forgejo/golang-forgejo-go-chi-captcha
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Adding upstream version 1.0.1.

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Signed-off-by: Daniel Baumann <daniel@debian.org>
This commit is contained in:
Daniel Baumann 2025-05-18 14:30:15 +02:00
parent 25c29c6190
commit cd7c72beb5
Signed by: daniel
GPG key ID: FBB4F0E80A80222F
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name: test
on:
pull_request:
push:
branches:
- main
jobs:
test:
runs-on: docker-global-bookworm
container:
image: 'code.forgejo.org/oci/node:20-bookworm'
steps:
- uses: https://code.forgejo.org/actions/checkout@v4
- uses: https://code.forgejo.org/actions/setup-go@v5
with:
go-version-file: "go.mod"
- name: golangci-lint
uses: https://github.com/golangci/golangci-lint-action@v6
with:
version: v1.60.3 # renovate: datasource=go depName=golangci-lint packageName=github.com/golangci/golangci-lint/cmd/golangci-lint
- name: test
run: go test -v ./...

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# Generated test captchas
capgen/*.png
capgen/*.wav
# Programs
capgen/capgen
cangensounds/cangensounds
capexample/capexample

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.golangci.yaml Normal file
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linters:
enable-all: false
disable-all: true
fast: false
enable:
- bidichk
- dupl
- errcheck
- forbidigo
- gocritic
- gofmt
- gofumpt
- gosimple
- govet
- ineffassign
- nakedret
- nolintlint
- revive
- staticcheck
- stylecheck
- tenv
- testifylint
- typecheck
- unconvert
- unused
- unparam
- wastedassign

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Copyright (c) 2011-2014 Dmitry Chestnykh <dmitry@codingrobots.com>
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.

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Package captcha
=====================
This is a fork of https://github.com/dchest/captcha
**:warning: Warning: this captcha can be broken by advanced OCR captcha breaking algorithms.**
import "code.forgejo.org/go-chi/captcha"
Package captcha implements generation and verification of image CAPTCHAs.
A captcha solution is the sequence of digits 0-9 with the defined length.
There is one captcha representations: image.
An image representation is a PNG-encoded image with the solution printed on
it in such a way that makes it hard for computers to solve it using OCR.
This package doesn't require external files or libraries to generate captcha
representations; it is self-contained.
To make captchas one-time, the package includes a memory storage that stores
captcha ids, their solutions, and expiration time. Used captchas are removed
from the store immediately after calling Verify or VerifyString, while
unused captchas (user loaded a page with captcha, but didn't submit the
form) are collected automatically after the predefined expiration time.
Developers can also provide custom store (for example, which saves captcha
ids and solutions in database) by implementing Store interface and
registering the object with SetCustomStore.
Captchas are created by calling New, which returns the captcha id. Their
representations, though, are created on-the-fly by calling WriteImage function.
Created representations are not stored anywhere, but subsequent calls to these
functions with the same id will write the same captcha solution. Reload function
will create a new different solution for the provided captcha, allowing users to
"reload" captcha if they can't solve the displayed one without reloading the
whole page. Verify and VerifyString are used to verify that the given solution
is the right one for the given captcha id.
Server provides an http.Handler which can serve image representations of
captchas automatically from the URL. It can also be used to reload captchas.
Refer to Server function documentation for details, or take a look at the
example in "capexample" subdirectory.
Examples
--------
![Image](https://github.com/dchest/captcha/raw/master/capgen/example.png)
Constants
---------
``` go
const (
// Default number of digits in captcha solution.
DefaultLen = 6
// The number of captchas created that triggers garbage collection used
// by default store.
CollectNum = 100
// Expiration time of captchas used by default store.
Expiration = 10 * time.Minute
)
```
``` go
const (
// Standard width and height of a captcha image.
StdWidth = 240
StdHeight = 80
)
```
Variables
---------
``` go
var (
ErrNotFound = errors.New("captcha: id not found")
)
```
Functions
---------
### func New
func New() string
New creates a new captcha with the standard length, saves it in the internal
storage and returns its id.
### func NewLen
func NewLen(length int) (id string)
NewLen is just like New, but accepts length of a captcha solution as the
argument.
### func RandomDigits
func RandomDigits(length int) (b []byte)
RandomDigits returns a byte slice of the given length containing
pseudorandom numbers in range 0-9. The slice can be used as a captcha
solution.
### func Reload
func Reload(id string) bool
Reload generates and remembers new digits for the given captcha id. This
function returns false if there is no captcha with the given id.
After calling this function, the image presented to a user must be refreshed to
show the new captcha representation (WriteImage will write the new one).
### func Server
func Server(imgWidth, imgHeight int) http.Handler
Server returns a handler that serves HTTP requests with image or
representations of captchas. Image dimensions are accepted as
arguments. The server decides which captcha to serve based on the last URL
path component: file name part must contain a captcha id, file extension —
its format (PNG or WAV).
For example, for file name "LBm5vMjHDtdUfaWYXiQX.png" it serves an image captcha
with id "LBm5vMjHDtdUfaWYXiQX".
To reload captcha (get a different solution for the same captcha id), append
"?reload=x" to URL, where x may be anything (for example, current time or a
random number to make browsers refetch an image instead of loading it from
cache).
### func SetCustomStore
func SetCustomStore(s Store)
SetCustomStore sets custom storage for captchas, replacing the default
memory store. This function must be called before generating any captchas.
### func Verify
func Verify(id string, digits []byte) bool
Verify returns true if the given digits are the ones that were used to
create the given captcha id.
The function deletes the captcha with the given id from the internal
storage, so that the same captcha can't be verified anymore.
### func VerifyString
func VerifyString(id string, digits string) bool
VerifyString is like Verify, but accepts a string of digits. It removes
spaces and commas from the string, but any other characters, apart from
digits and listed above, will cause the function to return false.
### func WriteImage
func WriteImage(w io.Writer, id string, width, height int) error
WriteImage writes PNG-encoded image representation of the captcha with the
given id. The image will have the given width and height.
Types
-----
``` go
type Image struct {
*image.Paletted
// contains unexported fields
}
```
### func NewImage
func NewImage(id string, digits []byte, width, height int) *Image
NewImage returns a new captcha image of the given width and height with the
given digits, where each digit must be in range 0-9.
### func (*Image) WriteTo
func (m *Image) WriteTo(w io.Writer) (int64, error)
WriteTo writes captcha image in PNG format into the given writer.
``` go
type Store interface {
// Set sets the digits for the captcha id.
Set(id string, digits []byte)
// Get returns stored digits for the captcha id. Clear indicates
// whether the captcha must be deleted from the store.
Get(id string, clear bool) (digits []byte)
}
```
An object implementing Store interface can be registered with SetCustomStore
function to handle storage and retrieval of captcha ids and solutions for
them, replacing the default memory store.
It is the responsibility of an object to delete expired and used captchas
when necessary (for example, the default memory store collects them in Set
method after the certain amount of captchas has been stored.)
### func NewMemoryStore
func NewMemoryStore(collectNum int, expiration time.Duration) Store
NewMemoryStore returns a new standard memory store for captchas with the
given collection threshold and expiration time in seconds. The returned
store must be registered with SetCustomStore to replace the default one.

