-*- org -*-
#+TITLE: sequoia-openpgp NEWS – history of user-visible changes
#+STARTUP: content hidestars


* Changes in 2.0.0
** Notable changes
   - This release adds support for RFC 9580, which revises RFC 4880.
     The revision adds new cryptographic algorithms, deprecates and
     removes old ones, and supports authenticated encryption.  The
     legacy protocol version is still supported.

** Notable fixes
   - We now gracefully handle memory allocation failures when
     computing Argon2.
   - We fixed an internal mapping from asymmetric algorithm to slots
     in a policy data structure.

* Changes in 2.0.0.alpha.2
** Notable changes
   - Our MSRV is now 1.79.

** API changes
   - ValidKeyAmalgamation::into_key_amalgamation removed
   - serialize::stream::Recipient::new now takes a KeyHandle
   - serialize::stream::Recipient::keyid renamed to key_handle, now
     returns an Option<KeyHandle>
   - serialize::stream::Recipient::set_keyid renamed to
     set_key_handle, now takes an Option<KeyHandle>, and is fallible
   - serialize::stream::Recipient new now also takes a Features
     argument
   - serialize::stream::Recipient now only implements
     From<ValidSubordinateKeyAmalgamation> and
     From<ValidErasedKeyAmalgamation>
   - KeyAmalgamationIter::key_handles2 renamed to key_handles
   - ValidKeyAmalgamationIter::key_handles2 renamed to key_handles
   - Cert::insert_packets2 renamed to insert_packets
   - Fingerprint no longer implements Borrow<[u8]>
   - KeyID no longer implements Borrow<[u8]>
   - packet::signature::subpacket::CLOCK_SKEW_TOLERANCE is now simply
     a std::time::Duration
   - cert::Preferences::preferred_aead_algorithms removed
   - Curve::len removed
   - PacketParser::encrypted removed
   - StandardPolicy::packet_tag_cutoff removed
   - Features::supports_mdc removed
   - Features::set_mdc removed
   - Features::clear_mdc removed
   - SignatureBuilder::set_preferred_aead_algorithms removed
   - SubpacketAreas::preferred_aead_algorithms removed
   - SubpacketValue::PreferredAEADAlgorithms removed

** New functionality
   - ValidCert::key_handle
   - ValidCert::fingerprint
   - ValidCert::keyid
   - ValidComponentAmalgamation::amalgamation
   - ValidKeyAmalgamation::amalgamation
   - armor::Writer::set_profile
   - CertBuilder::set_features

** Notable fixes
   - Generation of v6 certification approval signatures is fixed
   - Key encryption now only uses AEAD by default for v6 keys
   - Messages using SEIPDv1 for a v6 recipient, and those using
     SEIPDv2 for a v4 recipient are now correctly encrypted
   - stream::padding::Padder now emits padding packets when creating
     RFC9580 messages, and nothing when creating RFC4880 messages
   - X448 encryption and decryption fixed
   - Sequoia no longer ignores formatting errors when reading secret
     keys.  This reverts a change introduced with version 1.17.0.

