Add getters for OTP and PWS properties

This patch adds getters for the number of PWS, TOTP and HOTP slots on
the current device and the maximum length of a PWS slot name, login and
password as well as a OTP slot name and secret.

Fixes Nitrokey#197.

NK_C_API.cc

@@ -336,6 +336,38 @@ extern "C" {
 		});
 	}
 
+	NK_C_API uint8_t NK_get_pws_slot_count() {
+		return NitrokeyManager::instance()->get_pws_slot_count();
+	}
+
+	NK_C_API size_t NK_get_pws_name_length() {
+		return NitrokeyManager::instance()->get_pws_name_length();
+	}
+
+	NK_C_API size_t NK_get_pws_login_length() {
+		return NitrokeyManager::instance()->get_pws_login_length();
+	}
+
+	NK_C_API size_t NK_get_pws_password_length() {
+		return NitrokeyManager::instance()->get_pws_password_length();
+	}
+
+	NK_C_API uint8_t NK_get_totp_slot_count() {
+		return NitrokeyManager::instance()->get_totp_slot_count();
+	}
+
+	NK_C_API uint8_t NK_get_hotp_slot_count() {
+		return NitrokeyManager::instance()->get_hotp_slot_count();
+	}
+
+	NK_C_API size_t NK_get_otp_name_length() {
+		return NitrokeyManager::instance()->get_otp_name_length();
+	}
+
+	NK_C_API size_t NK_get_otp_secret_length() {
+		return NitrokeyManager::instance()->get_otp_secret_length();
+	}
+
 	NK_C_API char * NK_get_hotp_code(uint8_t slot_number) {
 		return NK_get_hotp_code_PIN(slot_number, "");
 	}

NK_C_API.h

@@ -23,6 +23,7 @@
 #define LIBNITROKEY_NK_C_API_H
 
 #include <stdbool.h>
+#include <stddef.h>
 #include <stdint.h>
 
 #include "deprecated.h"
@@ -527,6 +528,56 @@ extern "C" {
 	 */
 	NK_C_API int NK_read_config_struct(struct NK_config* out);
 
+	// OTP and PWS properties
+
+	/**
+	 * Returns the number of PWS slots provided by the connected device or
+	 * zero if no device is connected.
+	 */
+	NK_C_API uint8_t NK_get_pws_slot_count();
+
+	/**
+	 * Returns the maximum length of a PWS slot name in bytes for the
+	 * connected device or zero if no device is connected.
+	 */
+	NK_C_API size_t NK_get_pws_name_length();
+
+	/**
+	 * Returns the maximum length of a PWS login in bytes for the connected
+	 * device or zero if no device is connected.
+	 */
+	NK_C_API size_t NK_get_pws_login_length();
+
+	/**
+	 * Returns the maximum length of a PWS password in bytes for the
+	 * connected device or zero if no device is connected.
+	 */
+	NK_C_API size_t NK_get_pws_password_length();
+
+	/**
+	 * Returns the number of TOTP slots provided by the connected device or
+	 * zero if no device is connected.
+	 */
+	NK_C_API uint8_t NK_get_totp_slot_count();
+
+	/**
+	 * Returns the number of HOTP slots provided by the connected device or
+	 * zero if no device is connected.
+	 */
+	NK_C_API uint8_t NK_get_hotp_slot_count();
+
+	/**
+	 * Returns the maximum length of an OTP slot name in bytes for the
+	 * connected device or zero if no device is connected.
+	 */
+	NK_C_API size_t NK_get_otp_name_length();
+
+	/**
+	 * Returns the maximum length of an OTP secret in bytes for the
+	 * connected device or zero if no device is connected.
+	 */
+	NK_C_API size_t NK_get_otp_secret_length();
+
 	//OTP
 
 	/**

NitrokeyManager.cc

@@ -390,6 +390,69 @@ using nitrokey::misc::strcpyT;
         }
     }
 
+    uint8_t NitrokeyManager::get_pws_slot_count() {
+        if (device == nullptr) {
+            return 0;
+        } else {
+            return PWS_SLOT_COUNT;
+        }
+    }
+
+    size_t NitrokeyManager::get_pws_name_length() {
+        if (device == nullptr) {
+            return 0;
+        } else {
+            return PWS_SLOTNAME_LENGTH;
+        }
+    }
+
+    size_t NitrokeyManager::get_pws_login_length() {
+        if (device == nullptr) {
+            return 0;
+        } else {
+            return PWS_LOGINNAME_LENGTH;
+        }
+    }
+
+    size_t NitrokeyManager::get_pws_password_length() {
+        if (device == nullptr) {
+            return 0;
+        } else {
+            return PWS_PASSWORD_LENGTH;
+        }
+    }
+
+    uint8_t NitrokeyManager::get_totp_slot_count() {
+        if (device == nullptr) {
+            return 0;
+        } else {
+            return 15;
+        }
+    }
+
+    uint8_t NitrokeyManager::get_hotp_slot_count() {
+        if (device == nullptr) {
+            return 0;
+        } else {
+            return 3;
+        }
+    }
+
+    size_t NitrokeyManager::get_otp_name_length() {
+        if (device == nullptr) {
+            return 0;
+        } else {
+            return 15;
+        }
+    }
+
+    size_t NitrokeyManager::get_otp_secret_length() {
+        if (device == nullptr) {
+            return 0;
+        } else {
+            return 40;
+        }
+    }
 
