MessageVerifier Component

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The MessageVerifier component verifies digital signatures of data stored in the PKCS#7 format.

Syntax

TsbxMessageVerifier

Remarks

PKCS#7 (Public Key Cryptography Standard #7) is a common format used to store encrypted and signed data. It is used by a variety of protocols, including S/MIME and CMS.

Property List

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

Method List

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

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.

Config Settings

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

Certificates Property (MessageVerifier Component)

A collection of certificates included in the electronic signature.

Syntax

property Certificates: TsbxCertificateList read get_Certificates;

Remarks

Use this property to access all certificates included into the signature(s) by its creator.

This property is read-only and not available at design time.

ClaimedSigningTime Property (MessageVerifier Component)

Returns a signature's claimed signing time.

Syntax

property ClaimedSigningTime: String read get_ClaimedSigningTime;

Default Value

''

Remarks

Use this property to get the signature creation time from the signer's computer. Note that the claimed time is not covered by the signature and may be forfeited or wrong. Use ValidatedSigningTime to obtain the signing time figure verified by a trusted timestamping authority. The time is in UTC.

This property is read-only and not available at design time.

ContentType Property (MessageVerifier Component)

A content type property of the signed message.

Syntax

property ContentType: String read get_ContentType;

Default Value

''

Remarks

Use this property to check the content type property of the processed signed message.

This property is read-only and not available at design time.

DataBytes Property (MessageVerifier Component)

Use this property to pass the original signed data to component in the byte array form.

Syntax

property DataBytes: TBytes read get_DataBytes write set_DataBytes;

Remarks

When validating detached signatures, assign a byte array containing the signed data to this property.

This property is not available at design time.

DataFile Property (MessageVerifier Component)

The name of the file containing the original signed data.

Syntax

property DataFile: String read get_DataFile write set_DataFile;

Default Value

''

Remarks

Use this property to provide the original data when validating detached signatures with VerifyDetached.

FIPSMode Property (MessageVerifier Component)

Reserved.

Syntax

property FIPSMode: Boolean read get_FIPSMode write set_FIPSMode;

Default Value

false

Remarks

This property is reserved for future use.

HashAlgorithm Property (MessageVerifier Component)

Hash algorithm which was used to calculate the signature.

Syntax

property HashAlgorithm: String read get_HashAlgorithm write set_HashAlgorithm;

Default Value

''

Remarks

Check this property after calling Verify or VerifyDetached to get the hash algorithm that was used to calculate the signature message digest.

InputBytes Property (MessageVerifier Component)

Use this property to pass the input to component in the byte array form.

Syntax

property InputBytes: TBytes read get_InputBytes write set_InputBytes;

Remarks

Assign a byte array containing the data to be processed to this property.

This property is not available at design time.

InputFile Property (MessageVerifier Component)

Path to the file containing the signed message.

Syntax

property InputFile: String read get_InputFile write set_InputFile;

Default Value

''

Remarks

Use this property to provide a file containing the signed data, either enveloping or detached.

InputIsHash Property (MessageVerifier Component)

Specifies whether the input source contains the hash of the data or the actual data.

Syntax

property InputIsHash: Boolean read get_InputIsHash write set_InputIsHash;

Default Value

false

Remarks

Use this property to tell the component whether the input source contains the actual data or its hash.

This property is not available at design time.

KnownCertificates Property (MessageVerifier Component)

Additional certificates for chain validation.

Syntax

property KnownCertificates: TsbxCertificateList read get_KnownCertificates write set_KnownCertificates;

Remarks

Use this property to supply a list of additional certificates that might be needed for chain validation. An example of a scenario where you might want to do that is when intermediary CA certificates are absent from the standard system locations (or when there are no standard system locations), and therefore should be supplied to the component manually.

The purpose of certificates to be added to this collection is roughly equivalent to that of Intermediate Certification Authorities system store in Windows.

Do not add trust anchors or root certificates to this collection: add them to TrustedCertificates instead.

This property is not available at design time.

MACAlgorithm Property (MessageVerifier Component)

Specifies the hash algorithm to be used.

Syntax

property MACAlgorithm: String read get_MACAlgorithm;

Default Value

'SHA256'

Remarks

This property specifies the MAC algorithm that was used to calculate an authenticated signature.

This property is read-only.

OutputBytes Property (MessageVerifier Component)

Use this property to read the output the component object has produced.

Syntax

property OutputBytes: TBytes read get_OutputBytes;

Remarks

Read the contents of this property after the operation is completed to read the produced output. This property will only be set if OutputFile and OutputStream properties had not been assigned.

This property is read-only and not available at design time.

OutputFile Property (MessageVerifier Component)

Path to the file to save the extracted data to.

Syntax

property OutputFile: String read get_OutputFile write set_OutputFile;

Default Value

''

Remarks

Use this property when validating enveloping signatures to specify the output file where the extracted message should be saved.

SignatureType Property (MessageVerifier Component)

The type of the processed signature.

