Documentation ¶
Overview ¶
Taken from $GOROOT/src/pkg/net/http/chunked needed to write https responses to client.
Package goproxy provides a customizable HTTP proxy, supporting hijacking HTTPS connection.
The intent of the proxy, is to be usable with reasonable amount of traffic yet, customizable and programable.
The proxy itself is simply an `net/http` handler.
Typical usage is
proxy := goproxy.NewProxyHttpServer() proxy.OnRequest(..conditions..).Do(..requesthandler..) proxy.OnRequest(..conditions..).DoFunc(..requesthandlerFunction..) proxy.OnReponse(..conditions..).Do(..responesHandler..) proxy.OnReponse(..conditions..).DoFunc(..responesHandlerFunction..) http.ListenAndServe(":8080", proxy)
Adding a header to each request
proxy.OnRequest().DoFunc(func(r *http.Request,ctx *goproxy.ProxyCtx)*http.Request{ r.Header.Set("X-GoProxy","1") return r })
Note that the function is called before the proxy sends the request to the server ¶
For printing the content type of all incoming responses
proxy.OnReponse().DoFunc(func(r *http.Response, ctx *goproxy.ProxyCtx)*http.Response{ println(ctx.Req.Host,"->",r.Header.Get("Content-Type")) return r })
note that we used the ProxyCtx context variable here. It contains the request and the response (Req and Resp, Resp is nil if unavailable) of this specific client interaction with the proxy.
To print the content type of all responses from a certain url, we'll add a ReqCondition to the OnResponse function:
proxy.OnReponse(goproxy.UrlIs("golang.org/pkg")).DoFunc(func(r *http.Response, ctx *goproxy.ProxyCtx)*http.Response{ println(ctx.Req.Host,"->",r.Header.Get("Content-Type")) return r })
We can write the condition ourselves, conditions can be set on request and on response
var random = ReqConditionFunc(func(r *http.Request) bool { return rand.Intn(1) == 0 }) var hasGoProxyHeader = RespConditionFunc(func(resp *http.Response,req *http.Request)bool { return resp.Header.Get("X-GoProxy") != "" })
Caution! If you give a RespCondition to the OnRequest function, you'll get a run time panic! It doesn't make sense to read the response, if you still haven't got it!
Finally, we have convenience function to throw a quick response
proxy.OnResponse(hasGoProxyHeader).DoFunc(func(r*http.Response,ctx *goproxy.ProxyCtx)*http.Response { r.Body.Close() return goproxy.ForbiddenTextResponse(ctx.Req,"Can't see response with X-GoProxy header!") })
we close the body of the original repsonse, and return a new 403 response with a short message.
Example use cases:
https://github.com/ledzep2/goproxy/examples/avgSize
To measure the average size of an Html served in your site. One can ask all the QA team to access the website by a proxy, and the proxy will measure the average size of all text/html responses from your host.
[not yet implemented]
All requests to your web servers should be directed through the proxy, when the proxy will detect html pieces sent as a response to AJAX request, it'll send a warning email.
[not yet implemented]
Generate a real traffic to your website by real users using through proxy. Record the traffic, and try it again for more real load testing.
[not yet implemented]
Will allow browsing to reddit.com between 8:00am and 17:00pm
[not yet implemented]
Will warn if multiple versions of jquery are used in the same domain.
