[FFmpeg-cvslog] avformat/hlsenc: add hls encrypt options
Steven Liu
git at videolan.org
Fri Apr 14 18:34:07 EEST 2017
ffmpeg | branch: master | Steven Liu <lq at chinaffmpeg.org> | Fri Apr 14 23:30:29 2017 +0800| [5caaa3a49e76b084ff8a9840d541bad64d96d7f7] | committer: Steven Liu
avformat/hlsenc: add hls encrypt options
refer to:
https://git.libav.org/?p=libav.git;a=commitdiff;h=0a4b9d0ccd10b3c39105f99bd320f696f69a75a2
add hls encrypt options looks like libav's libavformat/hlsenc.c
Reviewed-by: Moritz Barsnick <barsnick at gmx.net>
Signed-off-by: Steven Liu <lq at chinaffmpeg.org>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5caaa3a49e76b084ff8a9840d541bad64d96d7f7
---
doc/muxers.texi | 16 +++++++
libavformat/hlsenc.c | 122 ++++++++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 133 insertions(+), 5 deletions(-)
diff --git a/doc/muxers.texi b/doc/muxers.texi
index 844bbce990..0866142d43 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -597,6 +597,22 @@ ffmpeg -f lavfi -re -i testsrc -c:v h264 -hls_flags delete_segments \
-hls_key_info_file file.keyinfo out.m3u8
@end example
+ at item -hls_enc @var{enc}
+Enable (1) or disable (0) the AES128 encryption.
+When enabled every segment generated is encrypted and the encryption key
+is saved as @var{playlist name}.key.
+
+ at item -hls_enc_key @var{key}
+Hex-coded 16byte key to encrypt the segments, by default it
+is randomly generated.
+
+ at item -hls_enc_key_url @var{keyurl}
+If set, @var{keyurl} is prepended instead of @var{baseurl} to the key filename
+in the playlist.
+
+ at item -hls_enc_iv @var{iv}
+Hex-coded 16byte initialization vector for every segment instead
+of the autogenerated ones.
@item hls_flags @var{flags}
Possible values:
diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
index e6c378df2e..27c8e3355d 100644
--- a/libavformat/hlsenc.c
+++ b/libavformat/hlsenc.c
@@ -26,10 +26,18 @@
#include <unistd.h>
#endif
+#if CONFIG_GCRYPT
+#include <gcrypt.h>
+#elif CONFIG_OPENSSL
+#include <openssl/rand.h>
+#endif
+
#include "libavutil/avassert.h"
#include "libavutil/mathematics.h"
#include "libavutil/parseutils.h"
#include "libavutil/avstring.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/random_seed.h"
#include "libavutil/opt.h"
#include "libavutil/log.h"
#include "libavutil/time_internal.h"
@@ -139,6 +147,12 @@ typedef struct HLSContext {
char *subtitle_filename;
AVDictionary *format_options;
+ int encrypt;
+ char *key;
+ char *key_url;
+ char *iv;
+ char *key_basename;
+
char *key_info_file;
char key_file[LINE_BUFFER_SIZE + 1];
char key_uri[LINE_BUFFER_SIZE + 1];
@@ -349,6 +363,89 @@ fail:
return ret;
}
+static int randomize(uint8_t *buf, int len)
+{
+#if CONFIG_GCRYPT
+ gcry_randomize(buf, len, GCRY_VERY_STRONG_RANDOM);
+ return 0;
+#elif CONFIG_OPENSSL
+ if (RAND_bytes(buf, len))
+ return 0;
+#else
+ return AVERROR(ENOSYS);
+#endif
+ return AVERROR(EINVAL);
+}
+
+static int do_encrypt(AVFormatContext *s)
+{
+ HLSContext *hls = s->priv_data;
+ int ret;
+ int len;
+ AVIOContext *pb;
+ uint8_t key[KEYSIZE];
+
+ len = strlen(hls->basename) + 4 + 1;
+ hls->key_basename = av_mallocz(len);
+ if (!hls->key_basename)
+ return AVERROR(ENOMEM);
+
+ av_strlcpy(hls->key_basename, s->filename, len);
+ av_strlcat(hls->key_basename, ".key", len);
+
+ if (hls->key_url) {
+ strncpy(hls->key_file, hls->key_url, sizeof(hls->key_file));
+ strncpy(hls->key_uri, hls->key_url, sizeof(hls->key_uri));
+ } else {
+ strncpy(hls->key_file, hls->key_basename, sizeof(hls->key_file));
+ strncpy(hls->key_uri, hls->key_basename, sizeof(hls->key_uri));
+ }
+
+ if (!*hls->iv_string) {
+ uint8_t iv[16] = { 0 };
+ char buf[33];
+
+ if (!hls->iv) {
+ AV_WB64(iv + 8, hls->sequence);
+ } else {
+ memcpy(iv, hls->iv, sizeof(iv));
+ }
+ ff_data_to_hex(buf, iv, sizeof(iv), 0);
+ buf[32] = '\0';
+ memcpy(hls->iv_string, buf, sizeof(hls->iv_string));
+ }
+
+ if (!*hls->key_uri) {
+ av_log(hls, AV_LOG_ERROR, "no key URI specified in key info file\n");
+ return AVERROR(EINVAL);