* Changes in 2.0.0.alpha.1
** API changes
   - ComponentBundle::self_signatures2 renamed to ComponentBundle::self_signatures
   - ComponentBundle::certifications2 renamed to ComponentBundle::certifications
   - ComponentBundle::self_revocations2 renamed to ComponentBundle::self_revocations
   - ComponentBundle::other_revocations2 renamed to ComponentBundle::other_revocations
   - Signature::verify renamed to Signature::verify_document
   - armor::Reader::new removed
   - Padding::with_policy now takes a closure
   - PKESK3::new now takes Option<KeyID>
   - PKESK3::recipient now returns Option<KeyID>
   - message::Token is now private
   - message::MessageParserError is now private
   - cert::CipherSuite no longer implements PartialOrd, Ord
   - SignatureBuilder::set_reference_time is now fallible
   - Fingerprint::Invalid is now called Fingerprint::Unknown and has a
     version field
   - Fingerprint::from_bytes now takes a version and is fallible
   - Padding::new is now fallible
   - SessionKey::new is now fallible
   - mem::Encrypted::new is now fallible
   - crypto::random is now fallible
   - RegexSet::everything is now infallible
   - Cert::revocation_keys now returns an unboxed iterator
   - ValidCert::revocation_keys no longer takes a policy argument
   - ValidCert::revocation_keys now returns an unboxed iterator
   - All hash functions defined on Signature and SignatureBuilder,
     such as Signature::hash_standalone, are now fallible
   - All hash functions defined on Signature and SignatureBuilder,
     such as Signature::hash_standalone, now check the signature type
   - crypto::hash::Hash::hash is now fallible
   - stream::Signer::new, stream::Signer::with_template, and
     stream::Signer::add_signer are now fallible: the streaming signer
     now computes the set of acceptable hash algorithms as signers are
     added via the constructors and Signer::add_signer, and returns an
     error if that set ever gets empty
   - stream::Signer::hash_algo now returns an error if the given
     algorithm is not acceptable for the set of signers
   - Error::UnsupportedCert2 renamed to Error::UnsupportedCert
   - TSK::set_filter now requires the filter to be Send + Sync
   - TSK::into_packets now returns an iterator that is Send + Sync
   - Cert no longer implements conversion into Vec<Packet>
   - Cert no longer implements IntoIterator
   - Cert::into_packets2 renamed to Cert::into_packets
   - ValidAmalgamation::cert renamed to ValidAmalgamation::valid_cert
   - Message no longer derefs to PacketPile, use Message::packets
   - CertRevocationBuilder no longer derefs to SignatureBuilder
   - SubkeyRevocationBuilder no longer derefs to SignatureBuilder
   - UserIDRevocationBuilder no longer derefs to SignatureBuilder
   - UserAttributeRevocationBuilder no longer derefs to SignatureBuilder
   - Parse::from_buffered_reader is now mandatory
   - Parse::from_reader is no longer mandatory
   - SKESK6 no longer derefs to SKESK4
   - PacketPileParser no longer derefs to PacketParserResult
   - ValidCert no longer derefs to Cert
   - ValidateAmalgamation::with_policy now takes a &self
   - ComponentBundle no longer derefs to the component
   - SignatureType::AttestationKey renamed to
     SignatureType::CertificationApproval
   - SubpacketTag::AttestedCertifications renamed to
     SubpacketTag::ApprovedCertifications
   - SubpacketValue::AttestedCertifications renamed to
     SubpacketValue::ApprovedCertifications
   - ComponentBundle::attestations renamed to
     ComponentBundle::approvals
   - SubpacketAreas::attested_certifications renamed to
     SubpacketAreas::approved_certifications
   - SignatureBuilder::set_attested_certifications renamed to
     SignatureBuilder::set_approved_certifications
   - ValidUserIDAmalgamation::attested_certifications renamed to
     ValidUserIDAmalgamation::approved_certifications
   - ValidUserIDAmalgamation::attestation_key_signatures renamed to
     ValidUserIDAmalgamation::certification_approval_key_signatures
   - ValidUserAttributeAmalgamation::attested_certifications renamed
     to ValidUserAttributeAmalgamation::approved_certifications
   - ValidUserAttributeAmalgamation::attestation_key_signatures
     renamed to
     ValidUserAttributeAmalgamation::certification_approval_key_signatures
   - Packet::AED removed
   - packet::aed::AED1 removed
   - serialize::stream::Encryptor2 renamed to Encryptor
   - crypto::ecdh::decrypt_unwrap2 renamed to decrypt_unwrap2
   - UserID::name2 renamed to UserID::name
   - UserID::comment2 renamed to UserID::comment
   - UserID::email2 renamed to UserID::email
   - UserID::uri2 renamed to UserID::uri
   - Features::supports_aead removed
   - Features::set_aead removed
   - Features::clear_aead removed
   - cert::amalgamation::ValidAmalgamation::map has been moved to
     cert::amalgamation::ValidBindingSignature::map
   - cert::amalgamation::ValidAmalgamation is now dyn-compatible
   - crypto::AEADAlgorithm::iv_size removed
   - DecryptionHelper::decrypt now uses dynamic dispatch for the
     `decryption` parameter
   - DecryptionHelper::decrypt now returns a Result<Option<Cert>>
   - UserIDAmalgamation::attest_certifications2 renamed to
     attest_certifications
   - UserAttributeAmalgamation::attest_certifications2 renamed to
     attest_certifications
   - ValidUserAttributeAmalgamation::attest_certifications renamed to
     approve_of_certifications
   - ValidUserIDAmalgamation::attest_certifications renamed to
     approve_of_certifications
   - UserAttributeAmalgamation::attest_certifications renamed to
     approve_of_certifications
   - UserIDAmalgamation::attest_certifications renamed to
     approve_of_certifications
   - ComponentAmalgamation no longer derefs to the ComponentBundle
   - KeyAmalgamation no longer derefs to ComponentAmalgamation<Key>
   - ValidComponentAmalgamation no longer derefs to ComponentAmalgamation
   - ValidKeyAmalgamation no longer derefs to KeyAmalgamation
   - Signature::hash_userid_attestation renamed to
     hash_userid_approval
   - Signature::hash_user_attribute_attestation renamed to
     hash_user_attribute_approval
   - Signature::verify_userid_attestation renamed to
     verify_userid_approval
   - Signature::verify_user_attribute_attestation renamed to
     hash_user_attribute_approval
   - packet::CompressedData::container_ref
   - packet::CompressedData::container_mut
   - packet::CompressedData no longer derefs to Container
   - packet::seip::SEIP1::container_ref
   - packet::seip::SEIP1::container_mut
   - packet::seip::SEIP1 no longer derefs to Container
   - packet::seip::SEIP2::container_ref
   - packet::seip::SEIP2::container_mut
   - packet::seip::SEIP2 no longer derefs to Container
   - PacketPile::pretty_print removed
   - parse::stream::MessageStructure no longer derefs to [MessageLayer]
   - packet::Container no longer derefs to packet::Body
   - Key6::import_public_cv25519 renamed to import_public_x25519
   - Key6::import_public_x25519 now produces a X25519 key, not an ECDH
     key
   - Key6::import_public_ed25519 now produces an Ed25519 key, not an
     EdDSALegacy key
   - CertBuilder::general_purpose is more ergonomic now.  Its first
     parameter is dropped, the second can take any number of user IDs.
   - UserID::from_address now uses distinct types for its arguments.
     The name and comment argument now take an Into<Option<&str>>.
   - UserID::from_unchecked address now uses distinct types for its
     arguments.  The name and comment argument now take an
     Into<Option<&str>>.
   - SignatureBuilder::set_revocation_key now takes a single key
   - parse::stream::VerificationError is now marked non-exhaustive
   - Parse is now sealed