Index ¶
- Constants
- Variables
- func NewResponse(r *http.Request, contentType string, status int, body string) *http.Response
- func TextResponse(r *http.Request, text string) *http.Response
- type ConnectAction
- type ConnectActionLiteral
- type FuncHttpsHandler
- type FuncReqHandler
- type FuncRespHandler
- type HttpsHandler
- type ProxyConds
- type ProxyCtx
- type ProxyHttpServer
- type ReqCondition
- type ReqConditionFunc
- func DstHostIs(host string) ReqConditionFunc
- func Not(r ReqCondition) ReqConditionFunc
- func ReqHostIs(hosts ...string) ReqConditionFunc
- func ReqHostMatches(regexps ...*regexp.Regexp) ReqConditionFunc
- func UrlHasPrefix(prefix string) ReqConditionFunc
- func UrlIs(urls ...string) ReqConditionFunc
- func UrlMatches(re *regexp.Regexp) ReqConditionFunc
- type ReqHandler
- type ReqProxyConds
- func (pcond *ReqProxyConds) Do(h ReqHandler)
- func (pcond *ReqProxyConds) DoFunc(f func(req *http.Request, ctx *ProxyCtx) (*http.Request, *http.Response))
- func (pcond *ReqProxyConds) HandleConnect(h HttpsHandler)
- func (pcond *ReqProxyConds) HandleConnectFunc(f func(host string, ctx *ProxyCtx) (*ConnectAction, string))
- type RespCondition
- type RespConditionFunc
- type RespHandler
Constants ¶
const ( ConnectAccept = iota ConnectReject ConnectMitm )
const ( ContentTypeText = "text/plain" ContentTypeHtml = "text/html" )
Variables ¶
var ( OkConnect = &ConnectAction{Action: ConnectAccept} MitmConnect = &ConnectAction{Action: ConnectMitm} RejectConnect = &ConnectAction{Action: ConnectReject} )
var CA_CERT = []byte(`-----BEGIN CERTIFICATE-----
MIICSjCCAbWgAwIBAgIBADALBgkqhkiG9w0BAQUwSjEjMCEGA1UEChMaZ2l0aHVi
LmNvbS9lbGF6YXJsL2dvcHJveHkxIzAhBgNVBAMTGmdpdGh1Yi5jb20vZWxhemFy
bC9nb3Byb3h5MB4XDTAwMDEwMTAwMDAwMFoXDTQ5MTIzMTIzNTk1OVowSjEjMCEG
A1UEChMaZ2l0aHViLmNvbS9lbGF6YXJsL2dvcHJveHkxIzAhBgNVBAMTGmdpdGh1
Yi5jb20vZWxhemFybC9nb3Byb3h5MIGdMAsGCSqGSIb3DQEBAQOBjQAwgYkCgYEA
vz9BbCaJjxs73Tvcq3leP32hAGerQ1RgvlZ68Z4nZmoVHfl+2Nr/m0dmW+GdOfpT
cs/KzfJjYGr/84x524fiuR8GdZ0HOtXJzyF5seoWnbBIuyr1PbEpgRhGQMqqOUuj
YExeLbfNHPIoJ8XZ1Vzyv3YxjbmjWA+S/uOe9HWtDbMCAwEAAaNGMEQwDgYDVR0P
AQH/BAQDAgCkMBMGA1UdJQQMMAoGCCsGAQUFBwMBMA8GA1UdEwEB/wQFMAMBAf8w
DAYDVR0RBAUwA4IBKjALBgkqhkiG9w0BAQUDgYEAIcL8huSmGMompNujsvePTUnM
oEUKtX4Eh/+s+DSfV/TyI0I+3GiPpLplEgFWuoBIJGios0r1dKh5N0TGjxX/RmGm
qo7E4jjJuo8Gs5U8/fgThZmshax2lwLtbRNwhvUVr65GdahLsZz8I+hySLuatVvR
qHHq/FQORIiNyNpq/Hg=
-----END CERTIFICATE-----`)
var CA_KEY = []byte(`-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----`)
var GoproxyCa, _ = tls.X509KeyPair(CA_CERT, CA_KEY)
Functions ¶
func NewResponse ¶
Will generate a valid http response to the given request the response will have the given contentType, and http status. Typical usage, refuse to process requests to local addresses:
proxy.OnRequest(IsLocalHost()).DoFunc(func(r *http.Request, ctx *goproxy.ProxyCtx) (*http.Request,*http.Response) { return nil,NewResponse(r,goproxy.ContentTypeHtml,http.StatusUnauthorized, `<!doctype html><html><head><title>Can't use proxy for local addresses</title></head><body/></html>`) })
Types ¶
type ConnectAction ¶
type ConnectAction struct { Action ConnectActionLiteral TlsConfig *tls.Config Ca *tls.Certificate }
type ConnectActionLiteral ¶
type ConnectActionLiteral int
type FuncHttpsHandler ¶
type FuncHttpsHandler func(host string, ctx *ProxyCtx) (*ConnectAction, string)
A wrapper that would convert a function to a HttpsHandler interface type
var AlwaysMitm FuncHttpsHandler = func(host string, ctx *ProxyCtx) (*ConnectAction, string) { return MitmConnect, host }
AlwaysMitm is a HttpsHandler that always eavesdrop https connections, for example to eavesdrop all https connections to www.google.com, we can use
proxy.OnRequest(goproxy.ReqHostIs("www.google.com")).HandleConnect(goproxy.AlwaysMitm)
var AlwaysReject FuncHttpsHandler = func(host string, ctx *ProxyCtx) (*ConnectAction, string) { return RejectConnect, host }
