From 6a5323b12bfa2619e66d4f24171b58fc7fe5a96a Mon Sep 17 00:00:00 2001
From: Alexander Bakker <ab@alexbakker.me>
Date: Mon, 7 Dec 2020 21:24:28 +0100
Subject: [PATCH] Make the Google Authenticator Protobuf parser more complete

I don't think Google Authenticator actually currently supports any of these
extra digit/algorithm options, but they're specified in the proto file, so we
should support them for completeness sake.
---
 .../aegis/otp/GoogleAuthInfo.java             | 41 +++++++++++++++++--
 app/src/main/proto/google_auth.proto          | 21 +++++++---
 2 files changed, 52 insertions(+), 10 deletions(-)

diff --git a/app/src/main/java/com/beemdevelopment/aegis/otp/GoogleAuthInfo.java b/app/src/main/java/com/beemdevelopment/aegis/otp/GoogleAuthInfo.java
index 227804be..ba5a2c0e 100644
--- a/app/src/main/java/com/beemdevelopment/aegis/otp/GoogleAuthInfo.java
+++ b/app/src/main/java/com/beemdevelopment/aegis/otp/GoogleAuthInfo.java
@@ -216,13 +216,46 @@ public class GoogleAuthInfo implements Serializable {
         for (GoogleAuthProtos.MigrationPayload.OtpParameters params : payload.getOtpParametersList()) {
             OtpInfo otp;
             try {
+                int digits;
+                switch (params.getDigits()) {
+                    case DIGIT_COUNT_UNSPECIFIED:
+                        // intentional fallthrough
+                    case DIGIT_COUNT_SIX:
+                        digits = 6;
+                        break;
+                    case DIGIT_COUNT_EIGHT:
+                        digits = 8;
+                        break;
+                    default:
+                        throw new GoogleAuthInfoException(String.format("Unsupported digits: %d", params.getDigits().ordinal()));
+                }
+
+                String algo;
+                switch (params.getAlgorithm()) {
+                    case ALGORITHM_UNSPECIFIED:
+                        // intentional fallthrough
+                    case ALGORITHM_SHA1:
+                        algo = "SHA1";
+                        break;
+                    case ALGORITHM_SHA256:
+                        algo = "SHA256";
+                        break;
+                    case ALGORITHM_SHA512:
+                        algo = "SHA512";
+                        break;
+                    default:
+                        throw new GoogleAuthInfoException(String.format("Unsupported hash algorithm: %d", params.getAlgorithm().ordinal()));
+                }
+
                 byte[] secret = params.getSecret().toByteArray();
                 switch (params.getType()) {
-                    case OTP_HOTP:
-                        otp = new HotpInfo(secret, params.getCounter());
+                    case OTP_TYPE_UNSPECIFIED:
+                        // intentional fallthrough
+                    case OTP_TYPE_TOTP:
+                        otp = new TotpInfo(secret, algo, digits, 30);
                         break;
-                    case OTP_TOTP:
-                        otp = new TotpInfo(secret);
+                    case OTP_TYPE_HOTP:
+                        otp = new HotpInfo(secret, algo, digits, params.getCounter());
                         break;
                     default:
                         throw new GoogleAuthInfoException(String.format("Unsupported algorithm: %d", params.getType().ordinal()));
diff --git a/app/src/main/proto/google_auth.proto b/app/src/main/proto/google_auth.proto
index 4346853f..e59f2d61 100644
--- a/app/src/main/proto/google_auth.proto
+++ b/app/src/main/proto/google_auth.proto
@@ -5,14 +5,23 @@ option java_outer_classname = "GoogleAuthProtos";
 
 message MigrationPayload {
   enum Algorithm {
-    ALGO_INVALID = 0;
-    ALGO_SHA1 = 1;
+    ALGORITHM_UNSPECIFIED = 0;
+    ALGORITHM_SHA1 = 1;
+    ALGORITHM_SHA256 = 2;
+    ALGORITHM_SHA512 = 3;
+    ALGORITHM_MD5 = 4;
+  }
+
+  enum DigitCount {
+    DIGIT_COUNT_UNSPECIFIED = 0;
+    DIGIT_COUNT_SIX = 1;
+    DIGIT_COUNT_EIGHT = 2;
   }
 
   enum OtpType {
-    OTP_INVALID = 0;
-    OTP_HOTP = 1;
-    OTP_TOTP = 2;
+    OTP_TYPE_UNSPECIFIED = 0;
+    OTP_TYPE_HOTP = 1;
+    OTP_TYPE_TOTP = 2;
   }
 
   message OtpParameters {
@@ -20,7 +29,7 @@ message MigrationPayload {
     string name = 2;
     string issuer = 3;
     Algorithm algorithm = 4;
-    int32 digits = 5;
+    DigitCount digits = 5;
     OtpType type = 6;
     int64 counter = 7;
   }