Display HOTP code if password contains HOTP secret, unify HOTP and TOTP code (#413)

* Display HOTP code if password contains HOTP secret, unify HOTP and TOTP code

* Add ability to show HOTP instead of showing every decrypt

* Fix off by 1 error

* fix return intent logic so that edits and HOTP increments are properly committed

* fix linting errors

* Fix broken logic for case when a password is created

* add ability to choose if password entry will be updated on HOTP code calculation

1 files changed, 64 insertions, 5 deletions

diff --git a/app/src/main/java/com/zeapo/pwdstore/PasswordEntry.java b/app/src/main/java/com/zeapo/pwdstore/PasswordEntry.java
index ba689fe9..590a779e 100644
--- a/app/src/main/java/com/zeapo/pwdstore/PasswordEntry.java
+++ b/app/src/main/java/com/zeapo/pwdstore/PasswordEntry.java
@@ -12,10 +12,14 @@ public class PasswordEntry {
 
     private static final String[] USERNAME_FIELDS = new String[]{"login", "username"};
 
-    private final String extraContent;
+    private String extraContent;
     private final String password;
     private final String username;
     private final String totpSecret;
+    private final String hotpSecret;
+    private final Long hotpCounter;
+    private final String content;
+    private boolean isIncremented = false;
 
     public PasswordEntry(final ByteArrayOutputStream os) throws UnsupportedEncodingException {
         this(os.toString("UTF-8"));
@@ -23,11 +27,14 @@ public class PasswordEntry {
 
     public PasswordEntry(final String decryptedContent) {
         final String[] passContent = decryptedContent.split("\n", 2);
+        content = decryptedContent;
         password = passContent[0];
-        extraContent = passContent.length > 1 ? passContent[1] : "";
+        totpSecret = findTotpSecret(content);
+        hotpSecret = findHotpSecret(content);
+        hotpCounter = findHotpCounter(content);
+        extraContent = findExtraContent(passContent);
         username = findUsername();
-        totpSecret = findTotpSecret(decryptedContent);
-    }
+     }
 
     public String getPassword() {
         return password;
@@ -45,6 +52,14 @@ public class PasswordEntry {
         return totpSecret;
     }
 
+    public Long getHotpCounter() {
+        return hotpCounter;
+    }
+
+    public String getHotpSecret() {
+        return hotpSecret;
+    }
+
     public boolean hasExtraContent() {
         return extraContent.length() != 0;
     }
@@ -53,7 +68,24 @@ public class PasswordEntry {
         return username != null;
     }
 
-    public boolean hasTotp() { return totpSecret != null; }
+    public boolean hasTotp() {
+        return totpSecret != null;
+    }
+
+    public boolean hasHotp() {
+        return hotpSecret != null && hotpCounter != null;
+    }
+
+    public boolean hotpIsIncremented() { return isIncremented; }
+
+    public void incrementHotp() {
+        for (String line : content.split("\n")) {
+            if (line.startsWith("otpauth://hotp/")) {
+                extraContent = extraContent.replaceFirst("counter=[0-9]+", "counter=" + Long.toString(hotpCounter + 1));
+                isIncremented = true;
+            }
+        }
+    }
 
     private String findUsername() {
         final String[] extraLines = extraContent.split("\n");
@@ -75,4 +107,31 @@ public class PasswordEntry {
         }
         return null;
     }
+
+    private String findHotpSecret(String decryptedContent) {
+        for (String line : decryptedContent.split("\n")) {
+            if (line.startsWith("otpauth://hotp/")) {
+                return Uri.parse(line).getQueryParameter("secret");
+            }
+        }
+        return null;
+    }
+
+    private Long findHotpCounter(String decryptedContent) {
+        for (String line : decryptedContent.split("\n")) {
+            if (line.startsWith("otpauth://hotp/")) {
+                return Long.parseLong(Uri.parse(line).getQueryParameter("counter"));
+            }
+        }
+        return null;
+    }
+
+    private String findExtraContent(String [] passContent) {
+        String extraContent = passContent.length > 1 ? passContent[1] : "";
+        // if there is a HOTP URI, we must return the extra content with the counter incremented
+        if (hasHotp()) {
+            return extraContent.replaceFirst("counter=[0-9]+", "counter=" + Long.toString(hotpCounter));
+        }
+        return extraContent;
+    }
 }