IPWorks Encrypt 2022 Python Edition
Version 22.0 [Build 8369]

Elgamal Class

Properties   Methods   Events   Config Settings   Errors  

Encrypt and decrypt data with the Elgamal asymmetric key encryption algorithm for public-key cryptography.

Syntax

class ipworksencrypt.Elgamal

Remarks

The ElGamal class is used to encrypt/decrypt data with the Elgamal asymmetric key encryption algorithm for public-key cryptography.

To begin you must either specify an existing key or create a new key. Existing public or private keys may be specified by setting the Key* properties. To create a new key pair call create_key.

After specifying a key, specify the data you wish to encrypt or decrypt. Call the encrypt or decrypt method to perform the operation.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

An Elgamal key is made up of a number of individual parameters.

The public key consists of the following parameters:

The class also includes the key_public_key property which holds the PEM formatted public key for ease of use. This is helpful if you are in control of both signature creation and verification process. When sending the public key to a recipient note that not all implementations will support using the PEM formatted value in key_public_key in which case the individual parameters must be sent.

The private key consists of the following parameters:

The class also include the key_private_key property which holds the PEM formatted private key for ease of use. This is helpful for storing the private key more easily.

Property List


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

input_fileThe file to process.
input_messageThe message to process.
keygRepresents the G parameter for the Elgamal algorithm.
keypRepresents the P parameter for the Elgamal algorithm.
key_private_keyThis property is a PEM formatted private key.
key_public_keyThis property is a PEM formatted public key.
keyxRepresents the X parameter for the Elgamal algorithm.
keyyRepresents the Y parameter for the Elgamal algorithm.
output_fileThe output file when encrypting or decrypting.
output_messageThe output message after processing.
overwriteIndicates whether or not the class should overwrite files.
recipient_keygRepresents the G parameter for the Elgamal algorithm.
recipient_keypRepresents the P parameter for the Elgamal algorithm.
recipient_key_public_keyThis property is a PEM formatted public key.
recipient_keyyRepresents the Y parameter for the Elgamal algorithm.
use_hexWhether input or output is hex encoded.

Method List


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

configSets or retrieves a configuration setting.
create_keyCreates a new key.
decryptDecrypts the input data using the specified private key.
encryptEncrypts the input data using the recipient's public key.
resetResets the class.

Event List


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

on_errorInformation about errors during data delivery.

Config Settings


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

KeySizeThe size, in bits, of the secret key.
BuildInfoInformation about the product's build.
CodePageThe system code page used for Unicode to Multibyte translations.
LicenseInfoInformation about the current license.
ProcessIdleEventsWhether the class uses its internal event loop to process events when the main thread is idle.
SelectWaitMillisThe length of time in milliseconds the class will wait when DoEvents is called if there are no events to process.
UseInternalSecurityAPITells the class whether or not to use the system security libraries or an internal implementation.

input_file Property

The file to process.

Syntax

def get_input_file() -> str: ...
def set_input_file(value: str) -> None: ...

input_file = property(get_input_file, set_input_file)

Default Value

""

Remarks

This property specifies the file to be processed. Set this property to the full or relative path to the file which will be processed.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

input_message Property

The message to process.

Syntax

def get_input_message() -> bytes: ...
def set_input_message(value: bytes) -> None: ...

input_message = property(get_input_message, set_input_message)

Default Value

""

Remarks

This property specifies the message to be processed.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

keyg Property

Represents the G parameter for the Elgamal algorithm.

Syntax

def get_keyg() -> bytes: ...
def set_keyg(value: bytes) -> None: ...

keyg = property(get_keyg, set_keyg)

Default Value

""

Remarks

Represents the G parameter for the Elgamal algorithm.

keyp Property

Represents the P parameter for the Elgamal algorithm.

Syntax

def get_keyp() -> bytes: ...
def set_keyp(value: bytes) -> None: ...

keyp = property(get_keyp, set_keyp)

Default Value

""

Remarks

Represents the P parameter for the Elgamal algorithm.

key_private_key Property

This property is a PEM formatted private key.

Syntax

def get_key_private_key() -> str: ...
def set_key_private_key(value: str) -> None: ...

key_private_key = property(get_key_private_key, set_key_private_key)

Default Value

""

Remarks

This property is a PEM formatted private key. The purpose of this property is to allow easier management of the private key parameters by using only a single value.

key_public_key Property

This property is a PEM formatted public key.