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// Copyright 2011 Dmitry Chestnykh. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
// example of HTTP server that uses the captcha package.
//
//nolint:forbidigo
package main
import (
"fmt"
"io"
"log"
"net/http"
"text/template"
"code.forgejo.org/go-chi/captcha"
)
var formTemplate = template.Must(template.New("example").Parse(formTemplateSrc))
func showFormHandler(w http.ResponseWriter, r *http.Request) {
if r.URL.Path != "/" {
http.NotFound(w, r)
return
}
d := struct {
CaptchaID string
}{
captcha.New(),
}
if err := formTemplate.Execute(w, &d); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
}
func processFormHandler(w http.ResponseWriter, r *http.Request) {
w.Header().Set("Content-Type", "text/html; charset=utf-8")
if !captcha.VerifyString(r.FormValue("captchaId"), r.FormValue("captchaSolution")) {
_, _ = io.WriteString(w, "Wrong captcha solution! No robots allowed!\n")
} else {
_, _ = io.WriteString(w, "Great job, human! You solved the captcha.\n")
}
_, _ = io.WriteString(w, "<br><a href='/'>Try another one</a>")
}
func main() {
http.HandleFunc("/", showFormHandler)
http.HandleFunc("/process", processFormHandler)
http.Handle("/captcha/", captcha.Server(captcha.StdWidth, captcha.StdHeight))
fmt.Println("Server is at localhost:8666")
if err := http.ListenAndServe("localhost:8666", nil); err != nil {
log.Fatal(err)
}
}
const formTemplateSrc = `<!doctype html>
<head><title>Captcha Example</title></head>
<body>
<script>
function setSrcQuery(e, q) {
var src = e.src;
var p = src.indexOf('?');
if (p >= 0) {
src = src.substr(0, p);
}
e.src = src + "?" + q
}
function reload() {
setSrcQuery(document.getElementById('image'), "reload=" + (new Date()).getTime());
return false;
}
</script>
<form action="/process" method=post>
<p>Type the numbers you see in the picture below:</p>
<p><img style="transform: scaleX(-1)" id=image src="/captcha/{{.CaptchaID}}.png" alt="Captcha image"></p>
<a href="#" onclick="reload()">Reload</a>
<input type=hidden name=captchaId value="{{.CaptchaID}}"><br>
<input name=captchaSolution>
<input type=submit value=Submit>
</form>
`

