SymmetricCrypto Component

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The SymmetricCrypto component provides capabilities of encrypting and decrypting binary data.

Syntax

TsbxSymmetricCrypto

Remarks

SymmetricCrypto allows you to encrypt and decrypt uninterpreted binary data with a symmetric block encryption cipher.

SymmetricCrypto is one of the low-level cryptography classes (alongside PublicKeyCrypto and HashFunction) offered by SecureBlackbox. It allows to encrypt pools of binary data with a chosen symmetric encryption cipher. It can be used as a standalone encryption mechanism (for example, for encrypting database data or setting files), or as part of a larger security system (such as PKCS#7 or PGP).

Encryption and decryption with SymmetricCrypto broadly consists of three steps: configuring the encryption parameters, setting up the key material, and actually encrypting or decrypting the data.

Configuring encryption parameters

When preparing SymmetricCrypto for action, you need to fine-tune several cryptographic encryption parameters. Normally these would be given to you by the party that expects you to encrypt or decrypt their data (for example: 'AES128-CBC, with the IV of all zeroes').

As a rule, the following parameters need to be selected/adjusted:

• EncryptionAlgorithm, such as AES128, 3DES, or Blowfish.
• Encryption Mode, such as CBC, CTR, GCM or CCM.
• Block Padding for data lengths that are not multiples of the cipher's block size (none, PKCS5, or ANXI X9.23).
• TagSize (for AEAD algorithms only).
• HashAlgorithm and MACAlgorithm (for algorithms that require them).

Setting up the key material

Symmetric algorithms use short (typically, 16-32 bytes) encryption keys. The exact key length depends on the encryption algorithm used (for example, 16 bytes for AES128). You can use the KeySize property to learn the expected key length for the chosen EncryptionAlgorithm.

In addition to keys, many encryption modes require additional data. These are typically represented by an Initialization Vector (IV) and a Nonce. The IV is a randomized public part of the encryption key, which is used to avoid re-use of the same encryption key for different data. Nonce is similar in meaning to the initialization vector, but applies to the algorithm and not the key.

Any key material that you assign to SymmetricCrypto should be first loaded into the CryptoKeyManager object. Once you have done that, simply assign the key object returned by the CryptoKeyManager to the Key property. Note that while the IV needs to be provided to the CryptoKeyManager, the Nonce needs to be assigned directly to Nonce property of the SymmetricCrypto object.

Note that CryptoKeyManager lets you to form the encryption key in a few ways: by loading it from memory or file, generating a new random key, or deriving it from a password. Use the method that is the most appropriate in your circumstances.

Encrypting and decrypting data

Now that the component has been set up, you can proceed to the actual encryption or decryption operation. There are a few options you can use here:

• Encrypt (or decrypt) a buffer to a buffer using Encrypt (Decrypt).
• Encrypt a file to a file using EncryptFile.
• Encrypt a stream to a stream using EncryptStream.
• Encrypt longer data chunk by chunk using a sequence of EncryptInit, EncryptUpdate, EncryptUpdate, ..., EncryptUpdate, EncryptFinal calls.

If you are using an authenticated encryption algorithm that can take additional associated data (AEAD), you can provide that via the AssociatedData property.

Please find an example of using SymmetricCrypto to encrypt and decrypt a file below: //encrypting a file SymmetricCrypto symmetricCrypto = new SymmetricCrypto(); symmetricCrypto.setEncryptionAlgorithm("RC4"); // default AES256 // generating a key from a password CryptoKeyManager keyManager = new CryptoKeyManager(); keyManager.deriveKey(256, "MyPassword",""); keyManager.getKey().setIV(new byte[16]); symmetricCrypto.setKey(keyManager.getKey()); // the encoding to apply to the output data, default cetDefault which depends on // the operation and type of key being used symmetricCrypto.setOutputEncoding(SymmetricCrypto.cetBinary); // first parameter is the path of the file you want to encrypt and the second is the path // of where the encrypted file will be saved symmetricCrypto.encryptFile("./message.txt","encryptedFile.bin"); // decrypting a file symmetricCrypto.reset(); symmetricCrypto.setKey(keyManager.getKey()); // first parameter is the path of the file you want to decrypt and the second is the path // of where the decrypted file will be saved symmetricCrypto.decryptFile("encryptedFile.bin","decryptedFile.bin");

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.

