JWE Class

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Create, Encrypt and Decrypt JSON Web Encryption (JWE) messages.

Syntax

ipworksencrypt.Jwe

Remarks

The JWE class supports encrypting and decrypting JSON Web Encryption (JWE) messages.

Specify any payload via input properties and use Encrypt to create a JWE message using a variety of algorithms including ECDH, RSA, and AES. Use Decrypt to decrypt the payload of any received JWE message. The following algorithms are supported:

• RSA1_5
• RSA-OAEP
• RSA-OAEP-256
• A128KW
• A192KW
• A256KW
• dir
• ECDH-ES
• ECDH-ES+A128KW
• ECDH-ES+A192KW
• ECDH-ES+A256KW
• A128GCMKW
• A192GCMKW
• A256GCMKW
• PBES2-HS256+A128KW
• PBES2-HS384+A192KW
• PBES2-HS512+A256KW

See EncryptionAlgorithm for more details about supported algorithms.

Encrypting

The Encrypt method may be used to encrypt a payload with a variety of algorithms. JSON Web Encryption (JWE) is performed by first generating a random key used to encrypt the content. The content encryption key is used to encrypt the content using the algorithm specified by ContentEncryptionAlgorithm. The content encryption key is then encrypted itself using the algorithm specified by EncryptionAlgorithm. The content encryption key is not directly exposed in the API as it is randomly generated.

After calling this method the compact serialized JWE string is written to the specified output location. For instance:

eyJhbGciOiJBMjU2R0NNS1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2IiwiaXYiOiJMa0tNeTZ5Qlpfbzh6QW92IiwidGFnIjoiSmpMTkRsV3l3bWt3V2pMa0NLU0xxQSJ9.wiwySYm6fXZre-3IdT1tb_02KMQDrMICwUawVf7Gjhc.k84s7ne8J41QnA5BQ31k_A.kjIveRjjNYV4x92CVE9Agw.uAygkyeO2KWeFQIy9JLU0A

The class is agnostic of the payload that is encrypted. Any value may be encrypted. KeyId may be set to include an identifier to help the receiving party identify the key or certificate used to encrypt the data. The following properties are applicable when calling this method:

• EncryptionAlgorithm (required)
• Key (conditional - required for AES)
• KeyPassword (conditional - required for PBES)
• Certificate (conditional - required for ECDH and RSA)
• ContentEncryptionAlgorithm
• CompressionAlgorithm
• HeaderParams
• Overwrite

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:

• SetInputStream
• InputFile
• InputMessage

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

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Notes for AES Algorithms (A128KW, A192KW, A256KW, A128GCMKW, A192GCMKW, A256GCMKW)

When EncryptionAlgorithm is set to a AES algorithm Key must be set to a key of appropriate length for the algorithm. For instance a 256 bit key would be used for A256KW.

The example below uses the EzRand class to generate a key, but the key may be created using any method. The key must be known by both parties in order for encryption and decryption to take place.

//Generate a 256 bit (32 byte) key Ezrand rand = new Ezrand(); rand.RandBytesLength = 32; rand.GetNextBytes(); byte[] key = rand.RandBytesB; //Encrypt the payload using A256KW Jwe jwe = new Jwe(); jwe.KeyB = key; jwe.InputMessage = "test data"; jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaA256KW; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

To use an existing AES key provide the bytes to the Key property. For instance:

byte[] key = new byte[] { 164, 60, 194, 0, 161, 189, 41, 38, 130, 89, 141, 164, 45, 170, 159, 209, 69, 137, 243, 216, 191, 131, 47, 250, 32, 107, 231, 117, 37, 158, 225, 234 }; //Encrypt the payload using A256KW Jwe jwe = new Jwe(); jwe.KeyB = key; jwe.InputMessage = "test data"; jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaA256KW; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

Notes for RSA Algorithms (RSA1_5, RSA-OEAP, RSA-OAEP-256)

The RSA based algorithms use asymmetric encryption. Encrypting is done with a public key and decryption is done with a private key. The public certificate should be in PEM (base64) format. For instance:

Jwe jwe = new Jwe(); jwe.Certificate = new Certificate("..\\recipient.cer"); jwe.InputMessage = "test data"; jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaRSA_OAEP; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

Notes for ECDH Algorithms (ECDH-ES, ECDH-ES+A128KW, ECDH-ES+A192KW, ECDH-ES+A256KW)

ECDH algorithms require a valid ECC public key to encrypt the message. If the key was originally created with the ECC class the PEM encoded PublicKey may be used directly with the Certificate property. An example PEM encoded public certificate created by the ECC component:

-----BEGIN PUBLIC KEY-----
MIIBMjCB7AYHKoZIzj0CATCB4AIBATAsBgcqhkjOPQEBAiEA/////wAAAAEAAAAAAAAAAAAA
AAD///////////////8wRAQg/////wAAAAEAAAAAAAAAAAAAAAD///////////////wEIFrG
NdiqOpPns+u9VXaYhrxlHQawzFOw9jvOPD4n0mBLBEEEaxfR8uEsQkf4vOblY6RA8ncDfYEt
6zOg9KE5RdiYwpZP40Li/hp/m47n60p8D54WK84zV2sxXs7LtkBoN79R9QIhAP////8AAAAA
//////////+85vqtpxeehPO5ysL8YyVRAgEBA0EEIC5rbLp11Mnz6cBXLLriaDIov3rm8RAY
x/OR0bOKiff0cQy+sLVaxjseqFk/+Xvl4ORSv5Z6HdHv5GyEpA0UoA==
-----END PUBLIC KEY-----

