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lua-resty-openssl

FFI-based OpenSSL binding for LuaJIT, supporting OpenSSL 3.0, 1.1 and 1.0.2 series

Build Status luarocks opm

Table of Contents

Description

lua-resty-openssl is a FFI-based OpenSSL binding library, currently supports OpenSSL 3.0.0, 1.1.1, 1.1.0 and 1.0.2 series.

Note: when using with OpenSSL 1.0.2, it's recommanded to not use this library with other FFI-based OpenSSL binding libraries to avoid potential mismatch of cdef.

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Status

Production.

Synopsis

This library is greatly inspired by luaossl, while uses the naming conversion closer to original OpenSSL API. For example, a function called X509_set_pubkey in OpenSSL C API will expect to exist as resty.openssl.x509:set_pubkey. CamelCases are replaced to underscore_cases, for exmaple X509_set_serialNumber becomes resty.openssl.x509:set_serial_number. Another difference than luaossl is that errors are never thrown using error() but instead return as last parameter.

Each Lua table returned by new() contains a cdata object ctx. User are not supposed to manully setting ffi.gc or calling corresponding destructor of the ctx struct (like *_free functions).

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resty.openssl

This meta module provides a version sanity check against linked OpenSSL library and returns all exported modules to a table.

return {
  _VERSION = 'x.y.z',
  bn = require("resty.openssl.bn"),
  cipher = require("resty.openssl.cipher"),
  digest = require("resty.openssl.digest"),
  hmac = require("resty.openssl.hmac"),
  kdf = require("resty.openssl.kdf"),
  pkey = require("resty.openssl.pkey"),
  objects = require("resty.openssl.objects"),
  rand = require("resty.openssl.rand"),
  version = require("resty.openssl.version"),
  x509 = require("resty.openssl.x509"),
  altname = require("resty.openssl.x509.altname"),
  chain = require("resty.openssl.x509.chain"),
  csr = require("resty.openssl.x509.csr"),
  crl = require("resty.openssl.x509.crl"),
  extension = require("resty.openssl.x509.extension"),
  name = require("resty.openssl.x509.name"),
  store = require("resty.openssl.x509.store"),
}

Starting OpenSSL 3.0, provider is also available.

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openssl.luaossl_compat

syntax: openssl.luaossl_compat()

Provides luaossl flavored API which uses camelCase naming; user can expect drop in replacement.

For example, pkey:get_parameters is mapped to pkey:getParameters.

Note that not all luaossl API has been implemented, please check readme for source of truth.

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openssl.resty_hmac_compat

syntax: openssl.resty_hmac_compat()

Call this function before require("resty.hmac") to allow these two libraries play nice with each other. This function is not available with OpenSSL 1.0.

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resty.openssl.version

A module to provide version info.

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version_num

The OpenSSL version number.

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version_text

The OpenSSL version text.

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version.version

syntax: text = version.version(types)

Returns various OpenSSL version information. Available values for types are:

VERSION
CFLAGS
BUILT_ON
PLATFORM
DIR
ENGINES_DIR
VERSION_STRING
FULL_VERSION_STRING
MODULES_DIR
CPU_INFO

For OpenSSL prior to 1.1.x, only VERSION, CFLAGS, BUILT_ON, PLATFORM and DIR are supported. Please refer to OPENSSL_VERSION_NUMBER(3) for explanation of each type.

local version = require("resty.openssl.version")
ngx.say(string.format("%x", version.version_num))
-- outputs "101000bf"
ngx.say(version.version_text)
-- outputs "OpenSSL 1.1.0k  28 May 2019"
ngx.say(version.version(version.PLATFORM))
-- outputs "darwin64-x86_64-cc"

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version.info

syntax: text = version.info(types)

Returns various OpenSSL information. Available values for types are:

INFO_ENGINES_DIR
INFO_DSO_EXTENSION
INFO_CPU_SETTINGS
INFO_LIST_SEPARATOR
INFO_DIR_FILENAME_SEPARATOR
INFO_CONFIG_DIR
INFO_SEED_SOURCE
INFO_MODULES_DIR

This function is only available on OpenSSL 3.0. Please refer to OPENSSL_VERSION_NUMBER(3) for explanation of each type.

local version = require("resty.openssl.version")
ngx.say(version.version(version.INFO_DSO_EXTENSION))
-- outputs ".so"

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OPENSSL_30

A boolean indicates whether the linked OpenSSL is 3.0 series.

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OPENSSL_11

A boolean indicates whether the linked OpenSSL is 1.1 series.

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OPENSSL_10

A boolean indicates whether the linked OpenSSL is 1.0 series.

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resty.openssl.pkey

Module to interact with private keys and public keys (EVP_PKEY).

Each key type may only support part of operations:

Key Type Load existing key Key generation Encrypt/Decrypt Sign/Verify Key Exchange
RSA Y Y Y Y
EC Y Y Y (ECDSA) Y (ECDH)
Ed25519 Y Y Y (PureEdDSA)
X25519 Y Y Y (ECDH)
Ed448 Y Y Y (PureEdDSA)
X448 Y Y Y (ECDH)

Ed25519, X25519, Ed448 and X448 keys are only supported since OpenSSL 1.1.0.

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pkey.new

syntax: pk, err = pkey.new(config)

syntax: pk, err = pkey.new(string, opts?)

syntax: pk, err = pkey.new()

Creates a new pkey instance. The first argument can be:

  1. A config table to create a new PKEY pair. Which defaults to:
pkey.new({
  type = 'RSA',
  bits = 2048,
  exp = 65537
})

to create EC private key:

pkey.new({
  type = 'EC',
  curve = 'prime196v1',
})

To see list of supported EC curves, use openssl ecparam -list_curves.

Other possible types are Ed25519, X25519, Ed448 and X448. No additional parameters can be set during key generation for those keys.

  1. A string of private or public key in PEM, DER or JWK format text; optionally accpet a table opts to explictly load format and key type. When loading a key in PEM format, passphrase or passphrase_cb may be provided to decrypt the key.
pkey.new(pem_or_der_text, {
  format = "*", -- choice of "PEM", "DER", "JWK" or "*" for auto detect
  type = "*", -- choice of "pr" for privatekey, "pu" for public key and "*" for auto detect
  passphrase = "secret password", -- the PEM encryption passphrase
  passphrase_cb = function()
    return "secret password"
  end, -- the PEM encryption passphrase callback function
}
  • When loading JWK, make sure the encoded JSON text is passed in.
  • Currently it's not supported to contraint type on JWK key, the parameters in provided JSON will decide if a private or public key is loaded.
  • Only JWK with key type of RSA, P-256, P-384 and P-512 EC, Ed25519, X25519, Ed448 and X448 OKP keys are supported.
  • Public key part for OKP keys (the x parameter) is always not honored and derived from private key part (the d parameter) if it's specified.
  1. nil to create a 2048 bits RSA key.
  2. A EVP_PKEY* pointer, to return a wrapped pkey instance. Normally user won't use this approach. User shouldn't free the pointer on their own, since the pointer is not copied.

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pkey.istype

syntax: ok = pkey.istype(table)

Returns true if table is an instance of pkey. Returns false otherwise.

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pkey:get_parameters

syntax: parameters, err = pk:get_parameters()

Returns a table containing the parameters of pkey instance.

