XMLSig Class

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The XMLSig class is used to sign XML and verify signed XML.

Syntax

class ipworksencrypt.XMLSig

Remarks

The XMLSig component provides an easy to use API for signing and verifying signed XML. The sign method will create signed XML with an enveloped signature. The verify_signature method will attempt to verify the signature(s) within a XML document.

Sign

Before calling sign specify the XML to sign by setting input_file, or input_xml.

The Reference* properties must be set. At least one reference must be set. A reference defines the XML element to sign, and the options that specify how it is transformed and hashed during the signing process.

Set certificate to a certificate with private key.

Optionally set the canonicalization_method. This determines how the signature itself is canonicalized. signing_algorithm defines the algorithm used to sign. The signature_xpath property may be set to specify the location in the XML document where the signature will be placed.

Lastly, call sign to sign the XML.

The following properties are applicable when calling this method:

• canonicalization_method
• certificate (required)
• Reference* (required)
• signature_xpath
• signing_algorithm

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:

• input_file
• input_xml

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

Verify a Signature

When verify_signature is called, the class will scan the XML document and fire the on_signature_info event for each signature that is found. When the on_signature_info event fires the Reference* properties will be populated.

Within the on_signature_info event the reference_xml_element property must be set to the location of the XML element to which the signature applies. The reference_uri property may contain data helpful to locating the XML element.

The reference_xml_element property specifies the XPath to the element. For instance:

The signature is verified either using a key parsed from the signed XML, or using the certificate specified by the SignerCert* properties. The class will automatically parse the signer certificate (if present) from the signed XML and populate the SignerCert* properties with the parsed value.

When on_signature_info fires, if the SignerCertParsed parameter is True the SignerCert* properties may be inspected to see the details of the parsed certificate. If SignerCertParsed is False, then the SignerCert* properties must be set to a valid certificate for signature verification to proceed.

When the on_signature_info event finishes firing, the certificate present in the SignerCert* properties will be used to verify the signature, whether this is the certificate automatically parsed by the class or a different certificate specified within the event.

If the signature was successfully verified the method will return without error. If the signature was not verified the method fails with an error.

Property List

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

Method List

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

Event List

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

Config Settings

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

canonicalization_method Property

The canonicalization method applied to the signature.

Syntax

def get_canonicalization_method() -> int: ...
def set_canonicalization_method(value: int) -> None: ...

canonicalization_method = property(get_canonicalization_method, set_canonicalization_method)

Default Value

0

Remarks

This property specifies the canonicalization method that is applied to the signature. This may be set before calling sign. This will be set automatically after calling verify_signature. Possible values are:

cert_encoded Property

This is the certificate (PEM/Base64 encoded).

Syntax

def get_cert_encoded() -> bytes: ...
def set_cert_encoded(value: bytes) -> None: ...

cert_encoded = property(get_cert_encoded, set_cert_encoded)

Default Value

""

Remarks

This is the certificate (PEM/Base64 encoded). This property is used to assign a specific certificate. The cert_store and cert_subject properties also may be used to specify a certificate.

When cert_encoded is set, a search is initiated in the current cert_store for the private key of the certificate. If the key is found, cert_subject is updated to reflect the full subject of the selected certificate; otherwise, cert_subject is set to an empty string.

cert_store Property

This is the name of the certificate store for the client certificate.

Syntax

def get_cert_store() -> bytes: ...
def set_cert_store(value: bytes) -> None: ...

cert_store = property(get_cert_store, set_cert_store)

Default Value

"MY"

Remarks

This is the name of the certificate store for the client certificate.

The cert_store_type property denotes the type of the certificate store specified by cert_store. If the store is password protected, specify the password in cert_store_password.

cert_store is used in conjunction with the cert_subject property to specify client certificates. If cert_store has a value, and cert_subject or cert_encoded is set, a search for a certificate is initiated. Please see the cert_subject property for details.

Designations of certificate stores are platform dependent.

The following designations are the most common User and Machine certificate stores in Windows:

When the certificate store type is PFXFile, this property must be set to the name of the file. When the type is PFXBlob, the property must be set to the binary contents of a PFX file (i.e., PKCS#12 certificate store).

cert_store_password Property

If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.

Syntax

def get_cert_store_password() -> str: ...
def set_cert_store_password(value: str) -> None: ...

cert_store_password = property(get_cert_store_password, set_cert_store_password)

Default Value

""

Remarks

If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.

cert_store_type Property

This is the type of certificate store for this certificate.