** New functionality
   - Signature::hash_userid_attestation
   - Signature::hash_user_attribute_attestation
   - Message::packets
   - PacketPileParser::packet
   - PacketPileParser::packet_mut
   - crypto::PublicKeyAlgorithm
   - crypto::Curve
   - crypto::SymmetricAlgorithm
   - crypto::AEADAlgorithm
   - crypto::HashAlgorithm
   - crypto::Curve::BrainpoolP384
   - public re-export of anyhow
   - cert::amalgamation::ValidBindingSignature
   - impl Borrow<[u8]> for Fingerprint
   - impl Borrow<[u8]> for KeyID
   - ComponentAmalgamation::binding_signature
   - ComponentAmalgamation::approvals
   - UserIDAmalgamation::revocation_status
   - UserAttributeAmalgamation::revocation_status
   - UnknownComponentAmalgamation::unknown
   - KeyAmalgamation::key
   - KeyAmalgamation::revocation_status
   - PrimaryKeyAmalgamation::binding_signature
   - SubordinateKeyAmalgamation::binding_signature
   - KeyAmalgamation::cert
   - KeyAmalgamation::bundle
   - KeyAmalgamation::component
   - KeyAmalgamation::self_signatures
   - KeyAmalgamation::certifications
   - KeyAmalgamation::self_revocations
   - KeyAmalgamation::other_revocations
   - KeyAmalgamation::signatures
   - ValidComponentAmalgamation::cert
   - ValidComponentAmalgamation::binding_signature
   - ValidComponentAmalgamation::bundle
   - ValidComponentAmalgamation::component
   - ValidComponentAmalgamation::approvals
   - ValidUserIDAmalgamation::userid
   - ValidUserAttributeAmalgamation::user_attribute
   - ValidKeyAmalgamation::cert
   - ValidKeyAmalgamation::binding_signature
   - ValidKeyAmalgamation::bundle
   - ValidKeyAmalgamation::component
   - ValidKeyAmalgamation::self_signatures
   - ValidKeyAmalgamation::certifications
   - ValidKeyAmalgamation::self_revocations
   - ValidKeyAmalgamation::other_revocations
   - ValidKeyAmalgamation::approvals
   - ValidKeyAmalgamation::signatures
   - parse::stream::MessageStructure::iter
   - Key6::import_secret_x25519
   - Key6::import_secret_ed25519
   - Key6::import_public_x448
   - Key6::import_secret_x448
   - Key6::import_public_ed448
   - Key6::import_secret_ed448
   - SignatureBuilder::add_revocation_key
   - parse::stream::VerificationError::UnknownSignature
   - RawCert::into_owned

