Release history

pyHanko

0.35.1

Release date: 2026-05-06

Dependency changes

Bump cryptography to 48.0.0.

Relax upper bound for uharfbuzz to <0.55.0.

New features and enhancements

Signing

Allow signing with ML-DSA

Validation

Allow validating ML-DSA signatures

0.35.0

Release date: 2026-05-03

Breaking changes

Remove support for deprecated LTV validation functionality. Call sites must be updated to use the AdES validation engine.

Several low-level API changes in generic_cms to allow refactoring the timestamp handling code.

extract_tst_data() was removed.

compute_signature_tst_digest() was removed.

Several functions that previously took a digest to validate against have been changed to take a (str) -> bytes callable.

Dependency changes

Bump cryptography to 47.0.0.

Relax upper bound on pytest-cov to <7.2.

Relax upper bound on certomancer to <0.15.

Introduce certifi as a mandatory dependency for testing.

New features and enhancements

Validation

Properly support harvesting PoE from multiple signature/content timestamps in the same signature container.

For the purposes of validation status reporting: if there are multiple signature timestamps, accept any one that passes validation (this is appropriate since the main value of timestamps is evidentiary). At some point in the future, we may want to add a way to report on the status of all timestamps>

Add revinfo archival data to local knowledge.

Restructure algorithm policy handling. Algorithm policy errors will typically not bubble up outside the validation engine anymore, but will instead be reflected in the validation status.

Miscellaneous

Replace FreeSerif usage in tests with SourceSerif

Tweak MediaBox retrieval.

Bugs fixed

Fix /AP positioning on field creation.

Fix annot dict not being re-serialised on signing when split from form dictionary.

Improve error handling in parse_pdf_date.

Fix handling of PoE requirements in past validation data.

0.34.1

Release date: 2026-03-08

Bugs fixed

Address a packaging error with tests directory in sdists.

0.34.0

Release date: 2026-03-05

Breaking changes

Drop support for Python 3.9

Dependency changes

Relax upper bound on xsdata to <27.0.

New features and enhancements

Miscellaneous

Include tests in sdists again, and graft common testing tooling onto the sdists so they can be tested in a self-contained way.

Bugs fixed

Fix signed attribute enumeration in AdES report.

FieldMDP INCLUDE/EXCLUDE incorrectly locking fields with shared name prefix.

0.33.0

Release date: 2026-02-08

Dependency changes

Fix inconsistent aiohttp version bounds.

Relax uharfbuzz upper bound to <0.54.0.

Bump python-barcode to ==0.16.1.

New features and enhancements

Signing

Explicitly define a no-op stamping style

Miscellaneous

Integrate some actual signing hardware into CI processes.

Bugs fixed

Use embedded intermediate certificates when validating existing timestamps.

0.32.0

Release date: 2025-11-22

Dependency changes

Support Python 3.14

Relax uharfbuzz upper bound to <0.51.0.

Warning

PyHanko currently does not test against free-threaded Python builds. Feel free to raise issues related to free-threaded Python in the discussion forum or on the issue tracker if you’re sure the problem is pyHanko-related, but there are currently no concrete plans to actively pursue support for this.

New features and enhancements

Signing

Support reading PKCS#12 data from memory.

Make PKCS#11 sign_kwargs easier to customise in subclasses.

Miscellaneous

Support basic text field filling.

Put in place scaffolding for content stream parsing.

0.31.0

Release date: 2025-09-12

Breaking changes

Some pieces of the configuration API were refactored or pushed fully into the CLI layer.

The old LTV validation functionality provided by async_validate_pdf_ltv_signature() has now been deprecated and may be removed in a future release.

0.30.0

Release date: 2025-08-23

Dependency changes

Bump python-pkcs11 to 0.9.x.

Introduce signxml>=4.2.0 into [etsi] dependency group.

New features and enhancements

Signing

Allow custom text and stamp border colours.

Validation

Allow slotting in a custom validation implementation (e.g. to support validating signatures that require cryptographic primitives that aren’t supported in-tree). This applies to certificate validation as well. See SignatureValidator.

Add support for validating against ETSI TS 119 612 trusted lists (as used in the EU’s eIDAS programme) and deriving qualification judgments from such lists for signatures and timestamps. This is an incubating feature; in particular it is not yet exposed in the CLI.

0.29.1

Release date: 2025-06-20

Dependency changes

Bump python-pkcs11 to 0.8.0.

Relax aiohttp upper bound to allow 3.12.x and make sure we test against the most recent version.

Bugs fixed

Correct buggy behaviour when reauthenticating with a security handler.

Fix registration of multiple extensions in encrypted files.

Tolerate key usage violations when the signer is a trust anchor.

Remove unnecessary 3.8 compatibility code.

Make it easier to customise PKCS#11 queries

0.29.0

Release date: 2025-05-27

Breaking changes

The root pyhanko package is now a namespace package.

The pyhanko.keys and pyhanko.stamp modules were turned into packages, exposing the same API in their respective __init__.py, so this change is source-compatible.

The __version__ and __version_info__ attributes are no longer exposed at the root package level, but have been moved into pyhanko.version (which was also turned into a subpackage).

Drop dependency on click in pyhanko distribution, move CLI code into pyhanko-cli instead.

The CLI code still installs as pyhanko.cli in the package hierarchy.

There are no code-level changes for CLI plugins other than the requirement to add a dependency on pyhanko-cli. In principle, this allows “old” plugins to keep working without needing a re-release as long as pyhanko-cli is installed together with pyhanko.

Make the dependency on qrcode optional (in the new [qr] dependency group)

Replace defusedxml with a dependency on lxml, configured appropriately. This was done in anticipation of some future feature work that will require a dependency on lxml either way.

0.28.0

Release date: 2025-05-24

Breaking changes

Drop support for Python 3.8

Dependency changes

Retool repository structure as uv multi-project workspace.

Include pyhanko-certvalidator as subproject.

Remove dev-only & testing dependencies from package metadata.

Bugs fixed

Fix error in SHA-3 detection when determining whether to include the ISO/TS 32001 extension metadata.

0.27.1

Release date: 2025-05-14

New features and enhancements

Reinstated support for decrypting files using public-key encryption where 3DES or RC2 are used as the envelope encryption algorithm. The new integration uses pyca/cryptography’s decrepit subpackage instead of oscrypto.

0.27.0

Release date: 2025-05-12

Dependency changes

Relax uharfbuzz upper bound to <0.51.0.

Constrain click to <8.2.0 while we address breaking changes.

Bump test dependencies.

New features and enhancements

Layout

Allow choosing whether to apply stamps in the page’s default coordinate system, or in the frame of reference that is active at the end of the page’s content stream. The former is now the default.

Bugs fixed

Fix handling of “plugin unavailable” error.

Clear /NeedAppearances when putting in a signature.

0.26.0

Release date: 2025-03-08

Breaking changes

Some outdated algos for encrypting the security handler seed in a public-key encrypted PDF were dropped to get rid of oscrypto as a direct dependency of pyhanko. It is still pulled in via pyhanko-certvalidator, but it is no longer used for any cryptographic operations (which is significant, because of compatibility issues on systems that no longer ship OpenSSL 1.1.1)

Dependency changes

Relax uharfbuzz upper bound to <0.47.0.

Make defusedxml a regular dependency, remove [xmp] dependency group.

Remove [extra-pubkey-algs] dependency group (see breaking change list)

New features and enhancements

Expose signature_mechanism parameter in PKCS#11 API.

0.25.3

Release date: 2024-11-17

Dependency changes

Workflow dependency bumps

Set aiohttp upper bound to 3.12

Bump pyhanko-certvalidator to 0.26.5

Bump certomancer to 0.12.3

Note: these changes make pyHanko compatible with the (unreleased) API change in asn1crypto #230, which is nevertheless already being shipped in some distros.

0.25.2

Release date: 2024-11-11

Dependency changes

Bump minimal cryptography version to 43.0.3.

Update uharfbuzz upper bound to 0.42.0.

Add Python 3.13 to the package metadata & include it in CI.

Some test dependencies bumped.

Bugs fixed

Properly propagate strict=False in post-signing instructions.

0.25.1

Release date: 2024-07-18

Bugs fixed

Align usage of SHAKE256 OIDs with Ed448 with RFC 8419

0.25.0

Release date: 2024-05-06

New features and enhancements

Encryption

Implement ISO/TS 32003 and ISO/TS 32004, to support AES-GCM streams and MAC authentication in encrypted PDF 2.0 documents, respectively. MACs are turned on by default when creating documents with PDF 2.0-style encryption.

0.24.0

Release date: 2024-04-27

Breaking changes

Setting & retrieving permission flags for encrypted files now comes with an ergonomic API that is much less error-prone. You no longer have to manually convert your permission bits to their signed integer representation. See pyhanko.pdf_utils.crypt.permissions.

