OTPServer Component

Properties Methods Events Config Settings Errors

The OTPServer component checks the validity of one-time passwords.

Syntax

nsoftware.SecureBlackbox.OTPServer

Remarks

A One-Time Password (OTP) is a password that is valid for only one session or transaction. OTPs were designed to overcome the weaknesses of traditional static passwords such as vulnerability to replay attacks. The OTPServer component can check the validity of HMAC-Based One-Time Passwords (HOTP) and Time-Based One-Time Passwords (TOTP).

Property List

The following is the full list of the properties of the component with short descriptions. Click on the links for further details.


BaseTime	Specifies the TOTP client's base time.
Delta	Specifies the resynchronization limit.
FIPSMode	Reserved.
Users	A database of users containing all the per-user password settings.

Method List

The following is the full list of the methods of the component with short descriptions. Click on the links for further details.


Config	Sets or retrieves a configuration setting.
DoAction	Performs an additional action.
IsHOTPPasswordValid	Validates a hash-based one-time password.
IsPasswordValid	Validates an OTP password for a user.
IsTOTPPasswordValid	Validates a time-based one-time password.
Reset	Resets the component settings.

Event List

The following is the full list of the events fired by the component with short descriptions. Click on the links for further details.


Error	Information about errors during one-time password (OTP) processing.
Notification	This event notifies the application about an underlying control flow event.

Config Settings

The following is a list of config settings for the component with short descriptions. Click on the links for further details.


ASN1UseGlobalTagCache	Controls whether ASN.1 module should use a global object cache.
AssignSystemSmartCardPins	Specifies whether CSP-level PINs should be assigned to CNG keys.
CheckKeyIntegrityBeforeUse	Enables or disable private key integrity check before use.
CookieCaching	Specifies whether a cookie cache should be used for HTTP(S) transports.
Cookies	Gets or sets local cookies for the component.
DefDeriveKeyIterations	Specifies the default key derivation algorithm iteration count.
DNSLocalSuffix	The suffix to assign for TLD names.
EnableClientSideSSLFFDHE	Enables or disables finite field DHE key exchange support in TLS clients.
GlobalCookies	Gets or sets global cookies for all the HTTP transports.
HardwareCryptoUsePolicy	The hardware crypto usage policy.
HttpUserAgent	Specifies the user agent name to be used by all HTTP clients.
HttpVersion	The HTTP version to use in any inner HTTP client components created.
IgnoreExpiredMSCTLSigningCert	Whether to tolerate the expired Windows Update signing certificate.
ListDelimiter	The delimiter character for multi-element lists.
LogDestination	Specifies the debug log destination.
LogDetails	Specifies the debug log details to dump.
LogFile	Specifies the debug log filename.
LogFilters	Specifies the debug log filters.
LogFlushMode	Specifies the log flush mode.
LogLevel	Specifies the debug log level.
LogMaxEventCount	Specifies the maximum number of events to cache before further action is taken.
LogRotationMode	Specifies the log rotation mode.
MaxASN1BufferLength	Specifies the maximal allowed length for ASN.1 primitive tag data.
MaxASN1TreeDepth	Specifies the maximal depth for processed ASN.1 trees.
OCSPHashAlgorithm	Specifies the hash algorithm to be used to identify certificates in OCSP requests.
OldClientSideRSAFallback	Specifies whether the SSH client should use a SHA1 fallback.
ProductVersion	Returns the version of the SecureBlackbox library.
ServerSSLDHKeyLength	Sets the size of the TLS DHE key exchange group.
StaticDNS	Specifies whether static DNS rules should be used.
StaticIPAddress[domain]	Gets or sets an IP address for the specified domain name.
StaticIPAddresses	Gets or sets all the static DNS rules.
Tag	Allows to store any custom data.
TLSSessionGroup	Specifies the group name of TLS sessions to be used for session resumption.
TLSSessionLifetime	Specifies lifetime in seconds of the cached TLS session.
TLSSessionPurgeInterval	Specifies how often the session cache should remove the expired TLS sessions.
UseInternalRandom	Switches between SecureBlackbox-own and platform PRNGs.
UseLegacyAdESValidation	Enables legacy AdES validation mode.
UseOwnDNSResolver	Specifies whether the client components should use own DNS resolver.
UseSharedSystemStorages	Specifies whether the validation engine should use a global per-process copy of the system certificate stores.
UseSystemNativeSizeCalculation	An internal CryptoAPI access tweak.
UseSystemOAEPAndPSS	Enforces or disables the use of system-driven RSA OAEP and PSS computations.
UseSystemRandom	Enables or disables the use of the OS PRNG.

