av_log(h, AV_LOG_ERROR, "Unable to open input\n");
+ goto err;
+ }
+ c->aes = av_mallocz(av_aes_size);
+ if (!c->aes) {
+ ret = AVERROR(ENOMEM);
+ goto err;
+ }
+
+ av_aes_init(c->aes, c->key, 128, 1);
+
+ h->is_streamed = 1;
+
+ return 0;
+err:
+ av_free(c->key);
+ av_free(c->iv);
+ return ret;
+}
+
+static int crypto_read(URLContext *h, uint8_t *buf, int size)
+{
+ CryptoContext *c = h->priv_data;
+ int blocks;
+retry:
+ if (c->outdata > 0) {
+ size = FFMIN(size, c->outdata);
+ memcpy(buf, c->outptr, size);
+ c->outptr += size;
+ c->outdata -= size;
+ return size;
+ }
+ // We avoid using the last block until we've found EOF,
+ // since we'll remove PKCS7 padding at the end. So make
+ // sure we've got at least 2 blocks, so we can decrypt
+ // at least one.
+ while (c->indata - c->indata_used < 2*BLOCKSIZE) {
+ int n = ffurl_read(c->hd, c->inbuffer + c->indata,
+ sizeof(c->inbuffer) - c->indata);
+ if (n <= 0) {
+ c->eof = 1;
+ break;
+ }
+ c->indata += n;
+ }
+ blocks = (c->indata - c->indata_used) / BLOCKSIZE;
+ if (!blocks)
+ return AVERROR_EOF;
+ if (!c->eof)
+ blocks--;
+ av_aes_crypt(c->aes, c->outbuffer, c->inbuffer + c->indata_used, blocks,
+ c->iv, 1);
+ c->outdata = BLOCKSIZE * blocks;
+ c->outptr = c->outbuffer;
+ c->indata_used += BLOCKSIZE * blocks;
+ if (c->indata_used >= sizeof(c->inbuffer)/2) {
+ memmove(c->inbuffer, c->inbuffer + c->indata_used,
+ c->indata - c->indata_used);
+ c->indata -= c->indata_used;
+ c->indata_used = 0;
+ }
+ if (c->eof) {
+ // Remove PKCS7 padding at the end
+ int padding = c->outbuffer[c->outdata - 1];
+ c->outdata -= padding;
+ }
+ goto retry;
+}
+
+static int crypto_close(URLContext *h)
+{
+ CryptoContext *c = h->priv_data;
+ if (c->hd)
+ ffurl_close(c->hd);
+ av_free(c->aes);
+ av_free(c->key);
+ av_free(c->iv);
+ return 0;
+}
+
+URLProtocol ff_crypto_protocol = {
+ .name = "crypto",
+ .url_open = crypto_open,
+ .url_read = crypto_read,
+ .url_close = crypto_close,
+ .priv_data_size = sizeof(CryptoContext),
+ .priv_data_class = &crypto_class,
+ .flags = URL_PROTOCOL_FLAG_NESTED_SCHEME,
+};