Dependency changes

Upgraded xsdata (optional) to 24.4.

Bugs fixed

Several issues with copying objects from encrypted documents (in particular, encrypted documents with signatures) have been fixed.

Tolerate unpadded empty ciphertext.

Improve error messages on malformed keys.

0.23.2

Release date: 2024-03-25

Dependency changes

Upgraded certomancer dependency for tests to 0.12.0.

Upgraded pytest-asyncio tot 0.23.6.

Bugs fixed

Fix handling of “OAEP preferred” flag when encrypting documents with a public key.

Fix endianness issue when reading & writing permissions in documents encrypted with a public key.

Tolerate AcroForm**s without a **Fields entry.

Increase resilience against issues with oscrypto.

0.23.1

Release date: 2024-03-14

Bugs fixed

Fix a regression in the way PKCS#11 objects are loaded.

0.23.0

Release date: 2024-03-10

Breaking changes

The BeID signer implementation and CLI command was moved into a separate package; see pyhanko-beid-plugin. While this integration was so far preserved in the core tree for historical reasons, pyHanko has matured beyond this kind of vendor/country-specific code. Note that CLI invocations will continue to work unchanged as long as pyhanko-beid-plugin is installed alongside pyHanko, thanks to Python’s package entry point mechanism.

0.22.0

Release date: 2024-03-07

Dependency changes

Relax upper bounds on xsdata and uharfbuzz.

cryptography` to ``42.0.1

Get rid of pytest-runner

New features and enhancements

Signing

Relax processing of PKCS#11 options, setting better defaults so users have to write less config to select their key/certificate. (see PR #296)

CLI

Add timestamp command to CLI to add a document timestamp without performing any PAdES validation.

Bugs fixed

Gracefully handle lack of /Type entry in signature objects vailidation.

0.21.0

Release date: 2023-11-26

Dependency changes

Bumped the minimal supported Python version to 3.8 (dropping 3.7).

Bumped the lower bound on qrcode to 7.3.1.

Bumped pyhanko-certvalidator to 0.26.x.

Bumped the lower bound on click to 8.1.3.

Bumped the lower bound on requests to 2.31.0.

Bumped the lower bound on pyyaml to 6.0.

Bumped the lower bound on cryptography to 41.0.5.

Bumped aiohttp to 3.9.x.

Bumped certomancer-csc-dummy test dependency to 0.2.3.

Introduced new dependency group etsi with xsdata for features implementing functionality from AdES and related ETSI standards.

New features and enhancements

Signing

Add support for /ContactInfo, /Prop_AuthTime and /Prop_AuthType.

Validation

Experimental support for AdES validation reports (requires new etsi optional deps)

New API function for simulating PAdES-LTA validation at a time in the future; see simulate_future_ades_lta_validation().

Add support for asserting the nonrevoked status of a certificate chain.

CLI

Add --resave flag to addfields subcommand.

Bugs fixed

Fixed an oversight in the serialisation of the /ByteRange entry in a signature that prevented large documents from being signed correctly.

Various adjustments to the (still experimental) AdES validation API.

Various local documentation fixes.

PDF signatures that do not omit the eContent field in their encapsulated content info are now rejected as invalid.

Miscellaneous

Include PyPDF2 licence file in package metadata.

Cleaned up loading logic in PdfFileReader. The most important impact of this change is that structural errors in the encryption dictionary will now cause exceptions to be thrown when decryption is attempted, not in the __init__ function.

0.20.1

Release date: 2023-09-17

Dependency changes

Upgrade pyhanko-certvalidator to 0.24.x

Miscellaneous

Tolerate missing D: in date strings (see PR #296).

Various minor documentation improvements.

Release workflow dependency bumps and minor improvements.

0.20.0

Release date: 2023-07-28

Dependency changes

Relax upper bound on uharfbuzz to <0.38.0 (allows more users to benefit from prebuilt wheels)

Bump python-barcode from 0.14.0 to 0.15.1.

Bump pytest-asyncio from 0.21.0 to 0.21.1.

Relax pytest-cov bound to allow 4.1.x

Miscellaneous

Various minor documentation improvements.

Improved unit test coverage, especially for error handling.

0.19.0

Release date: 2023-06-18

Dependency changes

Bump pyhanko-certvalidator to 0.23.0

certomancer updated to 0.11.0, certomancer-csc-dummy to 0.2.2

Breaking changes

Minor reorganisation of the EnvelopeKeyDecrypter. The change moves the cert property from an attribute to an abstract property, and adds a method to allow us to handle protocols based on key agreement in addition to key transport. Implementations need not implement both.

Move ignore_key_usage into to new RecipientEncryptionPolicy class.

New features and enhancements

Encryption

Support RSAES-OAEP for file encryption with the public-key security handler. This is not widely supported by PDF viewers in the wild.

Support some ECDH-based key exchange methods for file encryption with the public-key security handler. Concretely, pyHanko now supports the dhSinglePass-stdDH-sha*kdf family from RFC 5753, which is also implemented in Acrobat (for NIST curves). X25519 and X448 are also included.

CLI

Better UX for argument errors relating to visible signature creation.

Bugs fixed

Allow processing OCSP responses without nextUpdate.

Run non-cryptographic CLI commands in nonstrict mode.

Treat nulls the same as missing entries in dictionaries, as required by the standard.

Fix several default stamp style selection issues in CLI

0.18.1

Release date: 2023-04-29

Dependency changes

Remove dependency on pytz with fallback to backports.zoneinfo

Bump tzlocal version to 4.3.

Do not rely on deprecated timezone API anymore in the tests. See PR #257.

0.18.0

Release date: 2023-04-26

Note

This is largely a maintenance release in the sense that it adds relatively little in the way of core features, but it nevertheless comes with some major reorganisation and work to address technical debt.

This release also marks pyHanko’s move to beta status. That doesn’t mean that it’s feature-complete in every respect, but it does mean that we’ve now entered a stabilisation phase in anticipation of the 1.0.0 release, so until then the focus will be on fixing bugs and clearing up issues in the documentation (in particular regarding the API contract). After the 1.0.0 release, pyHanko will simply follow SemVer.

Breaking changes

Some changes have been made to the Signer class. For all practical purposes, these are mostly relevant for custom Signer implementations. Regular users should see fairly little impact.

The arguments to __init__ have been made keyword-only.

Several attributes have been turned into read-only properties:

signing_cert

cert_registry

attribute_certs

signature_mechanism

This change was made to better reflect the way the properties were used internally, and made it easier to set expectations for the API: it doesn’t make sense to allow arbitrary modifications to these properties for all Signer implementations. The parameters to __init__ have been extended to allow setting defaults more cleanly. Implementation-wise, the properties are backed by an underscored internal variable (e.g. _signing_cert for signing_cert). Subclasses can of course still elect to make some of these read-only properties writable by declaring setters.

get_signature_mechanism was renamed to get_signature_mechanism_for_digest() to make it more clear that it does more than just fetch the underlying value of signature_mechanism.

Concretely, this means that init logic of the form

class MySigner(Signer):
    def __init__(
        self,
        signing_cert: x509.Certificate,
        cert_registry: CertificateStore,
        *args, **kwargs
    ):
        self.signing_cert = signing_cert
        self.cert_registry = cert_registry
        self.signature_mechanism = signature_mechanism
        super().__init__()

needs to be rewritten as

class MySigner(Signer):
    def __init__(
        self,
        signing_cert: x509.Certificate,
        cert_registry: CertificateStore,
        *args, **kwargs
    ):
        self._signing_cert = signing_cert
        self._cert_registry = cert_registry
        self._signature_mechanism = signature_mechanism
        super().__init__()

or, alternatively, as

class MySigner(Signer):
    def __init__(
        self,
        signing_cert: x509.Certificate,
        cert_registry: CertificateStore,
        *args, **kwargs
    ):
        super().__init__(
            signing_cert=signing_cert,
            cert_registry=cert_registry,
            signature_mechanism=signature_mechanism
        )

Other than these, there have been some miscellaneous changes.

The CLI no longer allows signing files encrypted using public-key encryption targeted towards the signer’s certificate, because that feature didn’t make much sense in key management terms, was rarely used, and hard to integrate with the new plugin system.

APIs with status_cls parameters have made certain args keyword-only for strict type checking purposes.

Move add_content_to_page to add_to_page() to deal with a (conceptual) circular dependency between modules.

CertificateStore is no longer reexported by pyhanko.sign.general.

The BEIDSigner no longer allows convenient access to the authentication certificate.

Packaging-wise, underscores have been replaced with hyphens in optional dependency groups.

In pyhanko_certvalidator, InvalidCertificateError is no longer a subclass of PathValidationError.

Finally, some internal refactoring took place as well:

The cli.py module was refactored into a new subpackage (pyhanko.cli) and is now also tested systematically.

CLI config classes have been refactored, some configuration was moved to the new pyhanko.config package.