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// Copyright 2011 Dmitry Chestnykh. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
// capgen is an utility to test captcha generation.
//
//nolint:forbidigo
package main
import (
"flag"
"fmt"
"os"
"code.forgejo.org/go-chi/captcha"
)
var (
flagLen = flag.Int("len", captcha.DefaultLen, "length of captcha")
flagImgW = flag.Int("width", captcha.StdWidth, "image captcha width")
flagImgH = flag.Int("height", captcha.StdHeight, "image captcha height")
)
func usage() {
fmt.Fprintf(os.Stderr, "usage: capgen [flags] filename\n")
flag.PrintDefaults()
}
func main() {
flag.Parse()
fname := flag.Arg(0)
if fname == "" {
usage()
os.Exit(1)
}
f, err := os.Create(fname)
if err != nil {
panic(err)
}
defer f.Close()
d := captcha.RandomDigits(*flagLen)
if _, err := captcha.NewImage("", d, *flagImgW, *flagImgH).WriteTo(f); err != nil {
panic(err)
}
fmt.Println(d)
}

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// Copyright 2011 Dmitry Chestnykh. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
// Package captcha implements generation and verification of image and audio
// CAPTCHAs.
//
// A captcha solution is the sequence of digits 0-9 with the defined length.
// There are two captcha representations: image and audio.
//
// An image representation is a PNG-encoded image with the solution printed on
// it in such a way that makes it hard for computers to solve it using OCR.
//
// An audio representation is a WAVE-encoded (8 kHz unsigned 8-bit) sound with
// the spoken solution (currently in English, Russian, Chinese, and Japanese).
// To make it hard for computers to solve audio captcha, the voice that
// pronounces numbers has random speed and pitch, and there is a randomly
// generated background noise mixed into the sound.
//
// This package doesn't require external files or libraries to generate captcha
// representations; it is self-contained.
//
// To make captchas one-time, the package includes a memory storage that stores
// captcha ids, their solutions, and expiration time. Used captchas are removed
// from the store immediately after calling Verify or VerifyString, while
// unused captchas (user loaded a page with captcha, but didn't submit the
// form) are collected automatically after the predefined expiration time.
// Developers can also provide custom store (for example, which saves captcha
// ids and solutions in database) by implementing Store interface and
// registering the object with SetCustomStore.
//
// Captchas are created by calling New, which returns the captcha id. Their
// representations, though, are created on-the-fly by calling WriteImage or
// WriteAudio functions. Created representations are not stored anywhere, but
// subsequent calls to these functions with the same id will write the same
// captcha solution. Reload function will create a new different solution for
// the provided captcha, allowing users to "reload" captcha if they can't solve
// the displayed one without reloading the whole page. Verify and VerifyString
// are used to verify that the given solution is the right one for the given
// captcha id.
//
// Server provides an http.Handler which can serve image and audio
// representations of captchas automatically from the URL. It can also be used
// to reload captchas. Refer to Server function documentation for details, or
// take a look at the example in "capexample" subdirectory.
package captcha
import (
"bytes"
"errors"
"io"
"time"
)
const (
// Default number of digits in captcha solution.
DefaultLen = 6
// The number of captchas created that triggers garbage collection used
// by default store.
CollectNum = 100
// Expiration time of captchas used by default store.
Expiration = 10 * time.Minute
)
var (
ErrNotFound = errors.New("captcha: id not found")
// globalStore is a shared storage for captchas, generated by New function.
globalStore = NewMemoryStore(CollectNum, Expiration)
)
// SetCustomStore sets custom storage for captchas, replacing the default
// memory store. This function must be called before generating any captchas.
func SetCustomStore(s Store) {
globalStore = s
}
// New creates a new captcha with the standard length, saves it in the internal
// storage and returns its id.
func New() string {
return NewLen(DefaultLen)
}
// NewLen is just like New, but accepts length of a captcha solution as the
// argument.
func NewLen(length int) (id string) {
id = randomID()
globalStore.Set(id, RandomDigits(length))
return
}
// Reload generates and remembers new digits for the given captcha id. This
// function returns false if there is no captcha with the given id.
//
// After calling this function, the image or audio presented to a user must be
// refreshed to show the new captcha representation (WriteImage and WriteAudio
// will write the new one).
func Reload(id string) bool {
old := globalStore.Get(id, false)
if old == nil {
return false
}
globalStore.Set(id, RandomDigits(len(old)))
return true
}
// WriteImage writes PNG-encoded image representation of the captcha with the
// given id. The image will have the given width and height.
func WriteImage(w io.Writer, id string, width, height int) error {
d := globalStore.Get(id, false)
if d == nil {
return ErrNotFound
}
_, err := NewImage(id, d, width, height).WriteTo(w)
return err
}
// Verify returns true if the given digits are the ones that were used to
// create the given captcha id.
//
// The function deletes the captcha with the given id from the internal
// storage, so that the same captcha can't be verified anymore.
func Verify(id string, digits []byte) bool {
if len(digits) == 0 {
return false
}
reald := globalStore.Get(id, true)
if reald == nil {
return false
}
return bytes.Equal(digits, reald)
}
// VerifyString is like Verify, but accepts a string of digits. It removes
// spaces and commas from the string, but any other characters, apart from
// digits and listed above, will cause the function to return false.
func VerifyString(id string, digits string) bool {
if digits == "" {
return false
}
ns := make([]byte, len(digits))
for i := range ns {
d := digits[i]
switch {
case '0' <= d && d <= '9':
ns[i] = d - '0'
case d == ' ' || d == ',':
// ignore
default:
return false
}
}
return Verify(id, ns)
}