Jwe jwe = new Jwe(); jwe.Certificate = new Certificate(CertStoreTypes.cstPublicKeyFile, pubKeyFile, "", "*"); jwe.InputMessage = "test data"; jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaECDH_ES_A256KW; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

To use an ECC public key created by other means the ECC class may be used to import the key parameters. Populate the Rx and Ry properties of the ECC component first to obtain the PEM formatted public key. For instance:

byte[] x_bytes = new byte[] { 171, 170, 196, 151, 94, 196, 231, 12, 128, 232, 17, 61, 45, 105, 41, 209, 192, 187, 112, 242, 110, 178, 95, 240, 36, 55, 83, 171, 190, 176, 78, 13 }; byte[] y_bytes = new byte[] { 197, 75, 134, 245, 245, 28, 199, 9, 7, 117, 1, 54, 49, 178, 135, 252, 62, 89, 35, 180, 117, 80, 231, 23, 110, 250, 28, 124, 219, 253, 224, 156 }; Ecc ecc = new Ecc(); ecc.Key.RxB = x_bytes; ecc.Key.RyB = y_bytes; string pubKey = ecc.Key.PublicKey; Jwe jwe = new Jwe(); jwe.Certificate = new Certificate(CertStoreTypes.cstPublicKeyFile, pubKey, "", "*"); jwe.InputMessage = "test data"; jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaECDH_ES_A256KW; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

Notes for PBES Algorithms (PBES2-HS256+A128KW, PBES2-HS384+A192KW, PBES2-HS512+A256KW

PBES algorithms derive a content encryption key from the KeyPassword property. Set KeyPassword to a shared secret.

Jwe jwe = new Jwe(); jwe.KeyPassword = "secret"; jwe.InputMessage = "test data"; jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaPBES2_HS512_A256KW; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

Notes for Direct Shared Keys

When EncryptionAlgorithm is set to Direct the Key property must be set to a valid symmetric key that will be used directly by the ContentEncryptionAlgorithm. In this case a content encryption key is not generated randomly, the Key is used instead. The length of the specified Key must be valid for the selected ContentEncryptionAlgorithm. For instance:

//Generate a 256 bit (32 byte) key Ezrand rand = new Ezrand(); rand.RandBytesLength = 32; rand.GetNextBytes(); byte[] key = rand.RandBytesB; Jwe jwe = new Jwe(); jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaDir; jwe.ContentEncryptionAlgorithm = JweContentEncryptionAlgorithms.ceaA256GCM; jwe.KeyB = key; jwe.InputMessage = "test data"; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

Decrypting

The Decrypt method may be used to decrypt a received JWE message. Before calling the Decrypt method set InputMessage or InputFile to a valid compact serialized JWE string. For instance:

eyJhbGciOiJBMjU2R0NNS1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2IiwiaXYiOiJMa0tNeTZ5Qlpfbzh6QW92IiwidGFnIjoiSmpMTkRsV3l3bWt3V2pMa0NLU0xxQSJ9.wiwySYm6fXZre-3IdT1tb_02KMQDrMICwUawVf7Gjhc.k84s7ne8J41QnA5BQ31k_A.kjIveRjjNYV4x92CVE9Agw.uAygkyeO2KWeFQIy9JLU0A

The type and format of the private key depends on the algorithm used to encrypt the data. The following table summarizes the relationship:

If the correct Key or Certificate is not known ahead of time the KeyId parameter of the RecipientInfo event may be used to identify the correct key.

If this method returns without error decryption was successful. If decryption fails then this method throws an exception. After calling this method the payload will be present in the OutputMessage or file specified by OutputFile and the HeaderParams property will contain the headers. Headers of the parsed message are also available through the HeaderParam event.

The following properties are applicable when calling this method:

• Certificate (conditional - required for RSA and ECDH)
• Key (conditional - required for AES)
• ContentEncryptionAlgorithm (only if StrictValidation is True)
• EncryptionAlgorithm (only if StrictValidation is True)
• HeaderParams
• Overwrite
• StrictValidation

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:

• SetInputStream
• InputFile
• InputMessage

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

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Notes for AES Algorithms (A128KW, A192KW, A256KW, A128GCMKW, A192GCMKW, A256GCMKW)

To decrypt messages that use AES encryption Key must be set to a key of appropriate length for the algorithm. For instance a 256 bit key would be used for A256KW.

