PublicKeyCrypto Component

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The PublicKeyCrypto component supports encrypting, decrypting, signing and verifying messages.

Syntax

TsbxPublicKeyCrypto

Remarks

PublicKeyCrypto allows you to encrypt, decrypt, sign and verify uninterpreted data. It implements low-level, or "raw" cryptographic primitives, such as RSA-PKCS1. The cryptographic primitives are typically used internally in higher-level protocols, such as CMS or PGP.

Cryptographic primitives work on small quantities of data (up to a few kilobytes). If you are looking to encrypt or sign large blobs of data, it is very likely that you need to use higher-level classes, such as MessageEncryptor, CAdESSigner, or PGPWriter.

A code snippet below illustrates the use of PublicKeyCrypto to encrypt (and decrypt) a data piece with OpenSSL-generated RSA keypair. procedure TForm1.HandleKeyPasswordNeeded(Sender: TObject; const NeededFor: String; var Password: String; var Cancel: Boolean); begin Password := 'key-password'; end; procedure TForm1.btnRSAEncryptClick(Sender: TObject); var Crypto : TsbxPublicKeyCrypto; KeyMgr : TsbxCryptoKeyManager; Plaintext, Ciphertext, Decrypted : TBytes; begin // prep Plaintext := TEncoding.UTF8.GetBytes('Hello, World!'); // encryption KeyMgr := TsbxCryptoKeyManager.Create(nil); try KeyMgr.ImportFromFile('public.pem', kffPEM, '', '', '', ktPublic); Crypto := TsbxPublicKeyCrypto.Create(nil); try Crypto.Key := KeyMgr.Key; Ciphertext := Crypto.Encrypt(Plaintext); finally FreeAndNil(Crypto); end; finally FreeAndNil(KeyMgr); end; // decryption KeyMgr := TsbxCryptoKeyManager.Create(nil); try KeyMgr.OnPasswordNeeded := HandleKeyPasswordNeeded; KeyMgr.ImportFromFile('private.pem', kffPEM, '', '', '', ktSecret); Crypto := TsbxPublicKeyCrypto.Create(nil); try Crypto.Key := KeyMgr.Key; Decrypted := Crypto.Decrypt(Ciphertext); finally FreeAndNil(Crypto); end; finally FreeAndNil(KeyMgr); end; ShowMessage(TEncoding.UTF8.GetString(Decrypted)); end;

Property List

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

Method List

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

Event List

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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

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

CanEncrypt Property (PublicKeyCrypto Component)

Returns true if the crypto object can be used for encryption.

Syntax

property CanEncrypt: Boolean read get_CanEncrypt;

Default Value

false

Remarks

This property returns true if the crypto object can be used for encryption and decryption. This capability depends on the cryptographic algorithm.

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

CanSign Property (PublicKeyCrypto Component)

Returns true if the crypto object is capable of data signing.

Syntax

property CanSign: Boolean read get_CanSign;

Default Value

false

Remarks

This property returns true if the crypto object can be used for signing data and validating signatures. This capability depends on the cryptographic algorithm.

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

FIPSMode Property (PublicKeyCrypto 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 (PublicKeyCrypto Component)

The hash algorithm to be used during the crypto operation.

Syntax

property HashAlgorithm: String read get_HashAlgorithm write set_HashAlgorithm;

Default Value

'SHA256'

Remarks

Use this property to adjust the hash to be used during the cryptographic operation. This typically applies to signing and verification, but can also apply to more complex encryption primitives, such as RSA-OEAP.

InputEncoding Property (PublicKeyCrypto Component)

The encoding to apply to the input data.

Syntax

property InputEncoding: TsbxCryptoEncodingTypes read get_InputEncoding write set_InputEncoding;

TsbxCryptoEncodingTypes = (
  cetDefault,
  cetBinary,
  cetBase64,
  cetCompact,
  cetJSON
);

Default Value

cetDefault

Remarks

Use this property to specify the encoding to apply to the input data.

InputIsHash Property (PublicKeyCrypto Component)

Indicates whether the input data contains the hash or the actual data.

Syntax

property InputIsHash: Boolean read get_InputIsHash write set_InputIsHash;

Default Value

false

Remarks

Set this property to true to tell the component that the data you are passing to it is the hash of the data, rather than the actual (unhashed) data. If this property is set to false, component will hash the provided data internally if it is assumed by the algorithm.

This property is not available at design time.

JsonDetails Property (PublicKeyCrypto Component)

Provides a container for JSON settings.

