[FFmpeg-devel] [PATCH] Allow HLS to decrypt stream when using a data url for the key

[Simon Black]

If HLS is trying to play an encrypted stream where the key is a data URL rather
than a file based key HLS will not work.

a data url within the key is one such as:
#EXT-X-KEY:METHOD=AES-128,URI="data:;base64,dKbarMNMRSmPPEXQ3dDCNA=="

The error message is reported as:

[https @ 0x7f9eb00120c0] HTTP error 404 Not Found
Unable to open key file

https://BASE.URL.HERE/data:;base64,dKbarMNMRSmPPEXQ3dDCNA
==

This is caused as the URL is created with the value in URI field of the
EXT-X-KEY tag using 

ff_make_absolute_url(seg->key, sizeof(seg->key), url, key);

the data: schema is ignored.


Signed-off-by: Simon Black <sblack at omnifone.com>
---
 libavformat/hls.c | 32 +++++++++++++++++++++++---------
 1 file changed, 23 insertions(+), 9 deletions(-)

diff --git a/libavformat/hls.c b/libavformat/hls.c
index e291950..cba6cce 100644
--- a/libavformat/hls.c
+++ b/libavformat/hls.c
@@ -30,6 +30,7 @@
 #include "libavutil/mathematics.h"
 #include "libavutil/opt.h"
 #include "libavutil/dict.h"
+#include "libavutil/base64.h"
 #include "libavutil/time.h"
 #include "avformat.h"
 #include "internal.h"
@@ -367,7 +368,11 @@ static int parse_playlist(HLSContext *c, const char *url,
                     memset(seg->iv, 0, sizeof(seg->iv));
                     AV_WB32(seg->iv + 12, seq);
                 }
-                ff_make_absolute_url(seg->key, sizeof(seg->key), url, key);
+                if (key==strstr (key,"data:")) {
+                    av_strlcpy(seg->key, key, sizeof(seg->key));                                       
        
+                } else {
+                    ff_make_absolute_url(seg->key, sizeof(seg->key), url, key);
+                }                
                 ff_make_absolute_url(seg->url, sizeof(seg->url), url, line);
                 dynarray_add(&pls->segments, &pls->n_segments, seg);
                 is_segment = 0;
@@ -408,17 +413,26 @@ static int open_input(HLSContext *c, struct playlist *pls)
         char iv[33], key[33], url[MAX_URL_SIZE];
         if (strcmp(seg->key, pls->key_url)) {
             URLContext *uc;
-            if (ffurl_open(&uc, seg->key, AVIO_FLAG_READ,
+            if (seg->key==strstr (seg->key,"data:")) {
+               if (strstr(seg->key,"data:;base64,")) {
+                   av_base64_decode(pls->key, &seg->key[13], sizeof(pls->key));
+               } else {
+                   av_log(NULL, AV_LOG_ERROR, "Unable to use data key %s\n", seg->key);
+               }
+            } else {
+                if (ffurl_open(&uc, seg->key, AVIO_FLAG_READ,
                            &pls->parent->interrupt_callback, &opts2) == 0) {
-                if (ffurl_read_complete(uc, pls->key, sizeof(pls->key))
-                    != sizeof(pls->key)) {
-                    av_log(NULL, AV_LOG_ERROR, "Unable to read key file %s\n",
+                    if (ffurl_read_complete(uc, pls->key, sizeof(pls->key))
+                        != sizeof(pls->key)) {
+                        av_log(NULL, AV_LOG_ERROR, "Unable to read key file %s\n",
+                               seg->key);
+                    }
+                    ffurl_close(uc);
+                } else {
+                    av_log(NULL, AV_LOG_ERROR, "Unable to open key file %s\n",
                            seg->key);
                 }
-                ffurl_close(uc);
-            } else {
-                av_log(NULL, AV_LOG_ERROR, "Unable to open key file %s\n",
-                       seg->key);
+                ffurl_close(uc);               
             }
             av_strlcpy(pls->key_url, seg->key, sizeof(pls->key_url));
         }
-- 
1.8.5.2 (Apple Git-48)

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