[FFmpeg-devel] [PATCH] avformat/hls: add macros for iv and key size

[lance.lmwang at gmail.com]

From: Limin Wang <lance.lmwang at gmail.com>

Signed-off-by: Limin Wang <lance.lmwang at gmail.com>
---
 libavformat/hls.c      | 12 ++++++------
 libavformat/hlsenc.c   | 19 +++++++++----------
 libavformat/internal.h |  2 ++
 3 files changed, 17 insertions(+), 16 deletions(-)

diff --git a/libavformat/hls.c b/libavformat/hls.c
index 8fc6924..a215c6a 100644
--- a/libavformat/hls.c
+++ b/libavformat/hls.c
@@ -72,7 +72,7 @@ struct segment {
     char *url;
     char *key;
     enum KeyType key_type;
-    uint8_t iv[16];
+    uint8_t iv[KEYSIZE];
     /* associated Media Initialization Section, treated as a segment */
     struct segment *init_section;
 };
@@ -131,7 +131,7 @@ struct playlist {
     unsigned int init_sec_buf_read_offset;
 
     char key_url[MAX_URL_SIZE];
-    uint8_t key[16];
+    uint8_t key[KEYSIZE];
 
     /* ID3 timestamp handling (elementary audio streams have ID3 timestamps
      * (and possibly other ID3 tags) in the beginning of each segment) */
@@ -374,7 +374,7 @@ static void handle_variant_args(struct variant_info *info, const char *key,
 struct key_info {
      char uri[MAX_URL_SIZE];
      char method[11];
-     char iv[35];
+     char iv[KEY_STRING_SIZE + 2]; /* 2 -> 0x */
 };
 
 static void handle_key_args(struct key_info *info, const char *key,
@@ -714,7 +714,7 @@ static int parse_playlist(HLSContext *c, const char *url,
     int ret = 0, is_segment = 0, is_variant = 0;
     int64_t duration = 0;
     enum KeyType key_type = KEY_NONE;
-    uint8_t iv[16] = "";
+    uint8_t iv[KEYSIZE] = "";
     int has_iv = 0;
     char key[MAX_URL_SIZE] = "";
     char line[MAX_URL_SIZE];
@@ -1252,7 +1252,7 @@ static int open_input(HLSContext *c, struct playlist *pls, struct segment *seg,
     if (seg->key_type == KEY_NONE) {
         ret = open_url(pls->parent, in, seg->url, &c->avio_opts, opts, &is_http);
     } else if (seg->key_type == KEY_AES_128) {
-        char iv[33], key[33], url[MAX_URL_SIZE];
+        char iv[KEY_STRING_SIZE], key[KEY_STRING_SIZE], url[MAX_URL_SIZE];
         if (strcmp(seg->key, pls->key_url)) {
             AVIOContext *pb = NULL;
             if (open_url(pls->parent, &pb, seg->key, &c->avio_opts, opts, NULL) == 0) {
@@ -1270,7 +1270,7 @@ static int open_input(HLSContext *c, struct playlist *pls, struct segment *seg,
         }
         ff_data_to_hex(iv, seg->iv, sizeof(seg->iv), 0);
         ff_data_to_hex(key, pls->key, sizeof(pls->key), 0);
-        iv[32] = key[32] = '\0';
+        iv[KEY_STRING_SIZE - 1] = key[KEY_STRING_SIZE - 1] = '\0';
         if (strstr(seg->url, "://"))
             snprintf(url, sizeof(url), "crypto+%s", seg->url);
         else
diff --git a/libavformat/hlsenc.c b/libavformat/hlsenc.c
index c43d02c..d72edcf 100644
--- a/libavformat/hlsenc.c
+++ b/libavformat/hlsenc.c
@@ -67,7 +67,6 @@ typedef enum {
     CODEC_ATTRIBUTE_WILL_NOT_BE_WRITTEN,
 } CodecAttributeStatus;
 
-#define KEYSIZE 16
 #define LINE_BUFFER_SIZE MAX_URL_SIZE
 #define HLS_MICROSECOND_UNIT   1000000
 #define BUFSIZE (16 * 1024)
@@ -85,7 +84,7 @@ typedef struct HLSSegment {
     unsigned var_stream_idx;
 
     char key_uri[LINE_BUFFER_SIZE + 1];
-    char iv_string[KEYSIZE*2 + 1];
+    char iv_string[KEY_STRING_SIZE];
 
     struct HLSSegment *next;
     double discont_program_date_time;
@@ -169,8 +168,8 @@ typedef struct VariantStream {
 
     char key_file[LINE_BUFFER_SIZE + 1];
     char key_uri[LINE_BUFFER_SIZE + 1];
-    char key_string[KEYSIZE*2 + 1];
-    char iv_string[KEYSIZE*2 + 1];
+    char key_string[KEY_STRING_SIZE];
+    char iv_string[KEY_STRING_SIZE];
 
     AVStream **streams;
     char codec_attr[128];
@@ -228,8 +227,8 @@ typedef struct HLSContext {
     char *key_info_file;
     char key_file[LINE_BUFFER_SIZE + 1];
     char key_uri[LINE_BUFFER_SIZE + 1];
-    char key_string[KEYSIZE*2 + 1];
-    char iv_string[KEYSIZE*2 + 1];
+    char key_string[KEY_STRING_SIZE];
+    char iv_string[KEY_STRING_SIZE];
     AVDictionary *vtt_format_options;
 
     char *method;
@@ -734,8 +733,8 @@ static int do_encrypt(AVFormatContext *s, VariantStream *vs)
     }
 
     if (!*hls->iv_string) {
-        uint8_t iv[16] = { 0 };
-        char buf[33];
+        uint8_t iv[KEYSIZE] = { 0 };
+        char buf[KEY_STRING_SIZE];
 
         if (!hls->iv) {
             AV_WB64(iv + 8, vs->sequence);
@@ -743,7 +742,7 @@ static int do_encrypt(AVFormatContext *s, VariantStream *vs)
             memcpy(iv, hls->iv, sizeof(iv));
         }
         ff_data_to_hex(buf, iv, sizeof(iv), 0);
-        buf[32] = '\0';
+        buf[KEY_STRING_SIZE - 1] = '\0';
         memcpy(hls->iv_string, buf, sizeof(hls->iv_string));
     }
 
@@ -1674,7 +1673,7 @@ static int hls_start(AVFormatContext *s, VariantStream *vs)
     AVDictionary *options = NULL;
     const char *proto = NULL;
     int use_temp_file = 0;
-    char iv_string[KEYSIZE*2 + 1];
+    char iv_string[KEY_STRING_SIZE];
     int err = 0;
 
     if (c->flags & HLS_SINGLE_FILE) {
diff --git a/libavformat/internal.h b/libavformat/internal.h
index d57e63c..2aefac0 100644
--- a/libavformat/internal.h
+++ b/libavformat/internal.h
@@ -28,6 +28,8 @@
 #include "os_support.h"
 
 #define MAX_URL_SIZE 4096
+#define KEYSIZE 16
+#define KEY_STRING_SIZE (KEYSIZE * 2 + 1)
 
 /** size of probe buffer, for guessing file type from file contents */
 #define PROBE_BUF_MIN 2048
-- 
1.8.3.1