README

Installing

Quick-start examples

Serving current directory on port 8080 (Docker version)

docker run --rm -it -v "$PWD:/var/www/html:ro" -p 8080:80 korc/onefile-websrv

Serving current directory on port 8080 (Go version)

Install Go

go get -u github.com/korc/onefile-websrv
go/bin/onefile-websrv -listen :8080

Public HTTPS server with valid, auto-generated Let's Encrypt certificates

(replace example.com with your real public hostname)

go get -u github.com/korc/onefile-websrv
mkdir acme-certs
sudo go/bin/onefile-websrv -listen :443 -acmehost example.com -cert $PWD/acme-certs -map /=file:/var/www

Check out systemd approach below for more secure setup.

With Docker

Serving content from /data/web/html:

docker build -t websrv https://github.com/korc/onefile-websrv.git
docker run --name websrv -u 33:33 -p 80:8080 -v /data/web:/var/www websrv -listen :8080

Using with systemd

go install github.com/korc/onefile-websrv@latest
install go/bin/onefile-websrv /usr/local/bin/websrv
curl https://raw.githubusercontent.com/korc/onefile-websrv/master/websrv.service | sudo tee /etc/systemd/system/websrv.service
sudo vi /etc/systemd/system/websrv.service # modify command line options for your needs
systemctl daemon-reload && systemctl enable websrv && systemctl start websrv
systemctl status websrv

Listening on low-number ports, chroot and non-root user issues

websrv can change user id after start (required for low-level port listen and chroot), but unfortunately that's currently broken in Golang's Linux implementation (some process threads might remain running as root). If you don't want to run as root (not recommended anyway), and want to use those high-privileged functions, then it's best to set appropriate capabilities(7) with setcap(8) program (ex: setcap cap_net_bind_service,cap_sys_chroot=ep websrv), and then run as target user (ex: www-data).

Configuration

Command-line options

websrv -h
  -acl value
      [{<methods..>}]<path_regexp>=<role>[+<role2..>]:<role..> (multi-arg)
  -acmehost string
      Host names (comma-separated) allowed for automatically issued ([ACME](https://en.wikipedia.org/wiki/Automatic_Certificate_Management_Environment)) certificates, -cert will be cache dir
  -acmehttp string
      Listen address for ACME http-01 challenge (default ":80")
  -args-env string
        read arguments from environment <prefix>1..<prefix>N (default "WEBSRV_ARG")
  -args-file string
        read args from file, one per line
  -auth value
      [<role>[+<role2>]=]<method>:<auth> (multi-arg)
  -cert string
      SSL certificate file or autocert cache dir
  -cert-fallback
      Certificate file to use if ACME fails
  -chroot string
      chroot() to directory after start
  -key string
      SSL key file
  -listen string
      Listen ip:port or /path/to/unix-socket (default ":80")
  -loglevel string
      Max log level (one of FATAL, ERROR, WARNING, INFO, VERBOSE, DEBUG) (default "info")
  -map value
      [<vhost>]/<path>=<handler>:[<params>] (multi-arg, default '/=file:')
  -user string
      Switch to user (NOT RECOMMENDED)
  -cors value
      <path>=<allowed_origin> (multi-arg)
  -wstmout int
      Websocket alive check timer in seconds (default 60)
  -reqlog string
      URL to log request details to (supports also unix:///dir/unix-socket:/path URLs)

Options marked with multi-arg can be specified multiple times on command-line, and will add to previous configuration. Other options are meant to be set only once.

Command-line through environment

• by default, arguments can be also specified through environment variables WEBSRV_ARG1 .. WEBSRV_ARG<n>
  • the prefix of environment variable can be set via -args-env option

Command-line from file

• -args-file can be used to set a file to read arguments from, one per line
• -args-env is processed before, so WEBSRV_ARG1=-args-file WEBSRV_ARG2=/some/path/file can be used to set that file via environment as well
• -args-file is a multi-arg, and can be subsequently added via files themselves

