# MessageDecryptor Component

The MessageDecryptor class decrypts data that is stored in the PKCS#7 format.

## Syntax

```text
secureblackbox.MessageDecryptor
```

## Remarks

PKCS#7 (Public Key Cryptography Standard #7) is a common format used to store encrypted and signed data. It is used by a variety of protocols, including S/MIME and CMS.

MessageDecryptor is capable of decrypting encrypted PKCS#7 data stored in EnvelopedData (asymmetric encryption) and EncryptedData (symmetric encryption) subformats. RSA and ECDH key wrapping and all popular symmetric encryption algorithms are supported.

Setting up and using MessageDecryptor is easy:

- Set up your source and destination via [InputFile](#inputfile-property-messagedecryptor-component) ([InputBytes](#inputbytes-property-messagedecryptor-component)) and [OutputFile](#outputfile-property-messagedecryptor-component) ([OutputBytes](#outputbytes-property-messagedecryptor-component)) properties.
- For certificate-based (asymmetric) encryption, put the decryption certificate (with its private key included) to the Certificates collection.
- For key-based (symmetric) encryption, assign the symmetric key to [Key](#key-property-messagedecryptor-component) property. Note: you can find out whether asymmetric or symmetric encryption was used on the input message using the [CheckEncryptionType](#checkencryptiontype-method-messagedecryptor-component) method.
- Call [Decrypt](#decrypt-method-messagedecryptor-component) to execute the operation.

Note that MessageDecryptor only works with binary PKCS#7-compliant encrypted messages. For processing encrypted S/MIME emails, see [MailReader](MailReader.md#MailReader). For decrypting PGP messages, see [PGPReader](PGPReader.md#PGPReader). For raw symmetric encryption, see [SymmetricCrypto](SymmetricCrypto.md#SymmetricCrypto). For processing XML-ENC messages, see [XMLDecryptor](XMLDecryptor.md#XMLDecryptor).

```text
MessageDecryptor decryptor = new MessageDecryptor();

// Select the file which contains the message that will be decrypted
decryptor.setInputFile("encryptedMessage.bin");

// Select the file where the decrypted message will be written
decryptor.setOutputFile("decryptedMessage.txt");

// Providing the certificate with its private key to decrypt data
CertificateList certificateList = new CertificateList();
certificateList.add(new Certificate("cert.pfx","password"));
decryptor.setCertificates(certificateList);

decryptor.decrypt(); // Decrypt
```

## Property List

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

|  |  |
| --- | --- |
| [CertificateIndex](#certificateindex-property-messagedecryptor-component) | The index of certificate that was used to decrypt the message. |
| [CertCount](#certcount-property-messagedecryptor-component) | The number of records in the Cert arrays. |
| [CertBytes](#certbytes-property-messagedecryptor-component) | Returns the raw certificate data in DER format. |
| [CertHandle](#certhandle-property-messagedecryptor-component) | Allows to get or set a 'handle', a unique identifier of the underlying property object. |
| [EncryptionAlgorithm](#encryptionalgorithm-property-messagedecryptor-component) | The symmetric cipher that was used to encrypt the data. |
| [EncryptionType](#encryptiontype-property-messagedecryptor-component) | Specifies the kind of encrypted message to create. |
| [ExternalCryptoAsyncDocumentID](#externalcryptoasyncdocumentid-property-messagedecryptor-component) | Specifies an optional document ID for SignAsyncBegin() and SignAsyncEnd() calls. |
| [ExternalCryptoCustomParams](#externalcryptocustomparams-property-messagedecryptor-component) | Custom parameters to be passed to the signing service (uninterpreted). |
| [ExternalCryptoData](#externalcryptodata-property-messagedecryptor-component) | Additional data to be included in the async state and mirrored back by the requestor. |
| [ExternalCryptoExternalHashCalculation](#externalcryptoexternalhashcalculation-property-messagedecryptor-component) | Specifies whether the message hash is to be calculated at the external endpoint. |
| [ExternalCryptoHashAlgorithm](#externalcryptohashalgorithm-property-messagedecryptor-component) | Specifies the request's signature hash algorithm. |
| [ExternalCryptoKeyID](#externalcryptokeyid-property-messagedecryptor-component) | The ID of the pre-shared key used for DC request authentication. |
| [ExternalCryptoKeySecret](#externalcryptokeysecret-property-messagedecryptor-component) | The pre-shared key used for DC request authentication. |
| [ExternalCryptoMethod](#externalcryptomethod-property-messagedecryptor-component) | Specifies the asynchronous signing method. |
| [ExternalCryptoMode](#externalcryptomode-property-messagedecryptor-component) | Specifies the external cryptography mode. |
| [ExternalCryptoPublicKeyAlgorithm](#externalcryptopublickeyalgorithm-property-messagedecryptor-component) | Provide the public key algorithm here if the certificate is not available on the pre-signing stage. |
| [FIPSMode](#fipsmode-property-messagedecryptor-component) | Reserved. |
| [InputBytes](#inputbytes-property-messagedecryptor-component) | Use this property to pass the input to class in byte array form. |
| [InputFile](#inputfile-property-messagedecryptor-component) | Path to the file containing the encrypted message. |
| [Key](#key-property-messagedecryptor-component) | The symmetric key to use for decryption. |
| [OutputBytes](#outputbytes-property-messagedecryptor-component) | Use this property to read the output the class object has produced. |
| [OutputFile](#outputfile-property-messagedecryptor-component) | Path to the file to save the decrypted data to. |
| [SignedAttributeCount](#signedattributecount-property-messagedecryptor-component) | The number of records in the SignedAttribute arrays. |
| [SignedAttributeOID](#signedattributeoid-property-messagedecryptor-component) | The object identifier of the attribute. |
| [SignedAttributeValue](#signedattributevalue-property-messagedecryptor-component) | The value of the attribute. |
| [UnsignedAttributeCount](#unsignedattributecount-property-messagedecryptor-component) | The number of records in the UnsignedAttribute arrays. |
| [UnsignedAttributeOID](#unsignedattributeoid-property-messagedecryptor-component) | The object identifier of the attribute. |
| [UnsignedAttributeValue](#unsignedattributevalue-property-messagedecryptor-component) | The value of the attribute. |

## Method List

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

|  |  |
| --- | --- |
| [CheckEncryptionType](#checkencryptiontype-method-messagedecryptor-component) | Determines the type of encrypted message in the supplied file. |
| [Config](#config-method-messagedecryptor-component) | Sets or retrieves a configuration setting. |
| [Decrypt](#decrypt-method-messagedecryptor-component) | Attempts to decrypt an encrypted PKCS#7 message. |
| [DoAction](#doaction-method-messagedecryptor-component) | Performs an additional action. |
| [Reset](#reset-method-messagedecryptor-component) | Resets the class settings. |

## Event List

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

|  |  |
| --- | --- |
| [Error](#error-event-messagedecryptor-component) | Information about errors during PKCS#7 message decryption. |
| [ExternalDecrypt](#externaldecrypt-event-messagedecryptor-component) | Handles remote or external decryption. |
| [Notification](#notification-event-messagedecryptor-component) | This event notifies the application about an underlying control flow event. |
| [RecipientFound](#recipientfound-event-messagedecryptor-component) | Fires to report a message addressee parameters. |