Time tolerance config now passes around timedelta objects instead of second values.

The qualify() function in the difference analysis has been split into qualify() and qualify_transforming().

Organisational changes

Certificate and key loading was moved to a new pyhanko.keys module, but pyhanko.sign.general still reexports the relevant functions for backwards compatibility. Concretely, the affected functions are

pyhanko.keys.load_cert_from_pemder(),

pyhanko.keys.load_certs_from_pemder(),

pyhanko.keys.load_certs_from_pemder_data(),

pyhanko.keys.load_private_key_from_pemder(),

pyhanko.keys.load_private_key_from_pemder_data().

Onboarded mypy and flag pyHanko as a typed library by adding py.typed.

Package metadata and tooling settings have now been centralised to pyproject.toml. Other configuration files like setup.py, requirements.txt and most tool-specific config have been eliminated.

The docstring-based documentation for pyhanko_certvalidator was added to the API reference.

Some non-autogenerated API reference documentation pages were consolidated to reduce the sprawl.

Heavily reworked the CI/CD pipeline. PyHanko releases are now published via GitHub Actions and signed with Sigstore. GPG signatures will continue to be provided for the time being.

Dependency changes

Bump pyhanko-certvalidator to 0.22.0.

Relax the upper bound on uharfbuzz for better Python 3.11 support

Bugs fixed

The AdES LTA validator now tolerates documents that don’t have a DSS (assuming that all the required information is otherwise present).

Ensure that the trusted attribute on SignatureStatus is not set if the validation path is not actually available.

Correct the typing on validation_path.

Fix several result presentation bugs in the AdES code.

Fix overeager sharing of POEManager objects in AdES code.

Correct algo policy handling in AdES-with-time validation.

Ensure that container_ref is also populated on past versions of the trailer dictionary.

New features and enhancements

Signing

The CLI now features plugins! All current addsig subcommands have been reimplemented to use the plugin interface. Other plugins will be auto-detected through package entry points.

Validation

Refine algorithm policy handling; put in place a subclass of AlgorithmUsagePolicy specifically for CMS validation; see CMSAlgorithmUsagePolicy.

Try to remember paths when validation fails.

Make certificates from local CMS context available during path building for past certificate validation (subject to PoE checks).

Move docmdp_ok up in the hierarchy to ModificationInfo.

0.17.2

Release date: 2023-03-10

Note

This is a follow-up on yesterday’s bugfix release, addressing a number of similar issues.

Bugs fixed

Address another potential infinite loop in the comment processing logic.

Fix some (rather esoteric) correctness issues w.r.t. PDF whitespace.

0.17.1

Release date: 2023-03-09

Note

This is a maintenance release without significant functionality changes. It contains a bugfix, addresses some documentation issues and applies the Black formatter to the codebase.

Bugs fixed

Address a potential infinite loop in the PDF parsing logic. See PR #237.

0.17.0

Release date: 2023-01-31

Note

This is a bit of an odd release. It comes with relatively few functional changes or enhancements to existing features, but it has nevertheless been in the works for quite a long time.

In early 2022, I decided that the time was right to equip pyHanko with its own AdES validation engine, implementing the machinery specified by ETSI EN 319 102-1. I knew ahead of time that this would not be an easy task:

PyHanko’s own validation code was put together in a fairly ad-hoc manner starting from the provisions in the CMS specification, so some refactoring would be necessary.

pyhanko-certvalidator also was never designed to be anything more than an RFC 5280 validation engine, and retrofitting the fine-tuning required by the AdES spec definitely wasn’t easy.

Initially, I estimated that this effort would take a few months tops. Yet here we are, approximately one year down the road: pyhanko.sign.validation.ades.

Truth be told, the implementation isn’t yet ready for prime time, but it is in a state where it’s at least useful for experimentation purposes, and can be iterated on. Also, given the volume of subtle changes and far-reaching refactoring in the internals of both the pyhanko and pyhanko-certvalidator packages, continually rebasing the feature/ades-validation feature branch turned into a chore quite quickly.

So, if you’re keen to start playing around with AdES validation: please do so, and let me know what you think. If standards-based validation is not something you care about, feel free to disregard everything I wrote above, it almost certainly won’t affect any of your code.

My plan is to incrementally build upon and polish the code in pyhanko.sign.validation.ades, and eventually deprecate the current ad-hoc LTV validation logic in pyhanko.sign.validation.ltv.async_validate_pdf_ltv_signature(). That’s still a ways off from now, though.

Dependency updates

pyhanko-certvalidator updated to 0.20.0

Breaking changes

There are various changes in the validation internals that are not backwards compatible, but all of those concern internal APIs.

There are some noteworthy changes to the pyhanko-certvalidator API. Those are documented in the change log. Most of these do not affect basic usage.

New features and enhancements

Validation

Experimental AdES validation engine pyhanko.sign.validation.ades.

In the status API, make a more meaningful distinction between valid and intact, and document that distinction.

0.16.0

Release date: 2022-12-21

Dependency updates

pyhanko-certvalidator updated to 0.19.8

Breaking changes

This release includes breaking changes to the difference analysis engine. Unless you’re implementing your own difference analysis policies, this change should break your API usage.

New features and enhancements

Signing

Add support for Prop_Build metadata in signatures. See PR #192

Validation

Improvements to the difference analysis engine that allow more nuance to be expressed in the rule system.

Bugs fixed

Tolerate an indirect Extensions and MarkInfo dictionary in difference analysis. See PR #177.

Gracefully handle unreadable/undecodable producer strings.

0.15.1

Release date: 2022-10-27

Note

This release adds Python 3.11 to the list of supported Python versions.

Dependency updates

pyhanko-certvalidator updated to 0.19.6

certomancer updated to 0.9.1

Bugs fixed

Be more tolerant towards deviations from DER restrictions in signed attributes when validating signatures.

0.15.0

Release date: 2022-10-11

Note

Other than a few bug fixes, the highlight of this release is the addition of support for two very recently published PDF extension standards, ISO/TS 32001 and ISO/TS 32002.

Bugs fixed

Fix metadata handling in encrypted documents see issue #160.

Make sure XMP stream dictionaries contain the required typing entries.

Respect visible_sig_settings on field autocreation.

Fix a division by zero corner case in the stamp layout code; see issue #170.

New features and enhancements

Signing

Add support for the new PDF extensions defined by ISO/TS 32001 and ISO/TS 32002; see PR #169.

SHA-3 support

EdDSA support for both the PKCS#11 signer and the in-memory signer

Auto-register developer extensions in the file

Make it easier to extract keys from bytes objects.

Validation

Add support for validating EdDSA signatures (as defined in ISO/TS 32002)

0.14.0

Release date: 2022-09-17

Note

This release contains a mixture of minor and major changes. Of particular note is the addition of automated metadata management support, including XMP metadata. This change affects almost every PDF write operation in the background. While pyHanko has very good test coverage, some instability and regressions may ensue. Bug reports are obviously welcome.

Breaking changes

The breaking changes in this release are all relatively minor. Chances are that your code isn’t affected at all, other than perhaps by the change to PreparedByteRangeDigest.

md_algorithm attribute removed from PreparedByteRangeDigest since it wasn’t necessary for further processing.

Low-level change in raw_get for PDF container object types (ArrayObject and DictionaryObject): the decrypt parameter is no longer a boolean, but a tri-state enum value of type EncryptedObjAccess.

Developer extension management API moved into pyhanko.pdf_utils.extensions.

get_courier() convenience function moved into pyhanko.pdf_utils.font.basic and now takes a mandatory writer argument.

The token_label attribute was removed from PKCS11SignatureConfig, but will still be parsed (with a deprecation warning).

The prompt_pin attribute in PKCS11SignatureConfig was changed from a bool to an enum. See PKCS11PinEntryMode.

Dependency updates

pytest-aiohttp updated to 1.0.4

certomancer updated to 0.9.0

certomancer-csc-dummy updated to 0.2.1

Relax bounds on uharfbuzz to allow everything up to the current version (i.e. 0.30.0) as well.

New optional dependency group xmp, which for now only contains defusedxml

Bugs fixed

Allow certificates with no CN in the certificate subject.

The extension dictionary handling logic can now deal with encrypted documents without actually decrypting the document contents.

Fix processing error when passing empty strings to uharfbuzz; see issue #132.

Use proper PDF text string serialisation routine in simple font handler, to ensure everything is escaped correctly.

Ensure that output_version is set to at least the input version in incrementally updated files.

New features and enhancements

Signing

Drop the requirement for signing_cert to be set from the start of the signing process in an interrupted signing workflow. This has come up on several occasions in the past, since it’s necessary in remote signing scenarios where the certificate is generated or provided on-demand when submitting the document digest to the signing service. See pull #141 for details.

Add convenience API to set the /TU entry on a signature field; see readable_field_name.