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pkey:set_parameters

syntax: ok, err = pk:set_parameters(params)

Set the paramets of the pkey from a table params. If the parameter is not set in the params table, it remains untouched in the pkey instance.

local pk, err = require("resty.openssl.pkey").new()
local parameters, err = pk:get_parameters()
local e = parameters.e
ngx.say(e:to_number())
-- outputs 65537

local ok, err = pk:set_parameters({
  e = require("resty.openssl.bn").from_hex("100001")
})

local ok, err = pk:set_parameters(parameters)

Parameters for RSA key:

Parameter Description Type
n modulus common to both public and private key bn
e public exponent bn
d private exponent bn
p first factor of n bn
q second factor of n bn
dmp1 d mod (p - 1), exponent1 bn
dmq1 d mod (q - 1), exponent2 bn
iqmp (InverseQ)(q) = 1 mod p, coefficient bn

Parameters for EC key:

Parameter Description Type
private private key bn
public public key bn
x x coordinate of the public key bn
y y coordinate of the public key bn
group the named curve group NID as a number, when passed in as set_parameters(), it's also possible to use the text representation. This is different from luaossl where a EC_GROUP instance is returned.

It's not possible to set x, y with public at same time as x and y is basically another representation of public. Also currently it's only possible to set x and y at same time.

Parameters for Curve25519 and Curve448 keys:

Parameter Description Type
private raw private key represented as bytes string
public raw public key represented as bytes string

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pkey:get_key_type

syntax: obj, err = pk:get_key_type()

Returns a ASN1_OBJECT of key type of the private key as a table.

local pkey, err = require("resty.openssl.pkey").new({type="X448"})

ngx.say(require("cjson").encode(pkey:get_key_type()))
-- outputs '{"ln":"X448","nid":1035,"sn":"X448","id":"1.3.101.111"}'

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pkey:sign

syntax: signature, err = pk:sign(digest)

Sign a digest using the private key defined in pkey instance. The digest parameter must be a resty.openssl.digest instance. Returns the signed raw binary and error if any. For EC key, this function does a ECDSA signing.

The passed in digest parameter should not have been called final(), user should only use update().

Note that OpenSSL does not support EC digital signature (ECDSA) with the obsolete MD5 hash algorithm and will return error on this combination. See EVP_DigestSign(3) for a list of algorithms and associated public key algorithms.

For Ed25519 or Ed448 keys, this function does a PureEdDSA verification and requires digest to be the string that needs signing.

-- RSA and EC keys
local pk, err = require("resty.openssl.pkey").new()
local digest, err = require("resty.openssl.digest").new("SHA256")
digest:update("dog")
-- WRONG: 
-- digest:final("dog")
local signature, err = pk:sign(digest)
ngx.say(ngx.encode_base64(signature))

-- Ed25519 and Ed448 keys
local pk, err = require("resty.openssl.pkey").new({
  type = "Ed25519",
})
local signature, err = pk:sign("23333")
ngx.say(ngx.encode_base64(signature))

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pkey:verify

syntax: ok, err = pk:verify(signature, digest)

Verify a signture (which can be the string returned by pkey:sign). The second argument must be a resty.openssl.digest instance that uses the same digest algorithm as used in sign. ok returns true if verficiation is successful and false otherwise. Note when verfication failed err will not be set. For EC key, this function does a ECDSA verification.

For Ed25519 or Ed448 keys, this function does a PureEdDSA verification and requires both signature and digest to be string.

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pkey:encrypt

syntax: cipher_txt, err = pk:encrypt(txt, padding?)

Encrypts plain text txt with pkey instance, which must loaded a public key.

When key is a RSA key, the function accepts an optional second argument padding which can be:

  pkey.PADDINGS = {
    RSA_PKCS1_PADDING       = 1,
    RSA_SSLV23_PADDING      = 2,
    RSA_NO_PADDING          = 3,
    RSA_PKCS1_OAEP_PADDING  = 4,
    RSA_X931_PADDING        = 5,
    RSA_PKCS1_PSS_PADDING   = 6,
  }

If omitted, padding is default to pkey.PADDINGS.RSA_PKCS1_PADDING.

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pkey:decrypt

syntax: txt, err = pk:decrypt(cipher_txt, padding?)

Decrypts cipher text cipher_txt with pkey instance, which must loaded a private key.

The optional second argument padding has same meaning in pkey:encrypt.

local pkey = require("resty.openssl.pkey")
local privkey, err = pkey.new()
local pub_pem = privkey:to_PEM("public")
local pubkey, err = pkey.new(pub_pem)
local s, err = pubkey:encrypt("🦢", pkey.PADDINGS.RSA_PKCS1_PADDING)
ngx.say(#s)
-- outputs 256
local decrypted, err = privkey:decrypt(s)
ngx.say(decrypted)
-- outputs "🦢"

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pkey:derive

syntax: txt, err = pk:derive(peer_key)

Derive public key algorithm shared secret peer_key, which must be a pkey instance.

See examples/x25519-dh.lua for an example on how key exchange works for X25519 keys with DH algorithm.

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pkey:tostring

syntax: txt, err = pk:tostring(private_or_public?, fmt?)

Outputs private key or public key of pkey instance in PEM-formatted text. The first argument must be a choice of public, PublicKey, private, PrivateKey or nil. The second argument fmt can be PEM, DER, JWK or nil. If both arguments are omitted, this functions returns the PEM representation of public key.

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pkey:to_PEM

syntax: pem, err = pk:to_PEM(private_or_public?)

Equivalent to pk:tostring(private_or_public, "PEM").

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resty.openssl.bn

Module to expose BIGNUM structure. Note bignum is a big integer, no float operations (like square root) are supported.

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bn.new

syntax: b, err = bn.new(number?)

Creates a bn instance. The first argument can be a Lua number or nil to creates an empty instance.

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bn.dup

syntax: b, err = bn.dup(bn_ptr_cdata)

Duplicates a BIGNUM* to create a new bn instance.

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bn.istype

syntax: ok = bn.istype(table)

Returns true if table is an instance of bn. Returns false otherwise.

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bn.from_binary, bn:to_binary

syntax: bn, err = bn.from_binary(bin)

syntax: bin, err = bn:to_binary()

Creates a bn instance from binary string.

Exports the BIGNUM value in binary string.

local b, err = require("resty.openssl.bn").from_binary(ngx.decode_base64("WyU="))
local bin, err = b:to_binary()
ngx.say(ngx.encode_base64(bin))
-- outputs "WyU="

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bn.from_hex, bn:to_hex

syntax: bn, err = bn.from_hex(hex)

syntax: hex, err = bn:to_hex()

Creates a bn instance from hex encoded string. Note that the leading 0x should not be included. A leading - indicating the sign may be included.

Exports the bn instance to hex encoded string.

local bn = require("resty.openssl.bn")
local b = bn.from_hex("5B25")
local hex, err = b:to_hex()
ngx.say(hex)
-- outputs "5B25"

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bn.from_dec, bn:to_dec

syntax: bn, err = bn.from_dec(dec)

syntax: dec, err = bn:to_dec()

Creates a bn instance from decimal string. A leading - indicating the sign may be included.

