lavf/libsrt: enable other encryption parameters

Enable the SRTO_ENFORCEDENCRYPTION/SRTO_KMREFRESHRATE/
SRTO_KMPREANNOUNCE for srt encryption control.
Signed-off-by: Jun Zhao <barryjzhao@tencent.com>

doc/protocols.texi

@@ -1282,6 +1282,26 @@ only if @option{pbkeylen} is non-zero. It is used on
 the receiver only if the received data is encrypted.
 The configured passphrase cannot be recovered (write-only).
 
+@item enforced_encryption=@var{1|0}
+If true, both connection parties must have the same password
+set (including empty, that is, with no encryption). If the
+password doesn't match or only one side is unencrypted,
+the connection is rejected. Default is true.
+
+@item kmrefreshrate=@var{packets}
+The number of packets to be transmitted after which the
+encryption key is switched to a new key. Default is -1.
+-1 means auto (0x1000000 in srt library). The range for
+this option is integers in the 0 - @code{INT_MAX}.
+
+@item kmpreannounce=@var{packets}
+The interval between when a new encryption key is sent and
+when switchover occurs. This value also applies to the
+subsequent interval between when switchover occurs and
+when the old encryption key is decommissioned. Default is -1.
+-1 means auto (0x1000 in srt library). The range for
+this option is integers in the 0 - @code{INT_MAX}.
+
 @item payload_size=@var{bytes}
 Sets the maximum declared size of a packet transferred
 during the single call to the sending function in Live

libavformat/libsrt.c

@@ -62,6 +62,9 @@ typedef struct SRTContext {
     int64_t maxbw;
     int pbkeylen;
     char *passphrase;
+    int enforced_encryption;
+    int kmrefreshrate;
+    int kmpreannounce;
     int mss;
     int ffs;
     int ipttl;
@@ -102,6 +105,9 @@ static const AVOption libsrt_options[] = {
     { "maxbw",          "Maximum bandwidth (bytes per second) that the connection can use",     OFFSET(maxbw),            AV_OPT_TYPE_INT64,    { .i64 = -1 }, -1, INT64_MAX, .flags = D|E },
     { "pbkeylen",       "Crypto key len in bytes {16,24,32} Default: 16 (128-bit)",             OFFSET(pbkeylen),         AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, 32,        .flags = D|E },
     { "passphrase",     "Crypto PBKDF2 Passphrase size[0,10..64] 0:disable crypto",             OFFSET(passphrase),       AV_OPT_TYPE_STRING,   { .str = NULL },              .flags = D|E },
+    { "enforced_encryption", "Enforces that both connection parties have the same passphrase set ",                             OFFSET(enforced_encryption), AV_OPT_TYPE_BOOL,  { .i64 = -1 }, -1, 1,         .flags = D|E },
+    { "kmrefreshrate",       "The number of packets to be transmitted after which the encryption key is switched to a new key", OFFSET(kmrefreshrate),       AV_OPT_TYPE_INT,   { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },
+    { "kmpreannounce",       "The interval between when a new encryption key is sent and when switchover occurs",               OFFSET(kmpreannounce),       AV_OPT_TYPE_INT,   { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },
     { "mss",            "The Maximum Segment Size",                                             OFFSET(mss),              AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, 1500,      .flags = D|E },
     { "ffs",            "Flight flag size (window size) (in bytes)",                            OFFSET(ffs),              AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, INT_MAX,   .flags = D|E },
     { "ipttl",          "IP Time To Live",                                                      OFFSET(ipttl),            AV_OPT_TYPE_INT,      { .i64 = -1 }, -1, 255,       .flags = D|E },
@@ -321,6 +327,9 @@ static int libsrt_set_options_pre(URLContext *h, int fd)
         (s->maxbw >= 0 && libsrt_setsockopt(h, fd, SRTO_MAXBW, "SRTO_MAXBW", &s->maxbw, sizeof(s->maxbw)) < 0) ||
         (s->pbkeylen >= 0 && libsrt_setsockopt(h, fd, SRTO_PBKEYLEN, "SRTO_PBKEYLEN", &s->pbkeylen, sizeof(s->pbkeylen)) < 0) ||
         (s->passphrase && libsrt_setsockopt(h, fd, SRTO_PASSPHRASE, "SRTO_PASSPHRASE", s->passphrase, strlen(s->passphrase)) < 0) ||
+        (s->enforced_encryption >= 0 && libsrt_setsockopt(h, fd, SRTO_ENFORCEDENCRYPTION, "SRTO_ENFORCEDENCRYPTION", &s->enforced_encryption, sizeof(s->enforced_encryption)) < 0) ||
+        (s->kmrefreshrate >= 0 && libsrt_setsockopt(h, fd, SRTO_KMREFRESHRATE, "SRTO_KMREFRESHRATE", &s->kmrefreshrate, sizeof(s->kmrefreshrate)) < 0) ||
+        (s->kmpreannounce >= 0 && libsrt_setsockopt(h, fd, SRTO_KMPREANNOUNCE, "SRTO_KMPREANNOUNCE", &s->kmpreannounce, sizeof(s->kmpreannounce)) < 0) ||
         (s->mss >= 0 && libsrt_setsockopt(h, fd, SRTO_MSS, "SRTO_MMS", &s->mss, sizeof(s->mss)) < 0) ||
         (s->ffs >= 0 && libsrt_setsockopt(h, fd, SRTO_FC, "SRTO_FC", &s->ffs, sizeof(s->ffs)) < 0) ||
         (s->ipttl >= 0 && libsrt_setsockopt(h, fd, SRTO_IPTTL, "SRTO_UPTTL", &s->ipttl, sizeof(s->ipttl)) < 0) ||
@@ -507,6 +516,15 @@ static int libsrt_open(URLContext *h, const char *uri, int flags)
             av_freep(&s->passphrase);
             s->passphrase = av_strndup(buf, strlen(buf));
         }
+        if (av_find_info_tag(buf, sizeof(buf), "enforced_encryption", p)) {
+            s->enforced_encryption = strtol(buf, NULL, 10);
+        }
+        if (av_find_info_tag(buf, sizeof(buf), "kmrefreshrate", p)) {
+            s->kmrefreshrate = strtol(buf, NULL, 10);
+        }
+        if (av_find_info_tag(buf, sizeof(buf), "kmpreannounce", p)) {
+            s->kmpreannounce = strtol(buf, NULL, 10);
+        }
         if (av_find_info_tag(buf, sizeof(buf), "mss", p)) {
             s->mss = strtol(buf, NULL, 10);
         }