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// Copyright 2011 Dmitry Chestnykh. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package captcha
import (
"bytes"
"testing"
)
func TestNew(t *testing.T) {
c := New()
if c == "" {
t.Errorf("expected id, got empty string")
}
}
func TestVerify(t *testing.T) {
id := New()
if Verify(id, []byte{0, 0}) {
t.Errorf("verified wrong captcha")
}
id = New()
d := globalStore.Get(id, false) // cheating
if !Verify(id, d) {
t.Errorf("proper captcha not verified")
}
}
func TestReload(t *testing.T) {
id := New()
d1 := globalStore.Get(id, false) // cheating
Reload(id)
d2 := globalStore.Get(id, false) // cheating again
if bytes.Equal(d1, d2) {
t.Errorf("reload didn't work: %v = %v", d1, d2)
}
}
func TestRandomDigits(t *testing.T) {
d1 := RandomDigits(10)
for _, v := range d1 {
if v > 9 {
t.Errorf("digits not in range 0-9: %v", d1)
}
}
d2 := RandomDigits(10)
if bytes.Equal(d1, d2) {
t.Errorf("digits seem to be not random")
}
}

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// Copyright 2011 Dmitry Chestnykh. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package captcha
const (
fontWidth = 11
fontHeight = 18
blackChar = 1
)
//nolint:dupl
var font = [][]byte{
{ // 0
0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0,
0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0,
0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0,
0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0,
1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1,
0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0,
0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0,
0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0,
0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0,
},
{ // 1
0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0,
0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0,
0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0,
0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0,
0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0,
0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
},
{ // 2
0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0,
1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0,
0, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0,
0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0,
0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0,
0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0,
0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0,
0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
},
{ // 3
0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0,
1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0,
1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0,
0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0,
0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0,
0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1,
1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0,
1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0,
0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0,
},
{ // 4
0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0,
0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0,
0, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0,
0, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0,
0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0,
0, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0,
0, 0, 1, 1, 0, 0, 0, 1, 1, 0, 0,
0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0,
0, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0,
1, 1, 0, 0, 0, 0, 0, 1, 1, 0, 0,
1, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
},
{ // 5
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0,
0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1,
1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 0,
1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0,
0, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0,
},
{ // 6
0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0,
0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 0,
0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0,
0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,
0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0,
1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0,
1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0,
1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0,
1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
0, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1,
0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0,
0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0,
0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0,
},
{ // 7
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0,
0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0,
0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0,
0, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0,
0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0,
0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0,
0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0,
0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0,
0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0,
0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0,
0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0,
},
{ // 8
0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0,
0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1,
0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1,
0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1,
0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1,
0, 0, 1, 1, 0, 0, 0, 0, 1, 1, 0,
0, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0,
0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0,
0, 0, 1, 1, 1, 0, 1, 1, 1, 0, 0,
0, 1, 1, 1, 0, 0, 0, 1, 1, 1, 0,
1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0,
0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0,
},
{ // 9
0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0,
0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0,
0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 0,
1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 0,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1,
1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1,
0, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1,
0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1,
0, 0, 0, 1, 1, 1, 1, 0, 0, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0,
0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 0,
0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0,
0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
},
}

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module code.forgejo.org/go-chi/captcha
go 1.23
toolchain go1.23.4