BaseTime Property (OTPServer Component)

Specifies the TOTP client's base time.

public string BaseTime { get; set; }

Public Property BaseTime As String

Default Value

Remarks

Specifies the TOTP (Time-based OTP, RFC 6238) server's base time parameter.

Delta Property (OTPServer Component)

Specifies the resynchronization limit.

Syntax

C#
VB.NET

public int Delta { get; set; }

Public Property Delta As Integer

Default Value

Remarks

This property is used to overcome the asynchronicity between the one-time password (OTP) client and server. For HOTP servers (HMAC-based OTP, RFC 4226), Delta defines the maximum possible deviation of the client's counter value. For TOTP servers (Time-based OTP, RFC 6238), Delta contains the maximum number of time steps the client can be out of synch.

FIPSMode Property (OTPServer Component)

Reserved.

Syntax

C#
VB.NET

public bool FIPSMode { get; set; }

Public Property FIPSMode As Boolean

Default Value

False

Remarks

This property is reserved for future use.

Users Property (OTPServer Component)

A database of users containing all the per-user password settings.

Syntax

C#
VB.NET

public UserAccountList Users { get; }

Public Property Users As UserAccountList

Remarks

Use this property to provide a list of known users to the OTP server.

This property is not available at design time.

Please refer to the UserAccount type for a complete list of fields.

Config Method (OTPServer Component)

Sets or retrieves a configuration setting.

Syntax

C#
VB.NET

public string Config(string configurationString);

Public Function Config(ByVal ConfigurationString As String) As String

Remarks

Config is a generic method available in every component. It is used to set and retrieve configuration settings for the component.

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

DoAction Method (OTPServer Component)

Performs an additional action.

Syntax

C#
VB.NET

public string DoAction(string actionID, string actionParams);

Public Function DoAction(ByVal ActionID As String, ByVal ActionParams As String) As String

Remarks

DoAction is a generic method available in every component. It is used to perform an additional action introduced after the product major release. The list of actions is not fixed, and may be flexibly extended over time.

The unique identifier (case insensitive) of the action is provided in the ActionID parameter.

ActionParams contains the value of a single parameter, or a list of multiple parameters for the action in the form of PARAM1=VALUE1;PARAM2=VALUE2;....

IsHOTPPasswordValid Method (OTPServer Component)

Validates a hash-based one-time password.

Syntax

C#
VB.NET

public bool IsHOTPPasswordValid(byte[] keySecret, int passwordLength, int counter, string password);

Public Function IsHOTPPasswordValid(ByVal KeySecret As Byte(), ByVal PasswordLength As Integer, ByVal Counter As Integer, ByVal Password As String) As Boolean

Remarks

Use this method to validate a hash-based one-time password (HOTP) by using explicit HOTP parameters. For this method to work, no user details need to be provided in Users collection.

IsPasswordValid Method (OTPServer Component)

Validates an OTP password for a user.

Syntax

C#
VB.NET

public bool IsPasswordValid(string username, string password);

Public Function IsPasswordValid(ByVal Username As String, ByVal Password As String) As Boolean

Remarks

Use this method to check a one-time Password for a user specified by UserID. The known users' details need to be provided in Users list.

IsTOTPPasswordValid Method (OTPServer Component)

Validates a time-based one-time password.