URL path mapping

• -map option in hostname/path=handler:params format can be used to map different paths to different handlers
  • optional hostname can be used for virtual hosting, empty value for all hosts
• additional -map entries add more mappings
• supported handler types:
  • file: statically serve files from directory specified in params, or current working directory if empty
  • webdav: WebDAV handler for directory params, or memory-only storage if empty. Options between {..} before path:
    • ctype=<CONTENT_TYPE> use CONTENT_TYPE for file content type (was: -wdctype)
    • unsafe=1 use webdav.Dir instead of symlink-checking (more safe) custom FS provider
  • websocket: (alias ws) connects a websocket to TCP or UNIX socket
  • http: pass request to HTTP backend
  • debug: client request debug
    • comma-separated options available after :
      • json output data in JSON format
      • no-hdr do not include request headers in JSON output
      • no-auth do not include obtained roles info in json
      • path=x.y.z show only defined path from JSON output (ex: path=TLS.peers[0].cn)
      • tls-cs include full tls.ConnectionState in JSON output
  • cgi: Run a CGI script specified by params.
  • jwt: generate JWT token
  • ws-proxy: WebSocket proxy service, to be used with ws_proxy

WebSocket handler

• params contains target where websocket is connected to
  • HOST:PORT or tcp:HOST:PORT to connection via TCP to HOST:PORT
  • tls:HOST:PORT to connect using TLS over TCP
  • unix:/PATH/SOCKET for UNIX socket
  • exec:COMMAND to run COMMAND using sh -c
    • prefix {sh=SHELL} for alternate shell
    • prefix {no-c=1} for no -c option after shell command
    • prefix {sep=SEPARATOR} to split string after exec: into arguments with SEPARATOR
  • mux:ID to share a websocket with other clients connected to the same ID
• supported options before path in {...}
  • type=text to change default message type to text
  • re=REGEXP to match grouped params like $1 in address from request URL path with regexp

HTTP handler

• params must be complete URL starting with http:, https:, unix: or wsprx:
  • wsprx is handled by ws-proxy: mapped server, hostname component as name of it (example below)
• supports unix sockets in the format of unix:///path/to/unix-socket:/urlpath
• comma-separated options between {...} before URL:
  • cert and key options to set TLS backend client certificate and key files
  • forward client certificate data to backend in specified HTTP header:
    • fp-hdr SHA256 fingerprint
    • cn-hdr subject CN attribute
    • subj-hdr subject in text form
    • cert-hdr hex-encoded client certificate
  • del-hdr=x-header-name:x-header2-name to remove request header from client
  • set-hdr:x-header-name=VALUE to set a request header
  • no-xff=1 to remove X-Forwarded-For header containing client IP and do not send X-Forwarded-Proto
  • no-gzip=1 do not send Accept-Encoding: gzip
  • verify=0 to allow making insecure HTTPS requests
  • fix-ws-hdr=1 make sure Sec-Websocket-* headers are sent as Sec-WebSocket-*
  • ca=<filename> to set remote RootCAs PEM file

Example: Using HTTP handler with wsprx schema

Goal: passing backend http server to external front-end. External server possibly publicly accessible, backend possibly in the internal network (a'la ngrok).

• front-end web service: onefile-websrv -map /=http:wsprx://backend -map /.srv=ws-proxy:{listener=1}backend
• back-end web service: onefile-websrv -map /=file:/data/web/html -listen 127.0.0.1:8000
• back-end to front-end connector (from cmd/ws_proxy): ws_proxy -ws ws://front-end-srv/.srv -connect 127.0.0.1:8000

NOTE: If front-end is accessible from public internet, you should additionally protect /.srv endpoint properly with -acl options.

WebSocket Proxy handler

• params is a internal name for this proxy. options:
  • {listener=1} make this a server socket for ws_proxy endpoint
  • {re=...} searches URL.Path, and params as template for name
    • ex: -map /prx/=ws-proxy:{re=^/prx/(.+)}prx-$1

Debug handler

Includes client certificate hash, which can be used for -auth option's Cert method

CGI handler

Before program name, can specify environment and args with { }

Examples

• {AAAA,BBBB=123,arg:--dir,arg:/var/www}/usr/lib/cgi/program
  • AAAA will be copied from host env, BBBB will be set to 123, program will be executed with 2 arguments: --dir and /var/www

