summaryrefslogtreecommitdiffstats
path: root/modules/http/http_tls_cert.lua
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:26:00 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:26:00 +0000
commit830407e88f9d40d954356c3754f2647f91d5c06a (patch)
treed6a0ece6feea91f3c656166dbaa884ef8a29740e /modules/http/http_tls_cert.lua
parentInitial commit. (diff)
downloadknot-resolver-upstream.tar.xz
knot-resolver-upstream.zip
Adding upstream version 5.6.0.upstream/5.6.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'modules/http/http_tls_cert.lua')
-rw-r--r--modules/http/http_tls_cert.lua186
1 files changed, 186 insertions, 0 deletions
diff --git a/modules/http/http_tls_cert.lua b/modules/http/http_tls_cert.lua
new file mode 100644
index 0000000..7e557c4
--- /dev/null
+++ b/modules/http/http_tls_cert.lua
@@ -0,0 +1,186 @@
+-- SPDX-License-Identifier: GPL-3.0-or-later
+--[[
+ Conventions:
+ - key = private+public key-pair in openssl.pkey format
+ - certs = lua list of certificates (at least one), each in openssl.x509 format,
+ ordered from leaf to almost-root
+ - panic('...') is used on bad problems instead of returning nils or such
+--]]
+local tls_cert = {}
+
+local ffi = require('ffi')
+local x509, pkey = require('openssl.x509'), require('openssl.pkey')
+
+-- @function Create self-signed certificate; return certs, key
+local function new_ephemeral(host)
+ -- Import luaossl directly
+ local name = require('openssl.x509.name')
+ local altname = require('openssl.x509.altname')
+ local openssl_bignum = require('openssl.bignum')
+ local openssl_rand = require('openssl.rand')
+ -- Create self-signed certificate
+ host = host or hostname()
+ local crt = x509.new()
+ local now = os.time()
+ crt:setVersion(3)
+ -- serial needs to be unique or browsers will show uninformative error messages
+ crt:setSerial(openssl_bignum.fromBinary(openssl_rand.bytes(16)))
+ -- use the host we're listening on as canonical name
+ local dn = name.new()
+ dn:add("CN", host)
+ crt:setSubject(dn)
+ crt:setIssuer(dn) -- should match subject for a self-signed
+ local alt = altname.new()
+ alt:add("DNS", host)
+ crt:setSubjectAlt(alt)
+ -- Valid for 90 days
+ crt:setLifetime(now, now + 90*60*60*24)
+ -- Can't be used as a CA
+ crt:setBasicConstraints{CA=false}
+ crt:setBasicConstraintsCritical(true)
+ -- Create and set key (default: EC/P-256 as a most "interoperable")
+ local key = pkey.new {type = 'EC', curve = 'prime256v1'}
+ crt:setPublicKey(key)
+ crt:sign(key)
+ return { crt }, key
+end
+
+-- @function Write certs and key to files
+local function write_cert_files(certs, key, certfile, keyfile)
+ -- Write certs
+ local f = assert(io.open(certfile, 'w'), string.format('cannot open "%s" for writing', certfile))
+ for _, cert in ipairs(certs) do
+ f:write(tostring(cert))
+ end
+ f:close()
+ -- Write key as a pair
+ f = assert(io.open(keyfile, 'w'), string.format('cannot open "%s" for writing', keyfile))
+ local pub, priv = key:toPEM('public', 'private')
+ assert(f:write(pub .. priv))
+ f:close()
+end
+
+-- @function Start maintenance of a self-signed TLS context (at ephem_state.ctx).
+-- Keep updating the ephem_state.servers table. Stop updating by calling _destroy().
+-- TODO: each process maintains its own ephemeral cert ATM, and the files aren't ever read from.
+function tls_cert.ephemeral_state_maintain(ephem_state, certfile, keyfile)
+ local certs, key = new_ephemeral()
+ write_cert_files(certs, key, certfile, keyfile)
+ ephem_state.ctx = tls_cert.new_tls_context(certs, key)
+ -- Each server needs to have its ctx updated.