The key must be known by both parties in order for encryption and decryption to take place.

byte[] key = new byte[] { 164, 60, 194, 0, 161, 189, 41, 38, 130, 89, 141, 164, 45, 170, 159, 209, 69, 137, 243, 216, 191, 131, 47, 250, 32, 107, 231, 117, 37, 158, 225, 234 }; Jwe jwe = new Jwe(); jwe.KeyB = key; jwe.InputMessage = encryptedData; jwe.Decrypt(); string decryptedData = jwe.OutputMessage;

Notes for RSA Algorithms (RSA1_5, RSA-OEAP, RSA-OAEP-256)

The RSA based algorithms use asymmetric encryption. Encrypting is done with a public key and decryption is done with a private key. The certificate with private key must be specified. For instance:

Jwe jwe = new Jwe(); jwe.Certificate = new Certificate(CertStoreTypes.cstPFXFile, "..\\jwt.pfx", "password", "*"); jwe.InputMessage = encryptedData; jwe.Decrypt(); string decryptedData = jwe.OutputMessage;

Notes for ECDH Algorithms (ECDH-ES, ECDH-ES+A128KW, ECDH-ES+A192KW, ECDH-ES+A256KW)

ECDH algorithms require a valid ECC private key to decrypt the message. If the key was originally created with the ECC class the PEM encoded PrivateKey may be used directly with the Certificate property.

Jwe jwe = new Jwe(); jwe.Certificate = new Certificate(CertStoreTypes.cstPEMKeyFile, privKeyFile, "", "*"); jwe.InputMessage = encryptedData; jwe.Decrypt(); string decryptedData = jwe.OutputMessage;

To use an ECC private key created by other means the ECC class may be used to import the key parameters. Populate the Rx, Ry, and KB properties of the ECC component first to obtain the PEM formatted public key. For instance:

Ecc ecc = new Ecc(); byte[] x_bytes = new byte[] { 171, 170, 196, 151, 94, 196, 231, 12, 128, 232, 17, 61, 45, 105, 41, 209, 192, 187, 112, 242, 110, 178, 95, 240, 36, 55, 83, 171, 190, 176, 78, 13 }; byte[] y_bytes = new byte[] { 197, 75, 134, 245, 245, 28, 199, 9, 7, 117, 1, 54, 49, 178, 135, 252, 62, 89, 35, 180, 117, 80, 231, 23, 110, 250, 28, 124, 219, 253, 224, 156 }; byte[] k_bytes = new byte[] { 81, 65, 201, 24, 235, 249, 162, 148, 169, 150, 109, 181, 61, 238, 145, 122, 31, 30, 151, 94, 239, 90, 222, 217, 63, 103, 54, 2, 176, 232, 248, 168 }; ecc.Key.RxB = x_bytes; ecc.Key.RyB = y_bytes; ecc.Key.KB = k_bytes; string privKey = ecc.Key.PrivateKey; Jwe jwe = new Jwe(); jwe.Certificate = new Certificate(CertStoreTypes.cstPEMKeyBlob, privKey, "", "*"); jwe.InputMessage = encryptedData; jwe.Decrypt(); string decryptedData = jwe.OutputMessage;

Notes for PBES Algorithms (PBES2-HS256+A128KW, PBES2-HS384+A192KW, PBES2-HS512+A256KW

PBES algorithms derive a content encryption key from the KeyPassword property. Set KeyPassword to the shared secret.

Jwe jwe = new Jwe(); jwe.KeyPassword = "secret"; jwe.InputMessage = encryptedData; jwe.Decrypt(); string decryptedData = jwe.OutputMessage;

Notes for Direct Shared Keys

When Direct encryption is used the Key property must be set to a valid symmetric key that will be used directly by the ContentEncryptionAlgorithm. For instance:

byte[] key = new byte[] { 164, 60, 194, 0, 161, 189, 41, 38, 130, 89, 141, 164, 45, 170, 159, 209, 69, 137, 243, 216, 191, 131, 47, 250, 32, 107, 231, 117, 37, 158, 225, 234 }; Jwe jwe = new Jwe(); jwe.KeyB = key; jwe.InputMessage = encryptedData; jwe.Decrypt(); string decryptedData = jwe.OutputMessage;

Other Functionality

In addition to standard encrypting and decrypting the class also supports a variety of other features including:

• Adding custom header parameters with AddHeaderParam
• Enforcing algorithm restrictions when decrypting by setting StrictValidation
• Inspect the JWE headers without decrypting by calling Parse

Property List

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

Certificate Property (JWE Class)

The certificate used for encryption or decryption.

Syntax

public Certificate getCertificate();


public void setCertificate(Certificate certificate);

Remarks

This property specifies a certificate for encryption or decryption.

When calling Encrypt and EncryptionAlgorithm is set to an RSA or ECDH algorithm this property must be set to a public certificate of the recipient.

When calling Decrypt and the message was encrypted using an RSA or ECDH EncryptionAlgorithm this property specifies the certificate with private key used to decrypt the message.

Please refer to the Certificate type for a complete list of fields.

ContentEncryptionAlgorithm Property (JWE Class)

The algorithm used to encrypt the content.

Syntax

public int getContentEncryptionAlgorithm();


public void setContentEncryptionAlgorithm(int contentEncryptionAlgorithm);


Enumerated values:
  public final static int ceaA128CBC_HS256 = 0;
  public final static int ceaA192CBC_HS384 = 1;
  public final static int ceaA256CBC_HS512 = 2;
  public final static int ceaA128GCM = 3;
  public final static int ceaA192GCM = 4;
  public final static int ceaA256GCM = 5;

Default Value

0

Remarks

This property specifies the algorithm used to encrypt the content.

The following values are supported.

EncryptionAlgorithm Property (JWE Class)

The key encryption algorithm.