Allow greater control over the initialisation of document timestamp fields.

New class hierarchy for (un)signed attribute provisioning; see SignedAttributeProviderSpec and UnsignedAttributeProviderSpec.

Allow greater control over annotation flags for visible signatures. This is implemented using VisibleSigSettings. See discussion #150.

Factor out and improve PKCS#11 token finding; see TokenCriteria and issue #149.

Factor out and improve PKCS#11 mechanism selection, allowing more raw modes.

Change pin entry settings for PKCS#11 to be more granular, in order to also allow PROTECTED_AUTH; see issue #133.

Allow the PKCS#11 PIN to be sourced from an environment variable when pyHanko is invoked through the CLI and no PIN is provided in the configuration. PyHanko will now first check the PYHANKO_PKCS11_PIN variable before prompting for a PIN. This also works when prompting for PIN entry is disabled altogether.

Note

The PKCS#11 code is now also tested in CI, using SoftHSMv2.

Validation

Allow validation time overrides in the CLI. Passing in the special value claimed tells pyHanko to take the stated signing time in the file at face value. See issue #130.

Encryption

Also return permissions on owner access to allow for easier inspection.

Better version enforcement for security handlers.

Layout

Allow metrics to be specified for simple fonts.

Provide metrics for default Courier font.

Experimental option that allows graphics to be embedded in the central area of the QR code; see qr_inner_content.

Miscellaneous

Basic XMP metadata support with optional xmp dependency group.

Automated metadata management (document info dictionary, XMP metadata).

Refactor some low-level digesting and CMS validation code.

Make the CLI print a warning when the key passphrase is left empty.

Tweak configuration management utilities to better cope with fallback logic for deprecated configuration parameters.

Move all cross-reference writing logic into pyhanko.pdf_utils.xref.

Improve error classes and error reporting in the CLI so that errors in non-verbose mode still provide a little more info.

0.13.2

Release date: 2022-07-02

Note

This is a patch release to address some dependency issues and bugs.

Dependency updates

python-barcode updated and pinned to 0.14.0.

Bugs fixed

Fix lack of newline after XRef stream header.

Do not write DigestMethod in signature reference dictionaries (deprecated/nonfunctional entry).

Make pyhanko.pdf_utils.writer.copy_into_new_writer() more flexible by allowing caller-specified keyword arguments for the writer object.

Refine settings for invisible signature fields (see pyhanko.sign.fields.InvisSigSettings).

Correctly read objects from object streams in encrypted documents.

0.13.1

Release date: 2022-05-01

Note

This is a patch release to update fontTools and uharfbuzz to address a conflict between the latest fontTools and older uharfbuzz versions.

Dependency updates

fontTools updated to 4.33.3

uharfbuzz updated to 0.25.0

0.13.0

Release date: 2022-04-25

Note

Like the previous two releases, this is largely a maintenance release.

Dependency updates

asn1crypto updated to 1.5.1

pyhanko-certvalidator updated to 0.19.5

certomancer updated to 0.8.2

Depend on certomancer-csc-dummy for tests; get rid of python-pae test dependency.

Bugs fixed

Various parsing robustness improvements.

Be consistent with security handler version bounds.

Improve coverage of encryption code.

Ensure owner password gets prioritised in the legacy security handler.

New features and enhancements

Miscellaneous

Replaced some ValueError usages with PdfError

Improvements to error handling in strict mode.

Make CLI stack traces less noisy by default.

Encryption

Refactor internal crypt module into package.

Add support for serialising credentials.

Cleaner credential inheritance for incremental writers.

Signing

Allow post-signing actions on encrypted files with serialised credentials.

Improve --use-pades-lta ergonomics in CLI.

Add --no-pass parameter to pemder CLI.

Validation

Preparatory scaffolding for AdES status reporting.

Provide some tolerance against malformed ACs.

Increase robustness against invalid DNs.

0.12.1

Release date: 2022-02-26

Dependency updates

uharfbuzz updated to 0.19.0

pyhanko-certvalidator updated to 0.19.4

certomancer updated to 0.8.1

Bugs fixed

Fix typing issue in DSS reading logic (see issue #81)

0.12.0

Release date: 2022-01-26

Note

This is largely a maintenance release, and contains no new high-level features or public API changes. As such, upgrading is strongly recommended.

The most significant change is the (rather minimalistic) support for hybrid reference files. Since working with hybrid reference files means dealing with potential ambiguity (which is dangerous when dealing with signatures), creation and validation of signatures in hybrid reference documents is only enabled in nonstrict mode. Hybrid reference files are relatively rare these days, but the internals need to be able to cope with them either way, in order to be able to update such files safely.

New features and enhancements

Miscellaneous

Significant refactor of cross-reference parsing internals. This doesn’t affect any public API entrypoints, but read the reference documentation for pyhanko.pdf_utils.xref if you happen to have code that directly relies on that internal logic.

Minimal support for hybrid reference files.

Add strict flag to IncrementalPdfFileWriter.

Expose --no-strict-syntax CLI flag in the addsig subcommand.

Bugs fixed

Ensure that signature appearance bounding boxes are rounded to a reasonable precision. Failure to do so caused issues with some viewers.

To be consistent with the purpose of the strictness flag, non-essential xref consistency checking is now only enabled when running in strict mode (which is the default).

The hybrid reference support indirectly fixes some potential silent file corruption issues that could arise when working on particularly ill-behaved hybrid reference files.

0.11.0

Release date: 2021-12-23

Dependency changes

Update pyhanko-certvalidator to 0.19.2

Bump fontTools to 4.28.2

Update certomancer test dependency to 0.7.1

Breaking changes

Due to import order issues resulting from refactoring of the validation code, some classes and class hierarchies in the higher-level API had to be moved. The affected classes are listed below, with links to their respective new locations in the API reference.

KeyUsageConstraints

SignatureValidationError

WeakHashAlgorithmError

SigSeedValueValidationError

SignatureStatus

StandardCMSSignatureStatus

PdfSignatureStatus

TimestampSignatureStatus

DocumentTimestampStatus

The low-level function validate_sig_integrity() was also moved.

New features and enhancements

Signing

Support embedding attribute certificates into CMS signatures, either in the certificates field or using the CAdES signer-attrs-v2 attribute.

More explicit errors on unfulfilled text parameters

Better use of asyncio when collecting validation information for timestamps

Internally disambiguate PAdES and CAdES for the purpose of attribute handling.

Validation

Refactor diff_analysis module into sub-package

Refactor validation module into sub-package (together with portions of pyhanko.sign.general); see Breaking changes.

Make extracted certificate information more easily accessible.

Integrated attribute certificate validation (requires a separate validation context with trust roots for attribute authorities)

Report on signer attributes as supplied by the CAdES signer-attrs-v2 attribute.

Miscellaneous

Various parsing and error handling improvements to xref processing, object streams, and object header handling.

Use NotImplementedError for unimplemented stream filters instead of less-appropriate exceptions

Always drop GPOS/GDEF/GSUB when subsetting OpenType and TrueType fonts

Initial support for string-keyed CFF fonts as CIDFonts (subsetting is still inefficient)

copy_into_new_writer() is now smarter about how it deals with the /Producer line

Fix a typo in the ASN.1 definition of signature-policy-store

Various, largely aesthetic, cleanup & docstring fixes in internal APIs

Bugs fixed

Fix a critical bug in content timestamp generation causing the wrong message imprint to be sent to the timestamping service. The bug only affected the signed content-time-stamp attribute from CAdES, not the (much more widely used) signature-time-stamp attribute. The former timestamps the content (and is part of the signed data), while the latter timestamps the signature (and is therefore not part of the signed data).

Fix a bug causing an empty unsigned attribute sequence to be written if there were no unsigned attributes. This is not allowed (although many validators accept it), and was a regression introduced in 0.9.0.

Ensure non-PDF CAdES signatures always have signingTime set.

Fix and improve timestamp summary reporting

Corrected TrueType subtype handling

Properly set ts_validation_paths

Gracefully deal with unsupported certificate types in CMS

Ensure attribute inspection internals can deal with SignerInfo without signedAttrs.

0.10.0

Release date: 2021-11-28

Dependency changes

Update pyhanko-certvalidator to 0.18.0

Update aiohttp to 3.8.0 (optional dependency)

Introduce python-pae==0.1.0 (tests)

New features and enhancements

Signing

There’s a new Signer implementation that allows pyHanko to be used with remote signing services that implement the Cloud Signature Consortium API. Since auth handling differs from vendor to vendor, using this feature requires still the caller to supply an authentication handler implementation; see pyhanko.sign.signers.csc_signer for more information. This feature is currently incubating.

Validation

Add CLI option to skip diff analysis.

Add CLI flag to disable strict syntax checks.

Use chunked digests while validating.

Improved difference analysis logging.