Syntax

def get_key_public_key() -> str: ...
def set_key_public_key(value: str) -> None: ...

key_public_key = property(get_key_public_key, set_key_public_key)

Default Value

""

Remarks

This property is a PEM formatted public key. The purpose of this property is to allow easier management of the public key parameters by using only a single value.

keyx Property

Represents the X parameter for the Elgamal algorithm.

Syntax

def get_keyx() -> bytes: ...
def set_keyx(value: bytes) -> None: ...

keyx = property(get_keyx, set_keyx)

Default Value

""

Remarks

Represents the X parameter for the Elgamal algorithm.

keyy Property

Represents the Y parameter for the Elgamal algorithm.

Syntax

def get_keyy() -> bytes: ...
def set_keyy(value: bytes) -> None: ...

keyy = property(get_keyy, set_keyy)

Default Value

""

Remarks

Represents the Y parameter for the Elgamal algorithm.

output_file Property

The output file when encrypting or decrypting.

Syntax

def get_output_file() -> str: ...
def set_output_file(value: str) -> None: ...

output_file = property(get_output_file, set_output_file)

Default Value

""

Remarks

This property specifies the file to which the output will be written when encrypt or decrypt is called. This may be set to an absolute or relative path.

This property is only applicable to encrypt and decrypt.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

  • output_file
  • output_message: The output data is written to this property if no other destination is specified.

output_message Property

The output message after processing.

Syntax

def get_output_message() -> bytes: ...

output_message = property(get_output_message, None)

Default Value

""

Remarks

This property will be populated with the output from the operation if output_file is not set.

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

  • output_file
  • output_message: The output data is written to this property if no other destination is specified.

This property is read-only.

overwrite Property

Indicates whether or not the class should overwrite files.

Syntax

def get_overwrite() -> bool: ...
def set_overwrite(value: bool) -> None: ...

overwrite = property(get_overwrite, set_overwrite)

Default Value

FALSE

Remarks

This property indicates whether or not the class will overwrite output_file. If overwrite is False, an error will be thrown whenever output_file exists before an operation. The default value is False.

recipient_keyg Property

Represents the G parameter for the Elgamal algorithm.

Syntax

def get_recipient_keyg() -> bytes: ...
def set_recipient_keyg(value: bytes) -> None: ...

recipient_keyg = property(get_recipient_keyg, set_recipient_keyg)

Default Value

""

Remarks

Represents the G parameter for the Elgamal algorithm.

recipient_keyp Property

Represents the P parameter for the Elgamal algorithm.

Syntax

def get_recipient_keyp() -> bytes: ...
def set_recipient_keyp(value: bytes) -> None: ...

recipient_keyp = property(get_recipient_keyp, set_recipient_keyp)

Default Value

""

Remarks

Represents the P parameter for the Elgamal algorithm.

recipient_key_public_key Property

This property is a PEM formatted public key.

Syntax

def get_recipient_key_public_key() -> str: ...
def set_recipient_key_public_key(value: str) -> None: ...

recipient_key_public_key = property(get_recipient_key_public_key, set_recipient_key_public_key)

Default Value

""

Remarks

This property is a PEM formatted public key. The purpose of this property is to allow easier management of the public key parameters by using only a single value.

recipient_keyy Property

Represents the Y parameter for the Elgamal algorithm.

Syntax

def get_recipient_keyy() -> bytes: ...
def set_recipient_keyy(value: bytes) -> None: ...

recipient_keyy = property(get_recipient_keyy, set_recipient_keyy)

Default Value

""

Remarks

Represents the Y parameter for the Elgamal algorithm.

use_hex Property

Whether input or output is hex encoded.

Syntax

def get_use_hex() -> bool: ...
def set_use_hex(value: bool) -> None: ...

use_hex = property(get_use_hex, set_use_hex)

Default Value

FALSE

Remarks

This property specifies whether the encrypted data is hex encoded.

If set to True, when encrypt is called the class will perform the encryption as normal and then hex encode the output. output_message or output_file will hold hex encoded data.

If set to True, when decrypt is called the class will expect input_message or input_file to hold hex encoded data. The class will then hex decode the data and perform decryption as normal.

config Method

Sets or retrieves a configuration setting.

Syntax

def config(configuration_string: str) -> str: ...

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.

create_key Method

Creates a new key.

Syntax

def create_key() -> None: ...

Remarks

This method creates a new public and private key.

When calling create_key the Key* properties are populated with a new private and public key.

