diff --git a/daemon/crypto.c b/daemon/crypto.c
index 3b71591db..4eb4b4434 100644
--- a/daemon/crypto.c
+++ b/daemon/crypto.c
@@ -8,6 +8,12 @@
 #include "aux.h"
 #include "rtp.h"
 #include "rtcp.h"
+#include "log.h"
+
+
+
+
+#define CRYPTO_DEBUG 0
 
 
 
@@ -200,6 +206,28 @@ int crypto_gen_session_key(struct crypto_context *c, str *out, unsigned char lab
 
 	prf_n(out, c->master_key, (char *) x);
 
+#if CRYPTO_DEBUG
+	mylog(LOG_DEBUG, "Generated session key: master key "
+			"%02x%02x%02x%02x..., "
+			"master salt "
+			"%02x%02x%02x%02x..., "
+			"label %02x, length %i, result "
+			"%02x%02x%02x%02x...",
+			(unsigned char) c->master_key[0],
+			(unsigned char) c->master_key[1],
+			(unsigned char) c->master_key[2],
+			(unsigned char) c->master_key[3],
+			(unsigned char) c->master_salt[0],
+			(unsigned char) c->master_salt[1],
+			(unsigned char) c->master_salt[2],
+			(unsigned char) c->master_salt[3],
+			label, out->len,
+			(unsigned char) out->s[0],
+			(unsigned char) out->s[1],
+			(unsigned char) out->s[2],
+			(unsigned char) out->s[3]);
+#endif
+
 	return 0;
 }
 
diff --git a/tests/simulator-ng.pl b/tests/simulator-ng.pl
index 6333bc665..672e1387f 100755
--- a/tests/simulator-ng.pl
+++ b/tests/simulator-ng.pl
@@ -161,6 +161,11 @@ sub gen_rtp_session_keys {
 	my $session_key = prf_n(128, $master_key, xor_112($master_salt, "\0\0\0\0\0\0\0"));
 	my $auth_key = prf_n(160, $master_key, xor_112($master_salt, "\1\0\0\0\0\0\0"));
 	my $session_salt = prf_n(112, $master_key, xor_112($master_salt, "\2\0\0\0\0\0\0"));
+#	print("RTP keys generated for master key " . unpack("H8", $master_key) . "... and salt " .
+#		unpack("H8", $master_salt) . "... are: " .
+#		unpack("H8", $session_key) . "..., " .
+#		unpack("H*", $auth_key) . ", " .
+#		unpack("H8", $session_salt) . "...\n");
 
 	return ($session_key, $auth_key, $session_salt);
 }
@@ -171,6 +176,11 @@ sub gen_rtcp_session_keys {
 	my $session_key = prf_n(128, $master_key, xor_112($master_salt, "\3\0\0\0\0"));
 	my $auth_key = prf_n(160, $master_key, xor_112($master_salt, "\4\0\0\0\0"));
 	my $session_salt = prf_n(112, $master_key, xor_112($master_salt, "\5\0\0\0\0"));
+#	print("RTCP keys generated for master key " . unpack("H8", $master_key) . "... and salt " .
+#		unpack("H8", $master_salt) . "... are: " .
+#		unpack("H8", $session_key) . "..., " .
+#		unpack("H*", $auth_key) . ", " .
+#		unpack("H8", $session_salt) . "...\n");
 
 	return ($session_key, $auth_key, $session_salt);
 }
@@ -218,6 +228,7 @@ sub rtp_encrypt {
 	my $pkt = pack("a*na*a*a*", $hdr, $seq, $ts, $ssrc, $enc);
 
 	my $hmac = hmac_sha1($pkt . pack("N", $roc), $$ctx{$dir}{rtp_session_auth_key});
+#	print("HMAC for packet " . unpack("H*", $pkt) . " ROC $roc is " . unpack("H*", $hmac) . "\n");
 
 	#$pkt .= pack("N", 1); # mki
 	$pkt .= substr($hmac, 0, 10);
@@ -489,7 +500,7 @@ a=rtcp:$cp
 !
 		$$tr{sdp_media_params} and $sdp .= $$tr{sdp_media_params}($tcx);
 	}
-	print("transport is $$tr{name} -> $$tr_o{name}\n"); # XXX
+#	$i or print("transport is $$tr{name} -> $$tr_o{name}\n");
 
 	my $dict = {sdp => $sdp, command => $commands[$i], 'call-id' => $callid,
 		'from-tag' => $$tags[0],