** Deprecated functionality
   - Cert::insert_packets, use Cert::insert_packets2 instead

** Notable fixes
   - Fixed an integer overflow parsing PKESKv6 packets.

* Changes in 2.0.0.alpha.0
  The major new feature is the support for RFC9580, which modernizes
  the cryptographic primitives used in OpenPGP.  Notably, it adds
  Authenticated Encryption, Elliptic Curve Cryptography, and
  deprecates old algorithms.

  We have also used the opportunity to clean up our API.  Most
  programs should only require minor adjustments.

** API changes
   - Fingerprint::V5 removed
   - KeyID::V4 removed
   - HashAlgorithm::context now returns crypto::hash::Builder
   - crypto::Hash::hash now takes a &mut crypto::hash::Context
   - crypto::hash::Digest removed
   - SKESK::V5 removed
   - SKESK5 removed
   - PacketParser::decrypt: The parameter `algo` is now polymorphic
     over `Into<Option<SymmetricAlgorithm>>`.
   - DecryptionHelper::decrypt: The function `decrypt` now takes an
     optional symmetric algorithm.
   - SKESK::decrypt now returns an optional symmetric algorithm.
   - PKESK::decrypt now returns an optional symmetric algorithm.
   - key::SecretKeyMaterial::decrypt now takes a &Key.
   - key::SecretKeyMaterial::decrypt_in_place now takes a &Key.
   - key::SecretKeyMaterial::encrypt now takes a &Key.
   - key::SecretKeyMaterial::encrypt_in_place now takes a &Key.
   - key::Encrypted::decrypt now takes a &Key.
   - key::Unencrypted::encrypt now takes a &Key.
   - Curve is now marked as non-exhaustive
   - armor::Kind is now marked as non-exhaustive
   - armor::ReaderMode is now marked as non-exhaustive
   - cert::Ciphersuite is now marked as non-exhaustive
   - Profile is now marked as non-exhaustive
   - packet::Tag is now marked as non-exhaustive
   - user_attribute::Subpacket is now marked as non-exhaustive
   - user_attribute::Image is now marked as non-exhaustive
   - parse::Dearmor is now marked as non-exhaustive
   - impl From<MPI> for ProtectedMPI has been removed
   - NullPolicy::new is now marked as unsafe
   - DataFormat::MIME removed
   - DataFormat::Text is deprecated in favor of DataFormat::Unicode
   - DataFormat::Unknown is a u8 now
   - Curve::bits now returns Result<usize>
   - HashAlgorithm::from_str now returns Result<Self, crate::Error>

** Policy changes
   - Version 4 DSA keys and signatures will be rejected from the
     2030-02-01 on.
   - Version 4 ElGamal keys will be rejected from the 2025-02-01 on.
   - Version 1 SEIPD packets with IDEA or CAST5 be rejected from the
     2025-02-01 on.