Syntax

public int getEncryptionAlgorithm();


public void setEncryptionAlgorithm(int encryptionAlgorithm);


Enumerated values:
  public final static int eaRSA1_5 = 0;
  public final static int eaRSA_OAEP = 1;
  public final static int eaRSA_OAEP_256 = 2;
  public final static int eaA128KW = 3;
  public final static int eaA192KW = 4;
  public final static int eaA256KW = 5;
  public final static int eaDir = 6;
  public final static int eaECDH_ES = 7;
  public final static int eaECDH_ES_A128KW = 8;
  public final static int eaECDH_ES_A192KW = 9;
  public final static int eaECDH_ES_A256KW = 10;
  public final static int eaA128GCMKW = 11;
  public final static int eaA192GCMKW = 12;
  public final static int eaA256GCMKW = 13;
  public final static int eaPBES2_HS256_A128KW = 14;
  public final static int eaPBES2_HS384_A192KW = 15;
  public final static int eaPBES2_HS512_A256KW = 16;

Default Value

0

Remarks

This property specifies the algorithm used to encrypt the randomly generated content encryption key.

When using an AES algorithm Key must be specified. When using an RSA or ECDH algorithm Certificate must be specified. When using a PBES algorithm KeyPassword must be specified;. Possible values are:

When set to an ECDH algorithm the following settings are also applicable:

• PartyUInfo
• PartyVInfo

When set to a PBES algorithm the following settings are also applicable:

• PBES2Count
• PBES2SaltLength

HeaderParams Property (JWE Class)

The JOSE header parameters.

Syntax

public HeaderParamList getHeaderParams();


public void setHeaderParams(HeaderParamList headerParams);

Remarks

This property specifies the JOSE header parameters. This may be populated before calling Sign or Encrypt. This is populated with the parsed header values after calling Verify, Decrypt, or Parse.

This property is not available at design time.

Please refer to the HeaderParam type for a complete list of fields.

InputFile Property (JWE Class)

The file to process.

Syntax

public String getInputFile();


public void setInputFile(String inputFile);

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:

• SetInputStream
• InputFile
• InputMessage

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

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

InputMessage Property (JWE Class)

The message to process.

Syntax

public byte[] getInputMessage();


public void setInputMessage(byte[] inputMessage);

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:

• SetInputStream
• InputFile
• InputMessage

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

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Key Property (JWE Class)

The secret key for the AES algorithm.

Syntax

public byte[] getKey();


public void setKey(byte[] key);

Default Value

""

Remarks

This property specifies the key used for AES encryption and decryption.

When EncryptionAlgorithm is set to an AES algorithm this property must hold the symmetric key used for encryption and decryption. The size of the key must match the size of the algorithm. For instance when selecting the algorithm A256GCMKW (AES 256) the size of the key must also be 256 bits (32 bytes).

In the case where EncryptionAlgorithm is set to Direct this key is used directly with the algorithm specified by ContentEncryptionAlgorithm and must be an appropriate size for the selected ContentEncryptionAlgorithm.

KeyId Property (JWE Class)

The Id of the key used to encrypt the message.

Syntax

public String getKeyId();


public void setKeyId(String keyId);

Default Value

""

Remarks

This property optionally specifies the Id of the key used to encrypt the message.

Any string value may be supplied here to help the other party identify the key used to encrypt the message. This may be set before calling the Encrypt method.

KeyPassword Property (JWE Class)

The key password used in the PBES algorithm.

Syntax

public String getKeyPassword();


public void setKeyPassword(String keyPassword);

Default Value

""

Remarks

This property specifies the key password used to derive a key when using a PBES EncryptionAlgorithm.

This is only applicable to PBES algorithms and must be set before calling Encrypt or Decrypt.

OutputFile Property (JWE Class)

The output file when encrypting or decrypting.

Syntax

public String getOutputFile();


public void setOutputFile(String outputFile);

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:

• SetInputStream
• InputFile
• InputMessage

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

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

OutputMessage Property (JWE Class)

The output message after processing.

Syntax

public byte[] getOutputMessage();

Default Value

""

Remarks

This property will be populated with the output from the operation if OutputFile and SetOutputStream are 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:

• SetInputStream
• InputFile
• InputMessage

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

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

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

Overwrite Property (JWE Class)

Indicates whether or not the class should overwrite files.

Syntax

public boolean isOverwrite();


public void setOverwrite(boolean overwrite);

Default Value

False

Remarks

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

AddHeaderParam Method (Jwe Class)

Adds additional header parameters.

Syntax

public void addHeaderParam(String name, String value, int dataType);

Remarks

This method is used to add additional header parameters before calling Encrypt.

The Name and Value parameters define the name and value of the parameter respectively. The DataType parameter specifies the JSON data type of the value. Possible values for DataType are:

• 0 (Object)
• 1 (Array)
• 2 (String)
• 3 (Number)
• 4 (Bool)
• 5 (Null)

To add additional parameters to the JOSE header use this method. For instance to create this header:

{
	"alg": "A256GCMKW",
	"crit": [
		"exp"
	],
	"enc": "A128CBC-HS256",
	"exp": 12345687,
	"iv": "SFZ9o0KKN8qF8yod",
	"tag": "tREHGKuViLo7s3QpRTulkg",
	"type": "JWT"
}

The following code can be used:

Jwe jwe = new Jwe(); jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaA256GCMKW; jwe.KeyB = key; jwe.AddHeaderParam("type", "JWT", 2); jwe.AddHeaderParam("crit", "[\"exp\"]", 1); jwe.AddHeaderParam("exp", "12345687", 3); jwe.InputMessage = "test"; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

Note: When calling Encrypt the class will automatically add headers based on the selected EncryptionAlgorithm and other properties that may be set.

