Add option to define ID and modification token generation characters (#17)

README.md

@@ -73,14 +73,16 @@ Pasty will be available at http://localhost:8080.
 
 ## General environment variables
 | Environment Variable                  | Default Value                                                    | Type     | Description                                                                                                                |
-|-----------------------------------|---------------|----------|----------------------------------------------------------------------------------------------------------------------------|
+|---------------------------------------|------------------------------------------------------------------|----------|----------------------------------------------------------------------------------------------------------------------------|
 | `PASTY_WEB_ADDRESS`                   | `:8080`                                                          | `string` | Defines the address the web server listens to                                                                              |
 | `PASTY_STORAGE_TYPE`                  | `file`                                                           | `string` | Defines the storage type the pastes are saved to                                                                           |
 | `PASTY_HASTEBIN_SUPPORT`              | `false`                                                          | `bool`   | Defines whether or not the `POST /documents` endpoint should be enabled, as known from the hastebin servers                |
 | `PASTY_ID_LENGTH`                     | `6`                                                              | `number` | Defines the length of the ID of a paste                                                                                    |
+| `PASTY_ID_CHARACTERS`                 | `abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789` | `string` | Defines the characters to use when generating paste IDs                                                                    |
 | `PASTY_MODIFICATION_TOKENS`           | `true`                                                           | `bool`   | Defines whether or not modification tokens should be generated                                                             |
 | `PASTY_MODIFICATION_TOKEN_MASTER`     | `<empty>`                                                        | `string` | Defines the master modification token which is authorized to modify every paste (even if modification tokens are disabled) |
 | `PASTY_MODIFICATION_TOKEN_LENGTH`     | `12`                                                             | `number` | Defines the length of the modification token of a paste                                                                    |
+| `PASTY_MODIFICATION_TOKEN_CHARACTERS` | `abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789` | `string` | Defines the characters to use when generating modification tokens                                                          |
 | `PASTY_RATE_LIMIT`                    | `30-M`                                                           | `string` | Defines the rate limit of the API (see https://github.com/ulule/limiter#usage)                                             |
 | `PASTY_LENGTH_CAP`                    | `50000`                                                          | `number` | Defines the maximum amount of characters a paste is allowed to contain (a value `<= 0` means no limit)                     |
 

internal/config/config.go

@@ -14,9 +14,11 @@ type Config struct {
 	StorageType                 shared.StorageType
 	HastebinSupport             bool
 	IDLength                    int
+	IDCharacters                string
 	ModificationTokens          bool
 	ModificationTokenMaster     string
 	ModificationTokenLength     int
+	ModificationTokenCharacters string
 	RateLimit                   string
 	LengthCap                   int
 	AutoDelete                  *AutoDeleteConfig
@@ -81,9 +83,11 @@ func Load() {
 		StorageType:                 shared.StorageType(strings.ToLower(env.MustString("STORAGE_TYPE", "file"))),
 		HastebinSupport:             env.MustBool("HASTEBIN_SUPPORT", false),
 		IDLength:                    env.MustInt("ID_LENGTH", 6),
+		IDCharacters:                env.MustString("ID_CHARACTERS", "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"),
 		ModificationTokens:          env.MustBool("MODIFICATION_TOKENS", env.MustBool("DELETION_TOKENS", true)),               // ---
 		ModificationTokenMaster:     env.MustString("MODIFICATION_TOKEN_MASTER", env.MustString("DELETION_TOKEN_MASTER", "")), // - We don't want to destroy peoples old configuration
 		ModificationTokenLength:     env.MustInt("MODIFICATION_TOKEN_LENGTH", env.MustInt("DELETION_TOKEN_LENGTH", 12)),       // ---
+		ModificationTokenCharacters: env.MustString("MODIFICATION_TOKEN_CHARACTERS", "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"),
 		RateLimit:                   env.MustString("RATE_LIMIT", "30-M"),
 		LengthCap:                   env.MustInt("LENGTH_CAP", 50_000),
 		AutoDelete: &AutoDeleteConfig{

internal/storage/id_generation.go

@@ -8,7 +8,7 @@ import (
 // AcquireID generates a new unique ID
 func AcquireID() (string, error) {
 	for {
-		id := utils.RandomString(config.Current.IDLength)
+		id := utils.RandomString(config.Current.IDCharacters, config.Current.IDLength)
 		paste, err := Current.Get(id)
 		if err != nil {
 			return "", err

internal/utils/random_string.go

@@ -5,15 +5,12 @@ import (
 	"time"
 )
 
-// stringContents holds the chars a random string can contain
-const stringContents = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
-
 // RandomString returns a random string with the given length
-func RandomString(length int) string {
+func RandomString(characters string, length int) string {
 	rand.Seed(time.Now().UnixNano())
 	bytes := make([]byte, length)
 	for i := range bytes {
-		bytes[i] = stringContents[rand.Int63()%int64(len(stringContents))]
+		bytes[i] = characters[rand.Int63()%int64(len(characters))]
 	}
 	return string(bytes)
 }

internal/web/controllers/v1/hastebin_support.go

@@ -52,7 +52,7 @@ func HastebinSupportHandler(ctx *fasthttp.RequestCtx) {
 
 	// Set a modification token
 	if config.Current.ModificationTokens {
-		paste.ModificationToken = utils.RandomString(config.Current.ModificationTokenLength)
+		paste.ModificationToken = utils.RandomString(config.Current.ModificationTokenCharacters, config.Current.ModificationTokenLength)
 
 		err = paste.HashModificationToken()
 		if err != nil {

internal/web/controllers/v1/pastes.go

@@ -95,7 +95,7 @@ func v1PostPaste(ctx *fasthttp.RequestCtx) {
 	// Set a modification token
 	modificationToken := ""
 	if config.Current.ModificationTokens {
-		modificationToken = utils.RandomString(config.Current.ModificationTokenLength)
+		modificationToken = utils.RandomString(config.Current.ModificationTokenCharacters, config.Current.ModificationTokenLength)
 		paste.ModificationToken = modificationToken
 
 		err = paste.HashModificationToken()

internal/web/controllers/v2/pastes.go

@@ -146,7 +146,7 @@ func endpointCreatePaste(ctx *fasthttp.RequestCtx) {
 	// Create a new modification token if enabled
 	modificationToken := ""
 	if config.Current.ModificationTokens {
-		modificationToken = utils.RandomString(config.Current.ModificationTokenLength)
+		modificationToken = utils.RandomString(config.Current.ModificationTokenCharacters, config.Current.ModificationTokenLength)
 		paste.ModificationToken = modificationToken
 
 		err = paste.HashModificationToken()