Miscellaneous

Better handling of nonexistent objects: clearer errors in strict mode, better fallback behaviour in nonstrict mode. This applies to both regular object dereferencing and xref history analysis.

Added many new tests for various edge cases, mainly in validation code.

Added Python :: 3 and Python :: 3.10 classifiers to distribution.

Bugs fixed

Fix bug in output handler in timestamp updater that caused empty output in some configurations.

Fix a config parsing error when no stamp styles are defined in the configuration file.

0.9.0

Release date: 2021-10-31

Dependency changes

Update pyhanko-certvalidator to 0.17.3

Update fontTools to 4.27.1

Update certomancer to 0.6.0 (tests)

Introduce pytest-aiohttp~=0.3.0 and aiohttp>=3.7.4 (tests)

API-breaking changes

This is a pretty big release, with a number of far-reaching changes in the lower levels of the API that may cause breakage. Much of pyHanko’s internal logic has been refactored to prefer asynchronous I/O wherever possible (pyhanko-certvalidator was also refactored accordingly). Some compromises were made to allow non-async-aware code to continue working as-is.

If you’d like a quick overview of how you can take advantage of the new asynchronous library functions, take a look at this section in the signing docs.

Here’s an overview of low-level functionality that changed:

CMS signing logic was refactored and made asynchronous (only relevant if you implemented your own custom signers)

Time stamp client API was refactored and made asynchronous (only relevant if you implemented your own time stamping clients)

The interrupted signing workflow now involves more asyncio as well.

perform_presign_validation() was made asynchronous.

prepare_tbs_document(): the bytes_reserved parameter is mandatory now.

post_signature_processing() was made asynchronous.

collect_validation_info() was made asynchronous

Other functions have been deprecated in favour of asynchronous equivalents; such deprecations are documented in the API reference. The section on extending Signer has also been updated.

Warning

Even though we have pretty good test coverage, due to the volume of changes, some instability may ensue. Please do not hesitate to report bugs on the issue tracker!

New features and enhancements

Signing

Async-first signing API

Relax token-label requirements in PKCS#11 config, allowing slot-no as an alternative

Allow selecting keys and certificates by ID in the PKCS#11 signer

Allow the signer’s certificate to be sourced from a file in the PKCS#11 signer

Allow BeID module path to be specified in config

Tweak cert querying logic in PKCS#11 signer

Add support for raw ECDSA to the PKCS#11 signer

Basic DSA support (for completeness w.r.t. ISO 32000)

Choose a default message digest more cleverly, based on the signing algorithm and key size

Fail loudly when trying to add a certifying signature to an already-signed document using the high-level signing API

Provide a flag to skip embedding root certificates

Validation

Async-first validation API

Use non-zero exit code on failed CLI validation

Miscellaneous

Minor reorganisation of config.py functions

Move PKCS#11 pin prompt logic to cli.py

Improve font embedding efficiency (better stream management)

Ensure idempotence of object stream flushing

Improve PKCS#11 signer logging

Make stream_xrefs=False by default in copy_into_new_writer()

Removed a piece of fallback logic for md_algorithm that relied on obsolete parts of the standard

Fixed a number of issues related to unexpected cycles in PDF structures

Bugs fixed

Treat ASCII form feed (\f) as PDF whitespace

Fix a corner case with null incremental updates

Fix some font compatibility issues (relax assumptions about the presence of certain tables/entries)

Be more tolerant when parsing name objects

Correct some issues related to DSS update validation

Correct pdf_date() output for negative UTC offsets

0.8.0

Release date: 2021-08-23

Dependency changes

Update pyhanko-certvalidator to 0.16.0.

API-breaking changes

Some fields and method names in the config API misspelled pkcs11` as ``pcks11. This has been corrected in this release. This is unlikely to cause issues for library users (since the config API is primarily used by the CLI code), but it’s a breaking change all the same. If you do have code that relies on the config API, simply substituting s/pcks/pkcs/g should fix things.

New features and enhancements

Signing

Make certificate fetching in the PKCS#11 signer more flexible.

Allow passing in the signer’s certificate from outside the token.

Improve certificate registry initialisation.

Give more control over updating the DSS in complex signature workflows. By default, pyHanko now tries to update the DSS in the revision that adds a document timestamp, after the signature (if applicable). In the absence of a timestamp, the old behaviour persists.

Added a flag to (attempt to) produce CMS signature containers without any padding.

Use signing-certificate-v2 instead of signing-certificate when producing signatures.

Default to empty appearance streams for empty signature fields.

Much like the pkcs11-setups config entry, there are now pemder-setups and pkcs12-setups at the top level of pyHanko’s config file. You can use those to store arguments for the pemder and pkcs12 subcommands of pyHanko’s addsig command, together with passphrases for non-interactive use. See Named setups for on-disk key material.

Validation

Enforce the end-entity cert constraint imposed by the signing-certificate or signing-certificate-v2 attribute (if present).

Improve issuer-serial matching logic.

Improve CMS attribute lookup routines.

Encryption

Add a flag to suppress creating “legacy compatibility” entries in the encryption dictionary if they aren’t actually required or meaningful (for now, this only applies to /Length).

Miscellaneous

Lazily load the version entry in the catalog.

Minor internal I/O handling improvements.

Allow constructing an IncrementalPdfFileWriter from a PdfFileReader object.

Expose common API to modify (most) trailer entries.

Automatically recurse into all configurable fields when processing configuration data.

Replace some certificate storage/indexing classes by references to their corresponding classes in pyhanko-certvalidator.

Bugs fixed

Add /NeedAppearances in the AcroForm dictionary to the whitelist for incremental update analysis.

Fixed several bugs related to difference analysis on encrypted files.

Improve behaviour of dev extensions in difference analysis.

Fix encoding issues with SignedDigestAlgorithm, in particular ensuring that the signature mechanism encodes the relevant digest when using ECDSA.

Process passfile contents more robustly in the CLI.

Correct timestamp revinfo fetching (by ensuring that a dummy response is present)

0.7.0

Release date: 2021-07-25

Dependency changes

Warning

If you used OTF/TTF fonts with pyHanko prior to the 0.7.0 release, you’ll need HarfBuzz going forward. Install pyHanko with the [opentype] optional dependency group to grab everything you need.

Update pyhanko-certvalidator to 0.15.3
TrueType/OpenType support moved to new optional dependency group labelled [opentype].
- Dependency on fontTools moved from core dependencies to [opentype] group.
- We now use HarfBuzz (uharfbuzz==0.16.1) for text shaping with OTF/TTF fonts.

API-breaking changes

Warning

If you use any of pyHanko’s lower-level APIs, review this section carefully before updating.

Signing code refactor

This release includes a refactor of the pyhanko.sign.signers module into a package with several submodules. The original API exposed by this module is reexported in full at the package level, so existing code using pyHanko’s publicly documented signing APIs should continue to work without modification.

There is one notable exception: as part of this refactor, the low-level PdfCMSEmbedder protocol was tweaked slightly, to support the new interrupted signing workflow (see below). The required changes to existing code should be minimal; have a look at the relevant section in the library documentation for a concrete description of the changes, and an updated usage example.

In addition, if you extended the PdfSigner class, then you’ll have to adapt to the new internal signing workflow as well. This may be tricky due to the fact that the separation of concerns between different steps in the signing process is now enforced more strictly. I’m not aware of use cases requiring PdfSigner to be extended, but if you’re having trouble migrating your custom subclass to the new API structure, feel free to open an issue. Merely having subclassed Signer shouldn’t require you to change anything.

Fonts

The low-level font loading API has been refactored to make font resource handling less painful, to provide smoother HarfBuzz integration and to expose more OpenType tweaks in the API.

To this end, the old pyhanko.pdf_utils.font module was turned into a package containing three modules: api, basic and opentype. The api module contains the definitions for the general FontEngine and FontEngineFactory classes, together with some other general plumbing logic. The basic module provides a minimalist implementation with a (non-embedded) monospaced font. If you need TrueType/OpenType support, you’ll need the opentype module together with the optional dependencies in the [opentype] dependency group (currently fontTools and uharfbuzz, see above). Take a look at the section for pyhanko.pdf_utils.font in the API reference documentation for further details.

For the time being, there are no plans to support embedding Type1 fonts, or to offer support for Type3 fonts at all.

Miscellaneous

The content_stream parameter was removed from import_page_as_xobject(). Content streams are now merged automatically, since treating a page content stream array non-atomically is a bad idea.

PdfSigner is no longer a subclass of PdfTimeStamper.

New features and enhancements

Signing

Interrupted signing workflow: segmented signing workflow that can be interrupted partway through and resumed later (possibly in a different process or on a different machine). Useful for dealing with signing processes that rely on user interaction and/or remote signing services.

Generic data signing support: construct CMS signedData objects for arbitrary data (not necessarily for use in PDF signature fields).

Experimental API for signing individual embedded files (nonstandard).

PKCS#11 settings can now be set in the configuration file.