AssociatedData Property (SymmetricCrypto Component)

Provides Associated Data for AEAD algorithms.

Syntax

__property DynamicArray AssociatedData = { read=FAssociatedData, write=FSetAssociatedData };

Remarks

Use this property to set up Associated Data for AEAD encryption algorithms.

This property is not available at design time.

Data Type

Byte Array

BlockSize Property (SymmetricCrypto Component)

The block size of the chosen symmetric cipher.

Syntax

__property int BlockSize = { read=FBlockSize };

Default Value

0

Remarks

This property returns the block size of the chosen symmetric cipher.

Modern symmetric algorithms typically use blocks of 16 bytes. Some older algorithms, such as DES or Blowfish, use 8-byte blocks.

This property is read-only.

Data Type

Integer

EncryptionAlgorithm Property (SymmetricCrypto Component)

The encryption algorithm to use for encrypting the data.

Syntax

__property String EncryptionAlgorithm = { read=FEncryptionAlgorithm, write=FSetEncryptionAlgorithm };

Default Value

"AES256"

Remarks

This property specifies the base symmetric algorithm to use (e.g. AES128). Use it in conjunction with Mode to set up the complete encryption scheme (such as AES128-CBC or AES128-GCM).

Data Type

String

FIPSMode Property (SymmetricCrypto Component)

Reserved.

Syntax

__property bool FIPSMode = { read=FFIPSMode, write=FSetFIPSMode };

Default Value

false

Remarks

This property is reserved for future use.

Data Type

Boolean

HashAlgorithm Property (SymmetricCrypto Component)

The hash algorithm to use during encryption.

Syntax

__property String HashAlgorithm = { read=FHashAlgorithm, write=FSetHashAlgorithm };

Default Value

"SHA256"

Remarks

Use this property to provide the hash algorithm to be used with the encryption operation. This only applies to certain encryption algorithms/modes.

Data Type

String

InputEncoding Property (SymmetricCrypto Component)

The encoding to apply to the input data.

Syntax

__property TsbxSymmetricCryptoInputEncodings InputEncoding = { read=FInputEncoding, write=FSetInputEncoding };

enum TsbxSymmetricCryptoInputEncodings {
  cetDefault=0,
  cetBinary=1,
  cetBase64=2,
  cetCompact=3,
  cetJSON=4
};

Default Value

cetDefault

Remarks

Data Type

Integer

KeyHandle Property (SymmetricCrypto Component)

Allows to get or set a 'handle', a unique identifier of the underlying property object.

Syntax

__property __int64 KeyHandle = { read=FKeyHandle, write=FSetKeyHandle };

Default Value

0

Remarks

Allows to get or set a 'handle', a unique identifier of the underlying property object. Use this property to assign objects of the same type in a quicker manner, without copying them fieldwise.

When you pass a handle of one object to another, the source object is copied to the destination rather than assigned. It is safe to get rid of the original object after such operation. pdfSigner.setSigningCertHandle(certMgr.getCertHandle());

This property is not available at design time.

Data Type

Long64

KeyKey Property (SymmetricCrypto Component)

The byte array representation of the key.

Syntax

__property DynamicArray KeyKey = { read=FKeyKey };

Remarks

The byte array representation of the key. This may not be available for non-KeyExportable keys.

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

Data Type

Byte Array

KeySize Property (SymmetricCrypto Component)

Returns the cryptographic key size in bytes.

Syntax

__property int KeySize = { read=FKeySize };

Default Value

0

Remarks

Use this property to read the cryptographic key size. For the majority of the symmetric algorithms this is hard-coded in the algorithm itself (such as 16 bytes for AES128), but may be variable for certain exceptions, such as Blowfish or RC4.

This property is read-only.

Data Type

Integer

MACAlgorithm Property (SymmetricCrypto Component)

The (H)MAC algorithm to use during encryption.

Syntax

__property String MACAlgorithm = { read=FMACAlgorithm, write=FSetMACAlgorithm };

Default Value

""

Remarks

Use this property to configure the HMAC algorithm to use with the encryption operation. This only applies to a small subset of algorithms/modes.