Exports the bn instance to decimal string.

local bn = require("resty.openssl.bn")
local b = bn.from_dec("23333")
local dec, err = b:to_dec()
ngx.say(dec)
-- outputs "23333"

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bn:to_number

syntax: n, err = bn:to_number()

syntax: n, err = bn:tonumber()

Export the lowest 32 bits or 64 bits part (based on the ABI) of bn instance to a number. This is useful when user wants to perform bitwise operations.

local bn = require("resty.openssl.bn")
local b = bn.from_dec("23333")
local n, err = b:to_number()
ngx.say(n)
-- outputs 23333
ngx.say(type(n))
-- outputs "number"

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bn:__metamethods

Various mathematical operations can be performed as if it's a number.

local bn = require("resty.openssl.bn")
local a = bn.new(123456)
local b = bn.new(222)
 -- the following returns a bn
local r
r = -a
r = a + b
r = a - b
r = a * b
r = a / b -- equal to bn:idiv, returns floor division
r = a % b
-- all operations can be performed between number and bignum
r = a + 222
r = 222 + a
-- the following returns a bool
local bool
bool = a < b
bool = a >= b
-- compare between number will not work
-- WRONG: bool = a < 222

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bn:add, bn:sub, bn:mul, bn:div, bn:exp, bn:mod, bn:gcd

syntax: r = a:op(b)

syntax: r = bn.op(a, b)

Perform mathematical operations op.

  • add: add
  • sub: subtract
  • mul: multiply
  • div, idiv: floor division (division with rounding down to nearest integer)
  • exp, pow: the b-th power of a, this function is faster than repeated a * a * ....
  • mod: modulo
  • gcd: the greatest common divider of a and b.

Note that add, sub, mul, div, mod is also available with +, -, *, /, % operaters. See above section for examples.

local bn = require("resty.openssl.bn")
local a = bn.new(123456)
local b = bn.new(9876)
local r
-- the followings are equal
r = a:add(b)
r = bn.add(a, b)
r = a:add(9876)
r = bn.add(a, 9876)
r = bn.add(123456, b)
r = bn.add(123456, 9876)

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bn:sqr

syntax: r = a:sqr()

syntax: r = bn.sqr(a)

Computes the 2-th power of a. This function is faster than r = a * a.

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bn:mod_add, bn:mod_sub, bn:mod_mul, bn:mod_exp

syntax: r = a:op(b, m)

syntax: r = bn.op(a, b, m)

Perform modulo mathematical operations op.

  • mod_add: adds a to b modulo m
  • mod_sub: substracts b from a modulo m
  • mod_mul: multiplies a by b and finds the non-negative remainder respective to modulus m
  • mod_exp, mod_pow: computes a to the b-th power modulo m (r=a^b % m). This function uses less time and space than exp. Do not call this function when m is even and any of the parameters have the BN_FLG_CONSTTIME flag set.
local bn = require("resty.openssl.bn")
local a = bn.new(123456)
local b = bn.new(9876)
local r
-- the followings are equal
r = a:mod_add(b, 3)
r = bn.mod_add(a, b, 3)
r = a:mod_add(9876, 3)
r = bn.mod_add(a, 9876, 3)
r = bn.mod_add(123456, b, 3)
r = bn.mod_add(123456, 9876, 3)

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bn:mod_sqr

syntax: r = a:mod_sqr(m)

syntax: r = bn.mod_sqr(a, m)

Takes the square of a modulo m.

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bn:lshift, bn:rshift

syntax: r = bn:lshift(bit)

syntax: r = bn.lshift(a, bit)

syntax: r = bn:rshift(bit)

syntax: r = bn.rshift(a, bit)

Bit shift a to bit bits.

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bn:is_zero, bn:is_one, bn:is_odd, bn:is_word

syntax: ok = bn:is_zero()

syntax: ok = bn:is_one()

syntax: ok = bn:is_odd()

syntax: ok, err = bn:is_word(n)

Checks if bn is 0, 1, and odd number or a number n respectively.

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bn:is_prime

syntax: ok, err = bn:is_prime(nchecks?)

Checks if bn is a prime number. Returns true if it is prime with an error probability of less than 0.25^nchecks and error if any. If omitted, nchecks is set to 0 which means to select number of iterations basedon the size of the number

This function perform a Miller-Rabin probabilistic primality test with nchecks iterations. If nchecks == BN_prime_checks (0), a number of iterations is used that yields a false positive rate of at most 2^-64 for random input. The error rate depends on the size of the prime and goes down for bigger primes. The rate is 2^-80 starting at 308 bits, 2^-112 at 852 bits, 2^-128 at 1080 bits, 2^-192 at 3747 bits and 2^-256 at 6394 bits.

When the source of the prime is not random or not trusted, the number of checks needs to be much higher to reach the same level of assurance: It should equal half of the targeted security level in bits (rounded up to the next integer if necessary). For instance, to reach the 128 bit security level, nchecks should be set to 64.

See also BN_is_prime(3).

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resty.openssl.cipher

Module to interact with symmetric cryptography (EVP_CIPHER).

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cipher.new

syntax: d, err = cipher.new(cipher_name)

Creates a cipher instance. cipher_name is a case-insensitive string of cipher algorithm name. To view a list of cipher algorithms implemented, use openssl list -cipher-algorithms.

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cipher.istype

syntax: ok = cipher.istype(table)

Returns true if table is an instance of cipher. Returns false otherwise.

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cipher:encrypt

syntax: s, err = cipher:encrypt(key, iv?, s, no_padding?, aead_aad?)

Encrypt the text s with key key and IV iv. Returns the encrypted text in raw binary string and error if any. Optionally accepts a boolean no_padding which tells the cipher to enable or disable padding and default to false (enable padding). If no_padding is true, the length of s must then be a multiple of the block size or an error will occur.

When using GCM or CCM mode or chacha20-poly1305 cipher, it's also possible to pass the Additional Authenticated Data (AAD) as the fifth argument.

This function is a shorthand of cipher:init, cipher:set_aead_aad (if appliable) then cipher:final.

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cipher:decrypt

syntax: s, err = cipher:decrypt(key, iv?, s, no_padding?, aead_aad?, aead_tag?)

Decrypt the text s with key key and IV iv. Returns the decrypted text in raw binary string and error if any. Optionally accepts a boolean no_padding which tells the cipher to enable or disable padding and default to false (enable padding). If no_padding is true, the length of s must then be a multiple of the block size or an error will occur; also, padding in the decrypted text will not be removed.

When using GCM or CCM mode or chacha20-poly1305 cipher, it's also possible to pas the Additional Authenticated Data (AAD) as the fifth argument and authentication tag as the sixth argument.

This function is a shorthand of cipher:init, cipher:set_aead_aad (if appliable), cipher:set_aead_tag (if appliable) then cipher:final.

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cipher:init

syntax: ok, err = cipher:init(key, iv?, opts?)

Initialize the cipher with key key and IV iv. The optional third argument is a table consists of:

{
    is_encrypt = false,
    no_padding = false,
}

Calling function is needed before cipher:update and cipher:final if the cipher is not being initialized already. But not cipher:encrypt and cipher:decrypt.

If you wish to reuse cipher instance multiple times, calling this function is necessary to clear the internal state of the cipher. The shorthand functions cipher:encrypt and cipher:decrypt already take care of initialization and reset.

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cipher:update

syntax: s, err = cipher:update(partial, ...)