Validation

Add support for validating CMS signedData structures against arbitrary payloads (see also: Generic data signing)

Streamline CMS timestamp validation.

Support reporting on (CAdES) content timestamps in addition to signature timestamps.

Allow signer certificates to be identified by the subjectKeyIdentifier extension.

Encryption

Support granular crypt filters for embedded files

Add convenient API to encrypt and wrap a PDF document as a binary blob. The resulting file will open as usual in a viewer that supports PDF collections; a fallback page with alternative instructions is shown otherwise.

Miscellaneous

Complete overhaul of appearance generation & layout system. Most of these changes are internal, except for some font loading mechanics (see above). All use of OpenType / TrueType fonts now requires the [opentype] optional dependency group. New features:

Use HarfBuzz for shaping (incl. complex scripts)

Support TrueType fonts and OpenType fonts without a CFF table.

Support vertical writing (among other OpenType features).

Use ActualText marked content in addition to ToUnicode.

Introduce simple box layout & alignment rules, and apply them uniformly across all layout decisions where possible. See pyhanko.stamp and pyhanko.pdf_utils.layout for API documentation.

Refactored stamp style dataclass hierarchy. This should not affect existing code.

Allow externally generated PDF content to be used as a stamp appearance.

Utility API for embedding files into PDF documents.

Added support for PDF developer extension declarations.

Bugs fixed

Signing

Declare ESIC extension when producing a PAdES signature on a PDF 1.x file.

Validation

Fix handling of orphaned objects in diff analysis.

Tighten up tolerances for (visible) signature field creation.

Fix typo in BaseFieldModificationRule

Deal with some VRI-related corner cases in the DSS diffing logic.

Encryption

Improve identity crypt filter behaviour when applied to text strings.

Correct handling of non-default public-key crypt filters.

Miscellaneous

Promote stream manipulation methods to base writer.

Correct some edge cases w.r.t. PDF content import

Use floats for MediaBox.

Handle escapes in PDF name objects.

Correct ToUnicode CMap formatting.

Do not close over GSUB when computing font subsets.

Fix output_version handling oversight.

Misc. export list & type annotation corrections.

0.6.1

Release date: 2021-05-22

Dependency changes

Update pyhanko-certvalidator to 0.15.2

Replace constraint on certomancer and pyhanko-certvalidator by soft minor version constraint (~=)

Set version bound for freezegun

Bugs fixed

Add /Q and /DA keys to the whitelist for incremental update analysis on form fields.

0.6.0

Release date: 2021-05-15

Dependency changes

Warning

pyHanko’s 0.6.0 release includes quite a few changes to dependencies, some of which may break compatibility with existing code. Review this section carefully before updating.

The pyhanko-certvalidator dependency was updated to 0.15.1. This update adds support for name constraints, RSASSA-PSS and EdDSA for the purposes of X.509 path validation, OCSP checking and CRL validation.

Warning

Since pyhanko-certvalidator has considerably diverged from “mainline” certvalidator, the Python package containing its modules was also renamed from certvalidator to pyhanko_certvalidator, to avoid potential namespace conflicts down the line. You should update your code to reflect this change.

Concretely,

from certvalidator import ValidationContext

turns into

from pyhanko_certvalidator import ValidationContext

in the new release.

There were several changes to dependencies with native binary components:

The Pillow dependency has been relaxed to >=7.2.0, and is now optional. The same goes for python-barcode. Image & 1D barcode support now needs to be installed explicitly using the [image-support] installation parameter.

PKCS#11 support has also been made optional, and can be added using the [pkcs11] installation parameter.

The test suite now makes use of Certomancer. This also removed the dependency on ocspbuilder.

New features and enhancements

Signing

Make preferred hash inference more robust.

Populate /AP when creating an empty visible signature field (necessary in PDF 2.0)

Validation

Timestamp and DSS handling tweaks:

Preserve OCSP resps / CRLs from validation kwargs when reading the DSS.

Gracefully process revisions that don’t have a DSS.

When creating document timestamps, the validation_context parameter is now optional.

Enforce certvalidator’s weak_hash_algos when validating PDF signatures as well. Previously, this setting only applied to certificate validation. By default, MD5 and SHA-1 are considered weak (for digital signing purposes).

Expose DocTimeStamp/Sig distinction in a more user-friendly manner.

The sig_object_type property on EmbeddedPdfSignature now returns the signature’s type as a PDF name object.

PdfFileReader now has two extra convenience properties named embedded_regular_signatures and embedded_timestamp_signatures, that return a list of all regular signatures and document timestamps, respectively.

Encryption

Refactor internal APIs in pyHanko’s security handler implementation to make them easier to extend. Note that while anyone is free to register their own crypt filters for whatever purpose, pyHanko’s security handler is still considered internal API, so behaviour is subject to change between minor version upgrades (even after 1.0.0).

Miscellaneous

Broaden the scope of --soft-revocation-check.

Corrected a typo in the signature of validate_sig_integrity.

Less opaque error message on missing PKCS#11 key handle.

Ad-hoc hash selection now relies on pyca/cryptography rather than hashlib.

Bugs fixed

Correct handling of DocMDP permissions in approval signatures.

Refactor & correct handling of SigFlags when signing prepared form fields in unsigned files.

Fixed issue with trailing whitespace and/or NUL bytes in array literals.

Corrected the export lists of various modules.

0.5.1

Release date: 2021-03-24

Bugs fixed

Fixed a packaging blunder that caused an import error on fresh installs.

0.5.0

Release date: 2021-03-22

Dependency changes

Update pyhanko-certvalidator dependency to 0.13.0. Dependency on cryptography is now mandatory, and oscrypto has been marked optional. This is because we now use the cryptography library for all signing and encryption operations, but some cryptographic algorithms listed in the PDF standard are not available in cryptography, so we rely on oscrypto for those. This is only relevant for the decryption of files encrypted with a public-key security handler that uses DES, triple DES or RC2 to encrypt the key seed.

In the public API, we exclusively work with asn1crypto representations of ASN.1 objects, to remain as backend-independent as possible.

Note: While oscrypto is listed as optional in pyHanko’s dependency list, it is still required in practice, since pyhanko-certvalidator depends on it.

New features and enhancements

Encryption

Enforce keyEncipherment key extension by default when using public-key encryption

Show a warning when signing a document using public-key encryption through the CLI. We currently don’t support using separate encryption credentials in the CLI, and using the same key pair for decryption and signing is bad practice.

Several minor CLI updates.

Signing

Allow customisation of key usage requirements in signer & validator, also in the CLI.

Actively preserve document timestamp chain in new PAdES-LTA signatures.

Support setups where fields and annotations are separate (i.e. unmerged).

Set the lock bit in the annotation flags by default.

Tolerate signing fields that don’t have any annotation associated with them.

Broader support for PAdES / CAdES signed attributes.

Validation

Support validating PKCS #7 signatures that don’t use signedAttrs. Nowadays, those are rare in the wild, but there’s at least one common commercial PDF library that outputs such signatures by default (vendor name redacted to protect the guilty).

Timestamp-related fixes:

Improve signature vs. document timestamp handling in the validation CLI.

Improve & test handling of malformed signature dictionaries in PDF files.

Align document timestamp updating logic with validation logic.

Correct key usage check for time stamp validation.

Allow customisation of key usage requirements in signer & validator, also in the CLI.

Allow LTA update function to be used to start the timestamp chain as well as continue it.

Tolerate indirect references in signature reference dictionaries.

Improve some potential ambiguities in the PAdES-LT and PAdES-LTA validation logic.

Revocation info handling changes:

Support “retroactive” mode for revocation info (i.e. treat revocation info as valid in the past).

Added functionality to append current revocation information to existing signatures.

Related CLI updates.

Miscellaneous

Some key material loading functions were cleaned up a little to make them easier to use.

I/O tweaks: use chunked writes with a fixed buffer when copying data for an incremental update

Warn when revocation info is embedded with an offline validation context.

Improve SV validation reporting.

Bugs fixed

Fix issue with /Certs not being properly dereferenced in the DSS (#4).

Fix loss of precision on FloatObject serialisation (#5).

Add missing dunders to BooleanObject.

Do not use .dump() with force=True in validation.

Corrected digest algorithm selection in timestamp validation.

Correct handling of writes with empty user password.

Do not automatically add xref streams to the object cache. This avoids a class of bugs with some kinds of updates to files with broken xref streams.

Due to a typo, the /Annots array of a page would not get updated correctly if it was an indirect object. This has been corrected.