Data Type

String

Mode Property (SymmetricCrypto Component)

Specifies the symmetric cipher mode of operation.

Syntax

__property TsbxSymmetricCryptoModes Mode = { read=FMode, write=FSetMode };

enum TsbxSymmetricCryptoModes {
  scmDefault=0,
  scmECB=1,
  scmCBC=2,
  scmCTR=3,
  scmCFB8=4,
  scmGCM=5,
  scmCCM=6,
  scmPoly1305=7,
  scmOCB=8
};

Default Value

scmDefault

Remarks

Use this property to specify the mode of operation as required by your environment. The default setting is CBC.

Data Type

Integer

Nonce Property (SymmetricCrypto Component)

Specifies the Nonce value to employ.

Syntax

__property DynamicArray Nonce = { read=FNonce, write=FSetNonce };

Remarks

Use this property to specify the Nonce value for the symmetric operation. Not every algorithm or mode uses nonce.

This property is not available at design time.

Data Type

Byte Array

OutputEncoding Property (SymmetricCrypto Component)

The encoding to apply to the output data.

Syntax

__property TsbxSymmetricCryptoOutputEncodings OutputEncoding = { read=FOutputEncoding, write=FSetOutputEncoding };

enum TsbxSymmetricCryptoOutputEncodings {
  cetDefault=0,
  cetBinary=1,
  cetBase64=2,
  cetCompact=3,
  cetJSON=4
};

Default Value

cetDefault

Remarks

Data Type

Integer

Padding Property (SymmetricCrypto Component)

The padding type to apply to the encrypted data.

Syntax

__property TsbxSymmetricCryptoPaddings Padding = { read=FPadding, write=FSetPadding };

enum TsbxSymmetricCryptoPaddings {
  scpNone=0,
  scpPKCS5=1,
  scpANSIX923=2
};

Default Value

scpPKCS5

Remarks

Use this property to specify the padding type to use with the encrypted data. A padding type commonly used in modern security environments is PKCS#5.

Data Type

Integer

PayloadSize Property (SymmetricCrypto Component)

Specifies the payload size, in bytes.

Syntax

__property int PayloadSize = { read=FPayloadSize, write=FSetPayloadSize };

Default Value

0

Remarks

Use this property to specify the size of the input data in bytes. This is only used by a subset of algorithms/modes, such as CCM.

Data Type

Integer

StreamCipher Property (SymmetricCrypto Component)

Returns true if the selected algorithms works as a stream cipher.

Syntax

__property bool StreamCipher = { read=FStreamCipher };

Default Value

false

Remarks

This property returns true if the selected algorithm processes data as a stream (byte-by-byte), rather than block-by-block. This affects the need to use a proper padding settings.

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

Data Type

Boolean

TagSize Property (SymmetricCrypto Component)

Specifies the AEAD tag size, in bytes.

Syntax

__property int TagSize = { read=FTagSize, write=FSetTagSize };

Default Value

16

Remarks

Use this property to specify/customize the tag size for AEAD encryption.

Data Type

Integer

Config Method (SymmetricCrypto Component)

Sets or retrieves a configuration setting.

Syntax

String __fastcall Config(String ConfigurationString);

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 (SymmetricCrypto Component)

Decrypts a buffer.

Syntax

DynamicArray<Byte> __fastcall Decrypt(DynamicArray<Byte> Buffer);

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.

DecryptFile Method (SymmetricCrypto Component)

Decrypts a file.

Syntax

void __fastcall DecryptFile(String SourceFile, String DestFile);

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.

DecryptFinal Method (SymmetricCrypto Component)

Finalization of decryption by blocks.

Syntax

DynamicArray<Byte> __fastcall DecryptFinal();

Remarks

Use this method to finalize of decryption by blocks.

Specify decryption key in Key property.

DecryptInit Method (SymmetricCrypto Component)

Initializes a per-block decryption process.

Syntax

void __fastcall DecryptInit();

Remarks

Use this method to start a block-by-block decryption process.

Specify the decryption key in Key property before starting the decryption.

DecryptUpdate Method (SymmetricCrypto Component)

Decrypts the next block of encrypted data.

