Min secret length

argsParser.js

@@ -6,7 +6,7 @@ export default class ArgsParser {
   constructor () {
     this.args = yargs(hideBin(process.argv))
       .usage(
-        'Usage: jwt-cracker -t <token> [-a <alphabet>] [--max <maxLength>]'
+        'Usage: jwt-cracker -t <token> [-a <alphabet>] [--min <minLength>] [--max <maxLength>]'
       )
       .option('t', {
         alias: 'token',
@@ -20,10 +20,20 @@ export default class ArgsParser {
         describe: 'Alphabet to use for the brute force',
         default: Constants.DEFAULT_ALPHABET
       })
+      .option('min', {
+        describe: 'Minimum length of the secret. Note: 1<= min',
+        default: Constants.DEFAULT_MIN_SECRET_LENGTH
+      })
       .option('max', {
-        describe: 'Maximum length of the secret',
+        describe: 'Maximum length of the secret. Note: min <= max',
         default: Constants.DEFAULT_MAX_SECRET_LENGTH
       })
+      .check(argv => {
+        if (argv.min < 1 || argv.max < argv.min) {
+          throw new Error('Invalid min or max arguments. Remember: 1<= min <= max')
+        }
+        return true
+      })
       .help()
       .alias('h', 'help').argv
   }
@@ -36,6 +46,10 @@ export default class ArgsParser {
     return this.args.alphabet
   }
 
+  get minLength () {
+    return this.args.min
+  }
+
   get maxLength () {
     return this.args.max
   }

constants.js

@@ -3,6 +3,10 @@ export default class Constants {
     return 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789'
   }
 
+  static get DEFAULT_MIN_SECRET_LENGTH () {
+    return 1
+  }
+
   static get DEFAULT_MAX_SECRET_LENGTH () {
     return 12
   }

index.js

@@ -15,6 +15,7 @@ const args = new ArgsParser()
 
 const token = args.token
 const alphabet = args.alphabet
+const minLength = args.minLength
 const maxLength = args.maxLength
 
 const validToken = JWTValidator.validateToken(token)
@@ -43,11 +44,13 @@ let chunk = []
 
 variationsStream(alphabet, maxLength)
   .on('data', function (comb) {
-    chunk.push(comb)
-    if (chunk.length >= chunkSize) {
-      // save chunk and reset it
-      forkChunk(chunk)
-      chunk = []
+    if (comb.length >= minLength) {
+      chunk.push(comb)
+      if (chunk.length >= chunkSize) {
+        // save chunk and reset it
+        forkChunk(chunk)
+        chunk = []
+      }
     }
   })
   .on('end', function () {