** New functionality
   - Fingerprint::V6
   - KeyID::Long
   - S2K::Argon2
   - HashAlgorithm::SHA3_256
   - HashAlgorithm::SHA3_512
   - types::Features::clear_seipdv2
   - types::Features::set_seipdv2
   - types::Features::supports_seipdv2
   - SubpacketTag::PreferredAEADCiphersuites
   - SubpacketValue::PreferredAEADCiphersuites
   - SubpacketAreas::preferred_aead_ciphersuites
   - SignatureBuilder::set_preferred_aead_ciphersuites
   - Preferences::preferred_aead_ciphersuites
   - Profile
   - Key::V6
   - Key6
   - CertBuilder::set_profile
   - key::Encrypted::new_aead
   - key::Encrypted::aead_algo
   - key::Encrypted::aead_iv
   - mpi::PublicKey::X25519
   - mpi::PublicKey::X448
   - mpi::PublicKey::Ed25519
   - mpi::PublicKey::Ed448
   - mpi::SecretKeyMaterial::X25519
   - mpi::SecretKeyMaterial::X448
   - mpi::SecretKeyMaterial::Ed25519
   - mpi::SecretKeyMaterial::Ed448
   - mpi::Ciphertext::X25519
   - mpi::Ciphertext::X448
   - mpi::Signature::Ed25519
   - mpi::Signature::Ed448
   - Key4::generate_x25519
   - Key4::generate_x448
   - Key4::generate_ed25519
   - Key4::generate_ed448
   - policy::AsymmetricAlgorithm::X25519
   - policy::AsymmetricAlgorithm::X448
   - policy::AsymmetricAlgorithm::Ed25519
   - policy::AsymmetricAlgorithm::Ed448
   - PublicKeyAlgorithm::X25519
   - PublicKeyAlgorithm::X448
   - PublicKeyAlgorithm::Ed25519
   - PublicKeyAlgorithm::Ed448
   - crypto::hash::Context
   - HashAlgorithm::digest_size
   - crypto::hash::Builder
   - Signature::V6
   - Signature6
   - SignatureBuilder::prefix_salt
   - SignatureBuilder::set_prefix_salt
   - HashAlgorithm::salt_size
   - OnePassSig::V6
   - OnePassSig6
   - Packet::Padding
   - Padding
   - Tag::Padding
   - KeyAmalgamationIter::key_handles2
   - ValidKeyAmalgamationIter::key_handles2
   - SKESK::V6
   - SKESK6
   - impl From<Option<KeyHandle>> for KeyID
   - PKESK::V6
   - PKESK6
   - SEIP::V2
   - SEIP2
   - serialize::stream::Encryptor2::aead_algo
   - key::KeyRole::role
   - key::KeyRoleRT
   - key::SecretKeyMaterial::encrypt_with
   - key::SecretKeyMaterial::encrypt_in_place_with
   - key::Unencrypted::encrypt_with
   - The RustCrypto backend now supports OCB.
   - The Windows CNG backend backend now supports OCB implemented
     using the OCB implementation from RustCrypto.
   - Packet::is_critical
   - Tag::is_critical

** Deprecated functionality
   - SubpacketTag::PreferredAEADAlgorithms
   - SubpacketValue::PreferredAEADAlgorithms
   - SubpacketAreas::preferred_aead_algorithms
   - SignatureBuilder::set_preferred_aead_algorithms
   - KeyAmalgamationIter::key_handles
   - ValidKeyAmalgamationIter::key_handles
   - SymmetricAlgorithm::IDEA
   - SymmetricAlgorithm::TripleDES
   - SymmetricAlgorithm::CAST5