Syntax

def get_cert_store_type() -> int: ...
def set_cert_store_type(value: int) -> None: ...

cert_store_type = property(get_cert_store_type, set_cert_store_type)

Default Value

0

Remarks

This is the type of certificate store for this certificate.

The class supports both public and private keys in a variety of formats. When the cstAuto value is used, the class will automatically determine the type. This property can take one of the following values:

cert_subject Property

This is the subject of the certificate used for client authentication.

Syntax

def get_cert_subject() -> str: ...
def set_cert_subject(value: str) -> None: ...

cert_subject = property(get_cert_subject, set_cert_subject)

Default Value

""

Remarks

This is the subject of the certificate used for client authentication.

This property must be set after all other certificate properties are set. When this property is set, a search is performed in the current certificate store to locate a certificate with a matching subject.

If a matching certificate is found, the property is set to the full subject of the matching certificate.

If an exact match is not found, the store is searched for subjects containing the value of the property.

If a match is still not found, the property is set to an empty string, and no certificate is selected.

The special value "*" picks a random certificate in the certificate store.

The certificate subject is a comma-separated list of distinguished name fields and values. For instance, "CN=www.server.com, OU=test, C=US, E=support@nsoftware.com". Common fields and their meanings are as follows:

If a field value contains a comma, it must be quoted.

hmac_key Property

The HMAC key used with the 'HMAC-SHA1' signing algorithm.

Syntax

def get_hmac_key() -> bytes: ...
def set_hmac_key(value: bytes) -> None: ...

hmac_key = property(get_hmac_key, set_hmac_key)

Default Value

""

Remarks

This property defines the HMAC key to be used when signing_algorithm is set to "HMAC-SHA1". This must be set before calling before calling sign.

This property is also applicable when calling verify_signature. This may be set before calling verify_signature or from within the on_signature_info event.

input_file Property

The XML file to process.

Syntax

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

input_file = property(get_input_file, set_input_file)

Default Value

""

Remarks

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

Input and Output Properties

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

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

• input_file
• input_xml

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

input_xml Property

The XML to process.

Syntax

def get_input_xml() -> str: ...
def set_input_xml(value: str) -> None: ...

input_xml = property(get_input_xml, set_input_xml)

Default Value

""

Remarks

This property specifies the XML 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:

• input_file
• input_xml

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

output_file Property

The output file.

Syntax

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

output_file = property(get_output_file, set_output_file)

Default Value

""

Remarks

This property specifies the file to which the output will be written. This may be set to an absolute or relative path.

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:

• input_file
• input_xml

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

output_xml Property

The output XML after processing.

Syntax

def get_output_xml() -> str: ...
def set_output_xml(value: str) -> None: ...

output_xml = property(get_output_xml, set_output_xml)

Default Value

""

Remarks

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

Input and Output Properties

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

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

• input_file
• input_xml

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

overwrite Property

Indicates whether or not the class should overwrite files.

Syntax

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

overwrite = property(get_overwrite, set_overwrite)

Default Value

FALSE

Remarks

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

reference_count Property

The number of records in the Reference arrays.

Syntax

def get_reference_count() -> int: ...
def set_reference_count(value: int) -> None: ...

reference_count = property(get_reference_count, set_reference_count)

Default Value

0

Remarks

This property controls the size of the following arrays:

• reference_hash_algorithm
• reference_hash_value
• reference_transform_algorithms
• reference_uri
• reference_xml_element

The array indices start at 0 and end at reference_count - 1.

reference_hash_algorithm Property

This property defines the hash algorithm to apply to the element specified by XMLElement .

Syntax

def get_reference_hash_algorithm(reference_index: int) -> str: ...
def set_reference_hash_algorithm(reference_index: int, value: str) -> None: ...

Default Value

"SHA1"

Remarks

This property defines the hash algorithm to apply to the element specified by reference_xml_element. Possible values are:

• "SHA1" (default)
• "SHA256"
• "SHA512"

The reference_index parameter specifies the index of the item in the array. The size of the array is controlled by the reference_count property.

reference_hash_value Property

This property holds the calculated hash value for the specified XMLElement .

Syntax

def get_reference_hash_value(reference_index: int) -> str: ...

Default Value

""

Remarks

This property holds the calculated hash value for the specified reference_xml_element.

The reference_index parameter specifies the index of the item in the array. The size of the array is controlled by the reference_count property.

This property is read-only.

reference_transform_algorithms Property

This property specifies a comma separated list of canonicalization algorithms to be applied to XMLElement .