An Elgamal key is made up of a number of individual parameters.

The public key consists of the following parameters:

The class also includes the key_public_key property which holds the PEM formatted public key for ease of use. This is helpful if you are in control of both signature creation and verification process. When sending the public key to a recipient note that not all implementations will support using the PEM formatted value in key_public_key in which case the individual parameters must be sent.

The private key consists of the following parameters:

The class also include the key_private_key property which holds the PEM formatted private key for ease of use. This is helpful for storing the private key more easily.

decrypt Method

Decrypts the input data using the specified private key.

Syntax

def decrypt() -> None: ...

Remarks

This method decrypts the input data using the private key specified in the Key* properties. Alternatively, a certificate may be specified by setting certificate

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

Key Size and the Maximum Length of Data

RSA has an upper limit to the amount of data that can be encrypted or decrypted, also known as message length. This can typically be calculated as the size of the key minus the size of the RSA header and padding.

When not using OAEP, the following formula and table can be referenced. (RSA Key Bytes) - (Header Bytes) = Length of data, where Header Bytes is always 11.

RSA Key Length (bits)Length (bits)Length (bytes)
1024 936 117
2048 1960 245
3072 2984 373
4096 4008 501

When using OAEP, the following formula and table can be referenced. (RSA Key Bytes) - (2 * Hash Length Bytes) - 2 = Length of data. The table below assumes SHA-256 for the hash, so Hash Length Bytes is 32.

RSA Key Length (bits)Length (bits)Length (bytes)
1024 496 62
2048 1520 190
3072 2544 318
4096 3568 446

encrypt Method

Encrypts the input data using the recipient's public key.

Syntax

def encrypt() -> None: ...

Remarks

This method encrypts the input data using the public key specified in the RecipientKey* properties. Alternatively, a certificate may be specified by setting recipient_cert

Input and Output Properties

The class will determine the source and destination of the input and output based on which properties are set.

The order in which the input properties are checked is as follows:

When a valid source is found the search stops. The order in which the output properties are checked is as follows:

Key Size and the Maximum Length of Data

RSA has an upper limit to the amount of data that can be encrypted or decrypted, also known as message length. This can typically be calculated as the size of the key minus the size of the RSA header and padding.

When not using OAEP, the following formula and table can be referenced. (RSA Key Bytes) - (Header Bytes) = Length of data, where Header Bytes is always 11.

RSA Key Length (bits)Length (bits)Length (bytes)
1024 936 117
2048 1960 245
3072 2984 373
4096 4008 501

When using OAEP, the following formula and table can be referenced. (RSA Key Bytes) - (2 * Hash Length Bytes) - 2 = Length of data. The table below assumes SHA-256 for the hash, so Hash Length Bytes is 32.

RSA Key Length (bits)Length (bits)Length (bytes)
1024 496 62
2048 1520 190
3072 2544 318
4096 3568 446

reset Method

Resets the class.

Syntax

def reset() -> None: ...

Remarks

When called, the class will reset all of its properties to their default values.

on_error Event

Information about errors during data delivery.

Syntax

class ElgamalErrorEventParams(object):
  @property
  def error_code() -> int: ...

  @property
  def description() -> str: ...

# In class Elgamal:
@property
def on_error() -> Callable[[ElgamalErrorEventParams], None]: ...
@on_error.setter
def on_error(event_hook: Callable[[ElgamalErrorEventParams], None]) -> None: ...

Remarks

The on_error event is fired in case of exceptional conditions during message processing. Normally the class fails with an error.

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 Error Codes section.

Elgamal Config Settings

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

Elgamal Config Settings

KeySize:   The size, in bits, of the secret key.

This specifies the size, in bits, of the secret key. The minimum key size for Elgamal is 512. The maximum key size is 4096. Note that large values such as 4096 will impact performance. The default value is 1024.

Base Config Settings

BuildInfo:   Information about the product's build.

When queried, this setting will return a string containing information about the product's build.

CodePage:   The system code page used for Unicode to Multibyte translations.

The default code page is Unicode UTF-8 (65001).

