SymmetricCrypto Module

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

Syntax

SecureBlackbox.SymmetricCrypto

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

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

Method List

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

Event List

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

Config Settings

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

AssociatedData Property (SymmetricCrypto Module)

Provides Associated Data for AEAD algorithms.

Syntax

• Swift
• Objective-C

public var associatedData: Data {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=associatedData,setter=setAssociatedData:) NSData* associatedData;

- (NSData*)associatedData;
- (void)setAssociatedData :(NSData*)newAssociatedData;

Remarks

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

BlockSize Property (SymmetricCrypto Module)

The block size of the chosen symmetric cipher.

Syntax

• Swift
• Objective-C

public var blockSize: Int32 {
  get {...}
}

@property (nonatomic,readonly,assign,getter=blockSize) int blockSize;

- (int)blockSize;

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.

EncryptionAlgorithm Property (SymmetricCrypto Module)

The encryption algorithm to use for encrypting the data.

Syntax

• Swift
• Objective-C

public var encryptionAlgorithm: String {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=encryptionAlgorithm,setter=setEncryptionAlgorithm:) NSString* encryptionAlgorithm;

- (NSString*)encryptionAlgorithm;
- (void)setEncryptionAlgorithm :(NSString*)newEncryptionAlgorithm;

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).

FIPSMode Property (SymmetricCrypto Module)

Reserved.

Syntax

• Swift
• Objective-C

public var fipsMode: Bool {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=FIPSMode,setter=setFIPSMode:) BOOL FIPSMode;

- (BOOL)FIPSMode;
- (void)setFIPSMode :(BOOL)newFIPSMode;

Default Value

False

Remarks

This property is reserved for future use.

HashAlgorithm Property (SymmetricCrypto Module)

The hash algorithm to use during encryption.

Syntax

• Swift
• Objective-C

public var hashAlgorithm: String {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=hashAlgorithm,setter=setHashAlgorithm:) NSString* hashAlgorithm;

- (NSString*)hashAlgorithm;
- (void)setHashAlgorithm :(NSString*)newHashAlgorithm;

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.

InputEncoding Property (SymmetricCrypto Module)

The encoding to apply to the input data.

Syntax

• Swift
• Objective-C

public var inputEncoding: SymmetricCryptoInputEncodings {
  get {...}
  set {...}
}

public enum SymmetricCryptoInputEncodings: Int32 {
  case cetDefault = 0
  case cetBinary = 1
  case cetBase64 = 2
  case cetCompact = 3
  case cetJSON = 4
}

@property (nonatomic,readwrite,assign,getter=inputEncoding,setter=setInputEncoding:) int inputEncoding;

- (int)inputEncoding;
- (void)setInputEncoding :(int)newInputEncoding;

Default Value

0

Remarks

Key Property (SymmetricCrypto Module)

The key to use for the cryptographic operation.

Syntax

• Swift
• Objective-C

public var key: CryptoKey {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=keyHandle,setter=setKeyHandle:) long long keyHandle;

- (long long)keyHandle;
- (void)setKeyHandle :(long long)newKeyHandle;

@property (nonatomic,readonly,assign,getter=keyKey) NSData* keyKey;

- (NSData*)keyKey;

 

Default Value

16

Remarks

Use this property to provide the symmetric key to use for the cryptographic operation. Remember that this key should be of appropriate type and length, and any required additional settings (such as IV or Nonce) should be adjusted where appropriate.

KeySize Property (SymmetricCrypto Module)

Returns the cryptographic key size in bytes.

Syntax

• Swift
• Objective-C

public var keySize: Int32 {
  get {...}
}

@property (nonatomic,readonly,assign,getter=keySize) int keySize;

- (int)keySize;

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.

MACAlgorithm Property (SymmetricCrypto Module)

The (H)MAC algorithm to use during encryption.

Syntax

• Swift
• Objective-C

public var macAlgorithm: String {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=MACAlgorithm,setter=setMACAlgorithm:) NSString* MACAlgorithm;

- (NSString*)MACAlgorithm;
- (void)setMACAlgorithm :(NSString*)newMACAlgorithm;

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.

Mode Property (SymmetricCrypto Module)

Specifies the symmetric cipher mode of operation.

Syntax

• Swift
• Objective-C

public var mode: SymmetricCryptoModes {
  get {...}
  set {...}
}

public enum SymmetricCryptoModes: Int32 {
  case scmDefault = 0
  case scmECB = 1
  case scmCBC = 2
  case scmCTR = 3
  case scmCFB8 = 4
  case scmGCM = 5
  case scmCCM = 6
  case scmPoly1305 = 7
  case scmOCB = 8
}

@property (nonatomic,readwrite,assign,getter=mode,setter=setMode:) int mode;

- (int)mode;
- (void)setMode :(int)newMode;

Default Value

0

Remarks

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

Nonce Property (SymmetricCrypto Module)

Specifies the Nonce value to employ.

Syntax

• Swift
• Objective-C

public var nonce: Data {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=nonce,setter=setNonce:) NSData* nonce;

- (NSData*)nonce;
- (void)setNonce :(NSData*)newNonce;

Remarks

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

OutputEncoding Property (SymmetricCrypto Module)

The encoding to apply to the output data.

Syntax

• Swift
• Objective-C

public var outputEncoding: SymmetricCryptoOutputEncodings {
  get {...}
  set {...}
}

public enum SymmetricCryptoOutputEncodings: Int32 {
  case cetDefault = 0
  case cetBinary = 1
  case cetBase64 = 2
  case cetCompact = 3
  case cetJSON = 4
}

@property (nonatomic,readwrite,assign,getter=outputEncoding,setter=setOutputEncoding:) int outputEncoding;

- (int)outputEncoding;
- (void)setOutputEncoding :(int)newOutputEncoding;

Default Value

0

Remarks

Padding Property (SymmetricCrypto Module)

The padding type to apply to the encrypted data.

