lua-resty-hmac - HMAC functions for ngx_lua and LuaJIT
This library is still under active development and is considered production ready.
This library requires an nginx build with OpenSSL, the ngx_lua module, and LuaJIT 2.0.
# nginx.conf:
lua_package_path "/path/to/lua-resty-hmac/lib/?.lua;;";
server {
location = /test {
content_by_lua_file conf/test.lua;
}
}
-- conf/test.lua:
local hmac = require "resty.hmac"
local hmac_sha1 = hmac:new("secret_key", hmac.ALGOS.SHA1)
if not hmac_sha1 then
ngx.say("failed to create the hmac_sha1 object")
return
end
local ok = hmac_sha1:update("he")
if not ok then
ngx.say("failed to add data")
return
end
ok = hmac_sha1:update("llo")
if not ok then
ngx.say("failed to add data")
return
end
local mac = hmac_sha1:final() -- binary mac
local str = require "resty.string"
ngx.say("hmac_sha1: ", str.to_hex(mac))
-- output: "hmac_sha1: aee4b890b574ea8fa4f6a66aed96c3e590e5925a"
-- dont forget to reset after final!
if not hmac_sha1:reset() then
ngx.say("failed to reset hmac_sha1")
return
end
-- short version
ngx.say("hmac_sha1: ", hmac_sha1:final("world", true))
-- output: "hmac_sha1: 4e9538f1efbe565c522acfb72fce6092ea6b15e0"
To load this library,
- you need to specify this library's path in ngx_lua's lua_package_path directive. For example,
lua_package_path "/path/to/lua-resty-hmac/lib/?.lua;;";
. - you use
require
to load the library into a local Lua variable:
local hmac = require "resty.hmac"
syntax: local hmac_sha256 = hmac:new(key [, hash_algorithm])
Creates a new hmac instance. If failed, returns nil
.
The key
argument specifies the key to use when calculating the message authentication code (MAC).
key
is a lua string which may contain printable characters or binary data.
The hash_algorithm
argument specifies which hashing algorithm to use (hmac.ALGOS.MD5
, hmac.ALGOS.SHA1
, hmac.ALGOS.SHA256
, hmac.ALGOS.SHA512
).
The default value is hmac.ALGOS.MD5
.
syntax: hmac_sha256:update(data)
Updates the MAC calculation to include new data. If failed, returns false
.
The data
argument specifies the additional data to include in the MAC.
data
is a lua string which may contain printable characters or binary data.
syntax: local mac = hmac_sha256:final([data, output_hex])
Finalizes the MAC calculation and returns the final MAC value. If failed, returns nil
.
When output_hex
is not true
returns a lua string containing the raw, binary MAC. When output_hex
is true
returns a lua string containing the hexadecimal representation of the MAC.
The data
argument specifies the additional data to include in the MAC before finalizing the calculation.
The default value is nil
.
The output_hex
argument specifies wether the MAC should be returned as hex or binary. If true
the MAC will be returned as hex.
The default value is false
.
syntax: hmac_sha256:reset()
Resets the internal hmac context so it can be re-used to calculate a new MAC. If failed, returns false
.
If successful, the key
and hash_algorithm
remain the same but all other information is cleared.
This MUST be called after hmac_sha256:final()
in order to calculate a new MAC using the same hmac instance.
- LuaJIT 2.0+
- ngx_lua module
- lua-resty-string 0.8+
- OpenSSL 1.0.0+
It is recommended to use the latest ngx_openresty bundle directly. You'll need to enable LuaJIT when building your ngx_openresty
bundle by passing the --with-luajit
option to its ./configure
script.
Also, You need to configure the lua_package_path directive to add the path of your lua-resty-hmac source tree to ngx_lua's Lua module search path, as in
# nginx.conf
http {
lua_package_path "/path/to/lua-resty-hmac/lib/?.lua;;";
...
}
and then load the library in Lua:
local hmac = require "resty.hmac"
This module is licensed under the BSD license.
Copyright (C) 2012-2021, Thought Foundry Inc.
All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
-
Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
-
Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- the ngx_lua module: http://wiki.nginx.org/HttpLuaModule