Syntax

property JsonDetails: TsbxJWSettings read get_JsonDetails;

Remarks

Use this property when using JSON Web Encryption/Signature to tune up the JSON parameters.

This property is read-only.

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

Key Property (PublicKeyCrypto Component)

The key to employ for the crypto operation.

Syntax

property Key: TsbxCryptoKey read get_Key write set_Key;

Remarks

Use this property to specify the key to perform the crypto operation with.

Please note that the key assigned should be of a proper type (a public key, not a symmetric key), have a proper set of capabilities (signing and/or encryption), and include its private part for signing and decryption operations.

This property is not available at design time.

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

OutputEncoding Property (PublicKeyCrypto Component)

The encoding type to apply to the output data.

Syntax

property OutputEncoding: TsbxCryptoEncodingTypes read get_OutputEncoding write set_OutputEncoding;

TsbxCryptoEncodingTypes = (
  cetDefault,
  cetBinary,
  cetBase64,
  cetCompact,
  cetJSON
);

Default Value

cetDefault

Remarks

Use this property to specify the encoding type to apply to the protected data.

Scheme Property (PublicKeyCrypto Component)

The algorithm scheme to use.

Syntax

property Scheme: String read get_Scheme write set_Scheme;

Default Value

''

Remarks

Certain asymmetric algorithms are often accompanied with a specific algorithm scheme. Two typical examples are RSA's own OAEP and PSS schemes. Use this property to tune up the scheme to use. Leave it empty to proceed with the standard scheme (such as PKCS#1-v1.5 for RSA). Supported schemes:

RSA: PKCS#1, PSS, OAEP, SSL3

ECDSA: ed25519, ed448, ed25519ph, ed448ph

SchemeParams Property (PublicKeyCrypto Component)

The algorithm scheme parameters to employ.

Syntax

property SchemeParams: String read get_SchemeParams write set_SchemeParams;

Default Value

''

Remarks

Use this property to specify the parameters of the algorithm scheme if needed.

SignatureValidationResult Property (PublicKeyCrypto Component)

The signature validation result.

Syntax

property SignatureValidationResult: TsbxSignatureValidities read get_SignatureValidationResult;

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

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.

Config Method (PublicKeyCrypto 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.

Decrypt Method (PublicKeyCrypto Component)

Decrypts a buffer.

Syntax

function Decrypt(Buffer: TBytes): TBytes;

Remarks

Use this method to decrypt a byte array and get the encrypted message in another byte array.

Specify the decryption key in Key property before calling this method.

DecryptFile Method (PublicKeyCrypto Component)

Decrypts a file.

Syntax

procedure DecryptFile(SourceFile: String; DestFile: String);

Remarks

Use this method to decrypt an encrypted file and save the decrypted data to another file.

Specify the decryption key in Key property before calling this method.

DecryptStream Method (PublicKeyCrypto Component)

Decrypts a stream.

Syntax

procedure DecryptStream(SourceStream: TStream; DestStream: TStream);

Remarks

Use this method to decrypt a stream and save the decrypted message into another stream.

Specify the decryption key in Key property before calling this method.

DoAction Method (PublicKeyCrypto 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 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;....

Common ActionIDs:

Encrypt Method (PublicKeyCrypto Component)

Encrypts a buffer.

Syntax

function Encrypt(Buffer: TBytes): TBytes;

Remarks

Use this method to encrypt a byte array and get the protected message in another byte array.

Specify the encryption key in the Key property before commencing encryption.

EncryptFile Method (PublicKeyCrypto Component)

Encrypts a file.

Syntax

procedure EncryptFile(SourceFile: String; DestFile: String);

Remarks

Use this method to encrypt a file and save the protected message to another file.

Specify the encryption key in Key property before commencing encryption.

EncryptStream Method (PublicKeyCrypto Component)

Encrypts a stream.

Syntax

procedure EncryptStream(SourceStream: TStream; DestStream: TStream);

Remarks

Use this method to encrypt a stream and save the protected message into another stream.

Specify the encryption key in Key property before commencing encryption.

Reset Method (PublicKeyCrypto Component)

Resets the component settings.

Syntax

procedure Reset();

Remarks

Reset is a generic method available in every component.

Sign Method (PublicKeyCrypto Component)

Signs a buffer.

Syntax

function Sign(Buffer: TBytes; Detached: Boolean): TBytes;

Remarks

Use this method to sign a byte array and get the protected message in another byte array. Set the Detached parameter to false to create an enveloped/enveloping, rather than detached signature. Please note that certain signature algorithms/kinds only support detached signing.