Syntax

C#
VB.NET

public bool IsTOTPPasswordValid(byte[] keySecret, int passwordLength, int timeInterval, string hashAlgorithm, string password);

Public Function IsTOTPPasswordValid(ByVal KeySecret As Byte(), ByVal PasswordLength As Integer, ByVal TimeInterval As Integer, ByVal HashAlgorithm As String, ByVal Password As String) As Boolean

Remarks

Use this method to validate a time-based one-time password (TOTP) by using explicit TOTP parameters. For this method to work, no user details need to be provided in Users collection.

Supported hash algorithms:


SB_MAC_ALGORITHM_HMAC_SHA1	`SHA1`
SB_MAC_ALGORITHM_HMAC_SHA256	`SHA256`
SB_MAC_ALGORITHM_HMAC_SHA512	`SHA512`

Reset Method (OTPServer Component)

Resets the component settings.

Syntax

C#
VB.NET

public void Reset();

Public Sub Reset()

Remarks

Reset is a generic method available in every component.

Error Event (OTPServer Component)

Information about errors during one-time password (OTP) processing.

Syntax

C#
VB.NET

public event OnErrorHandler OnError;

public delegate void OnErrorHandler(object sender, OTPServerErrorEventArgs e);

public class OTPServerErrorEventArgs : EventArgs {
  public int ErrorCode { get; }
  public string Description { get; }
}

Public Event OnError As OnErrorHandler

Public Delegate Sub OnErrorHandler(sender As Object, e As OTPServerErrorEventArgs)

Public Class OTPServerErrorEventArgs Inherits EventArgs
  Public ReadOnly Property ErrorCode As Integer
  Public ReadOnly Property Description As String
End Class

Remarks

This event is fired in case of exceptional conditions during OTP checks.

ErrorCode contains an error code and Description contains a textual description of the error.

Notification Event (OTPServer Component)

This event notifies the application about an underlying control flow event.

Syntax

C#
VB.NET

public event OnNotificationHandler OnNotification;

public delegate void OnNotificationHandler(object sender, OTPServerNotificationEventArgs e);

public class OTPServerNotificationEventArgs : EventArgs {
  public string EventID { get; }
  public string EventParam { get; }
}

Public Event OnNotification As OnNotificationHandler

Public Delegate Sub OnNotificationHandler(sender As Object, e As OTPServerNotificationEventArgs)

Public Class OTPServerNotificationEventArgs Inherits EventArgs
  Public ReadOnly Property EventID As String
  Public ReadOnly Property EventParam As String
End Class

Remarks

The component fires this event to let the application know about some event, occurrence, or milestone in the component. For example, it may fire to report completion of the document processing. The list of events being reported is not fixed, and may be flexibly extended over time.

The unique identifier of the event is provided in the EventID parameter. EventParam contains any parameters accompanying the occurrence. Depending on the type of the component, the exact action it is performing, or the document being processed, one or both may be omitted.

UserAccount Type

A container for user account information.

Remarks

UserAccount objects are used to store user account information, such as logins and passwords.

The following fields are available:

Fields

AssociatedData
byte[]
Default: ""

Contains the user's Associated Data when SSH AEAD (Authenticated Encryption with Associated Data) algorithm is used.

BasePath
string
Default: ""

Base path for this user in the server's file system.

Certificate
byte[]
Default: ""

Contains the user's certificate.

Data
string
Default: ""

Contains uninterpreted user-defined data that should be associated with the user account, such as comments or custom settings.

Email
string
Default: ""

The user's email address.

HashAlgorithm
string
Default: ""

Specifies the hash algorithm used to generate TOTP (Time-based One-Time Passwords) passwords for this user. Three HMAC algorithms are supported, with SHA-1, SHA-256, and SHA-512 digests:


SB_MAC_ALGORITHM_HMAC_SHA1	`SHA1`
SB_MAC_ALGORITHM_HMAC_SHA256	`SHA256`
SB_MAC_ALGORITHM_HMAC_SHA512	`SHA512`

IncomingSpeedLimit
int
Default: 0

Specifies the incoming speed limit for this user. The value of 0 (zero) means "no limitation".