** Notable fixes

* Changes in 1.22.0
** New functionality
   - DetachedVerifier::verify_buffered_reader
** Notable fixes
   - UserIdAmalgamation::attest_certifications2,
     UserAttributeAmalgamation::attest_certifications2,
     ValidUserIdAmalgamation::attest_certifications, and
     ValidUserAttributeAmalgamation::attest_certifications now
     correctly set the creation time of newly created signatures.
* Changes in 1.21.2
** Notable fixes
   - A set of constructors for KeyFlags added in 1.21.0 mistakenly
     consumed a KeyFlags.  This patch release fixes that, even though
     it is technically an API break.
* Changes in 1.21.1
** Notable fixes
   - Leftover debugging statements introduced in 1.21.0 printed
     long-term Cv25519 secret key material to stderr during
     decryption.  This patch release fixes that.
* Changes in 1.21.0
** Notable fixes
   - The RawCertParser now correctly advance the input stream when
     encountering unsupported cert (primary key) versions.  Previously,
     this resulted in an infinite loop.
   - Sequoia built with the OpenSSL backend or the RustCrypto backend
     will now make sure that the secret primes of generated RSA keys
     are ordered the way OpenPGP demands (i.e. `p` < `q`).
   - Sequoia built with the OpenSSL backend, the CNG backend, or the
     RustCrypto backend will now make sure that the secret primes of
     imported RSA keys are ordered the way OpenPGP demands.
   - Loosen trait bounds on Key::clone and Key4::clone.
** Notable changes
   - All signature verification methods now take an immutable
     reference to the signature.  This will cause existing code to
     emit warnings about unused mutability, but should not break
     anything.
   - Sequoia now lazily verifies self signatures in certificates.
     Previously, they were eagerly verified during certificate
     canonicalization, incurring a substantial cost even for
     signatures that were not otherwise considered.
** New functionality
   - CipherSuite::variants.
   - ComponentBundle::certifications2
   - ComponentBundle::other_revocations2
   - ComponentBundle::self_revocations2
   - ComponentBundle::self_signatures2
   - Key::<PublicParts, _>::steal_secret
   - Key::<UnknownParts, _>::steal_secret
   - Key4::<PublicParts, _>::steal_secret
   - Key4::<UnknownParts, _>::steal_secret
   - cert::raw::Error::UnsupportedCert
   - packet::Unknown::into_error
   - The RustCrypto backend now supports ECDH and ECDSA over the NIST
     curve P-384.
   - The RustCrypto backend now supports ECDH and ECDSA over the NIST
     curve P-521.
   - UserAttributeAmalgamation::attest_certifications2
   - UserIDAmalgamation::attest_certifications2
   - KeyFlags::certification
   - KeyFlags::signing
   - KeyFlags::transport_encryption
   - KeyFlags::storage_encryption
   - KeyFlags::authentication
   - KeyFlags::split_key
   - KeyFlags::group_key
   - ValidKeyAmalgamation::primary_key_binding_signature
   - Fingerprint::aliases
   - KeyID::aliases
** Deprecated functionality
   - ComponentBundle::certifications
   - ComponentBundle::other_revocations
   - ComponentBundle::self_revocations
   - ComponentBundle::self_signatures
   - Add a signature verification cache, which is automatically
     consulted by the low-level signature verification functions, like
     `Signature::verify_digest`.
     - openpgp::packet::signature::cache::SignatureVerificationCache
     - openpgp::packet::signature::cache::Entry
   - UserAttributeAmalgamation::attest_certifications
   - UserIDAmalgamation::attest_certifications
* Changes in 1.20.0
** New functionality
   - S2K::Implicit
   - Signature::verify_signature
* Changes in 1.19.0
** Notable fixes
   - Key4::import_secret_cv25519 will now clamp some bits of the given
     secret scalar to make the generated secret key packet more
     compatible with implementations that do not implicitly do the
     clamping before decryption.
   - Sequoia built with the OpenSSL backend will now use the correct
     representation of points on Weierstrass curves.  OpenPGP uses the
     uncompressed representation.  Previously, the OpenSSL backend
     used the compressed representation by mistake.
** New functionality
   - Curve::variants
* Changes in 1.18.0
** New functionality
   - ComponentAmalgamation::certifications_by_key
   - UserIDAmalgamation::valid_certifications_by_key
   - KeyAmalgamation::valid_certifications_by_key
   - UserIDAmalgamation::active_certifications_by_key
   - KeyAmalgamation::active_certifications_by_key
   - UserIDAmalgamation::valid_third_party_revocations_by_key
   - KeyAmalgamation::valid_third_party_revocations_by_key
   - Parse::from_buffered_reader
   - armor::Reader::from_buffered_reader
   - Cert::exportable
   - CertBuilder::set_exportable
   - UserID::from_static_bytes
   - Error::ShortKeyID
   - Cert::into_packets2
   - TSK::into_packets
** Deprecated functionality
   - Cert::into_packets
* Changes in 1.17.0
** Notable fixes
   - Sequoia now ignores some formatting errors when reading secret
     keys.  Being lenient in this case helps the user recover their
     valuable key material.