## Config Settings

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

|  |  |
| --- | --- |
| [NoOuterContentInfo](#NoOuterContentInfo) | Whether the message has outer content. |
| [OAEPHashAlgorithm](#OAEPHashAlgorithm) | Hash algorithm to be used in RSA-OAEP. |
| [TempPath](#TempPath) | Path for storing temporary files. |
| [ASN1UseGlobalTagCache](#ASN1UseGlobalTagCache) | Controls whether ASN.1 module should use a global object cache. |
| [AssignSystemSmartCardPins](#AssignSystemSmartCardPins) | Specifies whether CSP-level PINs should be assigned to CNG keys. |
| [CheckKeyIntegrityBeforeUse](#CheckKeyIntegrityBeforeUse) | Enables or disable private key integrity check before use. |
| [CookieCaching](#CookieCaching) | Specifies whether a cookie cache should be used for HTTP(S) transports. |
| [Cookies](#Cookies) | Gets or sets local cookies for the class. |
| [DefDeriveKeyIterations](#DefDeriveKeyIterations) | Specifies the default key derivation algorithm iteration count. |
| [DNSLocalSuffix](#DNSLocalSuffix) | The suffix to assign for TLD names. |
| [EnableClientSideSSLFFDHE](#EnableClientSideSSLFFDHE) | Enables or disables finite field DHE key exchange support in TLS clients. |
| [EnableSSHMLKEM](#EnableSSHMLKEM) | Enables support for ML-KEM/hybrid key exchange algorithms in SSH client and server classes. |
| [EnableTLSMLKEM](#EnableTLSMLKEM) | Enables support for ML-KEM and hybrid groups in TLS client and server classes. |
| [GlobalCookies](#GlobalCookies) | Gets or sets global cookies for all the HTTP transports. |
| [HardwareCryptoUsePolicy](#HardwareCryptoUsePolicy) | The hardware crypto usage policy. |
| [HttpUserAgent](#HttpUserAgent) | Specifies the user agent name to be used by all HTTP clients. |
| [HttpVersion](#HttpVersion) | The HTTP version to use in any inner HTTP client classes created. |
| [IgnoreExpiredMSCTLSigningCert](#IgnoreExpiredMSCTLSigningCert) | Whether to tolerate the expired Windows Update signing certificate. |
| [ListDelimiter](#ListDelimiter) | The delimiter character for multi-element lists. |
| [LogDestination](#LogDestination) | Specifies the debug log destination. |
| [LogDetails](#LogDetails) | Specifies the debug log details to dump. |
| [LogFile](#LogFile) | Specifies the debug log filename. |
| [LogFilters](#LogFilters) | Specifies the debug log filters. |
| [LogFlushMode](#LogFlushMode) | Specifies the log flush mode. |
| [LogLevel](#LogLevel) | Specifies the debug log level. |
| [LogMaxEventCount](#LogMaxEventCount) | Specifies the maximum number of events to cache before further action is taken. |
| [LogRotationMode](#LogRotationMode) | Specifies the log rotation mode. |
| [MaxASN1BufferLength](#MaxASN1BufferLength) | Specifies the maximal allowed length for ASN.1 primitive tag data. |
| [MaxASN1TreeDepth](#MaxASN1TreeDepth) | Specifies the maximal depth for processed ASN.1 trees. |
| [OCSPHashAlgorithm](#OCSPHashAlgorithm) | Specifies the hash algorithm to be used to identify certificates in OCSP requests. |
| [OldClientSideRSAFallback](#OldClientSideRSAFallback) | Specifies whether the SSH client should use a SHA1 fallback. |
| [PKICache](#PKICache) | Specifies which PKI elements (certificates, CRLs, OCSP responses) should be cached. |
| [PKICachePath](#PKICachePath) | Specifies the file system path where cached PKI data is stored. |
| [ProductVersion](#ProductVersion) | Returns the version of the SecureBlackbox library. |
| [ServerSSLDHKeyLength](#ServerSSLDHKeyLength) | Sets the size of the TLS DHE key exchange group. |
| [StaticDNS](#StaticDNS) | Specifies whether static DNS rules should be used. |
| [StaticIPAddress\[domain\]](#StaticIPAddress[domain]) | Gets or sets an IP address for the specified domain name. |
| [StaticIPAddresses](#StaticIPAddresses) | Gets or sets all the static DNS rules. |
| [Tag](#Tag) | Allows to store any custom data. |
| [TLSSessionGroup](#TLSSessionGroup) | Specifies the group name of TLS sessions to be used for session resumption. |
| [TLSSessionLifetime](#TLSSessionLifetime) | Specifies lifetime in seconds of the cached TLS session. |
| [TLSSessionPurgeInterval](#TLSSessionPurgeInterval) | Specifies how often the session cache should remove the expired TLS sessions. |
| [UseCRLObjectCaching](#UseCRLObjectCaching) | Specifies whether reuse of loaded CRL objects is enabled. |
| [UseInternalRandom](#UseInternalRandom) | Switches between SecureBlackbox-own and platform PRNGs. |
| [UseLegacyAdESValidation](#UseLegacyAdESValidation) | Enables legacy AdES validation mode. |
| [UseOCSPResponseObjectCaching](#UseOCSPResponseObjectCaching) | Specifies whether reuse of loaded OCSP response objects is enabled. |
| [UseOwnDNSResolver](#UseOwnDNSResolver) | Specifies whether the client classes should use own DNS resolver. |
| [UseSharedSystemStorages](#UseSharedSystemStorages) | Specifies whether the validation engine should use a global per-process copy of the system certificate stores. |
| [UseSystemNativeSizeCalculation](#UseSystemNativeSizeCalculation) | An internal CryptoAPI access tweak. |
| [UseSystemOAEPAndPSS](#UseSystemOAEPAndPSS) | Enforces or disables the use of system-driven RSA OAEP and PSS computations. |
| [UseSystemRandom](#UseSystemRandom) | Enables or disables the use of the OS PRNG. |
| [XMLRDNDescriptorName\[OID\]](#XMLRDNDescriptorName[OID]) | Defines an OID mapping to descriptor names for the certificate's IssuerRDN or SubjectRDN. |
| [XMLRDNDescriptorPriority\[OID\]](#XMLRDNDescriptorPriority[OID]) | Specifies the priority of descriptor names associated with a specific OID. |
| [XMLRDNDescriptorReverseOrder](#XMLRDNDescriptorReverseOrder) | Specifies whether to reverse the order of descriptors in RDN. |
| [XMLRDNDescriptorSeparator](#XMLRDNDescriptorSeparator) | Specifies the separator used between descriptors in RDN. |

# CertificateIndex Property ([MessageDecryptor](#messagedecryptor-component) Component)

The index of certificate that was used to decrypt the message.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) CertificateIndex() (int32, error)
```

## Default Value

-1

## Remarks

This property contains the index of certificate (one of those residing in Certificates collection) that was used to decrypt the message.

This property is read-only.

## Data Type

**int32**

# CertCount Property ([MessageDecryptor](#messagedecryptor-component) Component)

The number of records in the Cert arrays.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) CertCount() (int32, error)func (obj *MessageDecryptor) SetCertCount(value int32) error
```

## Default Value

0

## Remarks

This property controls the size of the following arrays:

- [CertBytes](#certbytes-property-messagedecryptor-component)
- [CertHandle](#certhandle-property-messagedecryptor-component)

The array indices start at *0* and end at *CertCount - 1*.

## Data Type

**int32**

# CertBytes Property ([MessageDecryptor](#messagedecryptor-component) Component)

Returns the raw certificate data in DER format.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) CertBytes(CertIndex int32) ([]byte, error)
```

## Remarks

Returns the raw certificate data in DER format.

The *CertIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [CertCount](#certcount-property-messagedecryptor-component) property.

This property is read-only.

## Data Type

**[]byte**

# CertHandle Property ([MessageDecryptor](#messagedecryptor-component) Component)

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

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) CertHandle(CertIndex int32) (int64, error)func (obj *MessageDecryptor) SetCertHandle(CertIndex int32, value int64) error
```

## 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.

```text
  pdfSigner.setSigningCertHandle(certMgr.getCertHandle());
```

The *CertIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [CertCount](#certcount-property-messagedecryptor-component) property.

## Data Type

**int64**

# EncryptionAlgorithm Property ([MessageDecryptor](#messagedecryptor-component) Component)

The symmetric cipher that was used to encrypt the data.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) EncryptionAlgorithm() (string, error)
```

## Default Value

""

## Remarks

This property contains the symmetric algorithm that the creator had used to encrypt the message.

This property is read-only.

## Data Type

**string**

# EncryptionType Property ([MessageDecryptor](#messagedecryptor-component) Component)

Specifies the kind of encrypted message to create.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) EncryptionType() (int32, error)
```

## Possible Values

```text
0   // Unknown1   // CertEncrypted2   // KeyEncrypted3   // CertEncryptedAndAuthenticated
```

## Default Value

0

## Remarks

Possible values:

|  |  |  |
| --- | --- | --- |
| metUnknown | 0 | Unknown or unsupported encryption type |
| metCertEncrypted | 1 | Certificate-based encryption |
| metKeyEncrypted | 2 | Symmetric key-based encryption |
| metCertEncryptedAndAuthenticated | 3 | Certificate-based encryption with authentication (AEAD) |

This property is read-only.

## Data Type

**int32**

# ExternalCryptoAsyncDocumentID Property ([MessageDecryptor](#messagedecryptor-component) Component)

Specifies an optional document ID for SignAsyncBegin() and SignAsyncEnd() calls.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) ExternalCryptoAsyncDocumentID() (string, error)func (obj *MessageDecryptor) SetExternalCryptoAsyncDocumentID(value string) error
```

## Default Value

""

## Remarks

Specifies an optional document ID for SignAsyncBegin() and SignAsyncEnd() calls.

Use this property when working with multi-signature DCAuth requests and responses to uniquely identify documents signed within a larger batch. On the completion stage, this value helps the signing component identify the correct signature in the returned batch of responses.

If using batched requests, make sure to set this property to the same value on both the pre-signing (SignAsyncBegin) and completion (SignAsyncEnd) stages.

## Data Type

**string**

# ExternalCryptoCustomParams Property ([MessageDecryptor](#messagedecryptor-component) Component)

Custom parameters to be passed to the signing service (uninterpreted).

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) ExternalCryptoCustomParams() (string, error)func (obj *MessageDecryptor) SetExternalCryptoCustomParams(value string) error
```

## Default Value

""

## Remarks

Custom parameters to be passed to the signing service (uninterpreted).