278
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// Copyright 2011-2014 Dmitry Chestnykh. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package captcha
import (
"bytes"
"image"
"image/color"
"image/png"
"io"
"math"
mathRand "math/rand/v2"
)
const (
// Standard width and height of a captcha image.
StdWidth = 240
StdHeight = 80
// Maximum absolute skew factor of a single digit.
maxSkew = 0.7
// Number of background circles.
circleCount = 20
)
type Image struct {
*image.Paletted
numWidth int
numHeight int
dotSize int
rng *mathRand.Rand
}
// Int returns a pseudorandom int in the half-open interval [from, to].
func (m *Image) Int(from, to int) int {
return from + m.rng.IntN(to-from+1)
}
// Float returns a pseudorandom float64 in the half-open interval [from, to).
func (m *Image) Float(from, to float64) float64 {
return from + (to-from)*m.rng.Float64()
}
// NewImage returns a new captcha image of the given width and height with the
// given digits, where each digit must be in range 0-9.
func NewImage(id string, digits []byte, width, height int) *Image {
m := new(Image)
// Initialize PRNG.
m.rng = mathRand.New(mathRand.NewChaCha8(deriveSeed(imageSeedPurpose, id, digits)))
m.Paletted = image.NewPaletted(image.Rect(0, 0, width, height), m.getRandomPalette())
m.calculateSizes(width, height, len(digits))
// Randomly position captcha inside the image.
maxx := width - (m.numWidth+m.dotSize)*len(digits) - m.dotSize
maxy := height - m.numHeight - m.dotSize*2
var border int
if width > height {
border = height / 5
} else {
border = width / 5
}
x := m.Int(border, maxx-border)
y := m.Int(border, maxy-border)
// Draw digits.
for _, n := range digits {
m.drawDigit(font[n], x, y)
x += m.numWidth + m.dotSize
}
// Draw strike-through line.
m.strikeThrough()
// Apply wave distortion.
m.distort(m.Float(5, 10), m.Float(100, 200))
// Fill image with random circles.
m.fillWithCircles(circleCount, m.dotSize)
// Flip the image horizontally.
m.flipX()
return m
}
func (m *Image) getRandomPalette() color.Palette {
p := make([]color.Color, circleCount+1)
// Transparent color.
p[0] = color.RGBA{0xFF, 0xFF, 0xFF, 0x00}
// Primary color.
prim := color.RGBA{
uint8(m.rng.IntN(129)),
uint8(m.rng.IntN(129)),
uint8(m.rng.IntN(129)),
0xFF,
}
p[1] = prim
// Circle colors.
for i := 2; i <= circleCount; i++ {
p[i] = m.randomBrightness(prim, 255)
}
return p
}
// encodedPNG encodes an image to PNG and returns
// the result as a byte slice.
func (m *Image) encodedPNG() []byte {
var buf bytes.Buffer
if err := png.Encode(&buf, m.Paletted); err != nil {
panic(err.Error())
}
return buf.Bytes()
}
// WriteTo writes captcha image in PNG format into the given writer.
func (m *Image) WriteTo(w io.Writer) (int64, error) {
n, err := w.Write(m.encodedPNG())
return int64(n), err
}
func (m *Image) calculateSizes(width, height, ncount int) {
// Goal: fit all digits inside the image.
var border int
if width > height {
border = height / 4
} else {
border = width / 4
}
// Convert everything to floats for calculations.
w := float64(width - border*2)
h := float64(height - border*2)
// fw takes into account 1-dot spacing between digits.
fw := float64(fontWidth + 1)
fh := float64(fontHeight)
nc := float64(ncount)
