http://lists.mplayerhq.hu/pipermail/rtmpdump/2012-December/002252.html

Some servers (akamai) only include a 'challenge' parameter, no
'opaque' parameter, while others (wowza) include both 'opaque'
and 'challenge'. If 'opaque' is provided, it should be used here,
otherwise 'challenge', but never both.

After this patch, adobe auth works against both wowza and akamai
servers.
---
 librtmp/rtmp.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/librtmp/rtmp.c b/librtmp/rtmp.c
index d64a0bb..7f1c7ff 100644
--- a/librtmp/rtmp.c
+++ b/librtmp/rtmp.c
@@ -2609,7 +2609,7 @@ PublisherAuth(RTMP *r, AVal *description)
             /* response = base64enc(md5(hash1 + opaque + challenge2)) */
 	  if (opaque.av_len)
 	    MD5_Update(&md5ctx, opaque.av_val, opaque.av_len);
-	  if (challenge.av_len)
+	  else if (challenge.av_len)
 	    MD5_Update(&md5ctx, challenge.av_val, challenge.av_len);
 	  MD5_Update(&md5ctx, challenge2, B64INT_LEN);
 	  MD5_Final(md5sum_val, &md5ctx);
-- 
1.7.9.4