## Data Type

**string**

# ExternalCryptoData Property ([MessageDecryptor](#messagedecryptor-component) Component)

Additional data to be included in the async state and mirrored back by the requestor.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) ExternalCryptoData() (string, error)func (obj *MessageDecryptor) SetExternalCryptoData(value string) error
```

## Default Value

""

## Remarks

Additional data to be included in the async state and mirrored back by the requestor.

## Data Type

**string**

# ExternalCryptoExternalHashCalculation Property ([MessageDecryptor](#messagedecryptor-component) Component)

Specifies whether the message hash is to be calculated at the external endpoint.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) ExternalCryptoExternalHashCalculation() (bool, error)func (obj *MessageDecryptor) SetExternalCryptoExternalHashCalculation(value bool) error
```

## Default Value

false

## Remarks

Specifies whether the message hash is to be calculated at the external endpoint. Please note that this mode is not supported by the DCAuth struct.

If set to true, the struct will pass a few kilobytes of to-be-signed data from the document to the OnExternalSign event. This only applies when SignExternal() is called.

## Data Type

**bool**

# ExternalCryptoHashAlgorithm Property ([MessageDecryptor](#messagedecryptor-component) Component)

Specifies the request's signature hash algorithm.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) ExternalCryptoHashAlgorithm() (string, error)func (obj *MessageDecryptor) SetExternalCryptoHashAlgorithm(value string) error
```

## Default Value

"SHA256"

## Remarks

Specifies the request's signature hash algorithm.

|  |  |  |
| --- | --- | --- |
| SB_HASH_ALGORITHM_SHA1 | SHA1 |  |
| SB_HASH_ALGORITHM_SHA224 | SHA224 |  |
| SB_HASH_ALGORITHM_SHA256 | SHA256 |  |
| SB_HASH_ALGORITHM_SHA384 | SHA384 |  |
| SB_HASH_ALGORITHM_SHA512 | SHA512 |  |
| SB_HASH_ALGORITHM_MD2 | MD2 |  |
| SB_HASH_ALGORITHM_MD4 | MD4 |  |
| SB_HASH_ALGORITHM_MD5 | MD5 |  |
| SB_HASH_ALGORITHM_RIPEMD160 | RIPEMD160 |  |
| SB_HASH_ALGORITHM_CRC32 | CRC32 |  |
| SB_HASH_ALGORITHM_SSL3 | SSL3 |  |
| SB_HASH_ALGORITHM_GOST_R3411_1994 | GOST1994 |  |
| SB_HASH_ALGORITHM_WHIRLPOOL | WHIRLPOOL |  |
| SB_HASH_ALGORITHM_POLY1305 | POLY1305 |  |
| SB_HASH_ALGORITHM_SHA3_224 | SHA3_224 |  |
| SB_HASH_ALGORITHM_SHA3_256 | SHA3_256 |  |
| SB_HASH_ALGORITHM_SHA3_384 | SHA3_384 |  |
| SB_HASH_ALGORITHM_SHA3_512 | SHA3_512 |  |
| SB_HASH_ALGORITHM_BLAKE2S_128 | BLAKE2S_128 |  |
| SB_HASH_ALGORITHM_BLAKE2S_160 | BLAKE2S_160 |  |
| SB_HASH_ALGORITHM_BLAKE2S_224 | BLAKE2S_224 |  |
| SB_HASH_ALGORITHM_BLAKE2S_256 | BLAKE2S_256 |  |
| SB_HASH_ALGORITHM_BLAKE2B_160 | BLAKE2B_160 |  |
| SB_HASH_ALGORITHM_BLAKE2B_256 | BLAKE2B_256 |  |
| SB_HASH_ALGORITHM_BLAKE2B_384 | BLAKE2B_384 |  |
| SB_HASH_ALGORITHM_BLAKE2B_512 | BLAKE2B_512 |  |
| SB_HASH_ALGORITHM_SHAKE_128 | SHAKE_128 |  |
| SB_HASH_ALGORITHM_SHAKE_256 | SHAKE_256 |  |
| SB_HASH_ALGORITHM_SHAKE_128_LEN | SHAKE_128_LEN |  |
| SB_HASH_ALGORITHM_SHAKE_256_LEN | SHAKE_256_LEN |  |

## Data Type

**string**

# ExternalCryptoKeyID Property ([MessageDecryptor](#messagedecryptor-component) Component)

The ID of the pre-shared key used for DC request authentication.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) ExternalCryptoKeyID() (string, error)func (obj *MessageDecryptor) SetExternalCryptoKeyID(value string) error
```

## Default Value

""

## Remarks

The ID of the pre-shared key used for DC request authentication.

Asynchronous DCAuth-driven communication requires that parties authenticate each other with a secret pre-shared cryptographic key. This provides an extra protection layer for the protocol and diminishes the risk of the private key becoming abused by foreign parties. Use this property to provide the pre-shared key identifier, and use [ExternalCryptoKeySecret](#externalcryptokeysecret-property-messagedecryptor-component) to pass the key itself.

The same KeyID/KeySecret pair should be used on the DCAuth side for the signing requests to be accepted.

Note: The KeyID/KeySecret scheme is very similar to the AuthKey scheme used in various Cloud service providers to authenticate users.

Example:

```text
  signer.ExternalCrypto.KeyID = "MainSigningKey";
  signer.ExternalCrypto.KeySecret = "abcdef0123456789";
```

## Data Type

**string**

# ExternalCryptoKeySecret Property ([MessageDecryptor](#messagedecryptor-component) Component)

The pre-shared key used for DC request authentication.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) ExternalCryptoKeySecret() (string, error)func (obj *MessageDecryptor) SetExternalCryptoKeySecret(value string) error
```

## Default Value

""

## Remarks

The pre-shared key used for DC request authentication. This key must be set and match the key used by the DCAuth counterpart for the scheme to work.

Read more about configuring authentication in the [ExternalCryptoKeyID](#externalcryptokeyid-property-messagedecryptor-component) topic.

## Data Type

**string**

# ExternalCryptoMethod Property ([MessageDecryptor](#messagedecryptor-component) Component)

Specifies the asynchronous signing method.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) ExternalCryptoMethod() (int32, error)func (obj *MessageDecryptor) SetExternalCryptoMethod(value int32) error
```

## Possible Values

```text
0   // PKCS11   // PKCS7
```

## Default Value

0

## Remarks

Specifies the asynchronous signing method. This is typically defined by the DC server capabilities and setup.

Available options:

|  |  |
| --- | --- |
| asmdPKCS1 | 0 |
| asmdPKCS7 | 1 |

## Data Type

**int32**

# ExternalCryptoMode Property ([MessageDecryptor](#messagedecryptor-component) Component)

Specifies the external cryptography mode.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) ExternalCryptoMode() (int32, error)func (obj *MessageDecryptor) SetExternalCryptoMode(value int32) error
```

## Possible Values

```text
0   // Default1   // Disabled2   // Generic3   // DCAuth4   // DCAuthJSON
```

## Default Value

0

## Remarks

Specifies the external cryptography mode.

Available options:

|  |  |
| --- | --- |
| ecmDefault | The default value (0) |
| ecmDisabled | Do not use DC or external signing (1) |
| ecmGeneric | Generic external signing with the OnExternalSign event (2) |
| ecmDCAuth | DCAuth signing (3) |
| ecmDCAuthJSON | DCAuth signing in JSON format (4) |

## Data Type

**int32**

# ExternalCryptoPublicKeyAlgorithm Property ([MessageDecryptor](#messagedecryptor-component) Component)

Provide the public key algorithm here if the certificate is not available on the pre-signing stage.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) ExternalCryptoPublicKeyAlgorithm() (string, error)func (obj *MessageDecryptor) SetExternalCryptoPublicKeyAlgorithm(value string) error
```

## Default Value

""

## Remarks

Provide the public key algorithm here if the certificate is not available on the pre-signing stage.