OtpAlgorithm
OTPAlgorithms
Default: 0

The algorithm used to generate one-time passwords (OTP) for this user, either HOTP (Hash-based OTP) or TOTP (Time-based OTP). In the former case, a value of a dedicated counter is used to generate a unique password, while in the latter the password is generated on the basis of the current time value.


oaHmac	`0`
oaTime	`1`

OTPLen
int
Default: 0

Specifies the length of the user's OTP password.

OtpValue
int
Default: 0

The user's time interval (TOTP) or Counter (HOTP).

OutgoingSpeedLimit
int
Default: 0

Specifies the outgoing speed limit for this user. The value of 0 (zero) means "no limitation".

Password
string
Default: ""

The user's authentication password.

SharedSecret
byte[]
Default: ""

Contains the user's secret key, which is essentially a shared secret between the client and server.

Shared secrets can be used in TLS-driven protocols, as well as in OTP (where it is called a 'key secret') for generating one-time passwords on one side, and validate them on the other.

SSHKey
byte[]
Default: ""

Contains the user's SSH key.

Username
string
Default: ""

The registered name (login) of the user.

Constructors

C#
VB.NET

public UserAccount();

Public UserAccount()

Creates a new UserAccount object

Config Settings (OTPServer Component)

The component accepts one or more of the following configuration settings. Configuration settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the component, access to these internal properties is provided through the Config method.

Base Config Settings

ASN1UseGlobalTagCache: Controls whether ASN.1 module should use a global object cache.

This is a performance setting. It is unlikely that you will ever need to adjust it.

AssignSystemSmartCardPins: Specifies whether CSP-level PINs should be assigned to CNG keys.

This is a low-level tweak for certain cryptographic providers. It is unlikely that you will ever need to adjust it.

CheckKeyIntegrityBeforeUse: Enables or disable private key integrity check before use.

This global property enables or disables private key material check before each signing operation. This slows down performance a bit, but prevents a selection of attacks on RSA keys where keys with unknown origins are used.

You can switch this property off to improve performance if your project only uses known, good private keys.

CookieCaching: Specifies whether a cookie cache should be used for HTTP(S) transports.

Set this property to enable or disable cookies caching for the component.

Supported values are:


off		No caching (default)
local		Local caching
global		Global caching

Cookies: Gets or sets local cookies for the component.

Use this property to get cookies from the internal cookie storage of the component and/or restore them back between application sessions.

DefDeriveKeyIterations: Specifies the default key derivation algorithm iteration count.

This global property sets the default number of iterations for all supported key derivation algorithms. Note that you can provide the required number of iterations by using properties of the relevant key generation component; this global setting is used in scenarios where specific iteration count is not or cannot be provided.

DNSLocalSuffix: The suffix to assign for TLD names.

Use this global setting to adjust the default suffix to assign to top-level domain names. The default is .local.

EnableClientSideSSLFFDHE: Enables or disables finite field DHE key exchange support in TLS clients.

This global property enables or disables support for finite field DHE key exchange methods in TLS clients. FF DHE is a slower algorithm if compared to EC DHE; enabling it may result in slower connections.

This setting only applies to sessions negotiated with TLS version 1.3.

GlobalCookies: Gets or sets global cookies for all the HTTP transports.

Use this property to get cookies from the GLOBAL cookie storage or restore them back between application sessions. These cookies will be used by all the components that have its CookieCaching property set to "global".

HardwareCryptoUsePolicy: The hardware crypto usage policy.

This global setting controls the hardware cryptography usage policy: auto, enable, or disable.

HttpUserAgent: Specifies the user agent name to be used by all HTTP clients.

This global setting defines the User-Agent field of the HTTP request provides information about the software that initiates the request. This value will be used by all the HTTP clients including the ones used internally in other components.

HttpVersion: The HTTP version to use in any inner HTTP client components created.

Set this property to 1.0 or 1.1 to indicate the HTTP version that any internal HTTP clients should use.

IgnoreExpiredMSCTLSigningCert: Whether to tolerate the expired Windows Update signing certificate.

It is not uncommon for Microsoft Windows Update Certificate Trust List to be signed with an expired Microsoft certificate. Setting this global property to true makes SBB ignore the expired factor and take the Trust List into account.