Parameters Automatically Set:

Config Method (Jwe Class)

Sets or retrieves a configuration setting.

Syntax

public String config(String 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 (Jwe Class)

Decrypts the payload.

Syntax

public void decrypt();

Remarks

This method decrypts the input data.

Before calling the Decrypt method set InputMessage or InputFile to a valid compact serialized JWE string. For instance:

eyJhbGciOiJBMjU2R0NNS1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2IiwiaXYiOiJMa0tNeTZ5Qlpfbzh6QW92IiwidGFnIjoiSmpMTkRsV3l3bWt3V2pMa0NLU0xxQSJ9.wiwySYm6fXZre-3IdT1tb_02KMQDrMICwUawVf7Gjhc.k84s7ne8J41QnA5BQ31k_A.kjIveRjjNYV4x92CVE9Agw.uAygkyeO2KWeFQIy9JLU0A

The type and format of the private key depends on the algorithm used to encrypt the data. The following table summarizes the relationship:

If the correct Key or Certificate is not known ahead of time the KeyId parameter of the RecipientInfo event may be used to identify the correct key.

If this method returns without error decryption was successful. If decryption fails then this method throws an exception. After calling this method the payload will be present in the OutputMessage or file specified by OutputFile and the HeaderParams property will contain the headers. Headers of the parsed message are also available through the HeaderParam event.

The following properties are applicable when calling this method:

• Certificate (conditional - required for RSA and ECDH)
• Key (conditional - required for AES)
• ContentEncryptionAlgorithm (only if StrictValidation is True)
• EncryptionAlgorithm (only if StrictValidation is True)
• HeaderParams
• Overwrite
• StrictValidation

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:

• SetInputStream
• InputFile
• InputMessage

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

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Notes for AES Algorithms (A128KW, A192KW, A256KW, A128GCMKW, A192GCMKW, A256GCMKW)

To decrypt messages that use AES encryption Key must be set to a key of appropriate length for the algorithm. For instance a 256 bit key would be used for A256KW.

The key must be known by both parties in order for encryption and decryption to take place.

byte[] key = new byte[] { 164, 60, 194, 0, 161, 189, 41, 38, 130, 89, 141, 164, 45, 170, 159, 209, 69, 137, 243, 216, 191, 131, 47, 250, 32, 107, 231, 117, 37, 158, 225, 234 }; Jwe jwe = new Jwe(); jwe.KeyB = key; jwe.InputMessage = encryptedData; jwe.Decrypt(); string decryptedData = jwe.OutputMessage;

Notes for RSA Algorithms (RSA1_5, RSA-OEAP, RSA-OAEP-256)

The RSA based algorithms use asymmetric encryption. Encrypting is done with a public key and decryption is done with a private key. The certificate with private key must be specified. For instance:

Jwe jwe = new Jwe(); jwe.Certificate = new Certificate(CertStoreTypes.cstPFXFile, "..\\jwt.pfx", "password", "*"); jwe.InputMessage = encryptedData; jwe.Decrypt(); string decryptedData = jwe.OutputMessage;

Notes for ECDH Algorithms (ECDH-ES, ECDH-ES+A128KW, ECDH-ES+A192KW, ECDH-ES+A256KW)

ECDH algorithms require a valid ECC private key to decrypt the message. If the key was originally created with the ECC class the PEM encoded PrivateKey may be used directly with the Certificate property.

Jwe jwe = new Jwe(); jwe.Certificate = new Certificate(CertStoreTypes.cstPEMKeyFile, privKeyFile, "", "*"); jwe.InputMessage = encryptedData; jwe.Decrypt(); string decryptedData = jwe.OutputMessage;

To use an ECC private key created by other means the ECC class may be used to import the key parameters. Populate the Rx, Ry, and KB properties of the ECC component first to obtain the PEM formatted public key. For instance:

Ecc ecc = new Ecc(); byte[] x_bytes = new byte[] { 171, 170, 196, 151, 94, 196, 231, 12, 128, 232, 17, 61, 45, 105, 41, 209, 192, 187, 112, 242, 110, 178, 95, 240, 36, 55, 83, 171, 190, 176, 78, 13 }; byte[] y_bytes = new byte[] { 197, 75, 134, 245, 245, 28, 199, 9, 7, 117, 1, 54, 49, 178, 135, 252, 62, 89, 35, 180, 117, 80, 231, 23, 110, 250, 28, 124, 219, 253, 224, 156 }; byte[] k_bytes = new byte[] { 81, 65, 201, 24, 235, 249, 162, 148, 169, 150, 109, 181, 61, 238, 145, 122, 31, 30, 151, 94, 239, 90, 222, 217, 63, 103, 54, 2, 176, 232, 248, 168 }; ecc.Key.RxB = x_bytes; ecc.Key.RyB = y_bytes; ecc.Key.KB = k_bytes; string privKey = ecc.Key.PrivateKey; Jwe jwe = new Jwe(); jwe.Certificate = new Certificate(CertStoreTypes.cstPEMKeyBlob, privKey, "", "*"); jwe.InputMessage = encryptedData; jwe.Decrypt(); string decryptedData = jwe.OutputMessage;

Notes for PBES Algorithms (PBES2-HS256+A128KW, PBES2-HS384+A192KW, PBES2-HS512+A256KW

PBES algorithms derive a content encryption key from the KeyPassword property. Set KeyPassword to the shared secret.