The following is a list of valid code page identifiers:

IdentifierName
037IBM EBCDIC - U.S./Canada
437OEM - United States
500IBM EBCDIC - International
708Arabic - ASMO 708
709Arabic - ASMO 449+, BCON V4
710Arabic - Transparent Arabic
720Arabic - Transparent ASMO
737OEM - Greek (formerly 437G)
775OEM - Baltic
850OEM - Multilingual Latin I
852OEM - Latin II
855OEM - Cyrillic (primarily Russian)
857OEM - Turkish
858OEM - Multilingual Latin I + Euro symbol
860OEM - Portuguese
861OEM - Icelandic
862OEM - Hebrew
863OEM - Canadian-French
864OEM - Arabic
865OEM - Nordic
866OEM - Russian
869OEM - Modern Greek
870IBM EBCDIC - Multilingual/ROECE (Latin-2)
874ANSI/OEM - Thai (same as 28605, ISO 8859-15)
875IBM EBCDIC - Modern Greek
932ANSI/OEM - Japanese, Shift-JIS
936ANSI/OEM - Simplified Chinese (PRC, Singapore)
949ANSI/OEM - Korean (Unified Hangul Code)
950ANSI/OEM - Traditional Chinese (Taiwan; Hong Kong SAR, PRC)
1026IBM EBCDIC - Turkish (Latin-5)
1047IBM EBCDIC - Latin 1/Open System
1140IBM EBCDIC - U.S./Canada (037 + Euro symbol)
1141IBM EBCDIC - Germany (20273 + Euro symbol)
1142IBM EBCDIC - Denmark/Norway (20277 + Euro symbol)
1143IBM EBCDIC - Finland/Sweden (20278 + Euro symbol)
1144IBM EBCDIC - Italy (20280 + Euro symbol)
1145IBM EBCDIC - Latin America/Spain (20284 + Euro symbol)
1146IBM EBCDIC - United Kingdom (20285 + Euro symbol)
1147IBM EBCDIC - France (20297 + Euro symbol)
1148IBM EBCDIC - International (500 + Euro symbol)
1149IBM EBCDIC - Icelandic (20871 + Euro symbol)
1200Unicode UCS-2 Little-Endian (BMP of ISO 10646)
1201Unicode UCS-2 Big-Endian
1250ANSI - Central European
1251ANSI - Cyrillic
1252ANSI - Latin I
1253ANSI - Greek
1254ANSI - Turkish
1255ANSI - Hebrew
1256ANSI - Arabic
1257ANSI - Baltic
1258ANSI/OEM - Vietnamese
1361Korean (Johab)
10000MAC - Roman
10001MAC - Japanese
10002MAC - Traditional Chinese (Big5)
10003MAC - Korean
10004MAC - Arabic
10005MAC - Hebrew
10006MAC - Greek I
10007MAC - Cyrillic
10008MAC - Simplified Chinese (GB 2312)
10010MAC - Romania
10017MAC - Ukraine
10021MAC - Thai
10029MAC - Latin II
10079MAC - Icelandic
10081MAC - Turkish
10082MAC - Croatia
12000Unicode UCS-4 Little-Endian
12001Unicode UCS-4 Big-Endian
20000CNS - Taiwan
20001TCA - Taiwan
20002Eten - Taiwan
20003IBM5550 - Taiwan
20004TeleText - Taiwan
20005Wang - Taiwan
20105IA5 IRV International Alphabet No. 5 (7-bit)
20106IA5 German (7-bit)
20107IA5 Swedish (7-bit)
20108IA5 Norwegian (7-bit)
20127US-ASCII (7-bit)
20261T.61
20269ISO 6937 Non-Spacing Accent
20273IBM EBCDIC - Germany
20277IBM EBCDIC - Denmark/Norway
20278IBM EBCDIC - Finland/Sweden
20280IBM EBCDIC - Italy
20284IBM EBCDIC - Latin America/Spain
20285IBM EBCDIC - United Kingdom
20290IBM EBCDIC - Japanese Katakana Extended
20297IBM EBCDIC - France
20420IBM EBCDIC - Arabic
20423IBM EBCDIC - Greek
20424IBM EBCDIC - Hebrew
20833IBM EBCDIC - Korean Extended
20838IBM EBCDIC - Thai
20866Russian - KOI8-R
20871IBM EBCDIC - Icelandic
20880IBM EBCDIC - Cyrillic (Russian)
20905IBM EBCDIC - Turkish
20924IBM EBCDIC - Latin-1/Open System (1047 + Euro symbol)
20932JIS X 0208-1990 & 0121-1990
20936Simplified Chinese (GB2312)
21025IBM EBCDIC - Cyrillic (Serbian, Bulgarian)
21027Extended Alpha Lowercase
21866Ukrainian (KOI8-U)
28591ISO 8859-1 Latin I
28592ISO 8859-2 Central Europe
28593ISO 8859-3 Latin 3
28594ISO 8859-4 Baltic
28595ISO 8859-5 Cyrillic
28596ISO 8859-6 Arabic
28597ISO 8859-7 Greek
28598ISO 8859-8 Hebrew
28599ISO 8859-9 Latin 5
28605ISO 8859-15 Latin 9
29001Europa 3
38598ISO 8859-8 Hebrew
50220ISO 2022 Japanese with no halfwidth Katakana
50221ISO 2022 Japanese with halfwidth Katakana
50222ISO 2022 Japanese JIS X 0201-1989
50225ISO 2022 Korean
50227ISO 2022 Simplified Chinese
50229ISO 2022 Traditional Chinese
50930Japanese (Katakana) Extended
50931US/Canada and Japanese
50933Korean Extended and Korean
50935Simplified Chinese Extended and Simplified Chinese
50936Simplified Chinese
50937US/Canada and Traditional Chinese
50939Japanese (Latin) Extended and Japanese
51932EUC - Japanese
51936EUC - Simplified Chinese
51949EUC - Korean
51950EUC - Traditional Chinese
52936HZ-GB2312 Simplified Chinese
54936Windows XP: GB18030 Simplified Chinese (4 Byte)
57002ISCII Devanagari
57003ISCII Bengali
57004ISCII Tamil
57005ISCII Telugu
57006ISCII Assamese
57007ISCII Oriya
57008ISCII Kannada
57009ISCII Malayalam
57010ISCII Gujarati
57011ISCII Punjabi
65000Unicode UTF-7
65001Unicode UTF-8