Syntax

def get_reference_transform_algorithms(reference_index: int) -> str: ...
def set_reference_transform_algorithms(reference_index: int, value: str) -> None: ...

Default Value

"C14N"

Remarks

This property specifies a comma separated list of canonicalization algorithms to be applied to reference_xml_element. The XML data specified by reference_xml_element will be transformed using the specified algorithm(s) before the hash_algorithm is applied. The default value is "C14N". Possible values are:

The reference_index parameter specifies the index of the item in the array. The size of the array is controlled by the reference_count property.

reference_uri Property

This property is the URI of the reference.

Syntax

def get_reference_uri(reference_index: int) -> str: ...
def set_reference_uri(reference_index: int, value: str) -> None: ...

Default Value

""

Remarks

This property is the URI of the reference. The value specified here identifies the data within the document.

When signing, this value may be set to a URI reference which identifies reference_xml_element. reference_xml_element must be set separately.

When verifying, this value may be checked within the on_signature_info event to identify the location of reference_xml_element. reference_xml_element must be set separately.

The reference_index parameter specifies the index of the item in the array. The size of the array is controlled by the reference_count property.

reference_xml_element Property

This property specifies XML element to sign or verify using XPath notation.

Syntax

def get_reference_xml_element(reference_index: int) -> str: ...
def set_reference_xml_element(reference_index: int, value: str) -> None: ...

Default Value

"/"

Remarks

This property specifies XML element to sign or verify using XPath notation. When signing, this must be set before calling sign. When verifying, this must be set from within the on_signature_info event. The reference_uri property may be used to help identify the correct XML element.

The reference_index parameter specifies the index of the item in the array. The size of the array is controlled by the reference_count property.

signature_xpath Property

The XPath of the signature.

Syntax

def get_signature_xpath() -> str: ...
def set_signature_xpath(value: str) -> None: ...

signature_xpath = property(get_signature_xpath, set_signature_xpath)

Default Value

"/"

Remarks

This property specifies the XPath in the XML where the signature will be placed.

This may be set before calling sign. This property will be populated when calling verify_signature.

The default value is "/".

signer_cert_encoded Property

This is the certificate (PEM/Base64 encoded).

Syntax

def get_signer_cert_encoded() -> bytes: ...
def set_signer_cert_encoded(value: bytes) -> None: ...

signer_cert_encoded = property(get_signer_cert_encoded, set_signer_cert_encoded)

Default Value

""

Remarks

This is the certificate (PEM/Base64 encoded). This property is used to assign a specific certificate. The signer_cert_store and signer_cert_subject properties also may be used to specify a certificate.

When signer_cert_encoded is set, a search is initiated in the current signer_cert_store for the private key of the certificate. If the key is found, signer_cert_subject is updated to reflect the full subject of the selected certificate; otherwise, signer_cert_subject is set to an empty string.

signer_cert_store Property

This is the name of the certificate store for the client certificate.

Syntax

def get_signer_cert_store() -> bytes: ...
def set_signer_cert_store(value: bytes) -> None: ...

signer_cert_store = property(get_signer_cert_store, set_signer_cert_store)

Default Value

"MY"

Remarks

This is the name of the certificate store for the client certificate.

The signer_cert_store_type property denotes the type of the certificate store specified by signer_cert_store. If the store is password protected, specify the password in signer_cert_store_password.

signer_cert_store is used in conjunction with the signer_cert_subject property to specify client certificates. If signer_cert_store has a value, and signer_cert_subject or signer_cert_encoded is set, a search for a certificate is initiated. Please see the signer_cert_subject property for details.

Designations of certificate stores are platform dependent.

The following designations are the most common User and Machine certificate stores in Windows:

When the certificate store type is PFXFile, this property must be set to the name of the file. When the type is PFXBlob, the property must be set to the binary contents of a PFX file (i.e., PKCS#12 certificate store).

signer_cert_store_password Property

If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.

Syntax

def get_signer_cert_store_password() -> str: ...
def set_signer_cert_store_password(value: str) -> None: ...

signer_cert_store_password = property(get_signer_cert_store_password, set_signer_cert_store_password)

Default Value

""

Remarks

If the type of certificate store requires a password, this property is used to specify the password needed to open the certificate store.

signer_cert_store_type Property

This is the type of certificate store for this certificate.