   - Previously, Sequoia would buffer packet bodies when mapping is
     enabled in the parser, even if the packet parser is not
     configured to buffer the bodies.  This adds considerable
     overhead.

     Starting with this version, Sequoia no longer includes the packet
     bodies in the maps unless the parser is configured to buffer any
     unread content.

     This makes parsing packets faster if you don't rely on the packet
     body in the map, but changes the default behavior.  If you need
     the old behavior, please do adjust your code to buffer unread
     content.

   - To increase compatibility with early v4 certificates, if there is
     no key flags subpacket on either the active binding signature or
     the active direct key signature, we infer the key flags from the
     key's role and public key algorithm.

   - When creating an authentication-capable subkey, Sequoia now also
     adds a primary key binding signature.

   - The MSRV is now 1.67.

   - serialize::stream::Encryptor2 replaces
     serialize::stream::Encryptor, which fixes an issue with the
     lifetimes.
** New functionality
   - The RustCrypto backend now supports DSA.
   - cert::amalgamation::key::KeyAmalgamationIter::encrypted_secret
   - cert::amalgamation::key::ValidKeyAmalgamationIter::encrypted_secret
   - crypto::SessionKey::as_protected
   - crypto::ecdh::decrypt_unwrap2
   - packet::Key::generate_dsa
   - packet::Key::generate_elgamal
   - packet::UserID::comment2
   - packet::UserID::email2
   - packet::UserID::name2
   - packet::UserID::uri2
   - parse::PacketParser::start_hashing
   - parse::PacketParserBuilder::automatic_hashing
   - impl Eq, PartialEq for regex::Regex
   - regex::Regex::as_str
   - impl Eq, PartialEq for regex::RegexSet
   - regex::RegexSet::as_bytes
   - impl Default for types::AEADAlgorithm
   - serialize::stream::Encryptor2
   - types::AEADAlgorithm::GCM
   - types::Bitfield
   - types::Features::clear_seipdv1
   - types::Features::set_seipdv1
   - types::Features::supports_seipdv1
   - types::Features::as_bitfield
   - types::KeyFlags::as_bitfield
   - types::KeyServerPreferences::as_bitfield
** Deprecated functionality
   - cert::Preferences::preferred_aead_algorithms
   - crypto::ecdh::decrypt_unwrap
   - packet::UserID::comment
   - packet::UserID::email
   - packet::UserID::name
   - packet::UserID::uri
   - packet::signature::SignatureBuilder::set_preferred_aead_algorithms
   - packet::signature::subpacket::SubpacketAreas::preferred_aead_algorithms
   - packet::signature::subpacket::SubpacketTag::PreferredAEADAlgorithms
   - packet::signature::subpacket::SubpacketValue::PreferredAEADAlgorithms
   - serialize::stream::Encryptor
   - types::Curve::len, use types::Curve::bits instead
   - types::Features::clear_mdc
   - types::Features::set_mdc
   - types::Features::supports_mdc
   - types::Features::clear_aead
   - types::Features::set_aead
   - types::Features::supports_aead
* Changes in 1.16.0
** New functionality
   - Add KeyFlags::set_certification_to.
   - Add KeyFlags::set_signing_to.
   - Add KeyFlags::set_transport_encryption_to.
   - Add KeyFlags::set_storage_encryption_to.
   - Add KeyFlags::set_split_key_to.
   - Add KeyFlags::set_group_key_to.
** Notable fixes
   - Several parser bugs were fixed.  These are all low-severity as
     Rust correctly detects the out of bounds access and panics.
** Notable changes
   - The crypto/botan feature now selects Botan's v3 interface.  The
     crypt/botan2 feature can be used to select Botan's v2 interface.
* Changes in 1.15.0
** New functionality
   - StandardPolicy::accept_hash_property