+ for _, s in pairs(ephem_state.servers) do
+ s.server.ctx = ephem_state.ctx
+ s.config.ctx = ephem_state.ctx -- not required, but let's keep it synchronized
+ end
+ log_info(ffi.C.LOG_GRP_HTTP, 'created new ephemeral TLS certificate')
+ local _, expiry_stamp = certs[1]:getLifetime()
+ local wait_msec = 1000 * math.max(1, expiry_stamp - os.time() - 3 * 24 * 3600)
+ if not ephem_state.timer_id then
+ ephem_state.timer_id = event.after(wait_msec, function ()
+ tls_cert.ephemeral_state_maintain(ephem_state, certfile, keyfile)
+ end)
+ else
+ event.reschedule(ephem_state.timer_id, wait_msec)
+ end
+end
+function tls_cert.ephemeral_state_destroy(ephem_state)
+ if ephem_state and ephem_state.timer_id then
+ event.cancel(ephem_state.timer_id)
+ end
+end
+
+-- @function Read a certificate chain and a key from files; return certs, key
+function tls_cert.load(certfile, keyfile)
+ -- get key
+ local f, err = io.open(keyfile, 'r')
+ if not f then
+ panic('[http] unable to open TLS key file: %s', err)
+ end
+ local key = pkey.new(f:read('*all'))
+ f:close()
+ if not key then
+ panic('[http] unable to parse TLS key file %s', keyfile)
+ end
+
+ -- get certs list
+ local certs = {}
+ local f, err = io.open(certfile, 'r')
+ if not f then
+ panic('[http] unable to read TLS certificate file: %s', err)
+ end
+ while true do
+ -- Get the next "block" = single certificate as PEM string.
+ local block = nil
+ local line
+ repeat
+ line = f:read()
+ if not line then break end
+ if block then
+ block = block .. '\n' .. line
+ else
+ block = line
+ end
+ -- separator: "posteb" in https://tools.ietf.org/html/rfc7468#section-3
+ until string.sub(line, 1, 9) == '-----END '
+ -- Empty block means clean EOF.
+ if not block then break end
+ if not line then
+ panic('[http] unable to parse TLS certificate file %s, certificate number %d', certfile, 1 + #certs)
+ end
+
+ -- Parse the cert and append to the list.
+ local cert = x509.new(block, 'PEM')
+ if not cert then
+ panic('[http] unable to parse TLS certificate file %s, certificate number %d', certfile, 1 + #certs)
+ end
+ table.insert(certs, cert)
+ end
+ f:close()
+
+ return certs, key
+end
+
+
+-- @function Prefer HTTP/2 or HTTP/1.1
+local function alpnselect(_, protos)
+ for _, proto in ipairs(protos) do
+ if proto == 'h2' or proto == 'http/1.1' then
+ return proto
+ end
+ end
+ return nil
+end
+
+local warned_old_luaossl = false
+
+-- @function Return a new TLS context for a server.
+function tls_cert.new_tls_context(certs, key)
+ local ctx = require('http.tls').new_server_context()
+ if ctx.setAlpnSelect then
+ ctx:setAlpnSelect(alpnselect)
+ end
+ assert(ctx:setPrivateKey(key))
+ assert(ctx:setCertificate(certs[1]))
+
+ -- Set up certificate chain to be sent, if required and possible.
+ if #certs == 1 then return ctx end
+ if ctx.setCertificateChain then
+ local chain = require('openssl.x509.chain').new()
+ assert(chain)
+ for i = 2, #certs do
+ chain:add(certs[i])
+ assert(chain)
+ end
+ assert(ctx:setCertificateChain(chain))
+ elseif not warned_old_luaossl then
+ -- old luaossl version -> only final cert sent to clients
+ log_warn(ffi.C.LOG_GRP_HTTP,
+ 'need luaossl >= 20181207 to support sending intermediary certificate to clients')
+ warned_old_luaossl = true
+ end
+ return ctx
+end
+
+
+return tls_cert
+