Updates the cipher with one or more strings. If the cipher has larger than block size of data to flush, the function will return a non-empty string as first argument. This function can be used in a streaming fashion to encrypt or decrypt continous data stream.

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cipher:update_aead_aad

syntax: ok, err = cipher:update_aead_aad(aad)

Provides AAD data to the cipher, this function can be called more than one times.

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cipher:get_aead_tag

syntax: tag, err = cipher:get_aead_tag(size?)

Gets the authentication tag from cipher with length specified as size. If omitted, a tag with length of half of the block size will be returned. The size cannot exceed block size.

This function can only be called after encryption is finished.

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cipher:set_aead_tag

syntax: ok, err = cipher:set_aead_tag(tag)

Set the authentication tag of cipher with tag.

This function can only be called before decryption starts.

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cipher:final

syntax: s, err = cipher:final(partial?)

Returns the encrypted or decrypted text in raw binary string, optionally accept one string to encrypt or decrypt.

-- encryption
local c, err = require("resty.openssl.cipher").new("aes256")
c:init(string.rep("0", 32), string.rep("0", 16), {
    is_encrypt = true,
})
c:update("🦢")
local cipher, err = c:final()
ngx.say(ngx.encode_base64(cipher))
-- outputs "vGJRHufPYrbbnYYC0+BnwQ=="
-- OR:
local c, err = require("resty.openssl.cipher").new("aes256")
local cipher, err = c:encrypt(string.rep("0", 32), string.rep("0", 16), "🦢")
ngx.say(ngx.encode_base64(cipher))
-- outputs "vGJRHufPYrbbnYYC0+BnwQ=="

-- decryption
local encrypted = ngx.decode_base64("vGJRHufPYrbbnYYC0+BnwQ==")
local c, err = require("resty.openssl.cipher").new("aes256")
c:init(string.rep("0", 32), string.rep("0", 16), {
    is_encrypt = false,
})
c:update(encrypted)
local cipher, err = c:final()
ngx.say(cipher)
-- outputs "🦢"
-- OR:
local c, err = require("resty.openssl.cipher").new("aes256")
local cipher, err = c:decrypt(string.rep("0", 32), string.rep("0", 16), encrypted)
ngx.say(cipher)
-- outputs "🦢"

See examples/aes-gcm-aead.lua for an example to use AEAD modes with authentication.

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cipher:derive

syntax: key, iv, err = cipher:derive(key, salt?, count?, md?)

Derive a key and IV (if appliable) from given material that can be used in current cipher. This function is useful mainly to work with keys that were already derived from same algorithm. Newer applications should use a more modern algorithm such as PBKDF2 provided by kdf.derive.

count is the iteration count to perform. If it's omitted, it's set to 1. Note the recent version of openssl enc cli tool automatically use PBKDF2 if -iter is set to larger than 1, while this function will not. To use PBKDF2 to derive a key, please refer to kdf.derive.

md is the message digest name to use, it can take one of the values md2, md5, sha or sha1. If it's omitted, it's default to sha1.

local cipher = require("resty.openssl.cipher").new("aes-128-cfb")
local key, iv, err = cipher:derive("x")
-- equivalent to `openssl enc -aes-128-cfb -pass pass:x -nosalt -P -md sha1`

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resty.openssl.digest

Module to interact with message digest (EVP_MD_CTX).

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digest.new

syntax: d, err = digest.new(digest_name?)

Creates a digest instance. digest_name is a case-insensitive string of digest algorithm name. To view a list of digest algorithms implemented, use openssl list -digest-algorithms.

If digest_name is omitted, it's default to sha1. Specially, the digest_name "null" represents a "null" message digest that does nothing: i.e. the hash it returns is of zero length.

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digest.istype

syntax: ok = digest.istype(table)

Returns true if table is an instance of digest. Returns false otherwise.

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digest:update

syntax: ok, err = digest:update(partial, ...)

Updates the digest with one or more strings.

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digest:final

syntax: str, err = digest:final(partial?)

Returns the digest in raw binary string, optionally accept one string to digest.

local d, err = require("resty.openssl.digest").new("sha256")
d:update("🦢")
local digest, err = d:final()
ngx.say(ngx.encode_base64(digest))
-- outputs "tWW/2P/uOa/yIV1gRJySJLsHq1xwg0E1RWCvEUDlla0="
-- OR:
local d, err = require("resty.openssl.digest").new("sha256")
local digest, err = d:final("🦢")
ngx.say(ngx.encode_base64(digest))
-- outputs "tWW/2P/uOa/yIV1gRJySJLsHq1xwg0E1RWCvEUDlla0="

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digest:reset

syntax: ok, err = digest:reset()

Reset the internal state of digest instance as it's just created by digest:new. It calls EVP_DigestInit_ex under the hood.

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resty.openssl.hmac

Module to interact with hash-based message authentication code (HMAC_CTX).

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hmac.new

syntax: h, err = hmac.new(key, digest_name?)

Creates a hmac instance. digest_name is a case-insensitive string of digest algorithm name. To view a list of digest algorithms implemented, use openssl list -digest-algorithms.

If digest_name is omitted, it's default to sha1.

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hmac.istype

syntax: ok = hmac.istype(table)

Returns true if table is an instance of hmac. Returns false otherwise.

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hmac:update

syntax: ok, err = hmac:update(partial, ...)

Updates the HMAC with one or more strings.

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hmac:final

syntax: str, err = hmac:final(partial?)

Returns the HMAC in raw binary string, optionally accept one string to digest.

local d, err = require("resty.openssl.hmac").new("goose", "sha256")
d:update("🦢")
local hmac, err = d:final()
ngx.say(ngx.encode_base64(hmac))
-- outputs "k2UcrRp25tj1Spff89mJF3fAVQ0lodq/tJT53EYXp0c="
-- OR:
local d, err = require("resty.openssl.hmac").new("goose", "sha256")
local hmac, err = d:final("🦢")
ngx.say(ngx.encode_base64(hmac))
-- outputs "k2UcrRp25tj1Spff89mJF3fAVQ0lodq/tJT53EYXp0c="

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hmac:reset

syntax: ok, err = hmac:reset()

Reset the internal state of hmac instance as it's just created by hmac:new. It calls HMAC_Init_ex under the hood.

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resty.openssl.kdf

Module to interact with KDF (key derivation function).