Jwe jwe = new Jwe(); jwe.KeyPassword = "secret"; jwe.InputMessage = encryptedData; jwe.Decrypt(); string decryptedData = jwe.OutputMessage;

Notes for Direct Shared Keys

When Direct encryption is used the Key property must be set to a valid symmetric key that will be used directly by the ContentEncryptionAlgorithm. For instance:

byte[] key = new byte[] { 164, 60, 194, 0, 161, 189, 41, 38, 130, 89, 141, 164, 45, 170, 159, 209, 69, 137, 243, 216, 191, 131, 47, 250, 32, 107, 231, 117, 37, 158, 225, 234 }; Jwe jwe = new Jwe(); jwe.KeyB = key; jwe.InputMessage = encryptedData; jwe.Decrypt(); string decryptedData = jwe.OutputMessage;

Encrypt Method (Jwe Class)

Encrypts the payload with the specified algorithms.

Syntax

public void encrypt();

Remarks

This method encrypts the input data using the specified algorithms.

JSON Web Encryption (JWE) is performed by first generating a random key used to encrypt the content. The content encryption key is used to encrypt the content using the algorithm specified by ContentEncryptionAlgorithm. The content encryption key is then encrypted itself using the algorithm specified by EncryptionAlgorithm. The content encryption key is not directly exposed in the API as it is randomly generated.

After calling this method the compact serialized JWE string is written to the specified output location. For instance:

eyJhbGciOiJBMjU2R0NNS1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2IiwiaXYiOiJMa0tNeTZ5Qlpfbzh6QW92IiwidGFnIjoiSmpMTkRsV3l3bWt3V2pMa0NLU0xxQSJ9.wiwySYm6fXZre-3IdT1tb_02KMQDrMICwUawVf7Gjhc.k84s7ne8J41QnA5BQ31k_A.kjIveRjjNYV4x92CVE9Agw.uAygkyeO2KWeFQIy9JLU0A

The class is agnostic of the payload that is encrypted. Any value may be encrypted. KeyId may be set to include an identifier to help the receiving party identify the key or certificate used to encrypt the data. The following properties are applicable when calling this method:

• EncryptionAlgorithm (required)
• Key (conditional - required for AES)
• KeyPassword (conditional - required for PBES)
• Certificate (conditional - required for ECDH and RSA)
• ContentEncryptionAlgorithm
• CompressionAlgorithm
• HeaderParams
• Overwrite

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:

• SetInputStream
• InputFile
• InputMessage

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

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Notes for AES Algorithms (A128KW, A192KW, A256KW, A128GCMKW, A192GCMKW, A256GCMKW)

When EncryptionAlgorithm is set to a AES algorithm Key must be set to a key of appropriate length for the algorithm. For instance a 256 bit key would be used for A256KW.

The example below uses the EzRand class to generate a key, but the key may be created using any method. The key must be known by both parties in order for encryption and decryption to take place.

//Generate a 256 bit (32 byte) key Ezrand rand = new Ezrand(); rand.RandBytesLength = 32; rand.GetNextBytes(); byte[] key = rand.RandBytesB; //Encrypt the payload using A256KW Jwe jwe = new Jwe(); jwe.KeyB = key; jwe.InputMessage = "test data"; jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaA256KW; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

To use an existing AES key provide the bytes to the Key property. For instance:

byte[] key = new byte[] { 164, 60, 194, 0, 161, 189, 41, 38, 130, 89, 141, 164, 45, 170, 159, 209, 69, 137, 243, 216, 191, 131, 47, 250, 32, 107, 231, 117, 37, 158, 225, 234 }; //Encrypt the payload using A256KW Jwe jwe = new Jwe(); jwe.KeyB = key; jwe.InputMessage = "test data"; jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaA256KW; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

Notes for RSA Algorithms (RSA1_5, RSA-OEAP, RSA-OAEP-256)

The RSA based algorithms use asymmetric encryption. Encrypting is done with a public key and decryption is done with a private key. The public certificate should be in PEM (base64) format. For instance:

Jwe jwe = new Jwe(); jwe.Certificate = new Certificate("..\\recipient.cer"); jwe.InputMessage = "test data"; jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaRSA_OAEP; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

Notes for ECDH Algorithms (ECDH-ES, ECDH-ES+A128KW, ECDH-ES+A192KW, ECDH-ES+A256KW)

ECDH algorithms require a valid ECC public key to encrypt the message. If the key was originally created with the ECC class the PEM encoded PublicKey may be used directly with the Certificate property. An example PEM encoded public certificate created by the ECC component:

-----BEGIN PUBLIC KEY-----
MIIBMjCB7AYHKoZIzj0CATCB4AIBATAsBgcqhkjOPQEBAiEA/////wAAAAEAAAAAAAAAAAAA
AAD///////////////8wRAQg/////wAAAAEAAAAAAAAAAAAAAAD///////////////wEIFrG
NdiqOpPns+u9VXaYhrxlHQawzFOw9jvOPD4n0mBLBEEEaxfR8uEsQkf4vOblY6RA8ncDfYEt
6zOg9KE5RdiYwpZP40Li/hp/m47n60p8D54WK84zV2sxXs7LtkBoN79R9QIhAP////8AAAAA
//////////+85vqtpxeehPO5ysL8YyVRAgEBA0EEIC5rbLp11Mnz6cBXLLriaDIov3rm8RAY
x/OR0bOKiff0cQy+sLVaxjseqFk/+Xvl4ORSv5Z6HdHv5GyEpA0UoA==
-----END PUBLIC KEY-----

Jwe jwe = new Jwe(); jwe.Certificate = new Certificate(CertStoreTypes.cstPublicKeyFile, pubKeyFile, "", "*"); jwe.InputMessage = "test data"; jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaECDH_ES_A256KW; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

To use an ECC public key created by other means the ECC class may be used to import the key parameters. Populate the Rx and Ry properties of the ECC component first to obtain the PEM formatted public key. For instance:

byte[] x_bytes = new byte[] { 171, 170, 196, 151, 94, 196, 231, 12, 128, 232, 17, 61, 45, 105, 41, 209, 192, 187, 112, 242, 110, 178, 95, 240, 36, 55, 83, 171, 190, 176, 78, 13 }; byte[] y_bytes = new byte[] { 197, 75, 134, 245, 245, 28, 199, 9, 7, 117, 1, 54, 49, 178, 135, 252, 62, 89, 35, 180, 117, 80, 231, 23, 110, 250, 28, 124, 219, 253, 224, 156 }; Ecc ecc = new Ecc(); ecc.Key.RxB = x_bytes; ecc.Key.RyB = y_bytes; string pubKey = ecc.Key.PublicKey; Jwe jwe = new Jwe(); jwe.Certificate = new Certificate(CertStoreTypes.cstPublicKeyFile, pubKey, "", "*"); jwe.InputMessage = "test data"; jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaECDH_ES_A256KW; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

Notes for PBES Algorithms (PBES2-HS256+A128KW, PBES2-HS384+A192KW, PBES2-HS512+A256KW

PBES algorithms derive a content encryption key from the KeyPassword property. Set KeyPassword to a shared secret.

Jwe jwe = new Jwe(); jwe.KeyPassword = "secret"; jwe.InputMessage = "test data"; jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaPBES2_HS512_A256KW; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

Notes for Direct Shared Keys

When EncryptionAlgorithm is set to Direct the Key property must be set to a valid symmetric key that will be used directly by the ContentEncryptionAlgorithm. In this case a content encryption key is not generated randomly, the Key is used instead. The length of the specified Key must be valid for the selected ContentEncryptionAlgorithm. For instance:

//Generate a 256 bit (32 byte) key Ezrand rand = new Ezrand(); rand.RandBytesLength = 32; rand.GetNextBytes(); byte[] key = rand.RandBytesB; Jwe jwe = new Jwe(); jwe.EncryptionAlgorithm = JweEncryptionAlgorithms.eaDir; jwe.ContentEncryptionAlgorithm = JweContentEncryptionAlgorithms.ceaA256GCM; jwe.KeyB = key; jwe.InputMessage = "test data"; jwe.Encrypt(); string encryptedData = jwe.OutputMessage;

Parse Method (Jwe Class)

Parses the compact serialized JWE string.

Syntax

public void parse();

Remarks

This method parses, but does not decrypt, the JWE string.

Take care when using this method as no decryption is performed. This method may be helpful in cases where only header information is desired.

If decryption is desired, use Decrypt instead. It is not necessary to call this method before calling Decrypt. Decrypt will both parse and decrypt the message.

When calling this method the headers are parsed. The HeaderParam and RecipientInfo events will fire and the HeaderParams property will be populated.

Reset Method (Jwe Class)

Resets the class.

Syntax

public void reset();

Remarks

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

SetInputStream Method (Jwe Class)

Sets the stream from which the class will read data.

Syntax

public void setInputStream(java.io.InputStream inputStream);

Remarks

This method may be used to set a stream from which data will be read.

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:

• SetInputStream
• InputFile
• InputMessage

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

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

SetOutputStream Method (Jwe Class)

Sets the stream to which the class will write data.

Syntax

public void setOutputStream(java.io.OutputStream outputStream);

Remarks

This method may be used to specify a stream to which data will be written.

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:

• SetInputStream
• InputFile
• InputMessage

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

• SetOutputStream
• OutputFile
• OutputMessage: The output data is written to this property if no other destination is specified.

When using streams you may need to additionally set CloseInputStreamAfterProcessing or CloseOutputStreamAfterProcessing.

Error Event (Jwe Class)

Information about errors during data delivery.

Syntax

public class DefaultJweEventListener implements JweEventListener {
  ...
  public void error(JweErrorEvent e) {}
  ...
}

public class JweErrorEvent {
  public int errorCode;
  public String description;
}

Remarks

The Error event is fired in case of exceptional conditions during message processing. Normally the class throws an exception.

