Check whether we support the proposed channel binding type.

2 files changed, 16 insertions, 0 deletions

diff --git a/util/sasl.lua b/util/sasl.lua
index 93b79a86..37a234c9 100644
--- a/util/sasl.lua
+++ b/util/sasl.lua
@@ -27,6 +27,17 @@ Authentication Backend Prototypes:
 state = false : disabled
 state = true : enabled
 state = nil : non-existant
+
+Channel Binding:
+
+To enable support of channel binding in some mechanisms you need to provide appropriate callbacks in a table
+at profile.cb.
+
+Example:
+	profile.cb["tls-unique"] = function(self)
+		return self.user
+	end
+
 ]]
 
 local method = {};
diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua
index fbe3547b..76e9c152 100644
--- a/util/sasl/scram.lua
+++ b/util/sasl/scram.lua
@@ -137,6 +137,11 @@ local function scram_gen(hash_name, H_f, HMAC_f)
 				if string.sub(self.state.gs2_cbind_flag, 0, 1) == "y" then
 					return "failure", "malformed-request";
 				end
+				
+				-- check whether we support the proposed channel binding type
+				if not self.profile.cb[self.state.gs2_cbind_name] then
+					return "failure", "malformed-request", "Proposed channel binding type isn't supported.";
+				end
 			else
 				if self.state.gs2_cbind_flag ~= "n" and self.state.gs2_cbind_flag ~= "y" then
 					return "failure", "malformed-request";