[FFmpeg-devel] [PATCH] avformat/hls: add macros for iv and key size
lance.lmwang at gmail.com
lance.lmwang at gmail.com
Tue May 11 16:21:38 EEST 2021
On Tue, May 11, 2021 at 02:44:34PM +0200, Nicolas George wrote:
> 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.
Of course, it's not my intention. It's used by hls only and I haven't find a common header
for hls.c and hlsenc.c.
>
> >
> > /** size of probe buffer, for guessing file type from file contents */
> > #define PROBE_BUF_MIN 2048
>
> Regards,
>
> --
> Nicolas George
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--
Thanks,
Limin Wang
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