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kdf.derive

syntax: key, err = kdf.derive(options)

Derive a key from given material. Various KDFs are supported based on OpenSSL version:

options is a table that contains:

Key Type Description Required or default
type number Type of KDF function to use, one of kdf.PBKDF2, kdf.SCRYPT, kdf.TLS1_PRF or kdf.HKDF required
outlen number Desired key length to derive required
pass string Initial key material to derive from (empty string)
salt string Add some salt (empty string)
md string Message digest method name to use, not effective for scrypt type "sha1"
pbkdf2_iter number PBKDF2 iteration count. RFC 2898 suggests an iteration count of at least 1000. Any value less than 1 is treated as a single iteration. 1
hkdf_key string HKDF key required
hkdf_mode number HKDF mode to use, one of kdf.HKDEF_MODE_EXTRACT_AND_EXPAND, kdf.HKDEF_MODE_EXTRACT_ONLY or kdf.HKDEF_MODE_EXPAND_ONLY. This is only effective with OpenSSL >= 1.1.1. To learn about mode, please refer to EVP_PKEY_CTX_set1_hkdf_key(3). kdf.HKDEF_MODE_EXTRACT_AND_EXPAND
hkdf_info string HKDF info value (empty string)
tls1_prf_secret string TLS1-PRF secret required
tls1_prf_seed string TLS1-PRF seed required
scrypt_maxmem number Scrypt maximum memory usage in bytes 32 * 1024 * 1024
scrypt_N number Scrypt CPU/memory cost parameter, must be a power of 2 required
scrypt_r number Scrypt blocksize parameter (8 is commonly used) required
scrypt_p number Scrypt parallelization parameter required 
local kdf = require("resty.openssl.kdf")
local key, err = kdf.derive({
    type = kdf.PBKDF2,
    outlen = 16,
    pass = "1234567",
    md = "md5",
    pbkdf2_iter = 1000,
})
ngx.say(ngx.encode_base64(key))
-- outputs "cDRFLQ7NWt+AP4i0TdBzog=="

key, err = kdf.derive({
    type = kdf.SCRYPT,
    outlen = 16,
    pass = "1234567",
    scrypt_N = 1024,
    scrypt_r = 8,
    scrypt_p = 16,
})
ngx.say(ngx.encode_base64(key))
-- outputs "9giFtxace5sESmRb8qxuOw=="

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resty.openssl.objects

Helpfer module on ASN1_OBJECT.

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objects.obj2table

syntax: tbl = objects.bytes(asn1_obj)

Convert a ASN1_OBJECT pointer to a Lua table where

{
  id: OID of the object,
  nid: NID of the object,
  sn: short name of the object,
  ln: long name of the object,
}

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objects.nid2table

syntax: tbl, err = objects.nid2table(nid)

Convert a NID to a Lua table, returns the same format as objects.obj2table

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objects.txt2nid

syntax: nid, err = objects.txt2nid(txt)

Convert a text representation to NID.

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resty.openssl.rand

Module to interact with random number generator.

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rand.bytes

syntax: str, err = rand.bytes(length)

Generate random bytes with length of length.

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resty.openssl.x509

Module to interact with X.509 certificates.

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x509.new

syntax: crt, err = x509.new(txt?, fmt?)

Creates a x509 instance. txt can be PEM or DER formatted text; fmt is a choice of PEM, DER to load specific format, or * for auto detect.

When txt is omitted, new() creates an empty x509 instance.

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x509.dup

syntax: x509, err = x509.dup(x509_ptr_cdata)

Duplicates a X509* to create a new x509 instance.

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x509.istype

syntax: ok = x509.istype(table)

Returns true if table is an instance of x509. Returns false otherwise.

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x509:digest

syntax: d, err = x509:digest(digest_name?)

Returns a digest of the DER representation of the X509 certificate object in raw binary text.

digest_name is a case-insensitive string of digest algorithm name. To view a list of digest algorithms implemented, use openssl list -digest-algorithms.

If digest_name is omitted, it's default to sha1.

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x509:pubkey_digest

syntax: d, err = x509:pubkey_digest(digest_name?)

Returns a digest of the DER representation of the pubkey in the X509 object in raw binary text.

digest_name is a case-insensitive string of digest algorithm name. To view a list of digest algorithms implemented, use openssl list -digest-algorithms.

If digest_name is omitted, it's default to sha1.

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x509:get_, x509:set_

syntax: ok, err = x509:set_attribute(instance)

syntax: instance, err = x509:get_attribute()

Setters and getters for x509 attributes share the same syntax.

Attribute name Type Description
issuer_name x509.name Issuer of the certificate
not_before number Unix timestamp when certificate is not valid before
not_after number Unix timestamp when certificate is not valid after
pubkey pkey Public key of the certificate
serial_number bn Serial number of the certficate
subject_name x509.name Subject of the certificate
version number Version of the certificate, value is one less than version. For example, 2 represents version 3

Additionally, getters and setters for extensions are also available:

Extension name Type Description
subject_alt_name x509.altname Subject Alternative Name of the certificate, SANs are usually used to define "additional Common Names"
issuer_alt_name x509.altname Issuer Alternative Name of the certificate
basic_constraints table, { ca = bool, pathlen = int} Basic Constriants of the certificate
info_access x509.extension.info_access Authority Information Access of the certificate, contains information like OCSP reponder URL.
crl_distribution_points x509.extension.dist_points CRL Distribution Points of the certificate, contains information like Certificate Revocation List(CRL) URLs.

For all extensions, get_{extension}_critical and set_{extension}_critical is also supported to access the critical flag of the extension.

If the attribute is not found, getter will return nil, nil.

local x509, err = require("resty.openssl.x509").new()
err = x509:set_not_before(ngx.time())
local not_before, err = x509:get_not_before()
ngx.say(not_before)
-- outputs 1571875065

err = x509:set_basic_constraints_critical(true)

If type is a table, setter requires a table with case-insensitive keys to set; getter returns the value of the given case-insensitive key or a table of all keys if no key provided.

local x509, err = require("resty.openssl.x509").new()
err = x509:set_basic_constraints({
  cA = false,
  pathlen = 0,
})

ngx.say(x509:get_basic_constraints("pathlen"))
-- outputs 0

ngx.say(x509:get_basic_constraints())
-- outputs '{"ca":false,"pathlen":0}'

Note that user may also access the certain extension by x509:get_extension and x509:set_extension, while the later two function returns or requires extension instead. User may use getter and setters listed here if modification of current extensions is needed; use x509:get_extension or x509:set_extension if user are adding or replacing the whole extension or getters/setters are not implemented. If the getter returned a type of x509.* instance, it can be converted to a extension instance by extension:from_data, and thus used by x509:get_extension and x509:set_extension

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x509:get_lifetime

syntax: not_before, not_after, err = x509:get_lifetime()

A shortcut of x509:get_not_before plus x509:get_not_after

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x509:set_lifetime

syntax: ok, err = x509:set_lifetime(not_before, not_after)

A shortcut of x509:set_not_before plus x509:set_not_after.

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x509:get_extension

syntax: extension, pos, err = x509:get_extension(nid_or_txt, last_pos?)

Get X.509 extension matching the given NID to certificate, returns a resty.openssl.x509.extension instance and the found position.

If last_pos is defined, the function searchs from that position; otherwise it finds from beginning. Index is 1-based.

local ext, pos, err = x509:get_extension("keyUsage")

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x509:add_extension

syntax: ok, err = x509:add_extension(extension)

Adds an X.509 extension to certificate, the first argument must be a resty.openssl.x509.extension instance.

local extension, err = require("resty.openssl.extension").new({
    "keyUsage", "critical,keyCertSign,cRLSign",
})
local x509, err = require("resty.openssl.x509").new()
local ok, err = x509:add_extension(extension)

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x509:set_extension

syntax: ok, err = x509:set_extension(extension, last_pos?)

Adds an X.509 extension to certificate, the first argument must be a resty.openssl.x509.extension instance. The difference from x509:add_extension is that in this function if a extension with same type already exists, the old extension will be replaced.

If last_pos is defined, the function replaces the same extension from that position; otherwise it finds from beginning. Index is 1-based. Returns nil, nil if not found.

Note this function is not thread-safe.