+ }
+
+ if (!*hls->key_file) {
+ av_log(hls, AV_LOG_ERROR, "no key file specified in key info file\n");
+ return AVERROR(EINVAL);
+ }
+
+ if (!*hls->key_string) {
+ if (!hls->key) {
+ if ((ret = randomize(key, sizeof(key))) < 0) {
+ av_log(s, AV_LOG_ERROR, "Cannot generate a strong random key\n");
+ return ret;
+ }
+ } else {
+ memcpy(key, hls->key, sizeof(key));
+ }
+
+ ff_data_to_hex(hls->key_string, key, sizeof(key), 0);
+ if ((ret = s->io_open(s, &pb, hls->key_file, AVIO_FLAG_WRITE, NULL)) < 0)
+ return ret;
+ avio_seek(pb, 0, SEEK_CUR);
+ avio_write(pb, key, KEYSIZE);
+ avio_close(pb);
+ }
+ return 0;
+}
+
+
static int hls_encryption_start(AVFormatContext *s)
{
HLSContext *hls = s->priv_data;
@@ -662,7 +759,7 @@ static int hls_append_segment(struct AVFormatContext *s, HLSContext *hls, double
hls->discontinuity = 0;
}
- if (hls->key_info_file) {
+ if (hls->key_info_file || hls->encrypt) {
av_strlcpy(en->key_uri, hls->key_uri, sizeof(en->key_uri));
av_strlcpy(en->iv_string, hls->iv_string, sizeof(en->iv_string));
}
@@ -865,7 +962,7 @@ static int hls_window(AVFormatContext *s, int last)
hls->discontinuity_set = 1;
}
for (en = hls->segments; en; en = en->next) {
- if (hls->key_info_file && (!key_uri || strcmp(en->key_uri, key_uri) ||
+ if ((hls->encrypt || hls->key_info_file) && (!key_uri || strcmp(en->key_uri, key_uri) ||
av_strcasecmp(en->iv_string, iv_string))) {
avio_printf(out, "#EXT-X-KEY:METHOD=AES-128,URI=\"%s\"", en->key_uri);
if (*en->iv_string)
@@ -1031,9 +1128,18 @@ static int hls_start(AVFormatContext *s)
av_strlcat(oc->filename, ".tmp", sizeof(oc->filename));
}
- if (c->key_info_file) {
- if ((err = hls_encryption_start(s)) < 0)
- goto fail;
+ if (c->key_info_file || c->encrypt) {
+ if (c->key_info_file && c->encrypt) {
+ av_log(s, AV_LOG_WARNING, "Cannot use both -hls_key_info_file and -hls_enc,"
+ " will use -hls_key_info_file priority\n");
+ }
+ if (c->key_info_file) {
+ if ((err = hls_encryption_start(s)) < 0)
+ goto fail;
+ } else {
+ if ((err = do_encrypt(s)) < 0)
+ goto fail;
+ }
if ((err = av_dict_set(&options, "encryption_key", c->key_string, 0))
< 0)
goto fail;
@@ -1300,6 +1406,7 @@ fail:
if (ret < 0) {
av_freep(&hls->basename);
av_freep(&hls->vtt_basename);
+ av_freep(&hls->key_basename);
if (hls->avf)
avformat_free_context(hls->avf);
if (hls->vtt_avf)
@@ -1469,6 +1576,7 @@ static int hls_write_trailer(struct AVFormatContext *s)
ff_format_io_close(s, &vtt_oc->pb);
}
av_freep(&hls->basename);
+ av_freep(&hls->key_basename);
avformat_free_context(oc);
hls->avf = NULL;
@@ -1503,6 +1611,10 @@ static const AVOption options[] = {
{"hls_segment_filename", "filename template for segment files", OFFSET(segment_filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E},
{"hls_segment_size", "maximum size per segment file, (in bytes)", OFFSET(max_seg_size), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E},
{"hls_key_info_file", "file with key URI and key file path", OFFSET(key_info_file), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E},
+ {"hls_enc", "enable AES128 encryption support", OFFSET(encrypt), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, E},
+ {"hls_enc_key", "hex-coded 16 byte key to encrypt the segments", OFFSET(key), AV_OPT_TYPE_STRING, .flags = E},
+ {"hls_enc_key_url", "url to access the key to decrypt the segments", OFFSET(key_url), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E},
+ {"hls_enc_iv", "hex-coded 16 byte initialization vector", OFFSET(iv), AV_OPT_TYPE_STRING, .flags = E},
{"hls_subtitle_path", "set path of hls subtitles", OFFSET(subtitle_filename), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E},
{"hls_flags", "set flags affecting HLS playlist and media file generation", OFFSET(flags), AV_OPT_TYPE_FLAGS, {.i64 = 0 }, 0, UINT_MAX, E, "flags"},
{"single_file", "generate a single media file indexed with byte ranges", 0, AV_OPT_TYPE_CONST, {.i64 = HLS_SINGLE_FILE }, 0, UINT_MAX, E, "flags"},
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