feat: add main source file

gleam.toml

@@ -0,0 +1,18 @@
+name = "teotipi"
+version = "1.0.0"
+
+licences = ["MIT"]
+repository = { type = "gitea", host = "git.kharec.info", user = "Kharec", repo = "teotipi" }
+links = [
+  { title = "Repository", href = "https://git.kharec.info/Kharec/teotipi" },
+]
+
+[dependencies]
+gleam_stdlib = ">= 0.44.0 and < 2.0.0"
+thirtytwo = ">= 1.0.0 and < 2.0.0"
+gleam_time = ">= 1.8.0 and < 2.0.0"
+gleam_crypto = ">= 1.5.1 and < 2.0.0"
+argv = ">= 1.0.0 and < 2.0.0"
+
+[dev_dependencies]
+gleeunit = ">= 1.0.0 and < 2.0.0"

manifest.toml

@@ -0,0 +1,19 @@
+# This file was generated by Gleam
+# You typically do not need to edit this file
+
+packages = [
+  { name = "argv", version = "1.0.2", build_tools = ["gleam"], requirements = [], otp_app = "argv", source = "hex", outer_checksum = "BA1FF0929525DEBA1CE67256E5ADF77A7CDDFE729E3E3F57A5BDCAA031DED09D" },
+  { name = "gleam_crypto", version = "1.5.1", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_crypto", source = "hex", outer_checksum = "50774BAFFF1144E7872814C566C5D653D83A3EBF23ACC3156B757A1B6819086E" },
+  { name = "gleam_stdlib", version = "0.70.0", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "86949BF5D1F0E4AC0AB5B06F235D8A5CC11A2DFC33BF22F752156ED61CA7D0FF" },
+  { name = "gleam_time", version = "1.8.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_time", source = "hex", outer_checksum = "533D8723774D61AD4998324F5DD1DABDCDBFABAFB9E87CB5D03C6955448FC97D" },
+  { name = "gleeunit", version = "1.9.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "DA9553CE58B67924B3C631F96FE3370C49EB6D6DC6B384EC4862CC4AAA718F3C" },
+  { name = "thirtytwo", version = "1.0.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "thirtytwo", source = "hex", outer_checksum = "AB56E6C649BF73E6102F7DFCB5B24556CD77E87EA4DAA8E83D2BAACBE064FFC5" },
+]
+
+[requirements]
+argv = { version = ">= 1.0.0 and < 2.0.0" }
+gleam_crypto = { version = ">= 1.5.1 and < 2.0.0" }
+gleam_stdlib = { version = ">= 0.44.0 and < 2.0.0" }
+gleam_time = { version = ">= 1.8.0 and < 2.0.0" }
+gleeunit = { version = ">= 1.0.0 and < 2.0.0" }
+thirtytwo = { version = ">= 1.0.0 and < 2.0.0" }

src/teotipi.gleam

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+import argv
+import gleam/bit_array
+import gleam/crypto
+import gleam/int
+import gleam/io
+import gleam/result
+import gleam/string
+import gleam/time/timestamp
+import thirtytwo
+
+pub fn main() {
+  case argv.load().arguments {
+    [secret, ..] ->
+      case totp_string(secret) {
+        Ok(code) -> io.println(code)
+        Error(_) -> io.println("Error: invalid secret")
+      }
+    [] -> io.println("Usage: teotipi <base32-secret>")
+  }
+}
+
+pub fn totp_string(secret_b32: String) -> Result(String, Nil) {
+  use code <- result.map(totp(secret_b32))
+  code |> int.to_string |> string.pad_start(6, "0")
+}
+
+pub fn totp(secret_b32: String) -> Result(Int, Nil) {
+  use secret <- result.try(thirtytwo.decode(secret_b32))
+  let now = timestamp.system_time()
+  let #(seconds, _nanoseconds) = timestamp.to_unix_seconds_and_nanoseconds(now)
+  let counter = seconds / 30
+
+  let counter_bits = <<counter:big-int-size(64)>>
+  let mac = crypto.hmac(counter_bits, crypto.Sha1, secret)
+
+  Ok(truncate(mac))
+}
+
+fn truncate(mac: BitArray) -> Int {
+  let assert <<_:bytes-size(19), last:int>> = mac
+  let offset = int.bitwise_and(last, 0x0f)
+  let assert Ok(slice) = bit_array.slice(mac, offset, 4)
+  let assert <<b0:int, b1:int, b2:int, b3:int>> = slice
+  let code =
+    int.bitwise_and(b0, 0x7f)
+    |> int.bitwise_shift_left(24)
+    |> int.bitwise_or(int.bitwise_shift_left(b1, 16))
+    |> int.bitwise_or(int.bitwise_shift_left(b2, 8))
+    |> int.bitwise_or(b3)
+  code % 1_000_000
+}

test/teotipi_test.gleam

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+import gleam/string
+import gleeunit
+import gleeunit/should
+import teotipi
+
+pub fn main() -> Nil {
+  gleeunit.main()
+}
+
+pub fn totp_string_test() {
+  "GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ"
+  |> teotipi.totp_string
+  |> should.be_ok
+  |> string.length
+  |> should.equal(6)
+}
+
+pub fn totp_string_padding_test() {
+  "GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ"
+  |> teotipi.totp_string
+  |> should.be_ok
+}
+
+pub fn totp_string_invalid_secret_test() {
+  teotipi.totp_string("INVALID!!!")
+  |> should.be_error
+}
+
+pub fn totp_function_test() {
+  let code =
+    "GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ"
+    |> teotipi.totp
+    |> should.be_ok
+
+  should.be_true(code > 0)
+  should.be_true(code < 1_000_000)
+}
+
+pub fn totp_invalid_secret_test() {
+  teotipi.totp("INVALID!!!")
+  |> should.be_error
+}
+
+pub fn totp_consistency_test() {
+  let secret = "GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ"
+  let result1 = teotipi.totp(secret)
+  let result2 = teotipi.totp(secret)
+
+  should.equal(result1, result2)
+}
+
+pub fn totp_different_secrets_test() {
+  let code1 =
+    "GEZDGNBVGY3TQOJQGEZDGNBVGY3TQOJQ"
+    |> teotipi.totp
+    |> should.be_ok
+
+  let code2 =
+    "JBSWY3DPEHPK3PXPJBSWY3DPEHPK3PXP"
+    |> teotipi.totp
+    |> should.be_ok
+
+  should.be_true(code1 > 0)
+  should.be_true(code2 > 0)
+}