ListDelimiter: The delimiter character for multi-element lists.

Allows to set the delimiter for any multi-entry values returned by the component as a string object, such as file lists. For most of the components, this property is set to a newline sequence.

LogDestination: Specifies the debug log destination.

Contains a comma-separated list of values that specifies where debug log should be dumped.

Supported values are:


file		File
console		Console
systemlog		System Log (supported for Android only)
debugger		Debugger (supported for VCL for Windows and .Net)

LogDetails: Specifies the debug log details to dump.

Contains a comma-separated list of values that specifies which debug log details to dump.

Supported values are:


time		Current time
level		Level
package		Package name
module		Module name
class		Class name
method		Method name
threadid		Thread Id
contenttype		Content type
content		Content
all		All details

LogFile: Specifies the debug log filename.

Use this property to provide a path to the log file.

LogFilters: Specifies the debug log filters.

Contains a comma-separated list of value pairs ("name:value") that describe filters.

Supported filter names are:


exclude-package		Exclude a package specified in the value
exclude-module		Exclude a module specified in the value
exclude-class		Exclude a class specified in the value
exclude-method		Exclude a method specified in the value
include-package		Include a package specified in the value
include-module		Include a module specified in the value
include-class		Include a class specified in the value
include-method		Include a method specified in the value

LogFlushMode: Specifies the log flush mode.

Use this property to set the log flush mode. The following values are defined:


none		No flush (caching only)
immediate		Immediate flush (real-time logging)
maxcount		Flush cached entries upon reaching LogMaxEventCount entries in the cache.

LogLevel: Specifies the debug log level.

Use this property to provide the desired debug log level.

Supported values are:


none		None (by default)
fatal		Severe errors that cause premature termination.
error		Other runtime errors or unexpected conditions.
warning		Use of deprecated APIs, poor use of API, 'almost' errors, other runtime situations that are undesirable or unexpected, but not necessarily "wrong".
info		Interesting runtime events (startup/shutdown).
debug		Detailed information on flow of through the system.
trace		More detailed information.

LogMaxEventCount: Specifies the maximum number of events to cache before further action is taken.

Use this property to specify the log event number threshold. This threshold may have different effects, depending on the rotation setting and/or the flush mode.

The default value of this setting is 100.

LogRotationMode: Specifies the log rotation mode.

Use this property to set the log rotation mode. The following values are defined:


none		No rotation
deleteolder		Delete older entries from the cache upon reaching LogMaxEventCount
keepolder		Keep older entries in the cache upon reaching LogMaxEventCount (newer entries are discarded)

MaxASN1BufferLength: Specifies the maximal allowed length for ASN.1 primitive tag data.

This global property limits the maximal allowed length for ASN.1 tag data for non-content-carrying structures, such as certificates, CRLs, or timestamps. It does not affect structures that can carry content, such as CMS/CAdES messages. This is a security property aiming at preventing DoS attacks.

MaxASN1TreeDepth: Specifies the maximal depth for processed ASN.1 trees.

This global property limits the maximal depth of ASN.1 trees that the component can handle without throwing an error. This is a security property aiming at preventing DoS attacks.

OCSPHashAlgorithm: Specifies the hash algorithm to be used to identify certificates in OCSP requests.

This global setting defines the hash algorithm to use in OCSP requests during chain validation. Some OCSP responders can only use older algorithms, in which case setting this property to SHA1 may be helpful.

OldClientSideRSAFallback: Specifies whether the SSH client should use a SHA1 fallback.

Tells the SSH client to use a legacy ssh-rsa authentication even if the server indicates support for newer algorithms, such as rsa-sha-256. This is a backward-compatibility tweak.

ProductVersion: Returns the version of the SecureBlackbox library.

This property returns the long version string of the SecureBlackbox library being used (major.minor.build.revision).

ServerSSLDHKeyLength: Sets the size of the TLS DHE key exchange group.

Use this property to adjust the length, in bits, of the DHE prime to be used by the TLS server.

StaticDNS: Specifies whether static DNS rules should be used.

