Struct secureblackbox::SymmetricCrypto

Properties   Methods   Events   Config Settings   Errors  

The SymmetricCrypto struct 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:

• encryption_algorithm, 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 ANSI X9.23).
• tag_size (for AEAD algorithms only).
• hash_algorithm and mac_algorithm (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 key_size property to learn the expected key length for the chosen encryption_algorithm.

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 encrypt_file.
• Encrypt a stream to a stream using encrypt_stream.
• Encrypt longer data chunk by chunk using a sequence of encrypt_init, encrypt_update, encrypt_update, ..., encrypt_update, encrypt_final calls.

If you are using an authenticated encryption algorithm that can take additional associated data (AEAD), you can provide that via the associated_data 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");

Object Lifetime

The new() method returns a mutable reference to a struct instance. The object itself is kept in the global list maintained by SecureBlackbox. Due to this, the SymmetricCrypto struct cannot be disposed of automatically. Please, call the dispose(&mut self) method of SymmetricCrypto when you have finished using the instance.

Property List

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

associated_data property (SymmetricCrypto Struct)

Provides Associated Data for AEAD algorithms.

Syntax

fn associated_data(&self ) -> Result<Vec<u8>, SecureBlackboxError> 
fn set_associated_data(&self, value : Vec<u8>) ->  Option<SecureBlackboxError> 
fn set_associated_data_ref(&self, value : &[u8]) ->  Option<SecureBlackboxError> 

Remarks

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

Data Type

Vec

block_size property (SymmetricCrypto Struct)

The block size of the chosen symmetric cipher.

Syntax

fn block_size(&self ) -> Result<i32, SecureBlackboxError> 

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

i32

encryption_algorithm property (SymmetricCrypto Struct)

The encryption algorithm to use for encrypting the data.

Syntax

fn encryption_algorithm(&self ) -> Result<String, SecureBlackboxError> 
fn set_encryption_algorithm(&self, value : &str) ->  Option<SecureBlackboxError> 
fn set_encryption_algorithm_ref(&self, value : &String) ->  Option<SecureBlackboxError> 

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

fips_mode property (SymmetricCrypto Struct)

Reserved.

Syntax

fn fips_mode(&self ) -> Result<bool, SecureBlackboxError> 
fn set_fips_mode(&self, value : bool) ->  Option<SecureBlackboxError> 

Default Value

false

Remarks

This property is reserved for future use.

Data Type

bool

hash_algorithm property (SymmetricCrypto Struct)

The hash algorithm to use during encryption.

Syntax

fn hash_algorithm(&self ) -> Result<String, SecureBlackboxError> 
fn set_hash_algorithm(&self, value : &str) ->  Option<SecureBlackboxError> 
fn set_hash_algorithm_ref(&self, value : &String) ->  Option<SecureBlackboxError> 

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

input_encoding property (SymmetricCrypto Struct)

The encoding to apply to the input data.

Syntax

fn input_encoding(&self ) -> Result<i32, SecureBlackboxError> 
fn set_input_encoding(&self, value : i32) ->  Option<SecureBlackboxError> 

Possible Values

0   // Default
1   // Binary
2   // Base64
3   // Compact
4   // JSON

Default Value

0

Remarks

Data Type

i32

key_handle property (SymmetricCrypto Struct)

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

Syntax

fn key_handle(&self ) -> Result<i64, SecureBlackboxError> 
fn set_key_handle(&self, value : i64) ->  Option<SecureBlackboxError> 

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());

Data Type

i64

key_size property (SymmetricCrypto Struct)

Returns the cryptographic key size in bytes.

Syntax

fn key_size(&self ) -> Result<i32, SecureBlackboxError> 

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

i32

mac_algorithm property (SymmetricCrypto Struct)

The (H)MAC algorithm to use during encryption.

Syntax

fn mac_algorithm(&self ) -> Result<String, SecureBlackboxError> 
fn set_mac_algorithm(&self, value : &str) ->  Option<SecureBlackboxError> 
fn set_mac_algorithm_ref(&self, value : &String) ->  Option<SecureBlackboxError> 

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 Struct)

Specifies the symmetric cipher mode of operation.

