[vlc-devel] [PATCH] srt: parse srt parameters from url

Wed Mar 6 18:11:15 CET 2019

On Wed, Mar 6, 2019, at 17:59, Aaron Boxer wrote:
> 
> 
> On Wed, Mar 6, 2019 at 10:39 AM Thomas Guillem <thomas at gllm.fr> wrote:
>> __
>> 
>> On Wed, Mar 6, 2019, at 16:34, Aaron Boxer wrote:
>>> Thank you, Tristan. So, I see that vlc_credential API is a way of extracting the user credentials from the URL.
>>> But, there would still be the issue of credentials being displayed in window, logs etc, as mentioned by Remi ?
>> 
>> Hello,
>> This API handle credential from URL yes, but it's not its main purpose. This API handle interaction with the user (from a dialog generally) to ask for a password. This API will also save the password in VLC internal memory keystore and/or in the OS one (kwallet and co) if the user want to.
> 
> Thanks. SRT stream doesn't require a user name + password. It only has a passphrase. So, how would the credentials work in this case ?

No, but this can be fixed.

in vlc_keystore.h/keystore.c:

- vlc_credential_init(vlc_credential *p_credential, const vlc_url_t *p_url);
+ vlc_credential_init(vlc_credential *p_credential, const vlc_url_t *p_url, bool ask_user);

in vlc_dialog.h/dialog.c
Fix vlc_dialog_wait_login_va() to work with a NULL ppsz_username

in qt gui:
handle the NULL username to display only one text dialog.