Syntax

• Swift
• Objective-C

public var padding: SymmetricCryptoPaddings {
  get {...}
  set {...}
}

public enum SymmetricCryptoPaddings: Int32 {
  case scpNone = 0
  case scpPKCS5 = 1
  case scpANSIX923 = 2
}

@property (nonatomic,readwrite,assign,getter=padding,setter=setPadding:) int padding;

- (int)padding;
- (void)setPadding :(int)newPadding;

Default Value

1

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.

PayloadSize Property (SymmetricCrypto Module)

Specifies the payload size, in bytes.

Syntax

• Swift
• Objective-C

public var payloadSize: Int32 {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=payloadSize,setter=setPayloadSize:) int payloadSize;

- (int)payloadSize;
- (void)setPayloadSize :(int)newPayloadSize;

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.

StreamCipher Property (SymmetricCrypto Module)

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

Syntax

• Swift
• Objective-C

public var streamCipher: Bool {
  get {...}
}

@property (nonatomic,readonly,assign,getter=streamCipher) BOOL streamCipher;

- (BOOL)streamCipher;

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.

TagSize Property (SymmetricCrypto Module)

Specifies the AEAD tag size, in bytes.

Syntax

• Swift
• Objective-C

public var tagSize: Int32 {
  get {...}
  set {...}
}

@property (nonatomic,readwrite,assign,getter=tagSize,setter=setTagSize:) int tagSize;

- (int)tagSize;
- (void)setTagSize :(int)newTagSize;

Default Value

16

Remarks

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

Config Method (SymmetricCrypto Module)

Sets or retrieves a configuration setting.

Syntax

• Swift
• Objective-C

public func config(configurationString: String) throws -> String

- (NSString*)config:(NSString*)configurationString;

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, 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 Module)

Decrypts a buffer.

Syntax

• Swift
• Objective-C

public func decrypt(buffer: Data) throws -> Data

- (NSData*)decrypt:(NSData*)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 Module)

Decrypts a file.

Syntax

• Swift
• Objective-C

public func decryptFile(sourceFile: String, destFile: String) throws -> Void

- (void)decryptFile:(NSString*)sourceFile :(NSString*)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 Module)

Finalization of decryption by blocks.

Syntax

• Swift
• Objective-C

public func decryptFinal() throws -> Data

- (NSData*)decryptFinal;

Remarks

Use this method to finalize of decryption by blocks.

Specify decryption key in Key property.

DecryptInit Method (SymmetricCrypto Module)

Initializes a per-block decryption process.

Syntax

• Swift
• Objective-C

public func decryptInit() throws -> Void

- (void)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 Module)

Decrypts the next block of encrypted data.

Syntax

• Swift
• Objective-C

public func decryptUpdate(buffer: Data) throws -> Data

- (NSData*)decryptUpdate:(NSData*)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 Module)

Performs an additional action.

Syntax

• Swift
• Objective-C

public func doAction(actionID: String, actionParams: String) throws -> String

- (NSString*)doAction:(NSString*)actionID :(NSString*)actionParams;

Remarks

DoAction is a generic method available in every class. 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 Module)

Encrypts a buffer.

Syntax

• Swift
• Objective-C

public func encrypt(buffer: Data) throws -> Data

- (NSData*)encrypt:(NSData*)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 Module)

Encrypts a file.

Syntax

• Swift
• Objective-C

public func encryptFile(sourceFile: String, destFile: String) throws -> Void

- (void)encryptFile:(NSString*)sourceFile :(NSString*)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 Module)

Finalization of encryption by blocks.

Syntax

• Swift
• Objective-C

public func encryptFinal() throws -> Data

- (NSData*)encryptFinal;

Remarks

Use this method to finalize of encryption by blocks.

Specify encryption key in Key property.

EncryptInit Method (SymmetricCrypto Module)

Initializes a per-block encryption process.

Syntax

• Swift
• Objective-C

public func encryptInit() throws -> Void

- (void)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 Module)

Encrypts the next block of data.

Syntax

• Swift
• Objective-C

public func encryptUpdate(buffer: Data) throws -> Data

- (NSData*)encryptUpdate:(NSData*)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 Module)

Resets the component settings.

Syntax

• Swift
• Objective-C

public func reset() throws -> Void

- (void)reset;

Remarks

Reset is a generic method available in every class.

Error Event (SymmetricCrypto Module)

Reports errors during encryption or decryption.

Syntax

• Swift
• Objective-C

func onError(errorCode: Int32, description: String)

- (void)onError:(int)errorCode :(NSString*)description;

Remarks

class 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 Module)

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

Syntax

• Swift
• Objective-C

func onNotification(eventID: String, eventParam: String)

- (void)onNotification:(NSString*)eventID :(NSString*)eventParam;

Remarks

The class fires this event to let the application know about some event, occurrence, or milestone in the class. 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 class, the exact action it is performing, or the document being processed, one or both may be omitted.

Progress Event (SymmetricCrypto Module)

Reports the data encryption/decryption progress.

Syntax

• Swift
• Objective-C

func onProgress(total: Int64, current: Int64, cancel: inout Bool)

- (void)onProgress:(long long)total :(long long)current :(int*)cancel;

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.

CryptoKey Type

This container represents a cryptographic key.

Remarks

This type is a universal placeholder for cryptographic keys.

Fields

Constructors

public init()

Config Settings (SymmetricCrypto Module)

SymmetricCrypto Config Settings

Base Config Settings

Trappable Errors (SymmetricCrypto Module)

SymmetricCrypto Errors