The following is a list of valid code page identifiers for Mac OS only:

IdentifierName
1ASCII
2NEXTSTEP
3JapaneseEUC
4UTF8
5ISOLatin1
6Symbol
7NonLossyASCII
8ShiftJIS
9ISOLatin2
10Unicode
11WindowsCP1251
12WindowsCP1252
13WindowsCP1253
14WindowsCP1254
15WindowsCP1250
21ISO2022JP
30MacOSRoman
10UTF16String
0x90000100UTF16BigEndian
0x94000100UTF16LittleEndian
0x8c000100UTF32String
0x98000100UTF32BigEndian
0x9c000100UTF32LittleEndian
65536Proprietary

LicenseInfo:   Information about the current license.

When queried, this setting will return a string containing information about the license this instance of a class is using. It will return the following information:

  • Product: The product the license is for.
  • Product Key: The key the license was generated from.
  • License Source: Where the license was found (e.g., RuntimeLicense, License File).
  • License Type: The type of license installed (e.g., Royalty Free, Single Server).
  • Last Valid Build: The last valid build number for which the license will work.
ProcessIdleEvents:   Whether the class uses its internal event loop to process events when the main thread is idle.

If set to False, the class will not fire internal idle events. Set this to False to use the class in a background thread on Mac OS. By default, this setting is True.

SelectWaitMillis:   The length of time in milliseconds the class will wait when DoEvents is called if there are no events to process.

If there are no events to process when do_events is called, the class will wait for the amount of time specified here before returning. The default value is 20.

UseInternalSecurityAPI:   Tells the class whether or not to use the system security libraries or an internal implementation.

By default the class will use the system security libraries to perform cryptographic functions where applicable. Setting this to True tells the class to use the internal implementation instead of using the system's security API.

Elgamal Errors

Elgamal Errors

102   No Key specified.
104   Cannot read or write file.
105   key parameters incorrect.
111   OutputFile already exists and Overwrite is False.
112   Invalid length of input message.
304   Cannot write file.
305   Cannot read file.
306   Cannot create file.
1301   Specified ElGamal parameters are invalid.
1302   Missing the data to encrypt/decrypt.
1303   Public key must be specified.
1304   Key must be specified.
1305   Invalid cipher length. The data may not have been encrypted with the public key corresponding to the specified private key data.
1306   Invalid cipher text. The data may not have been encrypted with the public key corresponding to the specified private key data.
1307   Inadequate padding. The data may not have been encrypted with the public key corresponding to the specified private key data.
1308   Missing delimiter. The data may not have been encrypted with the public key corresponding to the specified private key data.
1309   Message too long.

Copyright (c) 2022 /n software inc. - All rights reserved.
IPWorks Encrypt 2022 Python Edition - Version 22.0 [Build 8369]