[FFmpeg-cvslog] avformat/rtmpproto: guard usage of undefined functions with preprocessor

[Kacper Michajłow]

ffmpeg | branch: master | Kacper Michajłow <kasper93 at gmail.com> | Mon Jul 21 01:45:23 2025 +0200| [d12863a6939edda4045aa8f7c6d97866c0b108c9] | committer: Kacper Michajłow

avformat/rtmpproto: guard usage of undefined functions with preprocessor

The asumption is that DCE will remove references to those functions.
However some compilers with certain instrumentation enabled doesn't DCE
those at all, resulting in linking failure. Tested with cl.exe -RTCu -RTCs.

Signed-off-by: Kacper Michajłow <kasper93 at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d12863a6939edda4045aa8f7c6d97866c0b108c9
---

 libavformat/rtmpproto.c | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/libavformat/rtmpproto.c b/libavformat/rtmpproto.c
index dd850f72ed..4f866eb76c 100644
--- a/libavformat/rtmpproto.c
+++ b/libavformat/rtmpproto.c
@@ -1256,7 +1256,10 @@ static int rtmp_handshake(URLContext *s, RTMPContext *rt)
     int i;
     int server_pos, client_pos;
     uint8_t digest[32], signature[32];
-    int ret, type = 0;
+    int ret;
+#if CONFIG_FFRTMPCRYPT_PROTOCOL
+    int type = 0;
+#endif
 
     av_log(s, AV_LOG_DEBUG, "Handshaking...\n");
 
@@ -1265,7 +1268,8 @@ static int rtmp_handshake(URLContext *s, RTMPContext *rt)
     for (i = 9; i <= RTMP_HANDSHAKE_PACKET_SIZE; i++)
         tosend[i] = av_lfg_get(&rnd) >> 24;
 
-    if (CONFIG_FFRTMPCRYPT_PROTOCOL && rt->encrypted) {
+#if CONFIG_FFRTMPCRYPT_PROTOCOL
+    if (rt->encrypted) {
         /* When the client wants to use RTMPE, we have to change the command
          * byte to 0x06 which means to use encrypted data and we have to set
          * the flash version to at least 9.0.115.0. */
@@ -1280,6 +1284,7 @@ static int rtmp_handshake(URLContext *s, RTMPContext *rt)
         if ((ret = ff_rtmpe_gen_pub_key(rt->stream, tosend + 1)) < 0)
             return ret;
     }
+#endif
 
     client_pos = rtmp_handshake_imprint_with_digest(tosend + 1, rt->encrypted);
     if (client_pos < 0)
@@ -1313,7 +1318,9 @@ static int rtmp_handshake(URLContext *s, RTMPContext *rt)
             return server_pos;
 
         if (!server_pos) {
+#if CONFIG_FFRTMPCRYPT_PROTOCOL
             type = 1;
+#endif
             server_pos = rtmp_validate_digest(serverdata + 1, 8);
             if (server_pos < 0)
                 return server_pos;
@@ -1343,7 +1350,8 @@ static int rtmp_handshake(URLContext *s, RTMPContext *rt)
         if (ret < 0)
             return ret;
 
-        if (CONFIG_FFRTMPCRYPT_PROTOCOL && rt->encrypted) {
+#if CONFIG_FFRTMPCRYPT_PROTOCOL
+        if (rt->encrypted) {
             /* Compute the shared secret key sent by the server and initialize
              * the RC4 encryption. */
             if ((ret = ff_rtmpe_compute_secret_key(rt->stream, serverdata + 1,
@@ -1353,6 +1361,7 @@ static int rtmp_handshake(URLContext *s, RTMPContext *rt)
             /* Encrypt the signature received by the server. */
             ff_rtmpe_encrypt_sig(rt->stream, signature, digest, serverdata[0]);
         }
+#endif
 
         if (memcmp(signature, clientdata + RTMP_HANDSHAKE_PACKET_SIZE - 32, 32)) {
             av_log(s, AV_LOG_ERROR, "Signature mismatch\n");
@@ -1373,25 +1382,30 @@ static int rtmp_handshake(URLContext *s, RTMPContext *rt)
         if (ret < 0)
             return ret;
 
-        if (CONFIG_FFRTMPCRYPT_PROTOCOL && rt->encrypted) {
+#if CONFIG_FFRTMPCRYPT_PROTOCOL
+        if (rt->encrypted) {
             /* Encrypt the signature to be send to the server. */
             ff_rtmpe_encrypt_sig(rt->stream, tosend +
                                  RTMP_HANDSHAKE_PACKET_SIZE - 32, digest,
                                  serverdata[0]);
         }
+#endif
 
         // write reply back to the server
         if ((ret = ffurl_write(rt->stream, tosend,
                                RTMP_HANDSHAKE_PACKET_SIZE)) < 0)
             return ret;
 
-        if (CONFIG_FFRTMPCRYPT_PROTOCOL && rt->encrypted) {
+#if CONFIG_FFRTMPCRYPT_PROTOCOL
+        if (rt->encrypted) {
             /* Set RC4 keys for encryption and update the keystreams. */
             if ((ret = ff_rtmpe_update_keystream(rt->stream)) < 0)
                 return ret;
         }
+#endif
     } else {
-        if (CONFIG_FFRTMPCRYPT_PROTOCOL && rt->encrypted) {
+#if CONFIG_FFRTMPCRYPT_PROTOCOL
+        if (rt->encrypted) {
             /* Compute the shared secret key sent by the server and initialize
              * the RC4 encryption. */
             if ((ret = ff_rtmpe_compute_secret_key(rt->stream, serverdata + 1,
@@ -1404,16 +1418,19 @@ static int rtmp_handshake(URLContext *s, RTMPContext *rt)
                                      serverdata[0]);
             }
         }
+#endif
 
         if ((ret = ffurl_write(rt->stream, serverdata + 1,
                                RTMP_HANDSHAKE_PACKET_SIZE)) < 0)
             return ret;
 
-        if (CONFIG_FFRTMPCRYPT_PROTOCOL && rt->encrypted) {
+#if CONFIG_FFRTMPCRYPT_PROTOCOL
+        if (rt->encrypted) {
             /* Set RC4 keys for encryption and update the keystreams. */
             if ((ret = ff_rtmpe_update_keystream(rt->stream)) < 0)
                 return ret;
         }
+#endif
     }
 
     return 0;