AlwaysReject is a HttpsHandler that drops any CONNECT request, for example, this code will disallow connections to hosts on any other port than 443
proxy.OnRequest(goproxy.Not(goproxy.ReqHostMatches(regexp.MustCompile(":443$"))). HandleConnect(goproxy.AlwaysReject)
func (FuncHttpsHandler) HandleConnect ¶
func (f FuncHttpsHandler) HandleConnect(host string, ctx *ProxyCtx) (*ConnectAction, string)
FuncHttpsHandler should implement the RespHandler interface
type FuncReqHandler ¶
A wrapper that would convert a function to a ReqHandler interface type
type FuncRespHandler ¶
A wrapper that would convert a function to a RespHandler interface type
type HttpsHandler ¶
type HttpsHandler interface {
HandleConnect(req string, ctx *ProxyCtx) (*ConnectAction, string)
}
When a client send a CONNECT request to a host, the request is filtered through all the HttpsHandlers the proxy has, and if one returns true, the connection is sniffed using Man in the Middle attack. That is, the proxy will create a TLS connection with the client, another TLS connection with the destination the client wished to connect to, and would send back and forth all messages from the server to the client and vice versa. The request and responses sent in this Man In the Middle channel are filtered through th eusual flow (request and response filtered through the ReqHanlders and RespHandlers)
type ProxyConds ¶
type ProxyConds struct {
// contains filtered or unexported fields
}
ProxyConds is used to aggregate RespConditions for a ProxyHttpServer. Upon calling ProxyConds.Do, it will register a RespHandler that would handle the HTTP response from remote server if all conditions on the HTTP response are met.
func (*ProxyConds) Do ¶
func (pcond *ProxyConds) Do(h RespHandler)
ProxyConds.Do will register the RespHandler on the proxy, h.Handle(resp,ctx) will be called on every request that matches the conditions aggregated in pcond.
type ProxyCtx ¶
type ProxyCtx struct { // Will contain the client request from the proxy Req *http.Request // Will contain the remote server's response (if available. nil if the request wasn't send yet) Resp *http.Response RoundTrip *transport.RoundTripDetails // will contain the recent error that occured while trying to send receive or parse traffic Error error // A handle for the user to keep data in the context, from the call of ReqHandler to the // call of RespHandler UserData interface{} // Will connect a request to a response Session int64 // Conn Conn net.Conn // contains filtered or unexported fields }
ProxyCtx is the Proxy context, contains useful information about every request. It is passed to every user function. Also used as a logger.
func (*ProxyCtx) Charset ¶
Will try to infer the character set of the request from the headers. Returns the empty string if we don't know which character set it used. Currently it will look for charset=<charset> in the Content-Type header of the request.
func (*ProxyCtx) Logf ¶
Logf prints a message to the proxy's log. Should be used in a ProxyHttpServer's filter This message will be printed only if the Verbose field of the ProxyHttpServer is set to true
proxy.OnRequest().DoFunc(func(r *http.Request,ctx *goproxy.ProxyCtx) *http.Request{ nr := atomic.AddInt32(&counter,1) ctx.Printf("So far %d requests",nr) return r })
func (*ProxyCtx) Warnf ¶
Warnf prints a message to the proxy's log. Should be used in a ProxyHttpServer's filter This message will always be printed.
proxy.OnRequest().DoFunc(func(r *http.Request,ctx *goproxy.ProxyCtx) *http.Request{ f,err := os.OpenFile(cachedContent) if err != nil { ctx.Warnf("error open file %v: %v",cachedContent,err) return r } return r })
type ProxyHttpServer ¶
type ProxyHttpServer struct { // setting Verbose to true will log information on each request sent to the proxy Verbose bool Logger func(fmt string, args ...interface{}) // contains filtered or unexported fields }
The basic proxy type. Implements http.Handler.
