Don't overwrite existing CheckRedirect

README.md

@@ -6,7 +6,7 @@ For technical details, you can try asking Josh (not me) or reverse engineer the
 
 <hr>
 
-Donations are always appreciated but never expected nor required:
+I do this shit for free, sometimes to my own detriment, for no good reason. Consider donating if you appreciate this monumental waste of my time.
 
 XMR: `8BjCARiV2uB2gZTbbiMUetfRxcAYZgVM5fXxjEbpmb2nAu8ND1grazZ1EhMGdRqVerAtvEJeiy7SzA3SLXpg2CtRDtCAFfn`
 

cerberus.go

@@ -30,8 +30,6 @@ type Solution struct {
 	Nonce    uint32 // Solution nonce. This is the "answer" to the problem.
 	Redirect string // Relative path to redirect to after Solution is accepted.
 
-	Steps int8 // Steps, as described in Challenge.
-
 	// TODO: Maybe make the redirect shit auto, idk.
 
 	host *url.URL
@@ -102,7 +100,6 @@ func genHashes(ctx context.Context, c Challenge) <-chan Solution {
 				Salt:     c.Salt,
 				Nonce:    nonce,
 				Redirect: "/", // Use sensible default for placeholder, for now.
-				Steps:    c.Steps - 1,
 			}
 			// Ensure we don't hang if out channel is full on ctx close.
 			select {

cerberus_test.go

@@ -4,9 +4,11 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"io"
 	"log"
 	"net"
 	"net/http"
+	"net/http/cookiejar"
 	"strings"
 	"testing"
 
@@ -31,12 +33,16 @@ func solveTest(ctx context.Context, hc http.Client, host string) error {
 		connType = "tor"
 	}
 
+	steps := int8(1)
+
+	for steps > 0 {
 		log.Printf("Fetching new %s challenge...", connType)
 		c, err := NewChallenge(ctx, hc, host)
 		if err != nil {
 			return err
 		}
 		log.Printf("Challenge: %s, Difficulty: %d, Steps: %d\n", c.Salt, c.Diff, c.Steps)
+		steps = c.Steps
 
 		s, err := Solve(ctx, c)
 		if err != nil {
@@ -48,9 +54,12 @@ func solveTest(ctx context.Context, hc http.Client, host string) error {
 		if err != nil {
 			return err
 		}
-	defer resp.Body.Close()
 
-	log.Printf("Response: %s\n\n", resp.Header.Get("Set-Cookie"))
+		b, err := io.ReadAll(resp.Body)
+		log.Printf("Response: %s\n\n", b[:60])
+
+		resp.Body.Close()
+	}
 
 	return nil
 }
@@ -67,9 +76,16 @@ func newProxyTransport() *http.Transport {
 func TestSubmit(t *testing.T) {
 	ctx := t.Context()
 
-	err := solveTest(ctx, http.Client{}, _TEST_HOST)
+	jar, err := cookiejar.New(nil)
 	if err != nil {
 		t.Error(err)
+		return
+	}
+
+	err = solveTest(ctx, http.Client{Jar: jar}, _TEST_HOST)
+	if err != nil {
+		t.Error(err)
+		return
 	}
 
 	var dnsErr *net.DNSError

go.mod

@@ -1,6 +1,6 @@
-module github.com/y-a-t-s/cerberus
+module gitgud.io/yats/cerberus
 
-go 1.25.5
+go 1.25.6
 
 require (
 	github.com/minio/sha256-simd v1.0.1

http.go

@@ -34,6 +34,7 @@ func NewChallenge(ctx context.Context, hc http.Client, host string) (Challenge,
 		return Challenge{}, err
 	}
 
+	if hc.CheckRedirect == nil {
 		// Update host url in case we get redirected across domains.
 		hc.CheckRedirect = func(req *http.Request, via []*http.Request) error {
 			rh := req.URL.Host
@@ -43,6 +44,7 @@ func NewChallenge(ctx context.Context, hc http.Client, host string) (Challenge,
 
 			return nil
 		}
+	}
 
 	req, err := http.NewRequestWithContext(ctx, "GET", u.String(), nil)
 	if err != nil {
@@ -95,31 +97,7 @@ func Submit(ctx context.Context, hc http.Client, s Solution, redirect string) (*
 		s.Redirect = redirect
 	}
 
-	resp, err := postSolution(ctx, hc, s)
-	if err != nil {
-		return nil, err
-	}
-
-	// This feels gross, but it works.
-	for s.Steps > 0 {
-		resp.Body.Close()
-
-		c, err := NewChallenge(ctx, hc, s.host.String())
-		if err != nil {
-			return nil, err
-		}
-
-		s, err = Solve(ctx, c)
-		if err != nil {
-			return nil, err
-		}
-		resp, err = Submit(ctx, hc, s, redirect)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	return resp, nil
+	return postSolution(ctx, hc, s)
 }
 
 func parseHost(addr string) (*url.URL, error) {
@@ -144,18 +122,7 @@ func postSolution(ctx context.Context, hc http.Client, s Solution) (*http.Respon
 		return nil, err
 	}
 
-	resp, err := hc.Do(req)
-	if err != nil {
-		return nil, err
-	}
-
-	// TODO: Additionally verify failure from response JSON. Maybe include resp body in err type.
-	// Rejected solution response: status=400 body={"success":false,"reason":"invalid_solution","action":"retry"}
-	if resp.StatusCode == 400 {
-		return resp, &ErrInvalidSolution{s}
-	}
-
-	return resp, nil
+	return hc.Do(req)
 }
 
 func parseTags(r io.Reader) (Challenge, error) {