Syntax

property SignatureType: TsbxMessageSignatureTypes read get_SignatureType;

TsbxMessageSignatureTypes = (
  stUnknown,
  stPKCS1Detached,
  stPKCS7Detached,
  stPKCS7Enveloping,
  stPKCS7MACDetached,
  stPKCS7MACEnveloping
);

Default Value

stUnknown

Remarks

Use this property to check the result of the most recent signature validation.

This property is read-only and not available at design time.

SignatureValidationResult Property (MessageVerifier Component)

The signature validation result.

Syntax

property SignatureValidationResult: TsbxSignatureValidities read get_SignatureValidationResult;

TsbxSignatureValidities = (
  svtValid,
  svtUnknown,
  svtCorrupted,
  svtSignerNotFound,
  svtFailure
);

Default Value

svtValid

Remarks

Use this property to check the result of the most recent signature validation.

This property is read-only and not available at design time.

SignedAttributes Property (MessageVerifier Component)

Custom signature attributes that are covered by the electronic signature.

Syntax

property SignedAttributes: TsbxSignatureAttributeList read get_SignedAttributes;

Remarks

Signature attributes are used to store auxiliary information in the signature. Values included as signed attributes are covered by the signature.

This property is read-only and not available at design time.

SigningCertificate Property (MessageVerifier Component)

The certificate that was used to create the signature.

Syntax

property SigningCertificate: TsbxCertificate read get_SigningCertificate;

Remarks

Use this property to access the certificate that was used to create the signature. This property might not be available if the signer chose not to include the certificate into the signature.

This property is read-only and not available at design time.

Timestamp Property (MessageVerifier Component)

Contains the timestamp which is being validated.

Syntax

property Timestamp: TsbxTimestampInfo read get_Timestamp;

Remarks

Use this property to access the timestamp which is currently being validated.

This property is read-only and not available at design time.

Timestamped Property (MessageVerifier Component)

Indicates whether or not the signature is timestamped.

Syntax

property Timestamped: Boolean read get_Timestamped;

Default Value

false

Remarks

This property returns True if the signature is timestamped, and False otherwise.

This property is read-only and not available at design time.

TSACertificate Property (MessageVerifier Component)

The certificate of the Time Stamping Authority.

Syntax

property TSACertificate: TsbxCertificate read get_TSACertificate;

Remarks

Use this property to access the certificate of the TSA that produced the timestamp.

Note that in some instances the TSA certificate might be unavailable, even for timestamped documents and signatures.

This property is read-only and not available at design time.

UnsignedAttributes Property (MessageVerifier Component)

Custom unsigned attributes included in the electronic signature.

Syntax

property UnsignedAttributes: TsbxSignatureAttributeList read get_UnsignedAttributes;

Remarks

Signature attributes are used to store auxiliary information in the signature. Values included as unsigned attributes are not covered by the signature and can be changed or removed without affecting the signature.

This property is read-only and not available at design time.

ValidatedSigningTime Property (MessageVerifier Component)

Contains the certified signing time.

Syntax

property ValidatedSigningTime: String read get_ValidatedSigningTime;

Default Value

''

Remarks

Use this property to obtain the signing time as certified by an external timestamp. The time is in UTC.

This property is read-only and not available at design time.

CheckSignatureType Method (MessageVerifier Component)

Determines the signature kind.

Syntax

function CheckSignatureType(): Integer;

Remarks

Use this method to determine the kind of the signature stored in InputFile (InputStream).

Config Method (MessageVerifier Component)

Sets or retrieves a configuration setting.

Syntax

function Config(ConfigurationString: String): 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 (MessageVerifier Component)

Performs an additional action.

Syntax

function DoAction(ActionID: String; ActionParams: String): 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 insencitive) 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;....

Verify Method (MessageVerifier Component)

Verifies digitally signed data.

Syntax

procedure Verify();

Remarks

PKCS#7 and its successor, CMS, support two types of signatures: (1) enveloping signatures, where the signed data and its signature are combined in the same message, and (2) detached signatures, where the signature is stored as a separate entity. This method verifies enveloped signatures and extracts data contained in them. Use VerifyDetached to verify detached signatures.

This method expects the enveloping signature to be provided via InputFile or InputStream properties.

Note that this method only checks the integrity of the signature, i.e., that it is signed with the claimed certificate and has not been altered. It does not validate the signing certificate chain. To validate the certificate chain, either use CertificateValidator component together with MessageVerifier, or consider using CAdESVerifier component instead.

VerifyDetached Method (MessageVerifier Component)

Verifies a detached signature.

Syntax

procedure VerifyDetached();

Remarks

Use this method to verify detached signatures. Pass the signature via InputFile (or InputStream) property, and the original data via DataFile (DataStream).

Error Event (MessageVerifier Component)

Information about errors during PKCS#7 message verification.

Syntax

type TErrorEvent = procedure (
  Sender: TObject;
  ErrorCode: Integer;
  const Description: String
) of Object;

property OnError: TErrorEvent read FOnError write FOnError;

Remarks

The event is fired in case of exceptional conditions during message processing.

ErrorCode contains an error code and Description contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Messages section.

Notification Event (MessageVerifier Component)

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

Syntax

type TNotificationEvent = procedure (
  Sender: TObject;
  const EventID: String;
  const EventParam: String
) of Object;

property OnNotification: TNotificationEvent read FOnNotification write FOnNotification;

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 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.