Syntax

fn mode(&self ) -> Result<i32, SecureBlackboxError> 
fn set_mode(&self, value : i32) ->  Option<SecureBlackboxError> 

Possible Values

0   // Default
1   // ECB
2   // CBC
3   // CTR
4   // CFB8
5   // GCM
6   // CCM
7   // Poly1305
8   // OCB

Default Value

0

Remarks

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

Data Type

i32

nonce property (SymmetricCrypto Struct)

Specifies the Nonce value to employ.

Syntax

fn nonce(&self ) -> Result<Vec<u8>, SecureBlackboxError> 
fn set_nonce(&self, value : Vec<u8>) ->  Option<SecureBlackboxError> 
fn set_nonce_ref(&self, value : &[u8]) ->  Option<SecureBlackboxError> 

Remarks

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

Data Type

Vec

output_encoding property (SymmetricCrypto Struct)

The encoding to apply to the output data.

Syntax

fn output_encoding(&self ) -> Result<i32, SecureBlackboxError> 
fn set_output_encoding(&self, value : i32) ->  Option<SecureBlackboxError> 

Possible Values

0   // Default
1   // Binary
2   // Base64
3   // Compact
4   // JSON

Default Value

0

Remarks

Data Type

i32

padding property (SymmetricCrypto Struct)

The padding type to apply to the encrypted data.

Syntax

fn padding(&self ) -> Result<i32, SecureBlackboxError> 
fn set_padding(&self, value : i32) ->  Option<SecureBlackboxError> 

Possible Values

0   // None
1   // PKCS5
2   // ANSIX923

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.

Data Type

i32

payload_size property (SymmetricCrypto Struct)

Specifies the payload size, in bytes.

Syntax

fn payload_size(&self ) -> Result<i32, SecureBlackboxError> 
fn set_payload_size(&self, value : i32) ->  Option<SecureBlackboxError> 

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

i32

stream_cipher property (SymmetricCrypto Struct)

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

Syntax

fn stream_cipher(&self ) -> Result<bool, SecureBlackboxError> 

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.

Data Type

bool

tag_size property (SymmetricCrypto Struct)

Specifies the AEAD tag size, in bytes.

Syntax

fn tag_size(&self ) -> Result<i32, SecureBlackboxError> 
fn set_tag_size(&self, value : i32) ->  Option<SecureBlackboxError> 

Default Value

16

Remarks

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

Data Type

i32

config method (SymmetricCrypto Struct)

Sets or retrieves a configuration setting.

Syntax

fn config(&self, configuration_string : &str) ->  Result<String, SecureBlackboxError>

Remarks

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

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

Decrypts a buffer.

Syntax

fn decrypt(&self, buffer : &[u8]) ->  Result<Vec<u8>, SecureBlackboxError>

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.

decrypt_file method (SymmetricCrypto Struct)

Decrypts a file.

Syntax

fn decrypt_file(&self, source_file : &str, dest_file : &str) -> Result<(), SecureBlackboxError>

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.

decrypt_final method (SymmetricCrypto Struct)

Finalization of decryption by blocks.

Syntax

fn decrypt_final(&self) ->  Result<Vec<u8>, SecureBlackboxError>

Remarks

Use this method to finalize of decryption by blocks.

Specify decryption key in key property.

decrypt_init method (SymmetricCrypto Struct)

Initializes a per-block decryption process.

Syntax

fn decrypt_init(&self) -> Result<(), SecureBlackboxError>

Remarks

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

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

decrypt_update method (SymmetricCrypto Struct)

Decrypts the next block of encrypted data.

Syntax

fn decrypt_update(&self, buffer : &[u8]) ->  Result<Vec<u8>, SecureBlackboxError>

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 decrypt_init before calling this method to prepare the control for the decryption process.

do_action method (SymmetricCrypto Struct)

Performs an additional action.

Syntax

fn do_action(&self, action_id : &str, action_params : &str) ->  Result<String, SecureBlackboxError>

Remarks

do_action is a generic method available in every struct. 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 Struct)

Encrypts a buffer.

Syntax

fn encrypt(&self, buffer : &[u8]) ->  Result<Vec<u8>, SecureBlackboxError>

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 (encrypt_init, encrypt_update, encrypt_final).

encrypt_file method (SymmetricCrypto Struct)

Encrypts a file.