// Calculate the width of a single digit taking into account only the
// width of the image.
nw := w / nc
// Calculate the height of a digit from this width.
nh := nw * fh / fw
// Digit too high?
if nh > h {
// Fit digits based on height.
nh = h
nw = fw / fh * nh
}
// Calculate dot size.
m.dotSize = int(nh / fh)
if m.dotSize < 1 {
m.dotSize = 1
}
// Save everything, making the actual width smaller by 1 dot to account
// for spacing between digits.
m.numWidth = int(nw) - m.dotSize
m.numHeight = int(nh)
}
func (m *Image) drawHorizLine(fromX, toX, y int, colorIdx uint8) {
for x := fromX; x <= toX; x++ {
m.SetColorIndex(x, y, colorIdx)
}
}
func (m *Image) drawCircle(x, y, radius int, colorIdx uint8) {
f := 1 - radius
dfx := 1
dfy := -2 * radius
xo := 0
yo := radius
m.SetColorIndex(x, y+radius, colorIdx)
m.SetColorIndex(x, y-radius, colorIdx)
m.drawHorizLine(x-radius, x+radius, y, colorIdx)
for xo < yo {
if f >= 0 {
yo--
dfy += 2
f += dfy
}
xo++
dfx += 2
f += dfx
m.drawHorizLine(x-xo, x+xo, y+yo, colorIdx)
m.drawHorizLine(x-xo, x+xo, y-yo, colorIdx)
m.drawHorizLine(x-yo, x+yo, y+xo, colorIdx)
m.drawHorizLine(x-yo, x+yo, y-xo, colorIdx)
}
}
func (m *Image) fillWithCircles(n, maxradius int) {
maxx := m.Bounds().Max.X
maxy := m.Bounds().Max.Y
for i := 0; i < n; i++ {
colorIdx := uint8(m.Int(1, circleCount-1))
r := m.Int(1, maxradius)
m.drawCircle(m.Int(r, maxx-r), m.Int(r, maxy-r), r, colorIdx)
}
}
func (m *Image) strikeThrough() {
maxx := m.Bounds().Max.X
maxy := m.Bounds().Max.Y
y := m.Int(maxy/3, maxy-maxy/3)
amplitude := m.Float(5, 20)
period := m.Float(80, 180)
dx := 2.0 * math.Pi / period
for x := 0; x < maxx; x++ {
xo := amplitude * math.Cos(float64(y)*dx)
yo := amplitude * math.Sin(float64(x)*dx)
for yn := 0; yn < m.dotSize; yn++ {
r := m.rng.IntN(m.dotSize + 1)
m.drawCircle(x+int(xo), y+int(yo)+(yn*m.dotSize), r/2, 1)
}
}
}
func (m *Image) drawDigit(digit []byte, x, y int) {
skf := m.Float(-maxSkew, maxSkew)
xs := float64(x)
r := m.dotSize / 2
y += m.Int(-r, r)
for yo := 0; yo < fontHeight; yo++ {
for xo := 0; xo < fontWidth; xo++ {
if digit[yo*fontWidth+xo] != blackChar {
continue
}
m.drawCircle(x+xo*m.dotSize, y+yo*m.dotSize, r, 1)
}
xs += skf
x = int(xs)
}
}
func (m *Image) distort(amplude float64, period float64) {
w := m.Bounds().Max.X
h := m.Bounds().Max.Y
oldm := m.Paletted
newm := image.NewPaletted(image.Rect(0, 0, w, h), oldm.Palette)
dx := 2.0 * math.Pi / period
for x := 0; x < w; x++ {
for y := 0; y < h; y++ {
xo := amplude * math.Sin(float64(y)*dx)
yo := amplude * math.Cos(float64(x)*dx)
newm.SetColorIndex(x, y, oldm.ColorIndexAt(x+int(xo), y+int(yo)))
}
}
m.Paletted = newm
}
func (m *Image) flipX() {
w := m.Bounds().Max.X
h := m.Bounds().Max.Y
src := m.Paletted
dst := image.NewPaletted(image.Rect(0, 0, w, h), src.Palette)
for x := 0; x < w; x++ {
for y := 0; y < h; y++ {
xo := w - x - 1
dst.SetColorIndex(x, y, src.ColorIndexAt(xo, y))
}
}
m.Paletted = dst
}
func (m *Image) randomBrightness(c color.RGBA, maxB uint8) color.RGBA {
minc := min(min(c.R, c.G), c.B)
maxc := max(max(c.R, c.G), c.B)
if maxc > maxB {
return c
}
n := m.rng.IntN(int(maxB-maxc)) - int(minc)
return color.RGBA{
uint8(int(c.R) + n),
uint8(int(c.G) + n),
uint8(int(c.B) + n),
c.A,
}
}