Syntax

def get_signer_cert_store_type() -> int: ...
def set_signer_cert_store_type(value: int) -> None: ...

signer_cert_store_type = property(get_signer_cert_store_type, set_signer_cert_store_type)

Default Value

0

Remarks

This is the type of certificate store for this certificate.

The class supports both public and private keys in a variety of formats. When the cstAuto value is used, the class will automatically determine the type. This property can take one of the following values:

signer_cert_subject Property

This is the subject of the certificate used for client authentication.

Syntax

def get_signer_cert_subject() -> str: ...
def set_signer_cert_subject(value: str) -> None: ...

signer_cert_subject = property(get_signer_cert_subject, set_signer_cert_subject)

Default Value

""

Remarks

This is the subject of the certificate used for client authentication.

This property must be set after all other certificate properties are set. When this property is set, a search is performed in the current certificate store to locate a certificate with a matching subject.

If a matching certificate is found, the property is set to the full subject of the matching certificate.

If an exact match is not found, the store is searched for subjects containing the value of the property.

If a match is still not found, the property is set to an empty string, and no certificate is selected.

The special value "*" picks a random certificate in the certificate store.

The certificate subject is a comma-separated list of distinguished name fields and values. For instance, "CN=www.server.com, OU=test, C=US, E=support@nsoftware.com". Common fields and their meanings are as follows:

If a field value contains a comma, it must be quoted.

signing_algorithm Property

The signing algorithm.

Syntax

def get_signing_algorithm() -> str: ...
def set_signing_algorithm(value: str) -> None: ...

signing_algorithm = property(get_signing_algorithm, set_signing_algorithm)

Default Value

""

Remarks

This property specifies the signing algorithm.

This may be set before calling sign. This value will be set after calling verify_signature. Possible values are:

• "RSA-SHA1" (default)
• "RSA-SHA256"
• "DSA-SHA1"
• "HMAC-SHA1"

config Method

Sets or retrieves a configuration setting.

Syntax

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

Remarks

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

These settings are similar in functionality to properties, but they are rarely used. In order to avoid "polluting" the property namespace of the class, access to these internal properties is provided through the config method.

To set a configuration setting named PROPERTY, you must call Config("PROPERTY=VALUE"), where VALUE is the value of the setting expressed as a string. For boolean values, use the strings "True", "False", "0", "1", "Yes", or "No" (case does not matter).

To read (query) the value of a configuration setting, you must call Config("PROPERTY"). The value will be returned as a string.

do_events Method

Processes events from the internal message queue.

Syntax

def do_events() -> None: ...

Remarks

When do_events is called, the class processes any available events. If no events are available, it waits for a preset period of time, and then returns.

reset Method

Resets the class.

Syntax

def reset() -> None: ...

Remarks

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

sign Method

Signs the XML.

Syntax

def sign() -> None: ...

Remarks

This methods signs the XML.

Before calling sign specify the XML to sign by setting input_file, or input_xml.

The Reference* properties must be set. At least one reference must be set. A reference defines the XML element to sign, and the options that specify how it is transformed and hashed during the signing process.

Set certificate to a certificate with private key.

Optionally set the canonicalization_method. This determines how the signature itself is canonicalized. signing_algorithm defines the algorithm used to sign. The signature_xpath property may be set to specify the location in the XML document where the signature will be placed.

Lastly, call sign to sign the XML.

The following properties are applicable when calling this method:

• canonicalization_method
• certificate (required)
• Reference* (required)
• signature_xpath
• signing_algorithm

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:

• input_file
• input_xml

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

verify_signature Method

Verifies signed XML.

Syntax

def verify_signature() -> None: ...

Remarks

This method verifies signatures contained in the XML.

When verify_signature is called, the class will scan the XML document and fire the on_signature_info event for each signature that is found. When the on_signature_info event fires the Reference* properties will be populated.

Within the on_signature_info event the reference_xml_element property must be set to the location of the XML element to which the signature applies. The reference_uri property may contain data helpful to locating the XML element.

The reference_xml_element property specifies the XPath to the element. For instance:

The signature is verified either using a key parsed from the signed XML, or using the certificate specified by the SignerCert* properties. The class will automatically parse the signer certificate (if present) from the signed XML and populate the SignerCert* properties with the parsed value.

When on_signature_info fires, if the SignerCertParsed parameter is True the SignerCert* properties may be inspected to see the details of the parsed certificate. If SignerCertParsed is False, then the SignerCert* properties must be set to a valid certificate for signature verification to proceed.