|  |  |  |
| --- | --- | --- |
| SB_CERT_ALGORITHM_ID_RSA_ENCRYPTION | rsaEncryption |  |
| SB_CERT_ALGORITHM_MD2_RSA_ENCRYPTION | md2withRSAEncryption |  |
| SB_CERT_ALGORITHM_MD5_RSA_ENCRYPTION | md5withRSAEncryption |  |
| SB_CERT_ALGORITHM_SHA1_RSA_ENCRYPTION | sha1withRSAEncryption |  |
| SB_CERT_ALGORITHM_ID_DSA | id-dsa |  |
| SB_CERT_ALGORITHM_ID_DSA_SHA1 | id-dsa-with-sha1 |  |
| SB_CERT_ALGORITHM_DH_PUBLIC | dhpublicnumber |  |
| SB_CERT_ALGORITHM_SHA224_RSA_ENCRYPTION | sha224WithRSAEncryption |  |
| SB_CERT_ALGORITHM_SHA256_RSA_ENCRYPTION | sha256WithRSAEncryption |  |
| SB_CERT_ALGORITHM_SHA384_RSA_ENCRYPTION | sha384WithRSAEncryption |  |
| SB_CERT_ALGORITHM_SHA512_RSA_ENCRYPTION | sha512WithRSAEncryption |  |
| SB_CERT_ALGORITHM_ID_RSAPSS | id-RSASSA-PSS |  |
| SB_CERT_ALGORITHM_ID_RSAOAEP | id-RSAES-OAEP |  |
| SB_CERT_ALGORITHM_RSASIGNATURE_RIPEMD160 | ripemd160withRSA |  |
| SB_CERT_ALGORITHM_ID_ELGAMAL | elGamal |  |
| SB_CERT_ALGORITHM_SHA1_ECDSA | ecdsa-with-SHA1 |  |
| SB_CERT_ALGORITHM_RECOMMENDED_ECDSA | ecdsa-recommended |  |
| SB_CERT_ALGORITHM_SHA224_ECDSA | ecdsa-with-SHA224 |  |
| SB_CERT_ALGORITHM_SHA256_ECDSA | ecdsa-with-SHA256 |  |
| SB_CERT_ALGORITHM_SHA384_ECDSA | ecdsa-with-SHA384 |  |
| SB_CERT_ALGORITHM_SHA512_ECDSA | ecdsa-with-SHA512 |  |
| SB_CERT_ALGORITHM_EC | id-ecPublicKey |  |
| SB_CERT_ALGORITHM_SPECIFIED_ECDSA | ecdsa-specified |  |
| SB_CERT_ALGORITHM_GOST_R3410_1994 | id-GostR3410-94 |  |
| SB_CERT_ALGORITHM_GOST_R3410_2001 | id-GostR3410-2001 |  |
| SB_CERT_ALGORITHM_GOST_R3411_WITH_R3410_1994 | id-GostR3411-94-with-GostR3410-94 |  |
| SB_CERT_ALGORITHM_GOST_R3411_WITH_R3410_2001 | id-GostR3411-94-with-GostR3410-2001 |  |
| SB_CERT_ALGORITHM_SHA1_ECDSA_PLAIN | ecdsa-plain-SHA1 |  |
| SB_CERT_ALGORITHM_SHA224_ECDSA_PLAIN | ecdsa-plain-SHA224 |  |
| SB_CERT_ALGORITHM_SHA256_ECDSA_PLAIN | ecdsa-plain-SHA256 |  |
| SB_CERT_ALGORITHM_SHA384_ECDSA_PLAIN | ecdsa-plain-SHA384 |  |
| SB_CERT_ALGORITHM_SHA512_ECDSA_PLAIN | ecdsa-plain-SHA512 |  |
| SB_CERT_ALGORITHM_RIPEMD160_ECDSA_PLAIN | ecdsa-plain-RIPEMD160 |  |
| SB_CERT_ALGORITHM_WHIRLPOOL_RSA_ENCRYPTION | whirlpoolWithRSAEncryption |  |
| SB_CERT_ALGORITHM_ID_DSA_SHA224 | id-dsa-with-sha224 |  |
| SB_CERT_ALGORITHM_ID_DSA_SHA256 | id-dsa-with-sha256 |  |
| SB_CERT_ALGORITHM_SHA3_224_RSA_ENCRYPTION | id-rsassa-pkcs1-v1_5-with-sha3-224 |  |
| SB_CERT_ALGORITHM_SHA3_256_RSA_ENCRYPTION | id-rsassa-pkcs1-v1_5-with-sha3-256 |  |
| SB_CERT_ALGORITHM_SHA3_384_RSA_ENCRYPTION | id-rsassa-pkcs1-v1_5-with-sha3-384 |  |
| SB_CERT_ALGORITHM_SHA3_512_RSA_ENCRYPTION | id-rsassa-pkcs1-v1_5-with-sha3-512 |  |
| SB_CERT_ALGORITHM_SHA3_224_ECDSA | id-ecdsa-with-sha3-224 |  |
| SB_CERT_ALGORITHM_SHA3_256_ECDSA | id-ecdsa-with-sha3-256 |  |
| SB_CERT_ALGORITHM_SHA3_384_ECDSA | id-ecdsa-with-sha3-384 |  |
| SB_CERT_ALGORITHM_SHA3_512_ECDSA | id-ecdsa-with-sha3-512 |  |
| SB_CERT_ALGORITHM_SHA3_224_ECDSA_PLAIN | id-ecdsa-plain-with-sha3-224 |  |
| SB_CERT_ALGORITHM_SHA3_256_ECDSA_PLAIN | id-ecdsa-plain-with-sha3-256 |  |
| SB_CERT_ALGORITHM_SHA3_384_ECDSA_PLAIN | id-ecdsa-plain-with-sha3-384 |  |
| SB_CERT_ALGORITHM_SHA3_512_ECDSA_PLAIN | id-ecdsa-plain-with-sha3-512 |  |
| SB_CERT_ALGORITHM_ID_DSA_SHA3_224 | id-dsa-with-sha3-224 |  |
| SB_CERT_ALGORITHM_ID_DSA_SHA3_256 | id-dsa-with-sha3-256 |  |
| SB_CERT_ALGORITHM_BLAKE2S_128_RSA_ENCRYPTION | id-rsassa-pkcs1-v1_5-with-blake2s128 |  |
| SB_CERT_ALGORITHM_BLAKE2S_160_RSA_ENCRYPTION | id-rsassa-pkcs1-v1_5-with-blake2s160 |  |
| SB_CERT_ALGORITHM_BLAKE2S_224_RSA_ENCRYPTION | id-rsassa-pkcs1-v1_5-with-blake2s224 |  |
| SB_CERT_ALGORITHM_BLAKE2S_256_RSA_ENCRYPTION | id-rsassa-pkcs1-v1_5-with-blake2s256 |  |
| SB_CERT_ALGORITHM_BLAKE2B_160_RSA_ENCRYPTION | id-rsassa-pkcs1-v1_5-with-blake2b160 |  |
| SB_CERT_ALGORITHM_BLAKE2B_256_RSA_ENCRYPTION | id-rsassa-pkcs1-v1_5-with-blake2b256 |  |
| SB_CERT_ALGORITHM_BLAKE2B_384_RSA_ENCRYPTION | id-rsassa-pkcs1-v1_5-with-blake2b384 |  |
| SB_CERT_ALGORITHM_BLAKE2B_512_RSA_ENCRYPTION | id-rsassa-pkcs1-v1_5-with-blake2b512 |  |
| SB_CERT_ALGORITHM_BLAKE2S_128_ECDSA | id-ecdsa-with-blake2s128 |  |
| SB_CERT_ALGORITHM_BLAKE2S_160_ECDSA | id-ecdsa-with-blake2s160 |  |
| SB_CERT_ALGORITHM_BLAKE2S_224_ECDSA | id-ecdsa-with-blake2s224 |  |
| SB_CERT_ALGORITHM_BLAKE2S_256_ECDSA | id-ecdsa-with-blake2s256 |  |
| SB_CERT_ALGORITHM_BLAKE2B_160_ECDSA | id-ecdsa-with-blake2b160 |  |
| SB_CERT_ALGORITHM_BLAKE2B_256_ECDSA | id-ecdsa-with-blake2b256 |  |
| SB_CERT_ALGORITHM_BLAKE2B_384_ECDSA | id-ecdsa-with-blake2b384 |  |
| SB_CERT_ALGORITHM_BLAKE2B_512_ECDSA | id-ecdsa-with-blake2b512 |  |
| SB_CERT_ALGORITHM_BLAKE2S_128_ECDSA_PLAIN | id-ecdsa-plain-with-blake2s128 |  |
| SB_CERT_ALGORITHM_BLAKE2S_160_ECDSA_PLAIN | id-ecdsa-plain-with-blake2s160 |  |
| SB_CERT_ALGORITHM_BLAKE2S_224_ECDSA_PLAIN | id-ecdsa-plain-with-blake2s224 |  |
| SB_CERT_ALGORITHM_BLAKE2S_256_ECDSA_PLAIN | id-ecdsa-plain-with-blake2s256 |  |
| SB_CERT_ALGORITHM_BLAKE2B_160_ECDSA_PLAIN | id-ecdsa-plain-with-blake2b160 |  |
| SB_CERT_ALGORITHM_BLAKE2B_256_ECDSA_PLAIN | id-ecdsa-plain-with-blake2b256 |  |
| SB_CERT_ALGORITHM_BLAKE2B_384_ECDSA_PLAIN | id-ecdsa-plain-with-blake2b384 |  |
| SB_CERT_ALGORITHM_BLAKE2B_512_ECDSA_PLAIN | id-ecdsa-plain-with-blake2b512 |  |
| SB_CERT_ALGORITHM_ID_DSA_BLAKE2S_224 | id-dsa-with-blake2s224 |  |
| SB_CERT_ALGORITHM_ID_DSA_BLAKE2S_256 | id-dsa-with-blake2s256 |  |
| SB_CERT_ALGORITHM_EDDSA_ED25519 | id-Ed25519 |  |
| SB_CERT_ALGORITHM_EDDSA_ED448 | id-Ed448 |  |
| SB_CERT_ALGORITHM_EDDSA_ED25519_PH | id-Ed25519ph |  |
| SB_CERT_ALGORITHM_EDDSA_ED448_PH | id-Ed448ph |  |
| SB_CERT_ALGORITHM_EDDSA | id-EdDSA |  |
| SB_CERT_ALGORITHM_EDDSA_SIGNATURE | id-EdDSA-sig |  |
| SB_CERT_ALGORITHM_MLDSA_44 | id-ml-dsa-44 |  |
| SB_CERT_ALGORITHM_MLDSA_65 | id-ml-dsa-65 |  |
| SB_CERT_ALGORITHM_MLDSA_87 | id-ml-dsa-87 |  |
| SB_CERT_ALGORITHM_HASH_MLDSA_44_SHA512 | id-hash-ml-dsa-44-with-sha512 |  |
| SB_CERT_ALGORITHM_HASH_MLDSA_65_SHA512 | id-hash-ml-dsa-65-with-sha512 |  |
| SB_CERT_ALGORITHM_HASH_MLDSA_87_SHA512 | id-hash-ml-dsa-87-with-sha512 |  |
| SB_CERT_ALGORITHM_MLKEM_512 | id-ml-kem-512 |  |
| SB_CERT_ALGORITHM_MLKEM_768 | id-ml-kem-768 |  |
| SB_CERT_ALGORITHM_MLKEM_1024 | id-ml-kem-1024 |  |

