Improve bin checking, shorter error correction duration (#6)

getbouncer · Apr 5, 2019 · 71aa6f1 · 71aa6f1
1 parent 8a28f4c
commit 71aa6f1
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Showing 3 changed files with 46 additions and 6 deletions.
diff --git a/CardScan.podspec b/CardScan.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = 'CardScan'
-  s.version          = '1.0.4037'
+  s.version          = '1.0.4040'
   s.summary          = 'Scan credit cards'
   s.description      = <<-DESC
 CardScan is a library for scanning credit cards.

diff --git a/CardScan/Classes/CreditCardUtils.swift b/CardScan/Classes/CreditCardUtils.swift
@@ -7,9 +7,7 @@ struct CreditCardUtils {
     static func luhnCheck(_ cardNumber: String) -> Bool {
         if cardNumber.count == 0 {
             return false
-        } else if cardNumber.count == 16 && !cardNumber.starts(with: "4") && !cardNumber.starts(with: "5") {
-            return false
-        } else if cardNumber.count == 15 && !cardNumber.starts(with: "3") {
+        } else if !isValidBin(number: cardNumber) {
             return false
         }
 
@@ -26,6 +24,46 @@ struct CreditCardUtils {
         return sum % 10 == 0
     }
 
+    static func isValidBin(number: String) -> Bool {
+        return isAmex(number: number) || isDiscover(number: number) || isVisa(number: number) || isMastercard(number: number)
+    }
+
+    static func isAmex(number: String) -> Bool {
+        guard let prefix = Int(String(number.prefix(2))) else {
+            return false
+        }
+
+        return number.count == 15 && (prefix == 34 || prefix == 37)
+    }
+
+    static func isDiscover(number: String) -> Bool {
+        guard let prefix2 = Int(String(number.prefix(2))), let prefix4 = Int(String(number.prefix(4))), let prefix6 = Int(String(number.prefix(6))) else {
+            return false
+        }
+
+        return prefix2 == 64 || prefix2 == 65 || prefix4 == 6011 ||
+            (prefix6 >= 622126 && prefix6 <= 622925) ||
+            (prefix6 >= 624000 && prefix6 <= 626999) ||
+            (prefix6 >= 628200 && prefix6 <= 628899)
+    }
+
+    static func isMastercard(number: String) -> Bool {
+        guard let prefix2 = Int(String(number.prefix(2))), let prefix4 = Int(String(number.prefix(4))) else {
+            return false
+        }
+
+        if number.count != 16 {
+            return false
+        }
+
+        return (prefix2 >= 51 && prefix2 <= 55) || (prefix4 >= 2221 && prefix4 <= 2720)
+    }
+
+    static func isVisa(number: String) -> Bool {
+        return number.count == 16 && number.starts(with: "4")
+    }
+
+
     static func format(number: String) -> String {
         if number.count == 16 {
             return format16(number: number)

diff --git a/CardScan/Classes/Ocr.swift b/CardScan/Classes/Ocr.swift
@@ -4,6 +4,8 @@ public class Ocr {
     public var scanStats = ScanStats()
     public var expiry: Expiry?
 
+    public var errorCorrectionDuration = 1.0
+
     public init() {}
 
     static func configure() {
@@ -68,9 +70,9 @@ public class Ocr {
 
         let numberResult = self.numbers.sorted { $0.1 > $1.1 }.map { $0.0 }.first
         let expiryResult = self.expiries.sorted { $0.1 > $1.1 }.map { $0.0 }.first
-        let done = interval >= 1.5
+        let done = interval >= self.errorCorrectionDuration
 
-        if interval >= 0.75 {
+        if interval >= (self.errorCorrectionDuration / 2.0) {
             return (numberResult, expiryResult, done)
         } else {
             return (numberResult, nil, done)