When the on_signature_info event finishes firing, the certificate present in the SignerCert* properties will be used to verify the signature, whether this is the certificate automatically parsed by the class or a different certificate specified within the event.

If the signature was successfully verified the method will return without error. If the signature was not verified the method fails with an error.

on_error Event

Fired when information is available about errors during data delivery.

Syntax

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

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

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

Remarks

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

The ErrorCode parameter contains an error code, and the Description parameter contains a textual description of the error. For a list of valid error codes and their descriptions, please refer to the Error Codes section.

on_progress Event

Fired as progress is made.

Syntax

class XMLSigProgressEventParams(object):
  @property
  def bytes_processed() -> int: ...

  @property
  def percent_processed() -> int: ...

  @property
  def operation() -> int: ...

  @property
  def is_eof() -> bool: ...
  @is_eof.setter
  def is_eof(value) -> None: ...

# In class XMLSig:
@property
def on_progress() -> Callable[[XMLSigProgressEventParams], None]: ...
@on_progress.setter
def on_progress(event_hook: Callable[[XMLSigProgressEventParams], None]) -> None: ...

Remarks

This event is fired automatically as data is processed by the class.

The PercentProcessed parameter indicates the current status of the operation.

The BytesProcessed parameter holds the total number of bytes processed so far.

The Operation parameter is only applicable when either ReadFromProgressEvent or WriteToProgressEvent is set to True. This parameter defines whether a Read or Write operation is required. If the configuration settings are not set this parameter will always return 0. Possible values are:

The IsEOF parameter is only applicable when either ReadFromProgressEvent or WriteToProgressEvent is set to True. This parameter defines whether the Read or Write operation is complete. When the Operation is Read (1) this parameter must be set to indicate that all data has been supplied to the class. When the Operation is Write (2) this value may be queried to determine when all data has been processed.

on_signature_info Event

Fired when a signature is found.

Syntax

class XMLSigSignatureInfoEventParams(object):
  @property
  def signature_id() -> str: ...

  @property
  def signer_cert_parsed() -> bool: ...

# In class XMLSig:
@property
def on_signature_info() -> Callable[[XMLSigSignatureInfoEventParams], None]: ...
@on_signature_info.setter
def on_signature_info(event_hook: Callable[[XMLSigSignatureInfoEventParams], None]) -> None: ...

Remarks

This event fires when calling verify_signature for each signature found within the XML document.

SignatureId is the id of the signature.

SignerCertParsed indicates whether the signer's certificate was automatically parsed from the signed XML.

Verification Notes

When verify_signature is called, the class will scan the XML document and fire the on_signature_info event for each signature that is found. When the on_signature_info event fires the Reference* properties will be populated.

Within the on_signature_info event the reference_xml_element property must be set to the location of the XML element to which the signature applies. The reference_uri property may contain data helpful to locating the XML element.

The reference_xml_element property specifies the XPath to the element. For instance:

The signature is verified either using a key parsed from the signed XML, or using the certificate specified by the SignerCert* properties. The class will automatically parse the signer certificate (if present) from the signed XML and populate the SignerCert* properties with the parsed value.

When on_signature_info fires, if the SignerCertParsed parameter is True the SignerCert* properties may be inspected to see the details of the parsed certificate. If SignerCertParsed is False, then the SignerCert* properties must be set to a valid certificate for signature verification to proceed.

When the on_signature_info event finishes firing, the certificate present in the SignerCert* properties will be used to verify the signature, whether this is the certificate automatically parsed by the class or a different certificate specified within the event.

If the signature was successfully verified the method will return without error. If the signature was not verified the method fails with an error.

on_status Event

Provides information about the current operation.

Syntax

class XMLSigStatusEventParams(object):
  @property
  def message() -> str: ...

# In class XMLSig:
@property
def on_status() -> Callable[[XMLSigStatusEventParams], None]: ...
@on_status.setter
def on_status(event_hook: Callable[[XMLSigStatusEventParams], None]) -> None: ...

Remarks

The event is fired for informational and logging purposes only. It may be used to track the progress of an operation.

The level of detail is controlled by the LogLevel setting.

XMLSig Config Settings

XMLSig Config Settings

<root>
  <node1>
    <ds:Signature>...</ds:Signature>
  </node1>
  <node2></node2>
  <node3></node3>
</root>

<root>
  <node1></node1>
  <ds:Signature>...</ds:Signature>
  <node2></node2>
  <node3></node3>
</root>

Base Config Settings

XMLSig Errors

XMLSig Errors

XML Errors