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// Copyright 2011 Dmitry Chestnykh. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package captcha
import "testing"
func BenchmarkNewImage(b *testing.B) {
b.StopTimer()
d := RandomDigits(DefaultLen)
id := randomID()
b.StartTimer()
for i := 0; i < b.N; i++ {
NewImage(id, d, StdWidth, StdHeight)
}
}

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// Copyright 2011-2014 Dmitry Chestnykh. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package captcha
import (
"crypto/hmac"
"crypto/rand"
"crypto/sha256"
"io"
)
// idLen is a length of captcha id string.
// (20 bytes of 62-letter alphabet give ~119 bits.)
const idLen = 20
// idChars are characters allowed in captcha id.
var idChars = []byte("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789")
// rngKey is a secret key used to deterministically derive seeds for
// PRNGs used in image. Generated once during initialization.
var rngKey [32]byte
func init() {
if _, err := io.ReadFull(rand.Reader, rngKey[:]); err != nil {
panic("captcha: error reading random source: " + err.Error())
}
}
// Purposes for seed derivation. The goal is to make deterministic PRNG produce
// different outputs for images and audio by using different derived seeds.
const (
imageSeedPurpose = 0x01
audioSeedPurpose = 0x02
)
// deriveSeed returns a 16-byte PRNG seed from rngKey, purpose, id and digits.
// Same purpose, id and digits will result in the same derived seed for this
// instance of running application.
//
// out = HMAC(rngKey, purpose || id || 0x00 || digits)
func deriveSeed(purpose byte, id string, digits []byte) (out [32]byte) {
var buf [sha256.Size]byte
h := hmac.New(sha256.New, rngKey[:])
h.Write([]byte{purpose})
h.Write([]byte(id))
h.Write([]byte{0})
h.Write(digits)
sum := h.Sum(buf[:0])
copy(out[:], sum)
return
}
// RandomDigits returns a byte slice of the given length containing
// pseudorandom numbers in range 0-9. The slice can be used as a captcha
// solution.
func RandomDigits(length int) []byte {
return randomBytesMod(length, 10)
}
// randomBytes returns a byte slice of the given length read from CSPRNG.
func randomBytes(length int) (b []byte) {
b = make([]byte, length)
if _, err := io.ReadFull(rand.Reader, b); err != nil {
panic("captcha: error reading random source: " + err.Error())
}
return
}
// randomBytesMod returns a byte slice of the given length, where each byte is
// a random number modulo mod.
func randomBytesMod(length int, mod byte) (b []byte) {
if length == 0 {
return nil
}
if mod == 0 {
panic("captcha: bad mod argument for randomBytesMod")
}
maxrb := 255 - byte(256%int(mod))
b = make([]byte, length)
i := 0
for {
r := randomBytes(length + (length / 4))
for _, c := range r {
if c > maxrb {
// Skip this number to avoid modulo bias.
continue
}
b[i] = c % mod
i++
if i == length {
return
}
}
}
}
// randomID returns a new random id string.
func randomID() string {
b := randomBytesMod(idLen, byte(len(idChars)))
for i, c := range b {
b[i] = idChars[c]
}
return string(b)
}

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{
"$schema": "https://docs.renovatebot.com/renovate-schema.json",
"extends": ["go-chi/renovate-config"]
}

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// Copyright 2011 Dmitry Chestnykh. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package captcha
import (
"bytes"
"net/http"
"path"
"time"
)
type captchaHandler struct {
imgWidth int
imgHeight int
}
// Server returns a handler that serves HTTP requests with image
// representations of captchas. Image dimensions are accepted as
// arguments. The server decides which captcha to serve based on the last URL
// path component: file name part must contain a captcha id, file extension —
// its format (PNG or WAV).
//
// For example, for file name "LBm5vMjHDtdUfaWYXiQX.png" it serves an image captcha
// with id "LBm5vMjHDtdUfaWYXiQX", and for "LBm5vMjHDtdUfaWYXiQX.wav" it serves the
// same captcha in audio format.
//
// To serve a captcha as a downloadable file, the URL must be constructed in
// such a way as if the file to serve is in the "download" subdirectory:
// "/download/LBm5vMjHDtdUfaWYXiQX.wav".
//
// To reload captcha (get a different solution for the same captcha id), append
// "?reload=x" to URL, where x may be anything (for example, current time or a
// random number to make browsers refetch an image instead of loading it from
// cache).
//
// By default, the Server serves audio in English language. To serve audio
// captcha in one of the other supported languages, append "lang" value, for
// example, "?lang=ru".
func Server(imgWidth, imgHeight int) http.Handler {
return &captchaHandler{imgWidth, imgHeight}
}
func (h *captchaHandler) serve(w http.ResponseWriter, r *http.Request, id, ext string, download bool) error {
w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
w.Header().Set("Pragma", "no-cache")
w.Header().Set("Expires", "0")
var content bytes.Buffer
switch ext {
case ".png":
w.Header().Set("Content-Type", "image/png")
if err := WriteImage(&content, id, h.imgWidth, h.imgHeight); err != nil {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
default:
return ErrNotFound
}
if download {
w.Header().Set("Content-Type", "application/octet-stream")
}
http.ServeContent(w, r, id+ext, time.Time{}, bytes.NewReader(content.Bytes()))
return nil
}
func (h *captchaHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
dir, file := path.Split(r.URL.Path)
ext := path.Ext(file)
id := file[:len(file)-len(ext)]
if ext == "" || id == "" {
http.NotFound(w, r)
return
}
if r.FormValue("reload") != "" {
Reload(id)
}
download := path.Base(dir) == "download"
if h.serve(w, r, id, ext, download) == ErrNotFound {
http.NotFound(w, r)
}
// Ignore other errors.
}

