Multiple improvements to KeyInfo.java

- Got rid of the setters as those won't be used anyway
- Renamed 'algo' to 'algorithm'
- KeyInfo.FromURL is now guaranteed to produce a valid result

app/src/main/java/me/impy/aegis/MainActivity.java

@@ -43,7 +43,7 @@ public class MainActivity extends AppCompatActivity {
                 KeyInfo info = (KeyInfo)data.getSerializableExtra("Keyinfo");
 
                 String nowTimeString = (Long.toHexString(System.currentTimeMillis() / 1000 / info.getPeriod()));
-                String totp = TOTP.generateTOTP(info.getSecret(), nowTimeString, info.getDigits(), info.getAlgo());
+                String totp = TOTP.generateTOTP(info.getSecret(), nowTimeString, info.getDigits(), info.getAlgorithm());
 
                 tvTotp.setText(totp);
             }

app/src/main/java/me/impy/aegis/crypto/KeyInfo.java

@@ -11,105 +11,87 @@ public class KeyInfo implements Serializable {
     private String label;
     private byte[] secret;
     private String issuer;
-    private String algo;
-    private int digits;
+    private String algorithm = "HmacSHA1";
+    private int digits = 6;
     private long counter;
-    private int period;
+    private int period = 30;
 
     public String getType() {
         return type;
     }
-
-    public KeyInfo setType(String type) {
-        this.type = type;
-        return this;
-    }
-
     public String getLabel() {
         return label;
     }
-
-    public KeyInfo setLabel(String label) {
-        this.label = label;
-        return this;
-    }
-
     public byte[] getSecret() {
         return secret;
     }
-
-    public KeyInfo setSecret(byte[] secret) {
-        this.secret = secret;
-        return this;
-    }
-
     public String getIssuer() {
         return issuer;
     }
-
-    public KeyInfo setIssuer(String issuer) {
-        this.issuer = issuer;
-        return this;
+    public String getAlgorithm() {
+        return algorithm;
     }
-
-    public String getAlgo() {
-        return algo;
-    }
-
-    public KeyInfo setAlgo(String algo) {
-        this.algo = algo;
-        return this;
-    }
-
     public int getDigits() {
         return digits;
     }
-
-    public KeyInfo setDigits(int digits) {
-        this.digits = digits;
-        return this;
-    }
-
     public long getCounter() {
         return counter;
     }
-
-    public KeyInfo setCounter(long counter) {
-        this.counter = counter;
-        return this;
-    }
-
     public int getPeriod() {
         return period;
     }
 
-    public KeyInfo setPeriod(int period) {
-        this.period = period;
-        return this;
-    }
-
-    private KeyInfo() {
-
-    }
+    private KeyInfo() { }
 
     public static KeyInfo FromURL(String s) throws Exception {
         final Uri url = Uri.parse(s);
-
         if (!url.getScheme().equals("otpauth")) {
             throw new Exception("unsupported protocol");
         }
 
         KeyInfo info = new KeyInfo();
-        info.type = url.getHost();
 
+        // only 'totp' and 'hotp' are supported
+        info.type = url.getHost();
+        if (info.type.equals("totp") && info.type.equals("hotp")) {
+            throw new Exception("unsupported type");
+        }
+
+        // 'secret' is a required parameter
         String secret = url.getQueryParameter("secret");
+        if (secret == null) {
+            throw new Exception("'secret' is not set");
+        }
         info.secret = Base32.decode(secret);
-        info.issuer = url.getQueryParameter("issuer");
-        info.label = url.getPath();
-        info.algo = url.getQueryParameter("algorithm") != null ? url.getQueryParameter("algorithm") : "HmacSHA1";
-        info.period = url.getQueryParameter("period") != null ? Integer.getInteger(url.getQueryParameter("period")) : 30;
-        info.digits = url.getQueryParameter("digits") != null ? Integer.getInteger(url.getQueryParameter("digits")) : 6;
-        info.counter = url.getQueryParameter("counter") != null ? Long.getLong(url.getQueryParameter("counter")) : 0;
+
+        // provider info used to disambiguate accounts
+        // these parameters are not required but I don't want them to be null either
+        String issuer = url.getQueryParameter("issuer");
+        String label = url.getQueryParameter("label");
+        info.issuer = issuer != null ? issuer : "";
+        info.label = label != null ? label : "";
+
+        // just use the defaults if these parameters aren't set
+        String algorithm = url.getQueryParameter("algorithm");
+        if (algorithm != null) {
+            info.algorithm = "Hmac" + algorithm;
+        }
+        String period = url.getQueryParameter("period");
+        if (period != null) {
+            info.period = Integer.getInteger(period);
+        }
+        String digits = url.getQueryParameter("digits");
+        if (digits != null) {
+            info.digits = Integer.getInteger(digits);
+        }
+
+        // 'counter' is required if the type is 'hotp'
+        String counter = url.getQueryParameter("counter");
+        if (counter != null) {
+            info.counter = Long.getLong(counter);
+        } else if (info.type.equals("hotp")) {
+            throw new Exception("'counter' was not set which is required for 'hotp'");
+        }
 
         return info;
     }

app/src/test/java/me/impy/aegis/HOTPTest.java

@@ -26,7 +26,9 @@ public class HOTPTest {
             new testVector(){{ Count = 9; OTP = "520489"; }},
     };
 
-    private final byte[] _secret = new byte[] {0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x30};
+    private final byte[] _secret = new byte[] { 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38,
+            0x39, 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x30
+    };
 
     @Test
     public void vectors_match() throws Exception {