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Version: 20 R5 BETA

CryptoKey

The CryptoKey class in the 4D language encapsulates an asymmetric encryption key pair.

This class is available from the 4D class store.

Example

The following sample code signs and verifies a message using a new ECDSA key pair, for example in order to make a ES256 JSON Web token.

 // Generate a new ECDSA key pair
$key:=4D.CryptoKey.new(New object("type";"ECDSA";"curve";"prime256v1"))

// Get signature as base64
$message:="hello world"
$signature:=$key.sign($message;New object("hash";"SHA256"))

// Verify signature
$status:=$key.verify($message;$signature;New object("hash";"SHA256"))
ASSERT($status.success)

Summary

4D.CryptoKey.new( settings : Object ) : 4D.CryptoKey
creates a new 4D.CryptoKey object encapsulating an encryption key pair
.curve : Text
normalised curve name of the key
.decrypt( message : Text ; options : Object ) : Object
decrypts the message parameter using the private key
.encrypt( message : Text ; options : Object ) : Text
encrypts the message parameter using the public key
.getPrivateKey() : Text
returns the private key of the CryptoKey object
.getPublicKey() : Text
returns the public key of the CryptoKey object
.sign (message : Text ; options : Object) : Text
signs the utf8 representation of a message string
.size : Integer
the size of the key in bits
.type : Text
name of the key type - "RSA", "ECDSA", "PEM"
.verify( message : Text ; signature : Text ; options : Object) : object
verifies the base64 signature against the utf8 representation of message

4D.CryptoKey.new()

History
ReleaseChanges
18 R4Added

4D.CryptoKey.new( settings : Object ) : 4D.CryptoKey

ParameterTypeDescription
settingsObject->Settings to generate or load a key pair
result4D.CryptoKey<-Object encapsulating an encryption key pair

The 4D.CryptoKey.new() function creates a new 4D.CryptoKey object encapsulating an encryption key pair, based upon the settings object parameter. It allows to generate a new RSA or ECDSA key, or to load an existing key pair from a PEM definition.

settings

PropertyTypeDescription
typetextDefines the type of the key to create:
  • "RSA": generates a RSA key pair, using .size as size.
  • "ECDSA": generates an Elliptic Curve Digital Signature Algorithm key pair, using .curve as curve. Note that ECDSA keys cannot be used for encryption but only for signature.
  • "PEM": loads a key pair definition in PEM format, using .pem.
  • curvetextName of ECDSA curve
    pemtextPEM definition of an encryption key to load
    sizeintegerSize of RSA key in bits

    CryptoKey

    The returned CryptoKey object encapsulates an encryption key pair. It is a shared object and can therefore be used by multiple 4D processes simultaneously.

    .curve

    History
    ReleaseChanges
    18 R4Added

    .curve : Text

    Defined only for ECDSA keys: the normalised curve name of the key. Usually "prime256v1" for ES256 (default), "secp384r1" for ES384, "secp521r1" for ES512.

    .decrypt()

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    18 R4Added

    .decrypt( message : Text ; options : Object ) : Object

    ParameterTypeDescription
    messageText->Message string to be decoded using options.encodingEncrypted and decrypted.
    optionsObject->Decoding options
    ResultObject<-Status

    The .decrypt() function decrypts the message parameter using the private key. The algorithm used depends on the type of the key.

    The key must be a RSA key, the algorithm is RSA-OAEP (see RFC 3447).

    options

    PropertyTypeDescription
    hashtextDigest algorithm to use. For example: "SHA256", "SHA384", or "SHA512".
    encodingEncryptedtextEncoding used to convert the message parameter into the binary representation to decrypt. Can be "Base64" or "Base64URL". Default is "Base64".
    encodingDecryptedtextEncoding used to convert the binary decrypted message into the result string. Can be "UTF-8", "Base64", or "Base64URL". Default is "UTF-8".

    Result

    The function returns a status object with success property set to true if the message could be successfully decrypted.

    PropertyTypeDescription
    successbooleanTrue if the message has been successfully decrypted
    resulttextMessage decrypted and decoded using the options.encodingDecrypted
    errorscollectionIf success is false, may contain a collection of errors

    In case the message couldn't be decrypted because it was not encrypted with the same key or algorithm, the status object being returned contains an error collection in status.errors.

    .encrypt()

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    18 R4Added

    .encrypt( message : Text ; options : Object ) : Text

    ParameterTypeDescription
    messageText->Message string to be encoded using options.encodingDecrypted and encrypted.
    optionsObject->Encoding options
    ResultText<-Message encrypted and encoded using the options.encodingEncrypted

    The .encrypt() function encrypts the message parameter using the public key. The algorithm used depends on the type of the key.