Specify the signing key in Key property before commencing the signing.

Please note that the key assigned must have a private key part.

SignFile Method (PublicKeyCrypto Component)

Signs a file.

Syntax

procedure SignFile(SourceFile: String; DestFile: String; Detached: Boolean);

Remarks

Use this method to sign a file and save the protected message to another file.

Specify the signing key in Key property before the signing. Please make sure the assigned key has a private key associated with it.

Set Detached parameter to false to create an enveloped/enveloping signature. This may not be supported by certain algorithms or encryption modes.

SignStream Method (PublicKeyCrypto Component)

Signs a stream.

Syntax

procedure SignStream(SourceStream: TStream; DestStream: TStream; Detached: Boolean);

Remarks

Use this method to sign a stream and save the protected message to another stream.

Specify the signing key in Key property before commencing the signing. Note that the signing key must come with its private key.

Set Detached parameter to false to produce enveloped/enveloping, and not detached signature. Many encryption algorithms/modes do not support non-detached signatures.

Verify Method (PublicKeyCrypto Component)

Verifies an enveloped or enveloping signature contained in a buffer.

Syntax

function Verify(Buffer: TBytes): TBytes;

Remarks

Use this method to verify an enveloped or enveloping signature contained in a byte array. The method verifies the signature and extracts the original signed content into another byte array.

The validation result is stored in SignatureValidationResult property.

Use VerifyDetached to verify detached signatures.

Specify the verification key in the Key property before commencing verification.

VerifyDetached Method (PublicKeyCrypto Component)

Verifies a detached signature.

Syntax

procedure VerifyDetached(SignedData: TBytes; Signature: TBytes);

Remarks

Use this method to verify a detached signature. Pass the original message via the SignedData parameter, and the signature via the Signature parameter.

The validation result is stored in SignatureValidationResult property.

Provide the verification key in Key property before commencing verification.

VerifyDetachedFile Method (PublicKeyCrypto Component)

Verifies a detached signature.

Syntax

procedure VerifyDetachedFile(SignedDataFile: String; SignatureFile: String);

Remarks

Use this method to verify a detached signature. Pass the original data via the SignedDataFile parameter, and the signature via the SignatureFile parameter.

The validation result is stored in SignatureValidationResult property.

Provide the verification key in Key property.

VerifyDetachedStream Method (PublicKeyCrypto Component)

Verifies a detached signature.

Syntax

procedure VerifyDetachedStream(SignedDataStream: TStream; SignatureStream: TStream);

Remarks

Use this method to verify a detached signature. Provide the original signed data via the SignedDataStream parameter, and the signature via the SignatureStream parameter.

The validation result will be stored in SignatureValidationResult property.

Specify the verification public key in Key property before commencing validation.

VerifyFile Method (PublicKeyCrypto Component)

Verifies an enveloped or enveloping signature contained in a file.

Syntax

procedure VerifyFile(SourceFile: String; DestFile: String);

Remarks

Use this method to verify an enveloped or enveloping signature and extract the original signed message to another file.

The validation result is stored in SignatureValidationResult property.

Specify the public verification key in Key property before commencing the validation.

VerifyStream Method (PublicKeyCrypto Component)

Verifies an enveloping or enveloped signature contained in a stream.

Syntax

procedure VerifyStream(SourceStream: TStream; DestStream: TStream);

Remarks

Use this method to verify an enveloping or enveloped signature and extract the original data into a stream.

The outcome of the validation is stored in SignatureValidationResult property.

Provide the public verification key via the Key property before commencing the validation.

Error Event (PublicKeyCrypto Component)

Reports error information during a crypto operation.

Syntax

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

property OnError: TErrorEvent read FOnError write FOnError;

Remarks

Component fires this event if an error is encountered during a cryptographic operation.

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

Notification Event (PublicKeyCrypto 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 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.

CryptoKey Type

This container represents a cryptographic key.

Remarks

This type is a universal placeholder for cryptographic keys.

Fields

Constructors

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constructor Create();

JWSettings Type

This container represents JSON web security settings.

Remarks

This type contains properties specific to JSON Web Security.

Fields

Constructors

>

constructor Create();

Config Settings (PublicKeyCrypto 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.

PublicKeyCrypto Config Settings

Base Config Settings

Trappable Errors (PublicKeyCrypto Component)

PublicKeyCrypto Errors