Syntax

fn encrypt_file(&self, source_file : &str, dest_file : &str) -> Result<(), SecureBlackboxError>

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.

encrypt_final method (SymmetricCrypto Struct)

Finalization of encryption by blocks.

Syntax

fn encrypt_final(&self) ->  Result<Vec<u8>, SecureBlackboxError>

Remarks

Use this method to finalize of encryption by blocks.

Specify encryption key in key property.

encrypt_init method (SymmetricCrypto Struct)

Initializes a per-block encryption process.

Syntax

fn encrypt_init(&self) -> Result<(), SecureBlackboxError>

Remarks

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

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

encrypt_update method (SymmetricCrypto Struct)

Encrypts the next block of data.

Syntax

fn encrypt_update(&self, buffer : &[u8]) ->  Result<Vec<u8>, SecureBlackboxError>

Remarks

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

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

reset method (SymmetricCrypto Struct)

Resets the struct settings.

Syntax

fn reset(&self) -> Result<(), SecureBlackboxError>

Remarks

reset is a generic method available in every struct.

on_error event (SymmetricCrypto Struct)

Reports errors during encryption or decryption.

Syntax

// SymmetricCryptoErrorEventArgs carries the SymmetricCrypto Error event's parameters.
pub struct SymmetricCryptoErrorEventArgs {
  fn error_code(&self) -> i32
  fn description(&self) -> &String
}

// SymmetricCryptoErrorEvent defines the signature of the SymmetricCrypto Error event's handler function.
pub trait SymmetricCryptoErrorEvent {
  fn on_error(&self, sender : SymmetricCrypto, e : &mut SymmetricCryptoErrorEventArgs);
}

impl <'a> SymmetricCrypto<'a> {
  pub fn on_error(&self) -> &'a dyn SymmetricCryptoErrorEvent;
  pub fn set_on_error(&mut self, value : &'a dyn SymmetricCryptoErrorEvent);
  ...
}

Remarks

struct 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.

on_notification event (SymmetricCrypto Struct)

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

Syntax

// SymmetricCryptoNotificationEventArgs carries the SymmetricCrypto Notification event's parameters.
pub struct SymmetricCryptoNotificationEventArgs {
  fn event_id(&self) -> &String
  fn event_param(&self) -> &String
}

// SymmetricCryptoNotificationEvent defines the signature of the SymmetricCrypto Notification event's handler function.
pub trait SymmetricCryptoNotificationEvent {
  fn on_notification(&self, sender : SymmetricCrypto, e : &mut SymmetricCryptoNotificationEventArgs);
}

impl <'a> SymmetricCrypto<'a> {
  pub fn on_notification(&self) -> &'a dyn SymmetricCryptoNotificationEvent;
  pub fn set_on_notification(&mut self, value : &'a dyn SymmetricCryptoNotificationEvent);
  ...
}

Remarks

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

on_progress event (SymmetricCrypto Struct)

Reports the data encryption/decryption progress.

Syntax

// SymmetricCryptoProgressEventArgs carries the SymmetricCrypto Progress event's parameters.
pub struct SymmetricCryptoProgressEventArgs {
  fn total(&self) -> i64
  fn current(&self) -> i64
  fn cancel(&self) -> bool
  fn set_cancel(&self, value : bool)
}

// SymmetricCryptoProgressEvent defines the signature of the SymmetricCrypto Progress event's handler function.
pub trait SymmetricCryptoProgressEvent {
  fn on_progress(&self, sender : SymmetricCrypto, e : &mut SymmetricCryptoProgressEventArgs);
}

impl <'a> SymmetricCrypto<'a> {
  pub fn on_progress(&self) -> &'a dyn SymmetricCryptoProgressEvent;
  pub fn set_on_progress(&mut self, value : &'a dyn SymmetricCryptoProgressEvent);
  ...
}

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 Struct)

The struct 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 struct, access to these internal properties is provided through the config method.

SymmetricCrypto Config Settings

Base Config Settings

Trappable Errors (SymmetricCrypto Struct)

SymmetricCrypto Errors