[FFmpeg-devel] [PATCH] avformat/hls: add macros for iv and key size
Nicolas George
george at nsup.org
Tue May 11 15:44:34 EEST 2021
lance.lmwang at gmail.com (12021-05-11):
> 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)
So, anything using internal.h can only deal with 128 bits keys? Seems
wrong.
>
> /** size of probe buffer, for guessing file type from file contents */
> #define PROBE_BUF_MIN 2048
Regards,
--
Nicolas George
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <https://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20210511/f46d54c5/attachment.sig>
More information about the ffmpeg-devel
mailing list