5 files changed, 34 insertions, 14 deletions
diff --git a/format-common/src/main/kotlin/app/passwordstore/data/passfile/PasswordEntry.kt b/format-common/src/main/kotlin/app/passwordstore/data/passfile/PasswordEntry.kt
index 9543eb8c..38aa4a20 100644
--- a/format-common/src/main/kotlin/app/passwordstore/data/passfile/PasswordEntry.kt
+++ b/format-common/src/main/kotlin/app/passwordstore/data/passfile/PasswordEntry.kt
@@ -62,7 +62,7 @@ constructor(
       do {
         val otp = calculateTotp()
         emit(otp)
-        delay(1000L)
+        delay(ONE_SECOND.seconds)
       } while (coroutineContext.isActive)
     } else {
       awaitCancellation()
@@ -90,6 +90,7 @@ constructor(
     return totpSecret != null
   }
 
+  @Suppress("ReturnCount")
   private fun findAndStripPassword(passContent: List<String>): Pair<String?, List<String>> {
     if (TotpFinder.TOTP_FIELDS.any { passContent[0].startsWith(it) }) return Pair(null, passContent)
     for (line in passContent) {
@@ -180,8 +181,14 @@ constructor(
     val totpAlgorithm = totpFinder.findAlgorithm(content)
     val issuer = totpFinder.findIssuer(content)
     val millis = clock.millis()
-    val remainingTime = (totpPeriod - ((millis / 1000) % totpPeriod)).seconds
-    Otp.calculateCode(totpSecret!!, millis / (1000 * totpPeriod), totpAlgorithm, digits, issuer)
+    val remainingTime = (totpPeriod - ((millis / ONE_SECOND) % totpPeriod)).seconds
+    Otp.calculateCode(
+        totpSecret!!,
+        millis / (ONE_SECOND * totpPeriod),
+        totpAlgorithm,
+        digits,
+        issuer
+      )
       .mapBoth(
         { code ->
           return Totp(code, remainingTime)
@@ -217,5 +224,6 @@ constructor(
         "secret:",
         "pass:",
       )
+    private const val ONE_SECOND = 1000
   }
 }
diff --git a/format-common/src/main/kotlin/app/passwordstore/util/time/Clocks.kt b/format-common/src/main/kotlin/app/passwordstore/util/time/UserClock.kt
index 4ffeb6a6..4ffeb6a6 100644
--- a/format-common/src/main/kotlin/app/passwordstore/util/time/Clocks.kt
+++ b/format-common/src/main/kotlin/app/passwordstore/util/time/UserClock.kt
diff --git a/format-common/src/main/kotlin/app/passwordstore/util/totp/Otp.kt b/format-common/src/main/kotlin/app/passwordstore/util/totp/Otp.kt
index 72d5cffe..5abc0337 100644
--- a/format-common/src/main/kotlin/app/passwordstore/util/totp/Otp.kt
+++ b/format-common/src/main/kotlin/app/passwordstore/util/totp/Otp.kt
@@ -18,6 +18,13 @@ internal object Otp {
 
   private val BASE_32 = Base32()
   private val STEAM_ALPHABET = "23456789BCDFGHJKMNPQRTVWXY".toCharArray()
+  private const val BYTE_BUFFER_CAPACITY = 8
+  private const val END_INDEX_OFFSET = 4
+  private const val STEAM_GUARD_DIGITS = 5
+  private const val MINIMUM_DIGITS = 6
+  private const val MAXIMUM_DIGITS = 10
+  private const val ALPHABET_LENGTH = 26
+  private const val MOST_SIGNIFICANT_BYTE = 0x7f
 