## Data Type

**string**

# FIPSMode Property ([MessageDecryptor](#messagedecryptor-component) Component)

Reserved.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) FIPSMode() (bool, error)func (obj *MessageDecryptor) SetFIPSMode(value bool) error
```

## Default Value

false

## Remarks

This property is reserved for future use.

## Data Type

**bool**

# InputBytes Property ([MessageDecryptor](#messagedecryptor-component) Component)

Use this property to pass the input to class in byte array form.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) InputBytes() ([]byte, error)func (obj *MessageDecryptor) SetInputBytes(value []byte) error
```

## Remarks

Assign a byte array containing the data to be processed to this property.

## Data Type

**[]byte**

# InputFile Property ([MessageDecryptor](#messagedecryptor-component) Component)

Path to the file containing the encrypted message.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) InputFile() (string, error)func (obj *MessageDecryptor) SetInputFile(value string) error
```

## Default Value

""

## Remarks

Use this property to provide a file containing the encrypted data.

## Data Type

**string**

# Key Property ([MessageDecryptor](#messagedecryptor-component) Component)

The symmetric key to use for decryption.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) Key() ([]byte, error)func (obj *MessageDecryptor) SetKey(value []byte) error
```

## Remarks

Use this property to provide the symmetric key to decrypt the data. This property is only applicable for processing data of EncryptedData subtype.

Assign this property before calling [Decrypt](#decrypt-method-messagedecryptor-component).

## Data Type

**[]byte**

# OutputBytes Property ([MessageDecryptor](#messagedecryptor-component) Component)

Use this property to read the output the class object has produced.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) OutputBytes() ([]byte, error)
```

## Remarks

Read the contents of this property after the operation has completed to read the produced output. This property will only be set if the [OutputFile](#outputfile-property-messagedecryptor-component) and OutputStream properties had not been assigned.

This property is read-only.

## Data Type

**[]byte**

# OutputFile Property ([MessageDecryptor](#messagedecryptor-component) Component)

Path to the file to save the decrypted data to.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) OutputFile() (string, error)func (obj *MessageDecryptor) SetOutputFile(value string) error
```

## Default Value

""

## Remarks

Use this property to specify the output file where the decrypted message should be saved.

## Data Type

**string**

# SignedAttributeCount Property ([MessageDecryptor](#messagedecryptor-component) Component)

The number of records in the SignedAttribute arrays.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) SignedAttributeCount() (int32, error)
```

## Default Value

0

## Remarks

This property controls the size of the following arrays:

- [SignedAttributeOID](#signedattributeoid-property-messagedecryptor-component)
- [SignedAttributeValue](#signedattributevalue-property-messagedecryptor-component)

The array indices start at *0* and end at *SignedAttributeCount - 1*.

This property is read-only.

## Data Type

**int32**

# SignedAttributeOID Property ([MessageDecryptor](#messagedecryptor-component) Component)

The object identifier of the attribute.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) SignedAttributeOID(SignedAttributeIndex int32) (string, error)
```

## Default Value

""

## Remarks

The object identifier of the attribute.

The *SignedAttributeIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [SignedAttributeCount](#signedattributecount-property-messagedecryptor-component) property.

This property is read-only.

## Data Type

**string**

# SignedAttributeValue Property ([MessageDecryptor](#messagedecryptor-component) Component)

The value of the attribute.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) SignedAttributeValue(SignedAttributeIndex int32) ([]byte, error)
```

## Remarks

The value of the attribute.

The *SignedAttributeIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [SignedAttributeCount](#signedattributecount-property-messagedecryptor-component) property.

This property is read-only.

## Data Type

**[]byte**

# UnsignedAttributeCount Property ([MessageDecryptor](#messagedecryptor-component) Component)

The number of records in the UnsignedAttribute arrays.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) UnsignedAttributeCount() (int32, error)
```

## Default Value

0

## Remarks

This property controls the size of the following arrays:

- [UnsignedAttributeOID](#unsignedattributeoid-property-messagedecryptor-component)
- [UnsignedAttributeValue](#unsignedattributevalue-property-messagedecryptor-component)

The array indices start at *0* and end at *UnsignedAttributeCount - 1*.

This property is read-only.

## Data Type

**int32**

# UnsignedAttributeOID Property ([MessageDecryptor](#messagedecryptor-component) Component)

The object identifier of the attribute.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) UnsignedAttributeOID(UnsignedAttributeIndex int32) (string, error)
```

## Default Value

""

## Remarks

The object identifier of the attribute.

The *UnsignedAttributeIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [UnsignedAttributeCount](#unsignedattributecount-property-messagedecryptor-component) property.

This property is read-only.

## Data Type

**string**

# UnsignedAttributeValue Property ([MessageDecryptor](#messagedecryptor-component) Component)

The value of the attribute.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) UnsignedAttributeValue(UnsignedAttributeIndex int32) ([]byte, error)
```

## Remarks

The value of the attribute.

The *UnsignedAttributeIndex* parameter specifies the index of the item in the array. The size of the array is controlled by the [UnsignedAttributeCount](#unsignedattributecount-property-messagedecryptor-component) property.

This property is read-only.

## Data Type

**[]byte**

# CheckEncryptionType Method ([MessageDecryptor](#messagedecryptor-component) Component)

Determines the type of encrypted message in the supplied file.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) CheckEncryptionType() (int32, error)
```

## Remarks

Use this method to determine the kind of the signature stored in [InputFile](#inputfile-property-messagedecryptor-component) (InputStream).

|  |  |  |
| --- | --- | --- |
| metUnknown | 0 | Unknown or unsupported encryption type |
| metCertEncrypted | 1 | Certificate-based encryption |
| metKeyEncrypted | 2 | Symmetric key-based encryption |
| metCertEncryptedAndAuthenticated | 3 | Certificate-based encryption with authentication (AEAD) |

# Config Method ([MessageDecryptor](#messagedecryptor-component) Component)

Sets or retrieves a configuration setting.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) Config(ConfigurationString string) (string, error)
```

## Remarks

Config is a generic method available in every struct. It is used to set and retrieve [configuration settings](#config-settings-messagedecryptor-component) 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](#config-settings-messagedecryptor-component), you must call *Config("PROPERTY")*. The value will be returned as a string.