func NewProxyHttpServer ¶
func NewProxyHttpServer(tr *transport.Transport) *ProxyHttpServer
New proxy server, logs to StdErr by default
func (*ProxyHttpServer) OnRequest ¶
func (proxy *ProxyHttpServer) OnRequest(conds ...ReqCondition) *ReqProxyConds
ProxyHttpServer.OnRequest Will return a temporary ReqProxyConds struct, aggregating the given condtions. You will use the ReqProxyConds struct to register a ReqHandler, that would filter the request, only if all the given ReqCondition matched. Typical usage:
proxy.OnRequest(UrlIs("example.com/foo"),UrlMatches(regexp.MustParse(`.*\.exampl.\com\./.*`)).Do(...)
func (*ProxyHttpServer) OnResponse ¶
func (proxy *ProxyHttpServer) OnResponse(conds ...RespCondition) *ProxyConds
OnResponse is used when adding a response-filter to the HTTP proxy, usual pattern is
proxy.OnResponse(cond1,cond2).Do(handler) // handler.Handle(resp,ctx) will be used // if cond1.HandleResp(resp) && cond2.HandleResp(resp)
func (*ProxyHttpServer) ServeHTTP ¶
func (proxy *ProxyHttpServer) ServeHTTP(w http.ResponseWriter, r *http.Request)
Standard net/http function. Shouldn't be used directly, http.Serve will use it.
type ReqCondition ¶
type ReqCondition interface { RespCondition HandleReq(req *http.Request, ctx *ProxyCtx) bool }
ReqCondition.HandleReq will decide whether or not to use the ReqHandler on an HTTP request before sending it to the remote server
func SrcIpIs ¶
func SrcIpIs(ip string) ReqCondition
SrcIpIs returns a ReqCondtion testing wether the source IP of the request is the given string
type ReqConditionFunc ¶
ReqConditionFunc.HandleReq(req,ctx) <=> ReqConditionFunc(req,ctx)
var IsLocalHost ReqConditionFunc = func(req *http.Request, ctx *ProxyCtx) bool {
return req.URL.Host == "::1" ||
req.URL.Host == "0:0:0:0:0:0:0:1" ||
localHostIpv4.MatchString(req.URL.Host) ||
req.URL.Host == "localhost"
}
IsLocalHost checks whether the destination host is explicitly local host (buggy, there can be IPv6 addresses it doesn't catch)
func DstHostIs ¶
func DstHostIs(host string) ReqConditionFunc
DstHostIs returns a ReqCondtion testing wether the host in the request url is the given string
func Not ¶
func Not(r ReqCondition) ReqConditionFunc
Not returns a ReqCondtion negating the given ReqCondition
func ReqHostIs ¶
func ReqHostIs(hosts ...string) ReqConditionFunc
ReqHostIs returns a ReqCondition, testing whether the host to which the request is directed to equal to one of the given strings
func ReqHostMatches ¶
func ReqHostMatches(regexps ...*regexp.Regexp) ReqConditionFunc
ReqHostMatches returns a ReqCondition, testing whether the host to which the request was directed to matches any of the given regular expressions.
func UrlHasPrefix ¶
func UrlHasPrefix(prefix string) ReqConditionFunc
UrlHasPrefix returns a ReqCondtion checking wether the destination URL the proxy client has requested has the given prefix, with or without the host. For example UrlHasPrefix("host/x") will match requests of the form 'GET host/x', and will match requests to url 'http://host/x'
func UrlIs ¶
func UrlIs(urls ...string) ReqConditionFunc
UrlIs returns a ReqCondition, testing whether or not the request URL is one of the given strings with or without the host prefix. UrlIs("google.com/","foo") will match requests 'GET /' to 'google.com', requests `'GET google.com/' to any host, and requests of the form 'GET foo'.
func UrlMatches ¶
func UrlMatches(re *regexp.Regexp) ReqConditionFunc
UrlMatches returns a ReqCondition testing whether the destination URL of the request matches the given regexp, with or without prefix
func (ReqConditionFunc) HandleReq ¶
func (c ReqConditionFunc) HandleReq(req *http.Request, ctx *ProxyCtx) bool
func (ReqConditionFunc) HandleResp ¶
func (c ReqConditionFunc) HandleResp(resp *http.Response, ctx *ProxyCtx) bool
RespConditionFunc cannot test requests. It only satisfies ReqCondition interface so that RespCondition and ReqCondition will be of the same type.