   fun calculateCode(
     secret: String,
@@ -32,13 +39,13 @@ internal object Otp {
     val digest =
       Mac.getInstance(algo).run {
         init(secretKey)
-        doFinal(ByteBuffer.allocate(8).putLong(counter).array())
+        doFinal(ByteBuffer.allocate(BYTE_BUFFER_CAPACITY).putLong(counter).array())
       }
     // Least significant 4 bits are used as an offset into the digest.
     val offset = (digest.last() and 0xf).toInt()
     // Extract 32 bits at the offset and clear the most significant bit.
-    val code = digest.copyOfRange(offset, offset + 4)
-    code[0] = (0x7f and code[0].toInt()).toByte()
+    val code = digest.copyOfRange(offset, offset.plus(END_INDEX_OFFSET))
+    code[0] = (MOST_SIGNIFICANT_BYTE and code[0].toInt()).toByte()
     val codeInt = ByteBuffer.wrap(code).int
     check(codeInt > 0)
     // SteamGuard is a horrible OTP implementation that generates non-standard 5 digit OTPs as
@@ -47,9 +54,9 @@ internal object Otp {
     if (digits == "s" || issuer == "Steam") {
       var remainingCodeInt = codeInt
       buildString {
-        repeat(5) {
+        repeat(STEAM_GUARD_DIGITS) {
           append(STEAM_ALPHABET[remainingCodeInt % STEAM_ALPHABET.size])
-          remainingCodeInt /= 26
+          remainingCodeInt /= ALPHABET_LENGTH
         }
       }
     } else {
@@ -59,17 +66,21 @@ internal object Otp {
         numDigits == null -> {
           return Err(IllegalArgumentException("Digits specifier has to be either 's' or numeric"))
         }
-        numDigits < 6 -> {
-          return Err(IllegalArgumentException("TOTP codes have to be at least 6 digits long"))
+        numDigits < MINIMUM_DIGITS -> {
+          return Err(
+            IllegalArgumentException("TOTP codes have to be at least $MINIMUM_DIGITS digits long")
+          )
         }
-        numDigits > 10 -> {
-          return Err(IllegalArgumentException("TOTP codes can be at most 10 digits long"))
+        numDigits > MAXIMUM_DIGITS -> {
+          return Err(
+            IllegalArgumentException("TOTP codes can be at most $MAXIMUM_DIGITS digits long")
+          )
         }
         else -> {
           // 2^31 = 2_147_483_648, so we can extract at most 10 digits with the first one
           // always being 0, 1, or 2. Pad with leading zeroes.
-          val codeStringBase10 = codeInt.toString(10).padStart(10, '0')
-          check(codeStringBase10.length == 10)
+          val codeStringBase10 = codeInt.toString(MAXIMUM_DIGITS).padStart(MAXIMUM_DIGITS, '0')
+          check(codeStringBase10.length == MAXIMUM_DIGITS)
           codeStringBase10.takeLast(numDigits)
         }
       }
diff --git a/format-common/src/test/kotlin/app/passwordstore/data/passfile/PasswordEntryTest.kt b/format-common/src/test/kotlin/app/passwordstore/data/passfile/PasswordEntryTest.kt
index f492604d..2022d968 100644
--- a/format-common/src/test/kotlin/app/passwordstore/data/passfile/PasswordEntryTest.kt
+++ b/format-common/src/test/kotlin/app/passwordstore/data/passfile/PasswordEntryTest.kt
@@ -194,6 +194,7 @@ class PasswordEntryTest {
 
   companion object {
 
+    @Suppress("MaxLineLength")
     const val TOTP_URI =
       "otpauth://totp/ACME%20Co:john@example.com?secret=HXDMVJECJJWSRB3HWIZR4IFUGFTMXBOZ&issuer=ACME%20Co&algorithm=SHA1&digits=6&period=30"
 
diff --git a/format-common/src/test/kotlin/app/passwordstore/util/time/TestClocks.kt b/format-common/src/test/kotlin/app/passwordstore/util/time/TestUserClock.kt
index 8a860a39..8a860a39 100644
--- a/format-common/src/test/kotlin/app/passwordstore/util/time/TestClocks.kt
+++ b/format-common/src/test/kotlin/app/passwordstore/util/time/TestUserClock.kt