# Decrypt Method ([MessageDecryptor](#messagedecryptor-component) Component)

Attempts to decrypt an encrypted PKCS#7 message.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) Decrypt() error
```

## Remarks

Call this method to attempt to decrypt the PKCS#7 encrypted data. This call supports EnvelopedData and EncryptedData subtypes on input.

Use [InputFile](#inputfile-property-messagedecryptor-component) or InputStream property to provide the data, and either Certificates or [Key](#key-property-messagedecryptor-component) to supply the decryption key material.

When processing enveloped data, the struct may fire [RecipientFound](#recipientfound-event-messagedecryptor-component) event to report recipient information.

# DoAction Method ([MessageDecryptor](#messagedecryptor-component) Component)

Performs an additional action.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) DoAction(ActionID string, ActionParams string) (string, error)
```

## Remarks

DoAction 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:

|  |  |  |  |
| --- | --- | --- | --- |
| Action | Parameters | Returned value | Description |
| ResetTrustedListCache | none | none | Clears the cached list of trusted lists. |
| ResetCertificateCache | none | none | Clears the cached certificates. |
| ResetCRLCache | none | none | Clears the cached CRLs. |
| ResetOCSPResponseCache | none | none | Clears the cached OCSP responses. |

# Reset Method ([MessageDecryptor](#messagedecryptor-component) Component)

Resets the class settings.

## Syntax

*Go Syntax*

```text
func (obj *MessageDecryptor) Reset() error
```

## Remarks

Reset is a generic method available in every struct.

# Error Event ([MessageDecryptor](#messagedecryptor-component) Component)

Information about errors during PKCS#7 message decryption.

## Syntax

*Go Syntax*

```text
// MessageDecryptorErrorEventArgs carries the MessageDecryptor Error event's parameters.
type MessageDecryptorErrorEventArgs struct {...}

func (args *MessageDecryptorErrorEventArgs) ErrorCode() int32
func (args *MessageDecryptorErrorEventArgs) Description() string
// MessageDecryptorErrorEvent defines the signature of the MessageDecryptor Error event's handler function.
type MessageDecryptorErrorEvent func(sender *MessageDecryptor, args *MessageDecryptorErrorEventArgs)

func (obj *MessageDecryptor) GetOnErrorHandler() MessageDecryptorErrorEvent
func (obj *MessageDecryptor) SetOnErrorHandler(handlerFunc MessageDecryptorErrorEvent)
```

## Remarks

The event is fired in case of exceptional conditions during message processing.

*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 [Messages](#trappable-errors-messagedecryptor-component) section.

# ExternalDecrypt Event ([MessageDecryptor](#messagedecryptor-component) Component)

Handles remote or external decryption.

## Syntax

*Go Syntax*

```text
// MessageDecryptorExternalDecryptEventArgs carries the MessageDecryptor ExternalDecrypt event's parameters.
type MessageDecryptorExternalDecryptEventArgs struct {...}

func (args *MessageDecryptorExternalDecryptEventArgs) OperationId() string
func (args *MessageDecryptorExternalDecryptEventArgs) Algorithm() string
func (args *MessageDecryptorExternalDecryptEventArgs) Pars() string
func (args *MessageDecryptorExternalDecryptEventArgs) EncryptedData() string
func (args *MessageDecryptorExternalDecryptEventArgs) Data() string
func (args *MessageDecryptorExternalDecryptEventArgs) SetData(value string)

// MessageDecryptorExternalDecryptEvent defines the signature of the MessageDecryptor ExternalDecrypt event's handler function.
type MessageDecryptorExternalDecryptEvent func(sender *MessageDecryptor, args *MessageDecryptorExternalDecryptEventArgs)

func (obj *MessageDecryptor) GetOnExternalDecryptHandler() MessageDecryptorExternalDecryptEvent
func (obj *MessageDecryptor) SetOnExternalDecryptHandler(handlerFunc MessageDecryptorExternalDecryptEvent)
```

## Remarks

Assign a handler to this event if you need to delegate a low-level decryption operation to an external, remote, or custom decryption engine. The handler receives an encrypted value in the *EncryptedData* parameter, and is expected to decrypt it and place the decrypted value into the *Data* parameter.

*OperationId* provides a comment about the operation and its origin. It depends on the exact struct being used, and may be empty. *Algorithm* specifies the encryption algorithm being used, and *Pars* contains algorithm-dependent parameters.

The struct uses base16 (hex) encoding for the *EncryptedData*, *Data*, and *Pars* parameters. If your decryption engine uses a different input and output encoding, you may need to decode and/or encode the data before and/or after the decryption.

Sample data encoded in base16: a0dee2a0382afbb09120ffa7ccd8a152 - lower case base16 A0DEE2A0382AFBB09120FFA7CCD8A152 - upper case base16

# Notification Event ([MessageDecryptor](#messagedecryptor-component) Component)

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

## Syntax

*Go Syntax*

```text
// MessageDecryptorNotificationEventArgs carries the MessageDecryptor Notification event's parameters.
type MessageDecryptorNotificationEventArgs struct {...}

func (args *MessageDecryptorNotificationEventArgs) EventID() string
func (args *MessageDecryptorNotificationEventArgs) EventParam() string
// MessageDecryptorNotificationEvent defines the signature of the MessageDecryptor Notification event's handler function.
type MessageDecryptorNotificationEvent func(sender *MessageDecryptor, args *MessageDecryptorNotificationEventArgs)

func (obj *MessageDecryptor) GetOnNotificationHandler() MessageDecryptorNotificationEvent
func (obj *MessageDecryptor) SetOnNotificationHandler(handlerFunc MessageDecryptorNotificationEvent)
```

## 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.

This struct can fire this event with the following *EventID* values:

|  |  |
| --- | --- |
| Progress | Fires periodically to report the progress of the current operation. The EventParam parameter contains a slash-separated pair of values (Current/Total). |

# RecipientFound Event ([MessageDecryptor](#messagedecryptor-component) Component)

Fires to report a message addressee parameters.

## Syntax

*Go Syntax*

```text
// MessageDecryptorRecipientFoundEventArgs carries the MessageDecryptor RecipientFound event's parameters.
type MessageDecryptorRecipientFoundEventArgs struct {...}

func (args *MessageDecryptorRecipientFoundEventArgs) IssuerRDN() string
func (args *MessageDecryptorRecipientFoundEventArgs) SerialNumber() []byte
func (args *MessageDecryptorRecipientFoundEventArgs) SubjectKeyID() []byte
func (args *MessageDecryptorRecipientFoundEventArgs) CertFound() bool
// MessageDecryptorRecipientFoundEvent defines the signature of the MessageDecryptor RecipientFound event's handler function.
type MessageDecryptorRecipientFoundEvent func(sender *MessageDecryptor, args *MessageDecryptorRecipientFoundEventArgs)

func (obj *MessageDecryptor) GetOnRecipientFoundHandler() MessageDecryptorRecipientFoundEvent
func (obj *MessageDecryptor) SetOnRecipientFoundHandler(handlerFunc MessageDecryptorRecipientFoundEvent)
```

## Remarks

This event is fired for each addressee the message is encrypted for. It may fire several times in a row if the message is encrypted for more than one recipient.

The *IssuerRDN*, *SerialNumber*, and *SubjectKeyID* parameters to identify the recipient's certificate. *CertFound* indicates if the specified certificate has been located in Certificates collection. If it wasn't, you might want to look up the certificate manually, and add it to the collection inside the event handler.

# Config Settings ([MessageDecryptor](#messagedecryptor-component) Component)

 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](#config-method-messagedecryptor-component) method.

### MessageDecryptor Config Settings

**NoOuterContentInfo**: Whether the message has outer content.Tells the component whether the message to be decrypted has any outer content.

**OAEPHashAlgorithm**: Hash algorithm to be used in RSA-OAEP.Defines which hash algorithm should be used in RSA-OAEP scheme.

**TempPath**: Path for storing temporary files.This setting specifies an absolute path to the location on disk where temporary files are stored. This setting is supported only in the Java edition for all applicable signing components except [PDFSigner](PDFSigner.md#PDFSigner), where this limitation does not apply.

### Base Config Settings

**ASN1UseGlobalTagCache**: Controls whether ASN.1 module should use a global object cache.This is a performance setting. It is unlikely that you will ever need to adjust it.