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.

HeaderParam Event (Jwe Class)

Fires once for each JOSE header parameter.

Syntax

public class DefaultJweEventListener implements JweEventListener {
  ...
  public void headerParam(JweHeaderParamEvent e) {}
  ...
}

public class JweHeaderParamEvent {
  public String name;
  public String value;
  public int dataType;
}

Remarks

When Decrypt or Parse is called this event will fire once for each JOSE header parameter.

Name is the name of the parameter.

Value is the value of the parameter.

DataType specifies the JSON data type of the value. Possible values are:

• 0 (Object)
• 1 (Array)
• 2 (String)
• 3 (Number)
• 4 (Bool)
• 5 (Null)

RecipientInfo Event (Jwe Class)

Fired with information about the recipient key of the encrypted message.

Syntax

public class DefaultJweEventListener implements JweEventListener {
  ...
  public void recipientInfo(JweRecipientInfoEvent e) {}
  ...
}

public class JweRecipientInfoEvent {
  public String keyId;
  public String algorithm;
}

Remarks

This event fires with information about the key used to encrypt the data. This may be used to help identify the Key or Certificate to load in order to decrypt the message. This event fires when Decrypt or Parse is called.

KeyId is the Id of the key as supplied by the entity that created the message. This may be empty.

Algorithm is the encryption algorithm used to encrypt the data.

Certificate Type

This is the digital certificate being used.

Remarks

This type describes the current digital certificate. The certificate may be a public or private key. The fields are used to identify or select certificates.

Fields

Constructors

public Certificate();

Creates a Certificate instance whose properties can be set. This is useful for use with CERTMGR when generating new certificates.

public Certificate( certificateFile);

Opens CertificateFile and reads out the contents as an X509 public key.

public Certificate( certificateData);

Parses CertificateData as an X509 public key.

public Certificate( certStoreType,  store,  storePassword,  subject);

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a file containing the certificate store. StorePassword is the password used to protect the store. After the store has been successfully opened, the class will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

public Certificate( certStoreType,  store,  storePassword,  subject,  configurationString);

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a file containing the certificate store. StorePassword is the password used to protect the store. ConfigurationString is a newline separated list of name-value pairs that may be used to modify the default behavior. Possible values include "PersistPFXKey", which shows whether or not the PFX key is persisted after performing operations with the private key. This correlates to the PKCS12_NO_PERSIST_KEY CyrptoAPI option. The default value is True (the key is persisted). "Thumbprint" - a MD5, SHA1, or SHA256 thumbprint of the certificate to load. When specified, this value is used to select the certificate in the store. This is applicable to cstUser, cstMachine, cstPublicKeyFile, and cstPFXFile store types. "UseInternalSecurityAPI" shows whether the platform (default) or the internal security API is used when performing certificate-related operations. After the store has been successfully opened, the class will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

public Certificate( certStoreType,  store,  storePassword,  encoded);

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a file containing the certificate store. StorePassword is the password used to protect the store. After the store has been successfully opened, the class will load Encoded as an X509 certificate and search the opened store for a corresponding private key.

public Certificate( certStoreType,  storeBlob,  storePassword,  subject);

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. StoreBlob is a string (binary- or base64-encoded) containing the certificate data. StorePassword is the password used to protect the store. After the store has been successfully opened, the class will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

public Certificate( certStoreType,  storeBlob,  storePassword,  subject,  configurationString);

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. StoreBlob is a string (binary- or base64-encoded) containing the certificate data. StorePassword is the password used to protect the store. After the store has been successfully opened, the class will attempt to find the certificate identified by Subject . This can be either a complete or a substring match of the X509 certificate's subject Distinguished Name (DN).

public Certificate( certStoreType,  storeBlob,  storePassword,  encoded);

CertStoreType identifies the type of certificate store to use. See StoreType for descriptions of the different certificate stores. Store is a string (binary- or base64-encoded) containing the certificate store. StorePassword is the password used to protect the store. After the store has been successfully opened, the class will load Encoded as an X509 certificate and search the opened store for a corresponding private key.

HeaderParam Type

The JOSE header parameter.

Remarks

This type holds the JOSE header parameters. The fields define the name, value, and data type of the parameter.

Fields

Constructors

public HeaderParam();

Creates a new header parameter with no name or value.

public HeaderParam( name,  value);

Creates a new header parameter. The DataType of the value will be a String.

public HeaderParam( name,  value,  dataType);

Creates a new header parameter with the specified DataType.

Config Settings (Jwe Class)

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.

JWE Config Settings

Base Config Settings

Trappable Errors (Jwe Class)

JWE Errors

	101   Invalid JWE message. See message for details.
	102   Unsupported compression algorithm.
	103   Unsupported content encryption algorithm.
	104   Unsupported key encryption algorithm.
	105   A required header for decryption was not found. See message for details.
	106   The specified key is not a valid length for the algorithm.
	107   OutputFile already exists and Overwrite is False.
	108   KeyPassword must be set for the selected algorithm.
	109   Key must be set for the selected algorithm.
	110   Certificate must be set for the selected algorithm.
	111   A header parameter defined to be critical is not present.
	112   Error writing data.
	113   Error reading data. Check message for details.
	114   Error encrypting. Check message for details.
	115   Error decrypting. Check message for details.