> 
>> 
>> 
>>> 
>>> On Wed, Mar 6, 2019 at 10:20 AM Tristan Matthews <tmatth at videolan.org> wrote:
>>>> On Wed, Mar 6, 2019 at 10:04 AM Aaron Boxer <boxerab at gmail.com> wrote:
>>>> >
>>>> > Thanks, Remi. Is there another better way of getting a user-configured passphrase to the srt module ?
>>>> 
>>>> I think you want the vlc_credential API, see e.g.,
>>>> https://git.videolan.org/?p=vlc.git;a=blob;f=modules/access/http.c;h=56d75687e27f10a6c1ef33cd32178dcc857e4136;hb=HEAD#l304
>>>> 
>>>> Best,
>>>> -t
>>>> 
>>>> > On Wed, Mar 6, 2019 at 5:57 AM Rémi Denis-Courmont <remi at remlab.net> wrote:
>>>> >>
>>>> >> Hi,
>>>> >>
>>>> >> Passing passwords in URLs is well-documented as a terrible idea. In VLC's case, the passphrase will show up in the OSD title, window title, logs, etc...
>>>> >>
>>>> >> Le 5 mars 2019 23:42:14 GMT+02:00, Aaron Boxer <boxerab at gmail.com> a écrit :
>>>> >>>
>>>> >>> Parse pass phrase and latency from url for incoming srt stream
>>>> >>>
>>>> >>>
>>>> >>> diff --git a/modules/access/srt.c b/modules/access/srt.c
>>>> >>> index d8d8cbe659..55c0efc201 100644
>>>> >>> --- a/modules/access/srt.c
>>>> >>> +++ b/modules/access/srt.c
>>>> >>> @@ -37,6 +37,9 @@
>>>> >>>
>>>> >>> #include <srt/srt.h>
>>>> >>>
>>>> >>> +const char* SRT_PARAM_PASSPHRASE = "passphrase";
>>>> >>> +const char* SRT_PARAM_LATENCY = "latency";
>>>> >>> +
>>>> >>> /* libsrt defines default packet size as 1316 internally
>>>> >>> * so srt module takes same value. */
>>>> >>> #define SRT_DEFAULT_CHUNK_SIZE 1316
>>>> >>> @@ -70,6 +73,85 @@ typedef struct
>>>> >>> int i_chunks; /* Number of chunks to allocate in the next read */
>>>> >>> } stream_sys_t;
>>>> >>>
>>>> >>> +
>>>> >>> +
>>>> >>> +struct parsed_param {
>>>> >>> + char *key;
>>>> >>> + char *val;
>>>> >>> +};
>>>> >>> +
>>>> >>> +static inline char *
>>>> >>> +find(char *str, char find)
>>>> >>> +{
>>>> >>> + str = strchr(str, find);
>>>> >>> + if (NULL == str) {
>>>> >>> + return NULL;
>>>> >>> + }
>>>> >>> + return str + 1;
>>>> >>> +}
>>>> >>> +
>>>> >>> +static inline char *
>>>> >>> +find_query(char *str)
>>>> >>> +{
>>>> >>> + return find(str, '?');
>>>> >>> +}
>>>> >>> +
>>>> >>> +/**
>>>> >>> + * Parse a query string into an array of key/value structs.
>>>> >>> + *
>>>> >>> + * The query string should be a null terminated string of parameters separated by
>>>> >>> + * a delimiter. Each parameter are checked for the equal sign character. If it
>>>> >>> + * appears in the parameter, it will be used as a null terminator and the part
>>>> >>> + * that comes after it will be the value of the parameter.
>>>> >>> + *
>>>> >>> + *
>>>> >>> + * param: query: the query string to parse. The string will be modified.
>>>> >>> + * param: delimiter: the character that separates the key/value pairs from each other.
>>>> >>> + * param: params: an array of parsed_param structs to hold the result.
>>>> >>> + * param: max_params: maximum number of parameters to parse.
>>>> >>> + *
>>>> >>> + * Return: the number of parsed items. -1 if there was an error.
>>>> >>> + */
>>>> >>> +static int
>>>> >>> +srt_url_parse_query(char *query, char delimiter, struct parsed_param *params, int max_params)
>>>> >>> +{
>>>> >>> + int i = 0;
>>>> >>> +
>>>> >>> + if (!query || *query == '\0')
>>>> >>> + {
>>>> >>> + return -1;
>>>> >>> + }
>>>> >>> + if (!params || max_params == 0)
>>>> >>> + {
>>>> >>> + return 0;
>>>> >>> + }
>>>> >>> +
>>>> >>> + params[i++].key = query;
>>>> >>> + while (i < max_params && NULL != (query = strchr(query, delimiter)))
>>>> >>> + {
>>>> >>> + *query = '\0';
>>>> >>> + params[i].key = ++query;
>>>> >>> + params[i].val = NULL;
>>>> >>> +
>>>> >>> + /* Go back and split previous param if one exists */
>>>> >>> + if (i > 0)
>>>> >>> + {
>>>> >>> + if ((params[i - 1].val = strchr(params[i - 1].key, '=')) != NULL)
>>>> >>> + {
>>>> >>> + *(params[i - 1].val)++ = '\0';
>>>> >>> + }
>>>> >>> + }
>>>> >>> + i++;
>>>> >>> + }
>>>> >>> + /* Go back and split last param */
>>>> >>> + if ((params[i - 1].val = strchr(params[i - 1].key, '=')) != NULL)
>>>> >>> + {
>>>> >>> + *(params[i - 1].val)++ = '\0';
>>>> >>> + }
>>>> >>> + return i;
>>>> >>> +}
>>>> >>> +
>>>> >>> +
>>>> >>> static void srt_wait_interrupted(void *p_data)
>>>> >>> {
>>>> >>> stream_t *p_stream = p_data;
>>>> >>> @@ -115,9 +197,11 @@ static int Control(stream_t *p_stream, int i_query, va_list args)
>>>> >>>
>>>> >>> static bool srt_schedule_reconnect(stream_t *p_stream)
>>>> >>> {
>>>> >>> - int i_latency;
>>>> >>> + int i_latency=-1;
>>>> >>> int stat;