**AssignSystemSmartCardPins**: Specifies whether CSP-level PINs should be assigned to CNG keys.This is a low-level tweak for certain cryptographic providers. It is unlikely that you will ever need to adjust it.

**CheckKeyIntegrityBeforeUse**: Enables or disable private key integrity check before use.This global property enables or disables private key material check before each signing operation. This slows down performance a bit, but prevents a selection of attacks on RSA keys where keys with unknown origins are used.

You can switch this property off to improve performance if your project only uses known, good private keys.

**CookieCaching**: Specifies whether a cookie cache should be used for HTTP(S) transports.Set this property to enable or disable cookies caching for the struct.

Supported values are:

|  |  |  |
| --- | --- | --- |
| off |  | No caching (default) |
| local |  | Local caching |
| global |  | Global caching |

**Cookies**: Gets or sets local cookies for the struct.Use this property to get cookies from the internal cookie storage of the struct and/or restore them back between application sessions.

**DefDeriveKeyIterations**: Specifies the default key derivation algorithm iteration count.This global property sets the default number of iterations for all supported key derivation algorithms. Note that you can provide the required number of iterations by using properties of the relevant key generation component; this global setting is used in scenarios where specific iteration count is not or cannot be provided.

**DNSLocalSuffix**: The suffix to assign for TLD names.Use this global setting to adjust the default suffix to assign to top-level domain names. The default is *.local*.

**EnableClientSideSSLFFDHE**: Enables or disables finite field DHE key exchange support in TLS clients.This global property enables or disables support for finite field DHE key exchange methods in TLS clients. FF DHE is a slower algorithm if compared to EC DHE; enabling it may result in slower connections.

This setting only applies to sessions negotiated with TLS version 1.3.

**EnableSSHMLKEM**: Enables support for ML-KEM/hybrid key exchange algorithms in SSH client and server components.Use this setting to enable hybrid key exchange algorithms in client and server SSH and SFTP components. This is a global setting that enables ML-KEM blanketly in all SSH-dependent components.

**EnableTLSMLKEM**: Enables support for ML-KEM and hybrid groups in TLS client and server components.Use this setting to enable ML-KEM and hybrid key exchange groups in client and server TLS components. This is a global setting that enables ML-KEM blanketly in all TLS-dependent components.

**GlobalCookies**: Gets or sets global cookies for all the HTTP transports.Use this property to get cookies from the GLOBAL cookie storage or restore them back between application sessions. These cookies will be used by all the structs that have its *CookieCaching* property set to "global".

**HardwareCryptoUsePolicy**: The hardware crypto usage policy.This global setting controls the hardware cryptography usage policy.

Supported Values:

|  |  |
| --- | --- |
| auto | Use hardware cryptography if available; otherwise, fall back to software-based cryptography (default). |
| enable | Always attempt to use hardware cryptography. If unavailable, exception will be thrown. |
| disable | Do not use hardware cryptography. |

**HttpUserAgent**: Specifies the user agent name to be used by all HTTP clients.This global setting defines the User-Agent field of the HTTP request provides information about the software that initiates the request. This value will be used by all the HTTP clients including the ones used internally in other structs.

**HttpVersion**: The HTTP version to use in any inner HTTP client components created.Set this property to 1.0 or 1.1 to indicate the HTTP version that any internal HTTP clients should use.

**IgnoreExpiredMSCTLSigningCert**: Whether to tolerate the expired Windows Update signing certificate.It is not uncommon for Microsoft Windows Update Certificate Trust List to be signed with an expired Microsoft certificate. Setting this global property to true makes SBB ignore the expired factor and take the Trust List into account.

**ListDelimiter**: The delimiter character for multi-element lists.Allows to set the delimiter for any multi-entry values returned by the component as a string object, such as file lists. For most of the components, this property is set to a newline sequence.

**LogDestination**: Specifies the debug log destination.Contains a comma-separated list of values that specifies where debug log should be dumped.

Supported values are:

|  |  |  |
| --- | --- | --- |
| file |  | File |
| console |  | Console |
| systemlog |  | System Log (supported for Android only) |
| debugger |  | Debugger (supported for VCL for Windows and .Net) |

**LogDetails**: Specifies the debug log details to dump.Contains a comma-separated list of values that specifies which debug log details to dump.

Supported values are:

|  |  |  |
| --- | --- | --- |
| time |  | Current time |
| level |  | Level |
| package |  | Package name |
| module |  | Module name |
| class |  | Class name |
| method |  | Method name |
| threadid |  | Thread Id |
| contenttype |  | Content type |
| content |  | Content |
| all |  | All details |

**LogFile**: Specifies the debug log filename.Use this property to provide a path to the log file.

**LogFilters**: Specifies the debug log filters.Contains a comma-separated list of value pairs ("name:value") that describe filters.

Supported filter names are:

|  |  |  |
| --- | --- | --- |
| exclude-package |  | Exclude a package specified in the value |
| exclude-module |  | Exclude a module specified in the value |
| exclude-class |  | Exclude a class specified in the value |
| exclude-method |  | Exclude a method specified in the value |
| include-package |  | Include a package specified in the value |
| include-module |  | Include a module specified in the value |
| include-class |  | Include a class specified in the value |
| include-method |  | Include a method specified in the value |

**LogFlushMode**: Specifies the log flush mode.Use this property to set the log flush mode. The following values are defined:

|  |  |  |
| --- | --- | --- |
| none |  | No flush (caching only) |
| immediate |  | Immediate flush (real-time logging) |
| maxcount |  | Flush cached entries upon reaching LogMaxEventCount entries in the cache. |

**LogLevel**: Specifies the debug log level.Use this property to provide the desired debug log level.

Supported values are:

|  |  |  |
| --- | --- | --- |
| none |  | None (by default) |
| fatal |  | Severe errors that cause premature termination. |
| error |  | Other runtime errors or unexpected conditions. |
| warning |  | Use of deprecated APIs, poor use of API, 'almost' errors, other runtime situations that are undesirable or unexpected, but not necessarily "wrong". |
| info |  | Interesting runtime events (startup/shutdown). |
| debug |  | Detailed information on flow of through the system. |
| trace |  | More detailed information. |

**LogMaxEventCount**: Specifies the maximum number of events to cache before further action is taken.Use this property to specify the log event number threshold. This threshold may have different effects, depending on the rotation setting and/or the flush mode.

The default value of this setting is 100.

**LogRotationMode**: Specifies the log rotation mode.Use this property to set the log rotation mode. The following values are defined:

|  |  |  |
| --- | --- | --- |
| none |  | No rotation |
| deleteolder |  | Delete older entries from the cache upon reaching LogMaxEventCount |
| keepolder |  | Keep older entries in the cache upon reaching LogMaxEventCount (newer entries are discarded) |

**MaxASN1BufferLength**: Specifies the maximal allowed length for ASN.1 primitive tag data.This global property limits the maximal allowed length for ASN.1 tag data for non-content-carrying structures, such as certificates, CRLs, or timestamps. It does not affect structures that can carry content, such as CMS/CAdES messages. This is a security property aiming at preventing DoS attacks.

**MaxASN1TreeDepth**: Specifies the maximal depth for processed ASN.1 trees.This global property limits the maximal depth of ASN.1 trees that the component can handle without throwing an error. This is a security property aiming at preventing DoS attacks.

**OCSPHashAlgorithm**: Specifies the hash algorithm to be used to identify certificates in OCSP requests.This global setting defines the hash algorithm to use in OCSP requests during chain validation. Some OCSP responders can only use older algorithms, in which case setting this property to SHA1 may be helpful.

**OldClientSideRSAFallback**: Specifies whether the SSH client should use a SHA1 fallback.Tells the SSH client to use a legacy ssh-rsa authentication even if the server indicates support for newer algorithms, such as rsa-sha-256. This is a backward-compatibility tweak.

**PKICache**: Specifies which PKI elements (certificates, CRLs, OCSP responses) should be cached.The PKICache setting specifies which Public Key Infrastructure (PKI) elements should be cached to optimize performance and reduce retrieval times. It supports comma-separated values to indicate the specific types of PKI data that should be cached.

Supported Values:

|  |  |
| --- | --- |
| certificate | Enables caching of certificates. |
| crl | Enables caching of Certificate Revocation Lists (CRLs). |
| ocsp | Enables caching of OCSP (Online Certificate Status Protocol) responses. |

Example (default value):

```text
PKICache=certificate,crl,ocsp
```

 In this example, the component caches certificates, CRLs, and OCSP responses.