type ReqHandler ¶
type ReqHandler interface {
Handle(req *http.Request, ctx *ProxyCtx) (*http.Request, *http.Response)
}
ReqHandler will "tamper" with the request coming to the proxy server If Handle returns req,nil the proxy will send the returned request to the destination server. If it returns nil,resp the proxy will skip sending any requests, and will simply return the response `resp` to the client.
type ReqProxyConds ¶
type ReqProxyConds struct {
// contains filtered or unexported fields
}
ReqProxyConds aggregate ReqConditions for a ProxyHttpServer. Upon calling Do, it will register a ReqHandler that would handle the request if all conditions on the HTTP request are met.
func (*ReqProxyConds) Do ¶
func (pcond *ReqProxyConds) Do(h ReqHandler)
ReqProxyConds.Do will register the ReqHandler on the proxy, the ReqHandler will handle the HTTP request if all the conditions aggregated in the ReqProxyConds are met. Typical usage:
proxy.OnRequest().Do(handler) // will call handler.Handle(req,ctx) on every request to the proxy proxy.OnRequest(cond1,cond2).Do(handler) // given request to the proxy, will test if cond1.HandleReq(req,ctx) && cond2.HandleReq(req,ctx) are true // if they are, will call handler.Handle(req,ctx)
func (*ReqProxyConds) DoFunc ¶
func (pcond *ReqProxyConds) DoFunc(f func(req *http.Request, ctx *ProxyCtx) (*http.Request, *http.Response))
DoFunc is equivalent to proxy.OnRequest().Do(FuncReqHandler(f))
func (*ReqProxyConds) HandleConnect ¶
func (pcond *ReqProxyConds) HandleConnect(h HttpsHandler)
HandleConnect is used when proxy receives an HTTP CONNECT request, it'll then use the HttpsHandler to determine what should it do with this request. The handler returns a ConnectAction struct, the Action field in the ConnectAction struct returned will determine what to do with this request. ConnectAccept will simply accept the request forwarding all bytes from the client to the remote host, ConnectReject will close the connection with the client, and ConnectMitm, will assume the underlying connection is an HTTPS connection, and will use Man in the Middle attack to eavesdrop the connection. All regular handler will be active on this eavesdropped connection. The ConnectAction struct contains possible tlsConfig that will be used for eavesdropping. If nil, the proxy will use the default tls configuration.
proxy.OnRequest().HandleConnect(goproxy.AlwaysReject) // rejects all CONNECT requests
func (*ReqProxyConds) HandleConnectFunc ¶
func (pcond *ReqProxyConds) HandleConnectFunc(f func(host string, ctx *ProxyCtx) (*ConnectAction, string))
HandleConnectFunc is equivalent to HandleConnect, for example, accepting CONNECT request if they contain a password in header
io.WriteString(h,password) passHash := h.Sum(nil) proxy.OnRequest().HandleConnectFunc(func(host string, ctx *ProxyCtx) (*ConnectAction, string) { c := sha1.New() io.WriteString(c,ctx.Req.Header.Get("X-GoProxy-Auth")) if c.Sum(nil) == passHash { return OkConnect, host } return RejectConnect, host })
type RespCondition ¶
ReqCondition.HandleReq will decide whether or not to use the RespHandler on an HTTP response before sending it to the proxy client
func ContentTypeIs ¶
func ContentTypeIs(typ string, types ...string) RespCondition
ContentTypeIs returns a RespCondition testing whether the HTTP response has Content-Type header equal to one of the given strings.
type RespConditionFunc ¶
RespConditionFunc.HandleResp(resp,ctx) <=> RespConditionFunc(resp,ctx)
func (RespConditionFunc) HandleResp ¶
func (c RespConditionFunc) HandleResp(resp *http.Response, ctx *ProxyCtx) bool
type RespHandler ¶
after the proxy have sent the request to the destination server, it will "filter" the response through the RespHandlers it has. The proxy server will send to the client the response returned by the RespHandler. In case of error, resp will be nil, and ctx.RoundTrip.Error will contain the error
func HandleBytes ¶
func HandleBytes(f func(b []byte, ctx *ProxyCtx) []byte) RespHandler
HandleBytes will return a RespHandler that read the entire body of the request to a byte array in memory, would run the user supplied f function on the byte arra, and will replace the body of the original response with the resulting byte array.