0.4.0

Release date: 2021-02-14

New features and enhancements

Encryption

Expose permission flags outside security handler
Make file encryption key straightforward to grab

Signing

Mildly refactor PdfSignedData for non-signing uses
Make DSS API more flexible
- Allow direct input of cert/ocsp/CRL objects as opposed to only certvalidator output
- Allow input to not be associated with any concrete VRI.
Greatly improved PKCS#11 support
- Added support for RSASSA-PSS and ECDSA.
- Added tests for RSA functionality using SoftHSMv2.
- Added a command to the CLI for generic PKCS#11.
- Note: Tests don’t run in CI, and ECDSA is not included in the test suite yet (SoftHSMv2 doesn’t seem to expose all the necessary mechanisms).
Factor out unsigned_attrs in signer, added a digest_algorithm parameter to signed_attrs.
Allow signing with any BasePdfFileWriter (in particular, this allows creating signatures in the initial revision of a PDF file)
Add CMSAlgorithmProtection attribute when possible * Note: Not added to PAdES signatures for the time being.
Improved support for deep fields in the form hierarchy (arguably orthogonal to the standard, but it doesn’t hurt to be flexible)

Validation

Path handling improvements:
- Paths in the structure tree are also simplified.
- Paths can be resolved relative to objects in a file.
Limited support for tagged PDF in the validator.
- Existing form fields can be filled in without tripping up the modification analysis module.
- Adding new form fields to the structure tree after signing is not allowed for the time being.
Internal refactoring in CMS validation logic:
- Isolate cryptographic integrity validation from trust validation
- Rename externally_invalid API parameter to encap_data_invalid
- Validate CMSAlgorithmProtection when present.
Improved support for deep fields in the form hierarchy (arguably orthogonal to the standard, but it doesn’t hurt to be flexible).
Added

Miscellaneous

Export copy_into_new_writer.
Transparently handle non-seekable output streams in the signer.
Remove unused __iadd__ implementation from VRI class.
Clean up some corner cases in container_ref handling.
Refactored SignatureFormField initialisation (internal API).

Bugs fixed

Deal with some XRef processing edge cases.
Make signed_revision on embedded signatures more robust.
Fix an issue where DocTimeStamp additions would trigger /All-type field locks.
Fix some issues with modification_level handling in validation status reports.
Fix a few logging calls.
Fix some minor issues with signing API input validation logic.

0.3.0

Release date: 2021-01-26

New features and enhancements

Encryption

Reworked internal crypto API.
Added support for PDF 2.0 encryption.
Added support for public key encryption.
Got rid of the homegrown RC4 class (not that it matters all to much, RC4 isn’t secure anyhow); all cryptographic operations in crypt.py are now delegated to oscrypto.

Signing

Encrypted files can now be signed from the CLI.
With the optional cryptography dependency, pyHanko can now create RSASSA-PSS signatures.
Factored out a low-level PdfCMSEmbedder API to cater to remote signing needs.

Miscellaneous

The document ID can now be accessed more conveniently.
The version number is now single-sourced in version.py.
Initialising the page tree in a PdfFileWriter is now optional.
Added a convenience function for copying files.

Validation

With the optional cryptography dependency, pyHanko can now validate RSASSA-PSS signatures.
Difference analysis checker was upgraded with capabilities to handle multiply referenced objects in a more straightforward way. This required API changes, and it comes at a significant performance cost, but the added cost is probably justified. The changes to the API are limited to the diff_analysis module itself, and do not impact the general validation API whatsoever.

Bugs fixed

Allow /DR and /Version updates in diff analysis
Fix revision handling in trailer.flatten()

0.2.0

Release date: 2021-01-10

New features and enhancements

Signing

Allow the caller to specify an output stream when signing.

Validation

The incremental update analysis functionality has been heavily refactored into something more rule-based and modular. The new difference analysis system is also much more user-configurable, and a (sufficiently motivated) library user could even plug in their own implementation.
The new validation system treats /Metadata updates more correctly, and fixes a number of other minor stability problems.
Improved validation logging and status reporting mechanisms.
Improved seed value constraint enforcement support: this includes added support for /V, /MDP, /LockDocument, /KeyUsage and (passive) support for /AppearanceFilter and /LegalAttestation.

CLI

You can now specify negative page numbers on the command line to refer to the pages of a document in reverse order.

General PDF API

Added convenience functions to retrieve references from dictionaries and arrays.
Tweaked handling of object freeing operations; these now produce PDF null objects instead of (Python) None.

Bugs fixed

root_ref now consistently returns a Reference object
Corrected wrong usage of @freeze_time in tests that caused some failures due to certificate expiry issues.
Fixed a gnarly caching bug in HistoricalResolver that sometimes leaked state from later revisions into older ones.
Prevented cross-reference stream updates from accidentally being saved with the same settings as their predecessor in the file. This was a problem when updating files generated by other PDF processing software.

0.1.0

Release date: 2020-12-30

Initial release.

pyhanko-certvalidator

0.31.1

Release date: 2026-05-06

Bump cryptography to 48.0.0.

ML-DSA support.

0.31.0

Release date: 2026-05-03

Bump cryptography to 47.0.0.

Always short-circuit OCSP fetching if no URLs.

Tests and testability fixes for AdES TS handling.

Get rid of unnecessary async marker on get_session() in the aiohttp fetcher.

Align default certs with certifi for aiohttp usage.

0.30.2

Release date: 2026-03-27

Fix issue #648, causing OCSP responses to fail to be processed if the responder certificate’s subject key identifier is not generated in the standard way.

0.30.1

Release date: 2026-03-08

Address a packaging error with tests directory in sdists.

0.30.0

Release date: 2026-03-05

Drop support for Python 3.9

Drop TLS-specific validation code (breaking change)

Drop poorly supported whitelist feature (breaking change)

Remove deprecated methods from ValidationContext (breaking change)

Clean up test fixtures

Include tests in sdist again.

0.29.1

Release date: 2026-02-08

Fix inconsistent aiohttp bounds.

Add nonstandard application/pkix-ca content type.

0.29.0

Release date: 2025-09-12

Minor adjustments to error handling and APIs to handle validation context derivation from policies.

0.28.0

Release date: 2025-08-23

Remove unneeded Python 3.8 compatibility code

Improve test coverage for some more exotic CRL processing scenarios, simplify code accordingly.

Supply more info on freshness check failures, ensure time tolerance is accounted for.

Support time-limited roots.

Fix various bugs in AdES validation and the handling of non-default TrustAnchor implementations.

Unify raw signature validation internals with pyHanko; make the validation implementation pluggable. See SignatureValidator.

0.27.0

Release date: 2025-05-24

Integrated into pyHanko repository as separate sub-package.

No functional changes.

0.26.8

Release date: 2025-03-15

Fixed bug where an HTTP(S) CRL URI appearing next to an LDAP one as part of the same DP entry would not always be picked up.

Dramatically improved processing speed for large CRLs.

0.26.7

Release date: 2025-03-12

No functional changes.

0.26.6

Release date: 2025-03-12

Drop Python 3.7

List qcStatements as a known extension

0.26.5

Release date: 2024-11-17

Future-proofing against an upcoming asn1crypto that is already being shipped in some distro packages.

Address some timing issues in tests.

0.26.4

Release date: 2024-11-12

Bump aiohttp requirement to >=3.8,<3.11.

Declare support for Python 3.12 and 3.13

0.26.3

Release date: 2023-12-13

Bump aiohttp requirement to >=3.8,<3.10.

Address two certificate fetching issues.

Tolerate CMS certificate-only message in response without Content-Type.

Deal with implicit reliance on order of certs when processing such messages.

0.26.2

Release date: 2023-11-18

Bump some dependency versions.

0.26.1

Release date: 2023-11-18

Handle nonspecific OCSP validation errors cleanly during validation.

0.26.0

Release date: 2023-11-14

Fix error reporting on banned algorithms in some cases

Allow caller to assert revocation status of a cert

More refined POE information tracking in experimental AdES API

0.25.0

Release date: 2023-10-06

Introduce a more precise error type to signal stale revocation information.

0.24.1

Release date: 2023-09-17

Ignore content types altogether when fetching certificates and the response payload is PEM.

0.24.0

Release date: 2023-09-07

Further increase leniency regarding content types when fetching certificates on-the-fly

Add SLSA provenance data to releases

Various updates in test dependencies and CI workflow dependencies.

0.23.0

Release date: 2023-05-14

Improve processing of OCSP responses without nextUpdate

Some more package metadata & release flow tweaks

0.22.0

Release date: 2023-04-23

No implementation changes compared to 0.21.2

Renamed async_http dependency group to async-http.

Move towards automated GitHub Actions-based release flow as a move towards better process standardisation.

Sign release artifacts with Sigstore.

0.21.2

Release date: 2023-04-17

Fix a typing issue caused by a typo in the requests cert fetcher.

Removed a piece of misbehaving and duplicative logic in the revocation freshness checker.

0.21.1

Release date: 2023-04-02

Fix DisallowedAlgorithmError parameters.

Preserve timestamp info in expiration-related errors.

Disable algo enforcement in prima facie past validation checks.