JWT handler

• secret source specified by params
• source can be prefixed with file: to read source from file, or env: to read from environment variable
• following comma-separated options can prefixed with {...} before source
  • b64=1 decode secret from base64
  • alg={ES256|ES384|ES512|RS256|RS384|RS512|PS256|PS384|PS512|HS256|HS384|HS512} generation algorithm
    • default algorithm is HS256
    • RS* and PS* source must be PEM-encoded RSA private key (PKCS#1)
    • ES* source is EC-DSA key
  • <key>=<value>: set key in the issued claim to value
    • if key ends with _claim, that is removed
    • if key ands with <claim>_repl, it must contain sed-like string replacement in @regex@replacement@ format, which will be applied to the claim <claim>
      • any character be used instead of @
      • ex: {aud=req:path,aud_repl=@.*/@@} assigns aud to a filename in the path
    • value can be value string, or a value solved from request (cf. Parameters from request section below)
      • also, ts:<format> for unix timestamp based on following:
        • basic format is +duration or -duration to add or subtract from current time
        • can prefix duration with
          • today to make relation based on start of the day in server localtime
          • q: get duration relative to issue time from URL query
    • exp is by default set to ts:+5m, use exp= with empty value to explicitly disable JWT expiration

Examples:

• -map /acl/get=jwt:{b64=1,exp=ts:+1h,aud=q:target,nbf=ts:q:nbf}bXktc2VjcmV0
  • HS256 signed with shared secret my-secret, 1 hour expiration, audience from target query parameter, valid-from time from nbf query parameter (default=time of request)
• -map /login=jwt:{exp=ts:today+25h,sub=crt:cn,alg=ES256}file:jwt.key
  • signed with EC-DSA key in jwt.key, sub in claims from client's x509 certificate subject CN attribute, expiring on next day at 1am

Parameters from request

Several options support retrieving a value from request. The syntax is as following:

• str: plain string following str:
• crt: client certificate data
  • cn subject common name
  • subj full subject
  • fp certificate sha256 fingerprint
  • crt base64-encoded certificate
• q:<name> value of URL query parameter <name>
• post:<name> POST form value
• hdr:<name> HTTP request header
• env:<name> server environment variable
• auth:<value>
  • bearer Authorization Bearer value
  • basic-usr, basic-pwd respective Basic auth user/password values
• req: a value from request parameter
  • raddr client remote address (with port number)
  • rip client remote IP
  • host requested Host
  • path URL path
• jwt:<claim>:<src>
  • parse JWT from <src> (same syntax as above), and retrieve value of claim named <claim>. The name is assumed to be must be URL-escaped.
• unescape:<src>
  • solve <src> via request, and url-unescape it
  • if <src> does not contain :, it is assumed to be verbatim string
• tmpl:<src>
  • construct string from template, which is parameter defined in <src>
  • .req data is set to current request
  • additional functions defined
    • rp <param> <req> function is added to retrieve other parameters from request
    • b64 <bytes>, b64url <bytes>, b64dec <str>, b64decurl <str> encode/decode with normal/url encoding. decode returns values in []byte type, encode in string
    • stob convert string to bytes
    • atoi convert string to integer
    • map <key> <value> ... create a map of values
    • json convert map to json []byte value
  • ex: tmpl:env:ENV_TEMPLATE_VAR, with ENV_TEMPLATE_VAR containing eyJhbGciOiJIUzI1NiJ9.{{b64url (json (map "sub" (rp "q:sub" .req)))}}.{{rp "q:sig" .req}}