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x509:get_extension_critical

syntax: ok, err = x509:get_extension_critical(nid_or_txt)

Get critical flag of the X.509 extension matching the given NID from certificate.

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x509:set_extension_critical

syntax: ok, err = x509:set_extension_critical(nid_or_txt, crit?)

Set critical flag of the X.509 extension matching the given NID to certificate.

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x509:get_ocsp_url

syntax: url_or_urls, err = x509:get_ocsp_url(return_all?)

Get OCSP URL(s) of the X.509 object. If return_all is set to true, returns a table containing all OCSP URLs; otherwise returns a string with first OCSP URL found. Returns nil if the extension is not found.

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x509:get_crl_url

syntax: url_or_urls, err = x509:get_crl_url(return_all?)

Get CRL URL(s) of the X.509 object. If return_all is set to true, returns a table containing all CRL URLs; otherwise returns a string with first CRL URL found. Returns nil if the extension is not found.

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x509:sign

syntax: ok, err = x509:sign(pkey, digest?)

Sign the certificate using the private key specified by pkey, which must be a resty.openssl.pkey that stores private key. Optionally accept digest parameter to set digest method, whichmust be a resty.openssl.digest instance. Returns a boolean indicating if signing is successful and error if any.

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x509:verify

syntax: ok, err = x509:verify(pkey)

Verify the certificate signature using the public key specified by pkey, which must be a resty.openssl.pkey. Returns a boolean indicating if verification is successful and error if any.

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x509:tostring

syntax: str, err = x509:tostring(fmt?)

Outputs certificate in PEM-formatted text or DER-formatted binary. The first argument can be a choice of PEM or DER; when omitted, this function outputs PEM by default.

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x509:to_PEM

syntax: pem, err = x509:to_PEM()

Outputs the certificate in PEM-formatted text.

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resty.openssl.x509.csr

Module to interact with certificate signing request (X509_REQ).

See examples/csr.lua for an example to generate CSR.

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csr.new

syntax: csr, err = csr.new(txt?, fmt?)

Create an empty csr instance. txt can be PEM or DER formatted text; fmt is a choice of PEM, DER to load specific format, or * for auto detect.

When txt is omitted, new() creates an empty csr instance.

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csr.istype

syntax: ok = csr.istype(table)

Returns true if table is an instance of csr. Returns false otherwise.

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csr:get_, csr:set_

syntax: ok, err = csr:set_attribute(instance)

syntax: instance, err = csr:get_attribute()

Setters and getters for x509 attributes share the same syntax.

Attribute name Type Description
pubkey pkey Public key of the certificate request
subject_name x509.name Subject of the certificate request
version number Version of the certificate request, value is one less than version. For example, 2 represents version 3

Additionally, getters and setters for extensions are also available:

Extension name Type Description
subject_alt_name x509.altname Subject Alternative Name of the certificate request, SANs are usually used to define "additional Common Names"

If the attribute is not found, getter will return nil, nil.

local csr, err = require("resty.openssl.csr").new()
err = csr:set_version(3)
local version, err = csr:get_version()
ngx.say(version)
-- outputs 3

Setters and getters for x509 attributes share the same syntax.

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csr:set_subject_alt

Same as csr:set_subject_alt_name, this function is deprecated to align with naming convension with other functions.

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csr:sign

syntax: ok, err = csr:sign(pkey, digest?)

Sign the certificate request using the private key specified by pkey, which must be a resty.openssl.pkey that stores private key. Optionally accept digest parameter to set digest method, whichmust be a resty.openssl.digest instance. Returns a boolean indicating if signing is successful and error if any.

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csr:verify

syntax: ok, err = csr:verify(pkey)

Verify the CSR signature using the public key specified by pkey, which must be a resty.openssl.pkey. Returns a boolean indicating if verification is successful and error if any.

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csr:tostring

syntax: str, err = csr:tostring(fmt?)

Outputs certificate request in PEM-formatted text or DER-formatted binary. The first argument can be a choice of PEM or DER; when omitted, this function outputs PEM by default.

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csr:to_PEM

syntax: pem, err = csr:to_PEM(?)

Outputs CSR in PEM-formatted text.

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resty.openssl.crl

Module to interact with X509_CRL(certificate revocation list).

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crl.new

syntax: crt, err = crl.new(txt?, fmt?)

Creates a crl instance. txt can be PEM or DER formatted text; fmt is a choice of PEM, DER to load specific format, or * for auto detect.

When txt is omitted, new() creates an empty crl instance.

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crl.dup

syntax: crl, err = crl.dup(crl_ptr_cdata)

Duplicates a X509_CRL* to create a new crl instance.

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crl.istype

syntax: ok = crl.istype(table)

Returns true if table is an instance of crl. Returns false otherwise.

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crl:get_, crl:set_

syntax: ok, err = crl:set_attribute(instance)

syntax: instance, err = crl:get_attribute()

Setters and getters for crl attributes share the same syntax.

Attribute name Type Description
issuer_name x509.name Issuer of the CRL
last_update number Unix timestamp when CRL is not valid before
next_update number Unix timestamp when CRL is not valid after
version number Version of the certificate, value is one less than version. For example, 2 represents version 3

Additionally, getters and setters for extensions are also available:

Extension name Type Description

For all extensions, get_{extension}_critical and set_{extension}_critical is also supported to access the critical flag of the extension.

If the attribute is not found, getter will return nil, nil.

local crl, err = require("resty.openssl.crl").new()
err = crl:set_next_update(ngx.time())
local not_before, err = crl:get_next_update()
ngx.say(not_before)
-- outputs 1571875065

Note that user may also access the certain extension by crl:get_extension and crl:set_extension, while the later two function returns or requires extension instead. User may use getter and setters listed here if modification of current extensions is needed; use crl:get_extension or crl:set_extension if user are adding or replacing the whole extension or getters/setters are not implemented. If the getter returned a type of crl.* instance, it can be converted to a extension instance by extension:from_data, and thus used by crl:get_extension and crl:set_extension

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crl:get_extension

syntax: extension, pos, err = crl:get_extension(nid_or_txt, last_pos?)

Get X.509 extension matching the given NID to CRL, returns a resty.openssl.x509.extension instance and the found position.

If last_pos is defined, the function searchs from that position; otherwise it finds from beginning. Index is 1-based.

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crl:add_extension

syntax: ok, err = crl:add_extension(extension)

Adds an X.509 extension to CRL, the first argument must be a resty.openssl.x509.extension instance.

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crl:set_extension

syntax: ok, err = crl:set_extension(extension, last_pos?)

Adds an X.509 extension to CRL, the first argument must be a resty.openssl.x509.extension instance. The difference from crl:add_extension is that in this function if a extension with same type already exists, the old extension will be replaced.

If last_pos is defined, the function replaces the same extension from that position; otherwise it finds from beginning. Index is 1-based. Returns nil, nil if not found.

Note this function is not thread-safe.

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crl:get_extension_critical

syntax: ok, err = crl:get_extension_critical(nid_or_txt)

Get critical flag of the X.509 extension matching the given NID from CRL.

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crl:set_extension_critical

syntax: ok, err = crl:set_extension_critical(nid_or_txt, crit?)

Set critical flag of the X.509 extension matching the given NID to CRL.

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crl:sign

syntax: ok, err = crl:sign(pkey, digest?)