Syntax

DynamicArray<Byte> __fastcall DecryptUpdate(DynamicArray<Byte> Buffer);

Remarks

When using block-by-block decryption, pass every subsequent block of the encrypted message to this method until the entire message is processed. For each encrypted block the method returns a piece of decrypted data.

Please note that in general case there is no direct correspondence between the data actually contained in the encrypted block with the output of this method. The component may choose to cache a piece of the provided buffer internally if it doesn't constitute a full block of encrypted data.

Remember to call DecryptInit before calling this method to prepare the control for the decryption process.

DoAction Method (SymmetricCrypto Component)

Performs an additional action.

Syntax

String __fastcall DoAction(String ActionID, String ActionParams);

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 (SymmetricCrypto Component)

Encrypts a buffer.

Syntax

DynamicArray<Byte> __fastcall Encrypt(DynamicArray<Byte> Buffer);

Remarks

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

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

This is a one-off encryption method. Don't use it with granular per-block methods (EncryptInit, EncryptUpdate, EncryptFinal).

EncryptFile Method (SymmetricCrypto Component)

Encrypts a file.

Syntax

void __fastcall EncryptFile(String SourceFile, String DestFile);

Remarks

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

Specify the encryption key in Key property before commencing encryption.

EncryptFinal Method (SymmetricCrypto Component)

Finalization of encryption by blocks.

Syntax

DynamicArray<Byte> __fastcall EncryptFinal();

Remarks

Use this method to finalize of encryption by blocks.

Specify encryption key in Key property.

EncryptInit Method (SymmetricCrypto Component)

Initializes a per-block encryption process.

Syntax

void __fastcall EncryptInit();

Remarks

Use this method to initialize a block-by-block encryption process. Follow it with calls to EncryptUpdate (as many as needed), and complete the encryption with an EncryptFinal call.

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

EncryptUpdate Method (SymmetricCrypto Component)

Encrypts the next block of data.

Syntax

DynamicArray<Byte> __fastcall EncryptUpdate(DynamicArray<Byte> Buffer);

Remarks

Use this method to encrypt the next block of data contained in Buffer.

Call this method after calling EncryptInit for as many times as needed, until the whole volume of data is processed. Having done that, call EncryptFinal to complete the encryption and get the terminating encrypted trailer.

Reset Method (SymmetricCrypto Component)

Resets the component settings.

Syntax

void __fastcall Reset();

Remarks

Reset is a generic method available in every component.

Error Event (SymmetricCrypto Component)

Reports errors during encryption or decryption.

Syntax

typedef struct {
  int ErrorCode;
  String Description;
} TsbxSymmetricCryptoErrorEventParams;
typedef void __fastcall (__closure *TsbxSymmetricCryptoErrorEvent)(System::TObject* Sender, TsbxSymmetricCryptoErrorEventParams *e);
__property TsbxSymmetricCryptoErrorEvent OnError = { read=FOnError, write=FOnError };

Remarks

component fires this event in case of exceptional conditions during a cryptographic operation.

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

Notification Event (SymmetricCrypto Component)

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

Syntax

typedef struct {
  String EventID;
  String EventParam;
} TsbxSymmetricCryptoNotificationEventParams;
typedef void __fastcall (__closure *TsbxSymmetricCryptoNotificationEvent)(System::TObject* Sender, TsbxSymmetricCryptoNotificationEventParams *e);
__property TsbxSymmetricCryptoNotificationEvent OnNotification = { 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.

Progress Event (SymmetricCrypto Component)

Reports the data encryption/decryption progress.

Syntax

typedef struct {
  __int64 Total;
  __int64 Current;
  bool Cancel;
} TsbxSymmetricCryptoProgressEventParams;
typedef void __fastcall (__closure *TsbxSymmetricCryptoProgressEvent)(System::TObject* Sender, TsbxSymmetricCryptoProgressEventParams *e);
__property TsbxSymmetricCryptoProgressEvent OnProgress = { read=FOnProgress, write=FOnProgress };

Remarks

This event fires periodically during a file encrypt/decrypt operation to report its progress.

Use the Cancel parameter to terminate the encryption/decryption if needed.

Config Settings (SymmetricCrypto 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.

SymmetricCrypto Config Settings

Base Config Settings

Trappable Errors (SymmetricCrypto Component)

SymmetricCrypto Errors