util.sasl.*, mod_auth_*, mod_saslauth: Pass SASL handler as first parameter to SASL...

[prosody.git] / util / sasl / scram.lua

diff --git a/util/sasl/scram.lua b/util/sasl/scram.lua
index 52656a89307398f39e7eacfc889d49ce4c6442f4..530ef5a005614837b2edd440b9df120b8cc203a3 100644 (file)
--- a/util/sasl/scram.lua
+++ b/util/sasl/scram.lua
@@ -27,7 +27,7 @@ local byte = string.byte;
 module "scram"
 
 --=========================
---SASL SCRAM-SHA-1 according to draft-ietf-sasl-scram-10
+--SASL SCRAM-SHA-1 according to RFC 5802
 
 --[[
 Supported Authentication Backends
@@ -35,7 +35,7 @@ Supported Authentication Backends
 scram_{MECH}:
        -- MECH being a standard hash name (like those at IANA's hash registry) with '-' replaced with '_'
        function(username, realm)
-               return salted_password, iteration_count, salt, state;
+               return stored_key, server_key, iteration_count, salt, state;
        end
 ]]
 
@@ -65,9 +65,9 @@ local function binaryXOR( a, b )
 end
 
 -- hash algorithm independent Hi(PBKDF2) implementation
-local function Hi(hmac, str, salt, i)
+function Hi(hmac, str, salt, i)
        local Ust = hmac(str, salt.."\0\0\0\1");
-       local res = Ust;        
+       local res = Ust;
        for n=1,i-1 do
                local Und = hmac(str, Ust)
                res = binaryXOR(res, Und)
@@ -80,8 +80,8 @@ local function validate_username(username)
        -- check for forbidden char sequences
        for eq in username:gmatch("=(.?.?)") do
                if eq ~= "2D" and eq ~= "3D" then
-                       return false 
-               end 
+                       return false
+               end
        end
        
        -- replace =2D with , and =3D with =
@@ -93,22 +93,21 @@ local function validate_username(username)
        return username;
 end
 
-local function hashprep( hashname ) 
-       local hash = hashname:lower()
-       hash = hash:gsub("-", "_")
-       return hash
+local function hashprep(hashname)
+       return hashname:lower():gsub("-", "_");
 end
 
-function saltedPasswordSHA1(password, salt, iteration_count)
-       local salted_password
+function getAuthenticationDatabaseSHA1(password, salt, iteration_count)
        if type(password) ~= "string" or type(salt) ~= "string" or type(iteration_count) ~= "number" then
                return false, "inappropriate argument types"
        end
        if iteration_count < 4096 then
-               log("warning", "Iteration count < 4096 which is the suggested minimum according to RFC 5802.")
+               log("warn", "Iteration count < 4096 which is the suggested minimum according to RFC 5802.")
        end
-
-       return true, Hi(hmac_sha1, password, salt, iteration_count);
+       local salted_password = Hi(hmac_sha1, password, salt, iteration_count);
+       local stored_key = sha1(hmac_sha1(salted_password, "Client Key"))
+       local server_key = hmac_sha1(salted_password, "Server Key");
+       return true, stored_key, server_key
 end
 
 local function scram_gen(hash_name, H_f, HMAC_f)
@@ -144,7 +143,7 @@ local function scram_gen(hash_name, H_f, HMAC_f)
                        
                        -- retreive credentials
                        if self.profile.plain then
-                               local password, state = self.profile.plain(self.state.name, self.realm)
+                               local password, state = self.profile.plain(self, self.state.name, self.realm)
                                if state == nil then return "failure", "not-authorized"
                                elseif state == false then return "failure", "account-disabled" end
                                
@@ -158,17 +157,18 @@ local function scram_gen(hash_name, H_f, HMAC_f)
                                self.state.iteration_count = default_i;
 
                                local succ = false;
-                               succ, self.state.salted_password = saltedPasswordSHA1(password, self.state.salt, default_i, self.state.iteration_count);
+                               succ, self.state.stored_key, self.state.server_key = getAuthenticationDatabaseSHA1(password, self.state.salt, default_i, self.state.iteration_count);
                                if not succ then
-                                       log("error", "Generating salted password failed. Reason: %s", self.state.salted_password);
+                                       log("error", "Generating authentication database failed. Reason: %s", self.state.stored_key);
                                        return "failure", "temporary-auth-failure";
                                end
                        elseif self.profile["scram_"..hashprep(hash_name)] then
-                               local salted_password, iteration_count, salt, state = self.profile["scram_"..hashprep(hash_name)](self.state.name, self.realm);
+                               local stored_key, server_key, iteration_count, salt, state = self.profile["scram_"..hashprep(hash_name)](self, self.state.name, self.realm);
                                if state == nil then return "failure", "not-authorized"
                                elseif state == false then return "failure", "account-disabled" end
                                
-                               self.state.salted_password = salted_password;
+                               self.state.stored_key = stored_key;
+                               self.state.server_key = server_key;
                                self.state.iteration_count = iteration_count;
                                self.state.salt = salt
                        end
@@ -190,16 +190,15 @@ local function scram_gen(hash_name, H_f, HMAC_f)
                                return "failure", "malformed-request", "Wrong nonce in client-final-message.";
                        end
                        
-                       local SaltedPassword = self.state.salted_password;
-                       local ClientKey = HMAC_f(SaltedPassword, "Client Key")
-                       local ServerKey = HMAC_f(SaltedPassword, "Server Key")
-                       local StoredKey = H_f(ClientKey)
+                       local ServerKey = self.state.server_key;
+                       local StoredKey = self.state.stored_key;
+                       
                        local AuthMessage = "n=" .. s_match(self.state.client_first_message,"n=(.+)") .. "," .. self.state.server_first_message .. "," .. s_match(client_final_message, "(.+),p=.+")
                        local ClientSignature = HMAC_f(StoredKey, AuthMessage)
-                       local ClientProof     = binaryXOR(ClientKey, ClientSignature)
+                       local ClientKey = binaryXOR(ClientSignature, base64.decode(self.state.proof))
                        local ServerSignature = HMAC_f(ServerKey, AuthMessage)
 
-                       if base64.encode(ClientProof) == self.state.proof then
+                       if StoredKey == H_f(ClientKey) then
                                local server_final_message = "v="..base64.encode(ServerSignature);
                                self["username"] = self.state.name;
                                return "success", server_final_message;