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// Copyright 2011 Dmitry Chestnykh. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package captcha
import (
"container/list"
"sync"
"time"
)
// An object implementing Store interface can be registered with SetCustomStore
// function to handle storage and retrieval of captcha ids and solutions for
// them, replacing the default memory store.
//
// It is the responsibility of an object to delete expired and used captchas
// when necessary (for example, the default memory store collects them in Set
// method after the certain amount of captchas has been stored.)
type Store interface {
// Set sets the digits for the captcha id.
Set(id string, digits []byte)
// Get returns stored digits for the captcha id. Clear indicates
// whether the captcha must be deleted from the store.
Get(id string, clear bool) (digits []byte)
}
// expValue stores timestamp and id of captchas. It is used in the list inside
// memoryStore for indexing generated captchas by timestamp to enable garbage
// collection of expired captchas.
type idByTimeValue struct {
timestamp time.Time
id string
}
// memoryStore is an internal store for captcha ids and their values.
type memoryStore struct {
sync.RWMutex
digitsByID map[string][]byte
idByTime *list.List
// Number of items stored since last collection.
numStored int
// Number of saved items that triggers collection.
collectNum int
// Expiration time of captchas.
expiration time.Duration
}
// NewMemoryStore returns a new standard memory store for captchas with the
// given collection threshold and expiration time (duration). The returned
// store must be registered with SetCustomStore to replace the default one.
func NewMemoryStore(collectNum int, expiration time.Duration) Store {
s := new(memoryStore)
s.digitsByID = make(map[string][]byte)
s.idByTime = list.New()
s.collectNum = collectNum
s.expiration = expiration
return s
}
func (s *memoryStore) Set(id string, digits []byte) {
s.Lock()
s.digitsByID[id] = digits
s.idByTime.PushBack(idByTimeValue{time.Now(), id})
s.numStored++
if s.numStored <= s.collectNum {
s.Unlock()
return
}
s.Unlock()
go s.collect()
}
func (s *memoryStore) Get(id string, clear bool) (digits []byte) {
if !clear {
// When we don't need to clear captcha, acquire read lock.
s.RLock()
defer s.RUnlock()
} else {
s.Lock()
defer s.Unlock()
}
digits, ok := s.digitsByID[id]
if !ok {
return
}
if clear {
delete(s.digitsByID, id)
// XXX(dchest) Index (s.idByTime) will be cleaned when
// collecting expired captchas. Can't clean it here, because
// we don't store reference to expValue in the map.
// Maybe store it?
}
return
}
func (s *memoryStore) collect() {
now := time.Now()
s.Lock()
defer s.Unlock()
s.numStored = 0
for e := s.idByTime.Front(); e != nil; {
ev, ok := e.Value.(idByTimeValue)
if !ok {
return
}
if ev.timestamp.Add(s.expiration).Before(now) {
delete(s.digitsByID, ev.id)
next := e.Next()
s.idByTime.Remove(e)
e = next
} else {
return
}
}
}

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// Copyright 2011 Dmitry Chestnykh. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package captcha
import (
"bytes"
"testing"
)
func TestSetGet(t *testing.T) {
s := NewMemoryStore(CollectNum, Expiration)
id := "captcha id"
d := RandomDigits(10)
s.Set(id, d)
d2 := s.Get(id, false)
if d2 == nil || !bytes.Equal(d, d2) {
t.Errorf("saved %v, getDigits returned got %v", d, d2)
}
}
func TestGetClear(t *testing.T) {
s := NewMemoryStore(CollectNum, Expiration)
id := "captcha id"
d := RandomDigits(10)
s.Set(id, d)
d2 := s.Get(id, true)
if d2 == nil || !bytes.Equal(d, d2) {
t.Errorf("saved %v, getDigitsClear returned got %v", d, d2)
}
d2 = s.Get(id, false)
if d2 != nil {
t.Errorf("getDigitClear didn't clear (%q=%v)", id, d2)
}
}
func TestCollect(t *testing.T) {
// TODO(dchest): can't test automatic collection when saving, because
// it's currently launched in a different goroutine.
s := NewMemoryStore(10, -1)
// create 10 ids
ids := make([]string, 10)
d := RandomDigits(10)
for i := range ids {
ids[i] = randomID()
s.Set(ids[i], d)
}
s.(*memoryStore).collect()
// Must be already collected
nc := 0
for i := range ids {
d2 := s.Get(ids[i], false)
if d2 != nil {
t.Errorf("%d: not collected", i)
nc++
}
}
if nc > 0 {
t.Errorf("= not collected %d out of %d captchas", nc, len(ids))
}
}
func BenchmarkSetCollect(b *testing.B) {
b.StopTimer()
d := RandomDigits(10)
s := NewMemoryStore(9999, -1)
ids := make([]string, 1000)
for i := range ids {
ids[i] = randomID()
}
b.StartTimer()
for i := 0; i < b.N; i++ {
for j := 0; j < 1000; j++ {
s.Set(ids[j], d)
}
s.(*memoryStore).collect()
}
}