**PKICachePath**: Specifies the file system path where cached PKI data is stored.The PKICachePath setting defines the file system path where cached PKI data (e.g., certificates, CRLs, OCSP responses and Trusted Lists) will be stored. This allows the system to persistently save and retrieve PKI cache data, even across application restarts.

The default value is an empty string - no cached PKI data is stored on disk.

Example:

```text
PKICachePath=C:\Temp\cache
```

 In this example, the cached PKI data is stored in the C:\Temp\cache directory.

**ProductVersion**: Returns the version of the SecureBlackbox library.This property returns the long version string of the SecureBlackbox library being used (major.minor.build.revision).

**ServerSSLDHKeyLength**: Sets the size of the TLS DHE key exchange group.Use this property to adjust the length, in bits, of the DHE prime to be used by the TLS server.

**StaticDNS**: Specifies whether static DNS rules should be used.Set this property to enable or disable static DNS rules for the struct. Works only if *UseOwnDNSResolver* is set to *true*.

Supported values are:

|  |  |  |
| --- | --- | --- |
| none |  | No static DNS rules (default) |
| local |  | Local static DNS rules |
| global |  | Global static DNS rules |

**StaticIPAddress[domain]**: Gets or sets an IP address for the specified domain name.Use this property to get or set an IP address for the specified domain name in the internal (of the struct) or global DNS rules storage depending on the *StaticDNS* value. The type of the IP address (IPv4 or IPv6) is determined automatically. If both addresses are available, they are divided by the | (pipe) character.

**StaticIPAddresses**: Gets or sets all the static DNS rules.Use this property to get static DNS rules from the current rules storage or restore them back between application sessions. If *StaticDNS* of the struct is set to "*local*", the property returns/restores the rules from/to the internal storage of the struct. If *StaticDNS* of the struct is set to "*global*", the property returns/restores the rules from/to the GLOBAL storage. The rules list is returned and accepted in JSON format.

**Tag**: Allows to store any custom data.Use this config property to store any custom data.

**TLSSessionGroup**: Specifies the group name of TLS sessions to be used for session resumption.Use this property to limit the search of cached TLS sessions to the specified group. Sessions from other groups will be ignored. By default, all sessions are cached with an empty group name and available to all the structs.

**TLSSessionLifetime**: Specifies lifetime in seconds of the cached TLS session.Use this property to specify how much time the TLS session should be kept in the session cache. After this time, the session expires and will be automatically removed from the cache. Default value is 300 seconds (5 minutes).

**TLSSessionPurgeInterval**: Specifies how often the session cache should remove the expired TLS sessions.Use this property to specify the time interval of purging the expired TLS sessions from the session cache. Default value is 60 seconds (1 minute).

**UseCRLObjectCaching**: Specifies whether reuse of loaded CRL objects is enabled.This setting enables or disables the caching of CRL objects. When set to true (the default value), the system checks if a CRL object is already loaded in memory before attempting to load a new instance. If the object is found, the existing instance is reused, and its reference count is incremented to track its usage. When the reference count reaches zero, indicating that no references to the object remain, the system will free the object from memory. This setting enhances performance by minimizing unnecessary object instantiation and promotes efficient memory management, particularly in scenarios where CRL objects are frequently used.

**UseInternalRandom**: Switches between SecureBlackbox-own and platform PRNGs.Allows to switch between internal/native PRNG implementation and the one provided by the platform.

**UseLegacyAdESValidation**: Enables legacy AdES validation mode.Use this setting to switch the AdES component to the validation approach that was used in SBB 2020/SBB 2022 (less attention to temporal details).

**UseOCSPResponseObjectCaching**: Specifies whether reuse of loaded OCSP response objects is enabled.This setting enables or disables the caching of OCSP response objects. When set to true (the default value), the system checks if a OCSP response object is already loaded in memory before attempting to load a new instance. If the object is found, the existing instance is reused, and its reference count is incremented to track its usage. When the reference count reaches zero, indicating that no references to the object remain, the system will free the object from memory. This setting enhances performance by minimizing unnecessary object instantiation and promotes efficient memory management, particularly in scenarios where OCSP response objects are frequently used.

**UseOwnDNSResolver**: Specifies whether the client components should use own DNS resolver.Set this global property to false to force all the client components to use the DNS resolver provided by the target OS instead of using own one.

**UseSharedSystemStorages**: Specifies whether the validation engine should use a global per-process copy of the system certificate stores.Set this global property to false to make each validation run use its own copy of system certificate stores.

**UseSystemNativeSizeCalculation**: An internal CryptoAPI access tweak.This is an internal setting. Please do not use it unless instructed by the support team.

**UseSystemOAEPAndPSS**: Enforces or disables the use of system-driven RSA OAEP and PSS computations.This global setting defines who is responsible for performing RSA-OAEP and RSA-PSS computations where the private key is stored in a Windows system store and is exportable. If set to true, SBB will delegate the computations to Windows via a CryptoAPI call. Otherwise, it will export the key material and perform the computations using its own OAEP/PSS implementation.

This setting only applies to certificates originating from a Windows system store.

**UseSystemRandom**: Enables or disables the use of the OS PRNG.Use this global property to enable or disable the use of operating system-driven pseudorandom number generation.

**XMLRDNDescriptorName[OID]**: Defines an OID mapping to descriptor names for the certificate's IssuerRDN or SubjectRDN.This property defines custom mappings between Object Identifiers (OIDs) and descriptor names. This mapping specifies how the certificate's issuer and subject information (ds:IssuerRDN and ds:SubjectRDN elements respectively) are represented in XML signatures.

The property accepts comma-separated values where the first descriptor name is used when the OID is mapped, and subsequent values act as aliases for parsing.

Syntax:

```text
Config("XMLRDNDescriptorName[OID]=PrimaryName,Alias1,Alias2");
```

Where:

OID: The Object Identifier from the certificate's IssuerRDN or SubjectRDN that you want to map.

PrimaryName: The main descriptor name used in the XML signature when the OID is encountered.

Alias1, Alias2, ...: Optional alternative names recognized during parsing.

Usage Examples:

Map OID 2.5.4.5 to SERIALNUMBER:

```text
Config("XMLRDNDescriptorName[2.5.4.5]=SERIALNUMBER");
```

Map OID 1.2.840.113549.1.9.1 to E, with aliases EMAIL and EMAILADDRESS:

```text
Config("XMLRDNDescriptorName[1.2.840.113549.1.9.1]=E,EMAIL,EMAILADDRESS");
```

**XMLRDNDescriptorPriority[OID]**: Specifies the priority of descriptor names associated with a specific OID.This property specifies the priority of descriptor names associated with a specific OID that allows to reorder descriptors in the ds:IssuerRDN and ds:SubjectRDN elements during signing.

**XMLRDNDescriptorReverseOrder**: Specifies whether to reverse the order of descriptors in RDN.Specifies whether to reverse the order of descriptors in the ds:IssuerRDN and ds:SubjectRDN elements during XML signing. By default, this property is set to true (as specified in RFC 2253, 2.1).

**XMLRDNDescriptorSeparator**: Specifies the separator used between descriptors in RDN.Specifies the separator used between descriptors in the ds:IssuerRDN and ds:SubjectRDN elements during XML signing. By default, this property is set to ", " value.

# Trappable Errors ([MessageDecryptor](#messagedecryptor-component) Component)

### MessageDecryptor Errors

|  |  |
| --- | --- |
| 1048577 | Invalid parameter ([SB_ERROR_INVALID_PARAMETER](constants.md#const_SBERRORINVALIDPARAMETER)) |
| 1048578 | Invalid configuration ([SB_ERROR_INVALID_SETUP](constants.md#const_SBERRORINVALIDSETUP)) |
| 1048579 | Invalid state ([SB_ERROR_INVALID_STATE](constants.md#const_SBERRORINVALIDSTATE)) |
| 1048580 | Invalid value ([SB_ERROR_INVALID_VALUE](constants.md#const_SBERRORINVALIDVALUE)) |
| 1048581 | Private key not found ([SB_ERROR_NO_PRIVATE_KEY](constants.md#const_SBERRORNOPRIVATEKEY)) |
| 1048582 | Cancelled by the user ([SB_ERROR_CANCELLED_BY_USER](constants.md#const_SBERRORCANCELLEDBYUSER)) |
| 1048583 | The file was not found ([SB_ERROR_NO_SUCH_FILE](constants.md#const_SBERRORNOSUCHFILE)) |
| 1048584 | Unsupported feature or operation ([SB_ERROR_UNSUPPORTED_FEATURE](constants.md#const_SBERRORUNSUPPORTEDFEATURE)) |
| 1048585 | General error ([SB_ERROR_GENERAL_ERROR](constants.md#const_SBERRORGENERALERROR)) |