Set this property to enable or disable static DNS rules for the component. Works only if UseOwnDNSResolver is set to true.

Supported values are:


none		No static DNS rules (default)
local		Local static DNS rules
global		Global static DNS rules

StaticIPAddress[domain]: Gets or sets an IP address for the specified domain name.

Use this property to get or set an IP address for the specified domain name in the internal (of the component) or global DNS rules storage depending on the StaticDNS value. The type of the IP address (IPv4 or IPv6) is determined automatically. If both addresses are available, they are devided by the | (pipe) character.

StaticIPAddresses: Gets or sets all the static DNS rules.

Use this property to get static DNS rules from the current rules storage or restore them back between application sessions. If StaticDNS of the component is set to "local", the property returns/restores the rules from/to the internal storage of the component. If StaticDNS of the component is set to "global", the property returns/restores the rules from/to the GLOBAL storage. The rules list is returned and accepted in JSON format.

Tag: Allows to store any custom data.

Use this config property to store any custom data.

TLSSessionGroup: Specifies the group name of TLS sessions to be used for session resumption.

Use this property to limit the search of chached TLS sessions to the specified group. Sessions from other groups will be ignored. By default, all sessions are cached with an empty group name and available to all the components.

TLSSessionLifetime: Specifies lifetime in seconds of the cached TLS session.

Use this property to specify how much time the TLS session should be kept in the session cache. After this time, the session expires and will be automatically removed from the cache. Default value is 300 seconds (5 minutes).

TLSSessionPurgeInterval: Specifies how often the session cache should remove the expired TLS sessions.

Use this property to specify the time interval of purging the expired TLS sessions from the session cache. Default value is 60 seconds (1 minute).

UseInternalRandom: Switches between SecureBlackbox-own and platform PRNGs.

Allows to switch between internal/native PRNG implementation and the one provided by the platform.

UseLegacyAdESValidation: Enables legacy AdES validation mode.

Use this setting to switch the AdES component to the validation approach that was used in SBB 2020/SBB 2022 (less attention to temporal details).

UseOwnDNSResolver: Specifies whether the client components should use own DNS resolver.

Set this global property to false to force all the client components to use the DNS resolver provided by the target OS instead of using own one.

UseSharedSystemStorages: Specifies whether the validation engine should use a global per-process copy of the system certificate stores.

Set this global property to false to make each validation run use its own copy of system certificate stores.

UseSystemNativeSizeCalculation: An internal CryptoAPI access tweak.

This is an internal setting. Please do not use it unless instructed by the support team.

UseSystemOAEPAndPSS: Enforces or disables the use of system-driven RSA OAEP and PSS computations.

This global setting defines who is responsible for performing RSA-OAEP and RSA-PSS computations where the private key is stored in a Windows system store and is exportable. If set to true, SBB will delegate the computations to Windows via a CryptoAPI call. Otherwise, it will export the key material and perform the computations using its own OAEP/PSS implementation.

This setting only applies to certificates originating from a Windows system store.

UseSystemRandom: Enables or disables the use of the OS PRNG.

Use this global property to enable or disable the use of operating system-driven pseudorandom number generation.

Trappable Errors (OTPServer Component)

OTPServer Errors

1048577	Invalid parameter (`SB_ERROR_INVALID_PARAMETER`)
1048578	Invalid configuration (`SB_ERROR_INVALID_SETUP`)
1048579	Invalid state (`SB_ERROR_INVALID_STATE`)
1048580	Invalid value (`SB_ERROR_INVALID_VALUE`)
1048581	Private key not found (`SB_ERROR_NO_PRIVATE_KEY`)
1048582	Cancelled by the user (`SB_ERROR_CANCELLED_BY_USER`)
1048583	The file was not found (`SB_ERROR_NO_SUCH_FILE`)
1048584	Unsupported feature or operation (`SB_ERROR_UNSUPPORTED_FEATURE`)
1048585	General error (`SB_ERROR_GENERAL_ERROR`)
25165825	User not found (`SB_ERROR_OTP_USER_NOT_FOUND`)