Sign the CRL using the private key specified by pkey, which must be a resty.openssl.pkey that stores private key. Optionally accept digest parameter to set digest method, whichmust be a resty.openssl.digest instance. Returns a boolean indicating if signing is successful and error if any.

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crl:verify

syntax: ok, err = crl:verify(pkey)

Verify the CRL signature using the public key specified by pkey, which must be a resty.openssl.pkey. Returns a boolean indicating if verification is successful and error if any.

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crl:tostring

syntax: str, err = crl:tostring(fmt?)

Outputs CRL in PEM-formatted text or DER-formatted binary. The first argument can be a choice of PEM or DER; when omitted, this function outputs PEM by default.

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crl:to_PEM

syntax: pem, err = crl:to_PEM()

Outputs the CRL in PEM-formatted text.

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resty.openssl.x509.name

Module to interact with X.509 names.

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name.new

syntax: name, err = name.new()

Creates an empty name instance.

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name.dup

syntax: name, err = name.dup(name_ptr_cdata)

Duplicates a X509_NAME* to create a new name instance.

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name.istype

syntax: ok = name.istype(table)

Returns true if table is an instance of name. Returns false otherwise.

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name:add

syntax: name, err = name:add(nid_text, txt)

Adds an ASN.1 object to name. First arguments in the text representation of NID. Second argument is the plain text value for the ASN.1 object.

Returns the name instance itself on success, or nil and an error on failure.

This function can be called multiple times in a chained fashion.

local name, err = require("resty.openssl.x509.name").new()
local _, err = name:add("CN", "example.com")

_, err = name
    :add("C", "US")
    :add("ST", "California")
    :add("L", "San Francisco")

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name:find

syntax: obj, pos, err = name:find(nid_text, last_pos?)

Finds the ASN.1 object with the given text representation of NID from the postition of last_pos. By omitting the last_pos parameter, find finds from the beginning.

Returns the object in a table as same format as decribed here, the position of the found object and error if any. Index is 1-based. Returns nil, nil if not found.

local name, err = require("resty.openssl.x509.name").new()
local _, err = name:add("CN", "example.com")
                    :add("CN", "example2.com")

local obj, pos, err = name:find("CN")
ngx.say(obj.blob, " at ", pos)
-- outputs "example.com at 1"
local obj, pos, err = name:find("2.5.4.3", 1)
ngx.say(obj.blob, " at ", pos)
-- outputs "example2.com at 2"

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name:__metamethods

syntax: for k, obj in pairs(name)

syntax: len = #name

syntax: k, v = name[i]

Access the underlying objects as it's a Lua table. Make sure your LuaJIT compiled with -DLUAJIT_ENABLE_LUA52COMPAT flag; otherwise use all, each, index and count instead.

See also functions for stack-like objects.

Each returned object is a table where:

{
  id: OID of the object,
  nid: NID of the object,
  sn: short name of the object,
  ln: long name of the object,
  blob: value of the object,
}

local name, err = require("resty.openssl.x509.name").new()
local _, err = name:add("CN", "example.com")

for k, obj in pairs(name) do
  ngx.say(k, ":", require("cjson").encode(obj))
end
-- outputs 'CN: {"sn":"CN","id":"2.5.4.3","nid":13,"blob":"3.example.com","ln":"commonName"}'

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resty.openssl.x509.altname

Module to interact with GENERAL_NAMES, an extension to X.509 names.

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altname.new

syntax: altname, err = altname.new()

Creates an empty altname instance.

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altname.istype

syntax: altname = digest.istype(table)

Returns true if table is an instance of altname. Returns false otherwise.

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altname:add

syntax: altname, err = altname:add(key, value)

Adds a name to altname stack, first argument is case-insensitive and can be one of

RFC822Name
RFC822
Email
UniformResourceIdentifier
URI
DNSName
DNS
IPAddress
IP
DirName

This function can be called multiple times in a chained fashion.

local altname, err = require("resty.openssl.x509").new()
local _, err = altname:add("DNS", "example.com")

_, err = altname
    :add("DNS", "2.example.com")
    :add("DnS", "3.example.com")

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altname:__metamethods

syntax: for k, obj in pairs(altname)

syntax: len = #altname

syntax: k, v = altname[i]

Access the underlying objects as it's a Lua table. Make sure your LuaJIT compiled with -DLUAJIT_ENABLE_LUA52COMPAT flag; otherwise use all, each, index and count instead.

See also functions for stack-like objects.

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resty.openssl.x509.extension

Module to interact with X.509 extensions.

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extension.new

syntax: ext, err = extension.new(name, value, data?)

Creates a new extension instance. name and value are strings in OpenSSL arbitrary extension format.

data can be a table or nil. Where data is a table, the following key will be looked up:

data = {
    issuer = resty.openssl.x509 instance,
    subject = resty.openssl.x509 instance,
    request = resty.openssl.x509.csr instance,
    crl = resty.openssl.x509.crl instance,
}

Example:

local x509, err = require("resty.openssl.x509").new()
local extension = require("resty.openssl.x509.extension")
local ext, err = extension.new("extendedKeyUsage", "serverAuth,clientAuth")
ext, err =  extension.new("subjectKeyIdentifier", "hash", {
    subject = crt
})

See examples/tls-alpn-01.lua for an example to create extension with an unknown nid.

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extension.dup

syntax: ext, err = extension.dup(extension_ptr_cdata)

Creates a new extension instance from X509_EXTENSION* pointer.

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extension.from_data

syntax: ext, ok = extension.from_data(table, nid, crit?)

Creates a new extension instance. table can be instance of:

nid is a number of NID and crit is the critical flag of the extension.

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extension.istype

syntax: ok = extension.istype(table)

Returns true if table is an instance of extension. Returns false otherwise.

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extension:get_extension_critical

syntax: crit, err = extension:get_extension_critical()

Returns true if extension is critical. Returns false otherwise.

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extension:set_extension_critical

syntax: ok, err = extension:set_extension_critical(crit)

Set the critical flag of the extension.

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extension:get_object

syntax: obj = extension:get_object()

Returns the name of extension as ASN.1 Object. User can further use helper functions in resty.openssl.objects to print human readable texts.

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extension:text

syntax: txt, err = extension:text()

Returns the text representation of extension

local objects = require "resty.openssl.objects"
ngx.say(cjson.encode(objects.obj2table(extension:get_object())))
-- outputs {"ln":"X509v3 Subject Key Identifier","nid":82,"sn":"subjectKeyIdentifier","id":"2.5.29.14"}
ngx.say(extension:text())
-- outputs C9:C2:53:61:66:9D:5F:AB:25:F4:26:CD:0F:38:9A:A8:49:EA:48:A9

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extension:tostring

syntax: txt, err = extension:tostring()

Same as extension:text.

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resty.openssl.x509.extension.dist_points

Module to interact with CRL Distribution Points(DIST_POINT stack).

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dist_points.new

syntax: dp, err = dist_points.new()

Creates a new dist_points instance.

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dist_points.dup

syntax: dp, err = dist_points.dup(dist_points_ptr_cdata)

Duplicates a STACK_OF(DIST_POINT) to create a new dist_points instance. The function creates a new stack and increases reference count for all elements by 1. But it won't duplicate the elements themselves.

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dist_points.istype

syntax: ok = dist_points.istype(table)

Returns true if table is an instance of dist_points. Returns false otherwise.