RecipientFound Event (MessageVerifier Component)

Fires to report a message addressee parameters.

Syntax

type TRecipientFoundEvent = procedure (
  Sender: TObject;
  const IssuerRDN: String;
  SerialNumber: TBytes;
  SubjectKeyID: TBytes;
  CertFound: Boolean
) of Object;

property OnRecipientFound: TRecipientFoundEvent read FOnRecipientFound write FOnRecipientFound;

Remarks

This event is fired for each addressee the message is encrypted for. It may fire several times in a row if the message is encrypted for more than one recipient.

The IssuerRDN, SerialNumber, and SubjectKeyID parameters to identify the recipient's certificate. CertFound indicates if the specified certificate has been located in Certificates collection. If it wasn't, you might want to look up the certificate manually, and add it to the collection inside the event handler.

SignatureFound Event (MessageVerifier Component)

Signifies the start of signature validation.

Syntax

type TSignatureFoundEvent = procedure (
  Sender: TObject;
  const IssuerRDN: String;
  SerialNumber: TBytes;
  SubjectKeyID: TBytes;
  CertFound: Boolean;
  var ValidateSignature: Boolean;
  var ValidateChain: Boolean
) of Object;

property OnSignatureFound: TSignatureFoundEvent read FOnSignatureFound write FOnSignatureFound;

Remarks

This event tells the application that signature validation is about to start, and provides the details about the signer's certificate via its IssuerRDN, SerialNumber, and SubjectKeyID parameters. It fires for every signature located in the verified document or message.

The CertFound is set to True if the component has found the needed certificate in one of the known locations, and to False otherwise, in which case you must provide it manually via KnownCertificates property.

Signature validation consists of two independent stages: cryptographic signature validation and chain validation. Separate validation results are reported for each, with SignatureValidationResult and ChainValidationResult properties respectively.

Use the ValidateSignature and ValidateChain parameters to tell the verifier which stages to include in the validation.

SignatureValidated Event (MessageVerifier Component)

Marks the completion of the signature validation routine.

Syntax

type TSignatureValidatedEvent = procedure (
  Sender: TObject;
  const IssuerRDN: String;
  SerialNumber: TBytes;
  SubjectKeyID: TBytes;
  ValidationResult: Integer
) of Object;

property OnSignatureValidated: TSignatureValidatedEvent read FOnSignatureValidated write FOnSignatureValidated;

Remarks

This event is fired upon the completion of the signature validation routine, and reports the respective validation result.

Use the IssuerRDN, SerialNumber, and/or SubjectKeyID parameters to identify the signing certificate.

ValidationResult is set to 0 if the validation has been successful, or to a non-zero value in case of a validation failure.

TimestampFound Event (MessageVerifier Component)

Signifies the start of a timestamp validation routine.

Syntax

type TTimestampFoundEvent = procedure (
  Sender: TObject;
  const IssuerRDN: String;
  SerialNumber: TBytes;
  SubjectKeyID: TBytes;
  CertFound: Boolean;
  var ValidateTimestamp: Boolean;
  var ValidateChain: Boolean
) of Object;

property OnTimestampFound: TTimestampFoundEvent read FOnTimestampFound write FOnTimestampFound;

Remarks

This event fires for every timestamp identified during signature processing, and reports the details about the signer's certificate via its IssuerRDN, SerialNumber, and SubjectKeyID parameters.

The CertFound is set to True if the component has found the needed certificate in one of the known locations, and to False otherwise, in which case you must provide it manually via KnownCertificates property.

Just like with signature validation, timestamp validation consists of two independent stages: cryptographic signature validation and chain validation. Separate validation results are reported for each, with SignatureValidationResult and ChainValidationResult properties respectively.

Use the ValidateSignature and ValidateChain parameters to tell the verifier which stages to include in the validation.

TimestampValidated Event (MessageVerifier Component)

Reports the completion of the timestamp validation routine.

Syntax

type TTimestampValidatedEvent = procedure (
  Sender: TObject;
  const IssuerRDN: String;
  SerialNumber: TBytes;
  SubjectKeyID: TBytes;
  const Time: String;
  ValidationResult: Integer;
  ChainValidationResult: Integer;
  ChainValidationDetails: Integer
) of Object;

property OnTimestampValidated: TTimestampValidatedEvent read FOnTimestampValidated write FOnTimestampValidated;

Remarks

This event is fired upon the completion of the timestamp validation routine, and reports the respective validation result.

ValidationResult is set to 0 if the validation has been successful, or to a non-zero value in case of a failure.

Certificate Type

Provides details of an individual X.509 certificate.

Remarks

This type provides access to X.509 certificate details.

Fields

constructor Create();

Attributes store auxiliary information about the signed message, the signature, or the owner. Each attribute is a OID=Value pair.

Common attributes are signing time, a content type, a policy identifier, and a signature timestamp.

Fields

constructor Create();

constructor Create();

Config Settings (MessageVerifier Component)

MessageVerifier Config Settings

Base Config Settings

Trappable Errors (MessageVerifier Component)

MessageVerifier Errors