     string NitrokeyManager::get_serial_number() {
       try {

libnitrokey/NitrokeyManager.h

@@ -28,6 +28,7 @@
 #include "stick10_commands.h"
 #include "stick10_commands_0.8.h"
 #include "stick20_commands.h"
+#include <cstddef>
 #include <vector>
 #include <memory>
 #include <unordered_map>
@@ -64,6 +65,54 @@ char * strndup(const char* str, size_t maxlen);
         stick10::ReadSlot::ResponsePayload get_TOTP_slot_data(const uint8_t slot_number);
         stick10::ReadSlot::ResponsePayload get_HOTP_slot_data(const uint8_t slot_number);
 
+        /**
+         * Returns the number of PWS slots provided by the connected device or
+         * zero if no device is connected.
+         */
+        uint8_t get_pws_slot_count();
+
+        /**
+         * Returns the maximum length of a PWS slot name in bytes for the
+         * connected device or zero if no device is connected.
+         */
+        size_t get_pws_name_length();
+
+        /**
+         * Returns the maximum length of a PWS login in bytes for the connected
+         * device or zero if no device is connected.
+         */
+        size_t get_pws_login_length();
+
+        /**
+         * Returns the maximum length of a PWS password in bytes for the
+         * connected device or zero if no device is connected.
+         */
+        size_t get_pws_password_length();
+
+        /**
+         * Returns the number of TOTP slots provided by the connected device or
+         * zero if no device is connected.
+         */
+        uint8_t get_totp_slot_count();
+
+        /**
+         * Returns the number of HOTP slots provided by the connected device or
+         * zero if no device is connected.
+         */
+        uint8_t get_hotp_slot_count();
+
+        /**
+         * Returns the maximum length of an OTP slot name in bytes for the
+         * connected device or zero if no device is connected.
+         */
+        size_t get_otp_name_length();
+
+        /**
+         * Returns the maximum length of an OTP secret in bytes for the
+         * connected device or zero if no device is connected.
+         */
+        size_t get_otp_secret_length();
+
         bool set_time(uint64_t time);
         /**
          * Set the device time used for TOTP to the given time.  Contrary to

unittest/test_offline.py

@@ -36,4 +36,14 @@ def test_offline(C_offline):
 
     # v3.4.1-29-g1f3d
     search = re.search(b'v\d\.\d(\.\d)?', libnk_version)
-    assert search is not None
+    assert search is not None
+
+    assert C_offline.NK_get_pws_slot_count() == 0
+    assert C_offline.NK_get_pws_name_length() == 0
+    assert C_offline.NK_get_pws_login_length() == 0
+    assert C_offline.NK_get_pws_password_length() == 0
+
+    assert C_offline.NK_get_hotp_slot_count() == 0
+    assert C_offline.NK_get_totp_slot_count() == 0
+    assert C_offline.NK_get_otp_name_length() == 0
+    assert C_offline.NK_get_otp_secret_length() == 0

unittest/test_pro.py

@@ -132,6 +132,14 @@ def test_password_safe_slot_status(C):
     assert is_slot_programmed[1] == 1
 
 
+@pytest.mark.PWS
+def test_password_safe_properties(C):
+    assert C.NK_get_pws_slot_count() == 16
+    assert C.NK_get_pws_name_length() == 11
+    assert C.NK_get_pws_login_length() == 32
+    assert C.NK_get_pws_password_length() == 20
+
+
 @pytest.mark.aes
 def test_issue_device_locks_on_second_key_generation_in_sequence(C):
 #    if is_pro_rtm_07(C) or is_pro_rtm_08(C):
@@ -1070,3 +1078,11 @@ def test_OTP_all_rw(C):
         all_codes.append(this_loop_codes)
     from pprint import pprint
     pprint(all_codes)
+
+
+@pytest.mark.otp
+def test_otp_properties(C):
+    assert C.NK_get_hotp_slot_count() == 3
+    assert C.NK_get_totp_slot_count() == 15
+    assert C.NK_get_otp_name_length() == 15
+    assert C.NK_get_otp_secret_length() == 40