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dist_points:__metamethods

syntax: for i, obj in ipairs(dist_points)

syntax: len = #dist_points

syntax: obj = dist_points[i]

Access the underlying objects as it's a Lua table. Make sure your LuaJIT compiled with -DLUAJIT_ENABLE_LUA52COMPAT flag; otherwise use all, each, index and count instead.

See also functions for stack-like objects.

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resty.openssl.x509.extension.info_access

Module to interact with Authority Information Access data (AUTHORITY_INFO_ACCESS, ACCESS_DESCRIPTION stack).

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info_access.new

syntax: aia, err = info_access.new()

Creates a new info_access instance.

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info_access.dup

syntax: aia, err = info_access.dup(info_access_ptr_cdata)

Duplicates a AUTHORITY_INFO_ACCESS to create a new info_access instance. The function creates a new stack and increases reference count for all elements by 1. But it won't duplicate the elements themselves.

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info_access.istype

syntax: ok = info_access.istype(table)

Returns true if table is an instance of info_access. Returns false otherwise.

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info_access:add

syntax: ok, err = info_access:add(x509)

Add a x509 object to the info_access. The first argument must be a resty.openssl.x509 instance.

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info_access:__metamethods

syntax: for i, obj in ipairs(info_access)

syntax: len = #info_access

syntax: obj = info_access[i]

Access the underlying objects as it's a Lua table. Make sure your LuaJIT compiled with -DLUAJIT_ENABLE_LUA52COMPAT flag; otherwise use all, each, index and count instead.

See also functions for stack-like objects.

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resty.openssl.x509.chain

Module to interact with X.509 stack.

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chain.new

syntax: ch, err = chain.new()

Creates a new chain instance.

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chain.dup

syntax: ch, err = chain.dup(chain_ptr_cdata)

Duplicates a STACK_OF(X509) to create a new chain instance. The function creates a new stack and increases reference count for all elements by 1. But it won't duplicate the elements themselves.

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chain.istype

syntax: ok = chain.istype(table)

Returns true if table is an instance of chain. Returns false otherwise.

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chain:add

syntax: ok, err = chain:add(x509)

Add a x509 object to the chain. The first argument must be a resty.openssl.x509 instance.

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chain:__metamethods

syntax: for i, obj in ipairs(chain)

syntax: len = #chain

syntax: obj = chain[i]

Access the underlying objects as it's a Lua table. Make sure your LuaJIT compiled with -DLUAJIT_ENABLE_LUA52COMPAT flag; otherwise use all, each, index and count instead.

See also functions for stack-like objects.

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resty.openssl.x509.store

Module to interact with X.509 certificate store (X509_STORE).

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store.new

syntax: st, err = store.new()

Creates a new store instance.

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store.istype

syntax: ok = store.istype(table)

Returns true if table is an instance of store. Returns false otherwise.

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store:use_default

syntax: ok, err = store:use_default()

Loads certificates into the X509_STORE from the hardcoded default paths.

Note that to load "default" CAs correctly, usually you need to install a CA certificates bundle. For example, the package in Debian/Ubuntu is called ca-certificates.

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store:add

syntax: ok, err = store:add(x509_or_crl)

Adds a X.509 or a CRL object into store. The argument must be a resty.openssl.x509 instance or a resty.openssl.x509.store instance.

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store:load_file

syntax: ok, err = store:load_file(path)

Loads a X.509 certificate on file system into store.

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store:load_directory

syntax: ok, err = store:load_directory(path)

Loads a directory of X.509 certificates on file system into store. The certificates in the directory must be in hashed form, as documented in X509_LOOKUP_hash_dir(3).

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store:verify

syntax: chain, err = store:verify(x509, chain?, return_chain?)

Verifies a X.509 object with the store. The first argument must be resty.openssl.x509 instance. Optionally accept a validation chain as second argument, which must be a resty.openssl.x509.chain instance.

If verification succeed, and return_chain is set to true, returns the proof of validation as a resty.openssl.x509.chain; otherwise returns true only. If verification failed, returns nil and error explaining the reason.

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Functions for stack-like objects

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metamethods

syntax: for k, obj in pairs(x)

syntax: for k, obj in ipairs(x)

syntax: len = #x

syntax: obj = x[i]

Access the underlying objects as it's a Lua table. Make sure your LuaJIT compiled with -DLUAJIT_ENABLE_LUA52COMPAT flag.

Each object may only support either pairs or ipairs. Index is 1-based.

local name, err = require("resty.openssl.x509.name").new()
local _, err = name:add("CN", "example.com")

for k, obj in pairs(name) do
  ngx.say(k, ":", require("cjson").encode(obj))
end
-- outputs 'CN: {"sn":"CN","id":"2.5.4.3","nid":13,"blob":"3.example.com","ln":"commonName"}'

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each

syntax: iter = x:each()

Return an iterator to traverse objects. Use this while LUAJIT_ENABLE_LUA52COMPAT is not enabled.

local name, err = require("resty.openssl.x509.name").new()
local _, err = name:add("CN", "example.com")

local iter = name:each()
while true do
  local k, obj = iter()
  if not k then
    break
  end
end

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all

syntax: objs, err = x:all()

Returns all objects in the table. Use this while LUAJIT_ENABLE_LUA52COMPAT is not enabled.

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count

syntax: len = x:count()

Returns count of objects of the table. Use this while LUAJIT_ENABLE_LUA52COMPAT is not enabled.

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index

syntax: obj = x:index(i)

Returns objects at index of i of the table, index is 1-based. If index is out of bound, nil is returned.

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General rules on garbage collection

  • When a type is added or returned to another type, it's internal cdata is always copied.
local name = require("resty.openssl.x509.name"):add("CN", "example.com")
local x509 = require("resty.openssl.x509").new()
-- `name` is copied when added to x509
x509:set_subject_name(name)

name:add("L", "Mars")
-- subject_name in x509 will not be modified
  • The creator set the GC handler; the user must not free it.
  • For a stack:
    • If it's created by new(): set GC handler to sk_TYPE_pop_free
      • The gc handler for elements being added to stack should not be set. Instead, rely on the gc handler of the stack to free each individual elements.
    • If it's created by dup() (shallow copy):
      • If elements support reference counter (like X509): increase ref count for all elements by 1; set GC handler to sk_TYPE_pop_free.
      • If not, set GC handler to sk_free
        • Additionally, the stack duplicates the element when it's added to stack, a GC handler for the duplicate must be set. But a reference should be kept in Lua land to prevent premature gc of individual elements. (See x509.altname)

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Compatibility

Although only a small combinations of CPU arch and OpenSSL version are tested, the library should function well as long as the linked OpenSSL library is API compatible. This means the same name of functions are exported with same argument types.

For OpenSSL 1.0.2 series however, binary/ABI compatibility must be ensured as some struct members are accessed directly. They are accessed by memory offset in assembly.

OpenSSL keeps ABI/binary compatibility with minor releases or letter releases. So all structs offsets and macro constants are kept same.

If you plan to use this library on an untested version of OpenSSL (like custom builds or pre releases), this can be a good source to consult.

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Copyright and License

This module is licensed under the BSD license.

Copyright (C) 2019-2020, by fffonion [email protected].

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.

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See Also

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FFI-based OpenSSL binding for OpenResty

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