>>>> >>> char *psz_passphrase = NULL;
>>>> >>> + bool parsed_passphrase = false;
>>>> >>> + char *url = NULL;
>>>> >>>
>>>> >>> struct addrinfo hints = {
>>>> >>> .ai_socktype = SOCK_DGRAM,
>>>> >>> @@ -153,6 +237,38 @@ static bool srt_schedule_reconnect(stream_t *p_stream)
>>>> >>> goto out;
>>>> >>> }
>>>> >>>
>>>> >>> + /* Parse URL parameters */
>>>> >>> + if (p_stream->psz_url && strlen(p_stream->psz_url) < 512)
>>>> >>> + {
>>>> >>> + char* query = NULL;
>>>> >>> + struct parsed_param params[32];
>>>> >>> + int num_params = 0;
>>>> >>> + int i=0;
>>>> >>> + size_t url_size = strlen(p_stream->psz_url)+1;
>>>> >>> +
>>>> >>> + url = malloc(url_size);
>>>> >>> + url[url_size-1] = 0;
>>>> >>> + strcpy(url, p_stream->psz_url);
>>>> >>> + query = find_query(url);
>>>> >>> + if (query)
>>>> >>> + {
>>>> >>> + num_params = srt_url_parse_query(query,'&', params, sizeof(params)/sizeof(struct parsed_param) );
>>>> >>> + if (num_params > 0) {
>>>> >>> + for (i = 0; i < num_params; ++i)
>>>> >>> + {
>>>> >>> + if (strcmp(params[i].key, SRT_PARAM_PASSPHRASE) == 0)
>>>> >>> + {
>>>> >>> + psz_passphrase = params[i].val;
>>>> >>> + parsed_passphrase = true;
>>>> >>> + }
>>>> >>> + else if (strcmp(params[i].key, SRT_PARAM_LATENCY) == 0)
>>>> >>> + i_latency = atoi(params[i].val);
>>>> >>> + }
>>>> >>> + }
>>>> >>> + }
>>>> >>> + }
>>>> >>> +
>>>> >>> +
>>>> >>> /* Make SRT non-blocking */
>>>> >>> srt_setsockopt( p_sys->sock, 0, SRTO_SNDSYN,
>>>> >>> &(bool) { false }, sizeof( bool ) );
>>>> >>> @@ -168,11 +284,13 @@ static bool srt_schedule_reconnect(stream_t *p_stream)
>>>> >>> &(int) { 0 }, sizeof( int ) );
>>>> >>>
>>>> >>> /* Set latency */
>>>> >>> - i_latency = var_InheritInteger( p_stream, "latency" );
>>>> >>> + if (i_latency == -1)
>>>> >>> + i_latency = var_InheritInteger( p_stream, SRT_PARAM_LATENCY );
>>>> >>> srt_setsockopt( p_sys->sock, 0, SRTO_TSBPDDELAY,
>>>> >>> &i_latency, sizeof( int ) );
>>>> >>>
>>>> >>> - psz_passphrase = var_InheritString( p_stream, "passphrase" );
>>>> >>> + if (!psz_passphrase)
>>>> >>> + psz_passphrase = var_InheritString( p_stream, SRT_PARAM_PASSPHRASE );
>>>> >>> if ( psz_passphrase != NULL && psz_passphrase[0] != '\0')
>>>> >>> {
>>>> >>> int i_key_length = var_InheritInteger( p_stream, "key-length" );
>>>> >>> @@ -211,7 +329,11 @@ out:
>>>> >>> }
>>>> >>>
>>>> >>> freeaddrinfo( res );
>>>> >>> - free( psz_passphrase );
>>>> >>> + if (!parsed_passphrase)
>>>> >>> + {
>>>> >>> + free( psz_passphrase );
>>>> >>> + }
>>>> >>> + free(url);
>>>> >>>
>>>> >>> return !failed;
>>>> >>> }
>>>> >>> @@ -422,8 +544,8 @@ vlc_module_begin ()
>>>> >>> N_("SRT chunk size (bytes)"), NULL, true )
>>>> >>> add_integer( "poll-timeout", SRT_DEFAULT_POLL_TIMEOUT,
>>>> >>> N_("Return poll wait after timeout milliseconds (-1 = infinite)"), NULL, true )
>>>> >>> - add_integer( "latency", SRT_DEFAULT_LATENCY, N_("SRT latency (ms)"), NULL, true )
>>>> >>> - add_password("passphrase", "", N_("Password for stream encryption"), NULL)
>>>> >>> + add_integer( SRT_PARAM_LATENCY, SRT_DEFAULT_LATENCY, N_("SRT latency (ms)"), NULL, true )
>>>> >>> + add_password(SRT_PARAM_PASSPHRASE, "", N_("Password for stream encryption"), NULL)
>>>> >>> add_integer( "key-length", SRT_DEFAULT_KEY_LENGTH,
>>>> >>> SRT_KEY_LENGTH_TEXT, SRT_KEY_LENGTH_TEXT, false )
>>>> >>> change_integer_list( srt_key_lengths, srt_key_length_names )
>>>> >>>
>>>> >>
>>>> >> --
>>>> >> Envoyé de mon appareil Android avec Courriel K-9 Mail. Veuillez excuser ma brièveté.
>>>> >
>>>> > _______________________________________________
>>>> > vlc-devel mailing list
>>>> > To unsubscribe or modify your subscription options:
>>>> > https://mailman.videolan.org/listinfo/vlc-devel
>>>> _______________________________________________
>>>> vlc-devel mailing list
>>>> To unsubscribe or modify your subscription options:
>>>> https://mailman.videolan.org/listinfo/vlc-devel
>>> _______________________________________________
>>> vlc-devel mailing list
>>> To unsubscribe or modify your subscription options:
>>> https://mailman.videolan.org/listinfo/vlc-devel
>> 
>> _______________________________________________
>>  vlc-devel mailing list
>>  To unsubscribe or modify your subscription options:
>> https://mailman.videolan.org/listinfo/vlc-devel
> _______________________________________________
> vlc-devel mailing list
> To unsubscribe or modify your subscription options:
> https://mailman.videolan.org/listinfo/vlc-devel
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.videolan.org/pipermail/vlc-devel/attachments/20190306/1656ba40/attachment.html>