Access control

• -acl option will define mapping between URL paths and required roles
  • path_regexp is defined by regular expression, like ^/admin/
    • add ? before regex (ex: ?^/xyz/.*session_id=.*) to check full RequestURI including query part (not only Path) for match
  • in curly braces before path regexp can set comma-separated params
    • host:<hostname> to apply only for particular virtual hosts (req with Host: hostname)
    • GET, POST, etc. to filter by HTTP methods
    • onfail:<URL> redirect to URL when auth fails. can use @param@ placeholders to solve into url-escaped values from request (ex: @req:host@)
  • : separates alternate roles (OR operation)
  • + makes all specified roles to be required (AND operation)
    • can be used to implement multi-factor auth
• -auth option can be used to add new roles
  • multiple roles can be assigned with one method
  • auth value is method-specific
  • can use environment variables in form of ${variable_name} in auth part (presence in environment is mandatory)
  • possible values for method parameter
    • Basic
      • HTTP Basic authentication (WEAK security)
      • auth is a Base64-encoded value of username:password
    • Cert
      • SSL Client X.509 certificate authentication
      • auth as hex-encoded value of SHA-256 hash of certificate's binary (DER) data
      • if auth starts with file:, certificate is read from file on disk and it's hash is used instead
    • CertBy
      • auth can be hex-encoded value of client CA certificate's binary
      • file: in the beginning of auth will load CA certificate from file
    • CertKeyHash auth is hex-encoded SHA256 hash of client certificate's public key (SHA256 of ASN1 from ssh-keygen -e -m pkcs8 and certtool --pubkey-info) file: prefix make keys to be loaded from specified file instead
      • can read OpenSSH authorized_keys with ssh-rsa keys, and PEM files with PUBLIC KEY or CERTIFICATE data
    • JWT
      • auth value is RSA or ECDSA private or public key in PEM format, unless {hs=1} option is given
        • use env:<varname> or file:<filename> to read value from environment or file
      • {..} options values
        • src=<req_param> define jwt source, cf. Parameters from request for <req_param> format
          • can use src_xxx to arbitrarily define multiple sources
        • no-bearer=1 do not check Authorization: Bearer ... header by default
        • hs=1 use auth value as secret key for HMAC signature
        • b64=1 decode auth value with base64
        • aud=<type>:<value> or aud=path - determine what is going to be checked for aud "Audience" claim
          • type and value use same syntax as claim string values in JWT handler (no ts: timestamp).
        • aud-re=<regexp> aud value (path by default, can be overwritten by aud=) will be matched against regexp, if subgroups found then first group will be used as value
        • test=claim:<name>:<test> or test_<xxx>=claim:<name>:<test>
          • <name> is a url-escaped name of a claim to test
          • <test> is a plain string, or a request parameter if contains :
    • JWTSecret DEPRECATED in favor of JWT
      • checks if JWT from Authentication: Bearer header is signed by specific authority
      • auth contains authority's shared secret
      • can prefix auth with {cookie|header|query=XXX} to additionally look JWT token from specified cookie, header or query parameter named XXX. multiple locations have to be separated with comma.
        • ex: -auth viewer=JWTSecret:{cookie=viewacces,query=va}MySecretJWTKey
    • IPRange
      • checks client's remote IP
      • auth is IP address with network mask length in format of ip/masklen
      • can start with file: to read ip ranges from file, lines starting with # are ignored
      • {xff=..} colon-separated list of reverse proxy IP's which can set X-Forwarded-For header for client IP
    • JWTFilePat DEPRECATED
      • auth specifies file (pattern) containing accepted JWT tokens signed with:
        • secrets, in format of hash:url-base64-encoded-secret
        • RSA public keys, in format of rsa:base64-encoded-n-value
          • e is assumed to be 0x10001
      • if letters "**" are found inside filename, they are replaced with pattern constructed from:
        • URL path, URL path with extensions of last element removed (one-by-one), and each path component removed one-by-one from the end
        • Ex: -acl ^/adm/=xxx -auth xxx=JWTFilePat:/data/webauth/**.jwt and access to /adm/test.123.html will result in checking of files
          • /data/webauth/adm/test.123.html.jwt
          • /data/webauth/adm/test.123.jwt
          • /data/webauth/adm/test.jwt
          • /data/webauth/adm.jwt
        • because of cost associated with checking for .jwt files, auth is applied only when path requires authentication
    • File
      • file existence check
      • options available with {..} prefix:
        • nofile inverse condition, and succeed if file does NOT exist
        • re-path treat auth value as regular expression, and re-path as pathname with $<nr> subgroup expansion pattern
          • ex: -map /=webdav:/data/ -auth nofile=File:{no-file=1,re-path=/data/$1}/(.+) -auth ip4all=IPRange:0.0.0.0/0 -acl {PUT}^/=nofile -acl {GET}^/=ip4all -acl ^/=nobody
            • create a WebDAV mapping for /data/, where you can upload only new files
    • HTTP
      • make a HTTP sub-request to URL at parameter
        • if value starts with tmpl:, it will be processed as template in Parameters from request, documented above
      • options set with {..}:
        • method use something else than GET
        • need-hdr colon-separated list of headers required to even start testing (ex. Authorization)
        • cp-hdr colon-separated list of headers to copy from original request
        • set-hdr:xxx set header xxx to a specified value when making request
          • value can start with tmpl:, see above
        • success response code which to be considered success
    • GeoIP
      • look up record from MaxMind's GeoIP database and check record value
      • options via {..}
        • file=<filename.mmdb> set database, MANDATORY
        • rprx=<ip1>:<ip2..> list of reverse proxy servers for X-Forwarded-For, from closest to farthest
        • key=<a>:<b..> set record value key, defaults to country:iso_code
      • example usage: -auth "jpn=GeoIP:{file=/usr/share/GeoIP/GeoLite2-Country.mmdb,rprx=127.0.0.1}JP"