    The key must be a RSA key, the algorithm is RSA-OAEP (see RFC 3447).

    options
    PropertyTypeDescription
    hashtextDigest algorithm to use. For example: "SHA256", "SHA384", or "SHA512".
    encodingEncryptedtextEncoding used to convert the binary encrypted message into the result string. Can be "Base64", or "Base64URL". Default is "Base64".
    encodingDecryptedtextEncoding used to convert the message parameter into the binary representation to encrypt. Can be "UTF-8", "Base64", or "Base64URL". Default is "UTF-8".

    Result

    The returned value is an encrypted message.

    .getPrivateKey()

    History
    ReleaseChanges
    18 R4Added

    .getPrivateKey() : Text

    ParameterTypeDescription
    ResultText<-Private key in PEM format

    The .getPrivateKey() function returns the private key of the CryptoKey object in PEM format, or an empty string if none is available.

    Result

    The returned value is the private key.

    .getPublicKey()

    History
    ReleaseChanges
    18 R4Added

    .getPublicKey() : Text

    ParameterTypeDescription
    ResultText<-Public key in PEM format

    The .getPublicKey() function returns the public key of the CryptoKey object in PEM format, or an empty string if none is available.

    Result

    The returned value is the public key.


    .pem

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    18 R4Added

    .pem : Text

    PEM definition of an encryption key to load. If the key is a private key, the RSA or ECDSA public key will be deduced from it.

    .sign()

    History
    ReleaseChanges
    18 R4Added

    .sign (message : Text ; options : Object) : Text

    ParameterTypeDescription
    messageText->Message string to sign
    optionsObject->Signing options
    ResultText<-Signature in Base64 or Base64URL representation, depending on "encoding" option

    The .sign() function signs the utf8 representation of a message string using the CryptoKey object keys and provided options. It returns its signature in base64 or base64URL format, depending on the value of the options.encoding attribute you passed.

    The CryptoKey must contain a valid private key.

    options

    PropertyTypeDescription
    hashtextDigest algorithm to use. For example: "SHA256", "SHA384", or "SHA512". When used to produce a JWT, the hash size must match the PS@, ES@, RS@, or PS@ algorithm size
    encodingEncryptedtextEncoding used to convert the binary encrypted message into the result string. Can be "Base64", or "Base64URL". Default is "Base64".
    pssbooleanUse Probabilistic Signature Scheme (PSS). Ignored if the key is not an RSA key. Pass true when producing a JWT for PS@ algorithm
    encodingtextERepresentation to be used for result signature. Possible values: "Base64" or "Base64URL". Default is "Base64".

    Result

    The utf8 representation of the message string.

    .size

    History
    ReleaseChanges
    18 R4Added

    .size : Integer

    Defined only for RSA keys: the size of the key in bits. Typically 2048 (default).

    .type

    History
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    18 R4Added

    .type : Text

    Contains the name of the key type - "RSA", "ECDSA", "PEM" .

    • "RSA": an RSA key pair, using settings.size as .size.
    • "ECDSA": an Elliptic Curve Digital Signature Algorithm key pair, using settings.curve as .curve. Note that ECDSA keys cannot be used for encryption but only for signature.
    • "PEM": a key pair definition in PEM format, using settings.pem as .pem.

    .verify()

    History
    ReleaseChanges
    18 R4Added

    .verify( message : Text ; signature : Text ; options : Object) : object

    ParameterTypeDescription
    messageText->Message string that was used to produce the signature
    signatureText->Signature to verify, in Base64 or Base64URL representation, depending on options.encoding value
    optionsObject->Signing options
    ResultObject<-Status of the verification

    The .verify() function verifies the base64 signature against the utf8 representation of message using the CryptoKey object keys and provided options.

    The CryptoKey must contain a valid public key.

    options

    PropertyTypeDescription
    hashtextDigest algorithm to use. For example: "SHA256", "SHA384", or "SHA512". When used to produce a JWT, the hash size must match the PS@, ES@, RS@, or PS@ algorithm size
    pssbooleanUse Probabilistic Signature Scheme (PSS). Ignored if the key is not an RSA key. Pass true when verifying a JWT for PS@ algorithm
    encodingtextRepresentation of provided signature. Possible values are "Base64" or "Base64URL". Default is "Base64".

    Result

    The function returns a status object with success property set to true if message could be successfully verified (i.e. the signature matches).

    In case the signature couldn't be verified because it was not signed with the same message, key or algorithm, the status object being returned contains an error collection in status.errors.

    PropertyTypeDescription
    successbooleanTrue if the signature matches the message
    errorscollectionIf success is false, may contain a collection of errors