Correct a misunderstanding in the interaction between the AdES code and the old “retroactive revinfo” setting.

0.21.0

Release date: 2023-04-01

Switch to pyproject.toml to manage project metadata.

Path validation errors now carry information about the paths that triggered them.

InvalidCertificateError is no longer a subclass of PathValidationError, only of ValidationError. This is a minor but nonetheless breaking change.

0.20.1

Release date: 2023-02-21

Minor maintenance release without functional changes, only to metadata, documentation and typing.

0.20.0

Release date: 2023-01-23

This is a big release, with many breaking changes in the “deeper” APIs. The impact on the high-level API should be small to nonexistent, but caution when upgrading is advised.

More uniform and machine-processable errors.

Move towards a setup using “policy objects” that can be used to construct ValidationContext objects in a systematic way.

Move revinfo gathering to a separate revinfo manager class. Some arguably internal methods on ValidationContext were moved to the RevinfoManager class.

Incubating API for AdES validation primitives (freshness, POE handling, more sophisticated revinfo gathering, time slide) and some certificate-related validation routines.

Introduce a more fully-fledged API to manage permissible algorithms.

Broaden trust root provisioning beyond certificates: trust roots can now have qualifiers, and be provisioned as a name-key pair as opposed to a (self-signed) certificate. This implies breaking changes for ValidationPath. In general, issuance semantics in the internals are now expressed through the Authority API as much as possible.

In the same vein, CertificateRegistry was refactored into TrustManager, CertificateRegistry and PathBuilder. These are respectively responsible for managing trust, maintaining the certificate cache, and building paths.

Thorough clean-up of legacy dev tooling; put in place mypy and black, move to pytest, get rid of pretty_message in favour of f-strings.

0.19.8

Release date: 2022-12-20

Fix double encoding when generating OCSP nonces

0.19.7

Release date: 2022-12-11

Make certificate fetcher more tolerant (see #2)

0.19.6

Release date: 2022-10-27

Update asn1crypto to 1.5.1

Declare Python 3.11 support

0.19.5

Release date: 2022-03-08

Maintenance update to bump asn1crypto to 1.5.0 and get rid of a number of compatibility shims for fixes that were upstreamed to asn1crypto.

0.19.4

Release date: 2022-02-10

Fix improper error handling when dealing with expired or not-yet-valid attribute certificates.

0.19.3

Release date: 2022-02-03

Correct and improve behaviour of certificate fetcher when the server does not supply a Content-Type header.

0.19.2

Release date: 2021-12-22

Patch asn1crypto to work around tagging issue in AC issuer field

0.19.1

Release date: 2021-12-22

Properly enforce algo matching in AC validation

0.19.0

Release date: 2021-12-14

Attribute certificate validation support

Support for AAControls extension

Refactored OCSP and CRL logic to work with attribute certificate validation

Many nominal type checks removed in favour of type annotations

Many API entry points now accept both asn1crypto.x509.Certificate and asn1crypto.cms.AttributeCertificateV2

Minor breaking change: bytes is no longer acceptable as a substitute for asn1crypto.x509.Certificate in the public API

0.18.1

Release date: 2021-12-04

Various improvements to error handling in certificate fetchers

0.18.0

Release date: 2021-11-26

Replace revocation_mode with more flexible revocation policy controls, aligned with ETSI TS 119 172. Old revocation_mode params will be transparently translated to corresponding ‘refined’ policies, but the revocation_mode property on ValidationContext was removed.

Handle soft fails as part of revocation policies. Concretely, this means that the SoftFailError exception type was removed. Exceptions arising from quashed ‘soft’ failures can still be retrieved via the soft_fail_exceptions property on ValidationContext instances; the resulting list can contain any exception type.

Fix various hiccups in CRL and OCSP handling.

0.17.4

Release date: 2021-11-13

Fix mistaken assumption when a certificate’s MIME type is announced as application/x-x509-ca-cert.

Update aiohttp to 3.8.0

0.17.3

Release date: 2021-10-28

Fix a deadlocking bug caused by improper exception handling in the fetcher code.

Exceptions are now communicated to fetch jobs waiting for results.

0.17.2

Release date: 2021-10-19

Replace run_until_complete() with asyncio.run() for better event loop state management.

0.17.1

Release date: 2021-10-11

Fixes a packaging error in 0.17.0

0.17.0

Release date: 2021-10-11

Warning

This release contains breaking changes in lower-level APIs. High-level API functions should continue to work as-is, although some have been deprecated. However, the rewrite of the CRL & OCSP fetch logic breaks compatibility with the previous version’s API.

Refactor OCSP/certificate/CRL fetch logic to be more modular and swappable.
Automatically fetch missing issuer certificates if there is an AIA record indicating where to find them
Favour asynchronous I/O throughout the API. CertificateValidator.validate_usage, CertificateValidator.validate_tls and the ValidationContext.retrieve_XYZ methods were deprecated in favour of their asynchronous equivalents.
Support two backends for fetching revocation information and certificates: requests (legacy) and aiohttp (via the async-http optional dependency group).
It is expected that using aiohttp fetchers will yield better performance with the
asynchronous APIs, but as these require some resource management on the caller’s part, requests is still the default.
Fetcher backends can be swapped out by means of the fetcher_backend argument to
ValidationContext.

0.16.0

Release date: 2021-08-22

Refactor CertificateRegistry

Change OCSP responder cert selection procedure to give priority to certificates embedded into the response data (if there are any).

0.15.3

Release date: 2021-07-25

Short-circuit anyPolicy when reporting policies

Export PKIXValidationParams

Limit CRL client to HTTP-based URLs

0.15.2

Release date: 2021-05-22

Properly handle missing Content-Type header in server response when fetching CA certificates referenced in a CRL.

0.15.1

Release date: 2021-05-12

Gracefully handle lack of thisUpdate / nextUpdate in OCSP responses.

0.15.0

Release date: 2021-05-09

Use pyca/cryptography for signature validation. oscrypto is still included to access the system trust list.

Support RSASSA-PSS and EdDSA certificates.

Support name constraints.

Support all input parameters to the PKIX validation algorithm (acceptable policy set, policy mapping inhibition, …).

Further increase PKITS coverage.

0.14.1

Release date: 2021-04-03

No code changes, rerelease because distribution package was polluted due to improper build cache cleanup.

0.14.0

Release date: 2021-04-03

Raise RequestError if CRL / OCSP client returns a status code other than 200. Previously, this would fail with a cryptic ASN.1 deserialisation error instead.

Rename Python package to pyhanko_certvalidator to avoid the potential name conflict with the upstream certvalidator package.

0.13.1

Release date: 2021-03-24

Consider SHA-1 weak by default, and do not hard-code the list of potential weak hash algos.

0.13.0

Release date: 2021-03-19

Added an optional retroactive_revinfo flag to ValidationContext to ignore the thisUpdate field in OCSP responses and CRLs. The effect of this is that CRLs and OCSP responses are also considered valid for point-in-time validation with respect to a time in the past. This is useful for some validation profiles. The default state of the flag remains False nonetheless.

0.12.1

Release date: 2020-12-05

Fixed a packaging error.

0.12.0

Release date: 2020-12-05

Forked from certvalidator. to add patches for pyHanko.

Replaced urllib calls with requests library for universal mocking.

Added a time_tolerance parameter to the validation context to allow for some time drift on CRLs and OCSP responses.

Deal with no-matches on OCSP and CRLs strictly in hard-fail mode.

Drop support for Python 2, and all Python 3 versions prior to 3.7. It is likely that the code still runs on older Python 3 versions, but I have no interest in maintaining support for those.

pyhanko-cli

0.4.0

Release date: 2026-05-03

Introduce addsig identity subcommand to allow recalling the parameters for specific addsign subcommands from configuration (incubating).

Genericise password prompting in CLI.

Remove legacy LTV validation code, including all associated CLI hooks.

0.3.1

Release date: 2026-03-08

Address a packaging error with tests directory in sdists.

0.3.0

Release date: 2026-03-05

Drop support for Python 3.9

0.2.1

Release date: 2025-11-22

Maintenance release for Python 3.14 support.

0.2.0

Release date: 2025-09-12

Breaking changes

The --ltv-profile argument to pyhanko sign validate is now deprecated.

The redundant --apply-lta-timestamp argument to ltvfix was removed.

Some pieces of the configuration API were refactored or pushed fully into the CLI layer. This includes the way CLIConfig deals with validation context config.

New features and enhancements

Support EUTL usage and AdES validation in the CLI.

0.1.2

Release date: 2025-06-20

New features and enhancements

Auto-open document when validating an encrypted document using the CLI and there is no user password.

Support --text-param argument for stamps.

0.1.1

Release date: 2025-05-29

Dependency changes

Remove upper bound on click (excluding version 8.2.0 as incompatible)

0.1.0

Release date: 2025-05-27

Initial release split off from main pyHanko distribution artifact.