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104 lines
2.9 KiB
Lua

local Hi = require("resty.moongoo.utils").pbkdf2_hmac_sha1
local saslprep = require("resty.moongoo.utils").saslprep
local pass_digest = require("resty.moongoo.utils").pass_digest
local xor_bytestr = require("resty.moongoo.utils").xor_bytestr
local b64 = ngx and ngx.encode_base64 or require("mime").b64
local unb64 = ngx and ngx.decode_base64 or require("mime").unb64
local hmac_sha1 = ngx and ngx.hmac_sha1 or function(str, key) return require("crypto").hmac.digest("sha1", key, str, true) end
local sha1_bin = ngx and ngx.sha1_bin or function(str) return require("crypto").digest("sha1", str, true) end
local cbson = require("cbson")
local function auth(db, username, password)
local username = saslprep(username)
local c_nonce = b64(string.sub(tostring(math.random()), 3 , 14))
local first_bare = "n=" .. username .. ",r=" .. c_nonce
local sasl_start_payload = b64("n,," .. first_bare)
r, err = db:_cmd("saslStart", {
mechanism = "SCRAM-SHA-1" ;
autoAuthorize = 1 ;
payload = cbson.binary(sasl_start_payload);
})
if not r then
return nil, err
end
local conversationId = r['conversationId']
local server_first = r['payload']:raw()
local parsed_t = {}
for k, v in string.gmatch(server_first, "(%w+)=([^,]*)") do
parsed_t[k] = v
end
local iterations = tonumber(parsed_t['i'])
local salt = parsed_t['s']
local s_nonce = parsed_t['r']
if not string.sub(s_nonce, 1, 12) == c_nonce then
return nil, 'Server returned an invalid nonce.'
end
local without_proof = "c=biws,r=" .. s_nonce
local pbkdf2_key = pass_digest ( username , password )
local salted_pass = Hi(pbkdf2_key, iterations, unb64(salt), 20)
local client_key = hmac_sha1(salted_pass, "Client Key")
local stored_key = sha1_bin(client_key)
local auth_msg = first_bare .. ',' .. server_first .. ',' .. without_proof
local client_sig = hmac_sha1(stored_key, auth_msg)
local client_key_xor_sig = xor_bytestr(client_key, client_sig)
local client_proof = "p=" .. b64(client_key_xor_sig)
local client_final = b64(without_proof .. ',' .. client_proof)
local server_key = hmac_sha1(salted_pass, "Server Key")
local server_sig = b64(hmac_sha1(server_key, auth_msg))
r, err = db:_cmd("saslContinue",{
conversationId = conversationId ;
payload = cbson.binary(client_final);
})
if not r then
return nil, err
end
local parsed_s = r['payload']:raw()
parsed_t = {}
for k, v in string.gmatch(parsed_s, "(%w+)=([^,]*)") do
parsed_t[k] = v
end
if parsed_t['v'] ~= server_sig then
return nil, "Server returned an invalid signature."
end
if not r['done'] then
r, err = db:_cmd("saslContinue", {
conversationId = conversationId ;
payload = cbson.binary("") ;
})
if not r then
return nil, err
end
if not r['done'] then
return nil, 'SASL conversation failed to complete.'
end
return 1
end
return 1
end
return auth