** Notable changes
   - Updated the crypto-rust backend.
   - Updated the crypto-cng backend.
* Changes in 1.14.0
** New cryptographic backends
   - We added a backend that uses Botan.
** New functionality
   - crypto::mem::Protected::new
   - crypto::mpi::SecretKeyMaterial::from_bytes
   - crypto::mpi::SecretKeyMaterial::from_bytes_with_checksum
   - fmt::hex::Dumper::with_offset
   - parse::buffered_reader re-export
   - policy::AsymmetricAlgorithm::BrainpoolP384
   - RawCert implements Parse
** Deprecated functionality
   - crypto::mpi::SecretKeyMaterial::parse
   - crypto::mpi::SecretKeyMaterial::parse_with_checksum
* Changes in 1.13.0
** New cryptographic backends
   - We added a backend that uses OpenSSL.
** New functionality
   - RawCertParser
   - RawCert
   - RawPacket
* Changes in 1.12.0
   - Bug fix release.
* Changes in 1.11.0
** New functionality
   - Signature3 implements support for parsing, verifying, and
     reserializing version 3 signature packages.
   - AsymmetricAlgorithm implements PartialEq, Eq, and Copy.
   - AsymmetricAlgorithm::variants.
   - PublicKeyAlgorithm::variants.
   - SymmetricAlgorithm::variants.
   - AEADAlgorithm::variants.
   - CompressionAlgorithm::variants.
   - HashAlgorithm::variants.
   - SignatureType::variants.
   - ReasonForRevocation::variants.
   - DataFormat::variants.
   - packet::Tag::variants.
   - SubpacketTag::variants.
   - StandardPolicy::reject_all_hashes
   - StandardPolicy::reject_all_critical_subpackets
   - StandardPolicy::reject_all_asymmetric_algos
   - StandardPolicy::reject_all_symmetric_algos
   - StandardPolicy::reject_all_aead_algos
   - StandardPolicy::reject_all_packet_tags
   - StandardPolicy::accept_packet_tag_version
   - StandardPolicy::reject_packet_tag_version
   - StandardPolicy::reject_packet_tag_version_at
   - StandardPolicy::packet_tag_version_cutoff
** Deprecated functionality
   - StandardPolicy::packet_tag_cutoff
* Changes in 1.10.0
** New functionality
   - Cert::insert_packets2
   - Cert::insert_packets_merge
   - crypto::ecdh::aes_key_wrap
   - crypto::ecdh::aes_key_unwrap
   - Error::UnsupportedCert2
   - TryFrom<Packet> for Unknown
   - types::{Curve, SymmetricAlgorithm, AEADAlgorithm,
     PublicKeyAlgorithm}'s Display implementation now provides short
     names by default. The long descriptions are provided by the
     alternate formatter (e.g. =format!("{:#}", ...)=)
   - cert::KeyBuilder
   - cert::SubkeyBuilder
   - HashAlgorithm::oid is available on all crypto backends
     (previously only on Nettle)
** Deprecated functionality
   - Error::UnsupportedCert, use Error::UnsupportedCert2 instead
   - DataFormat::MIME, no replacement, see #863 for details
   - PacketParser::encrypted, use the negation of PacketParser::processed
* Changes in 1.9.0
** New functionality
   - AEADAlgorithm::nonce_size replaces AEADAlgorithm::iv_size
   - crypto::backend
   - Curve::field_size
   - MPI::is_zero
   - MPI::zero
   - packet::Any
   - Packet::version
   - SignatureBuilder::set_reference_time
   - SignatureBuilder::effective_signature_creation_time
** Deprecated functionality
   - armor::Reader::new, use armor::Reader::from_reader instead
   - message::Token is not covered by SemVer guarantees, DO NOT match on it
   - AEADAlgorithm::iv_size, use AEADAlgorithm::nonce_size
* Changes in 1.8.0
** New functionality
   - crypto::Signer::acceptable_hashes
   - Fingerprint::V5
* Changes in 1.7.0
** Notable fixes
   - sequoia-openpgp can now be compiled to WASM.
   - The MSRV is now 1.56.1.
* Changes in 1.6.0
** Notable fixes
   - Decryption of encrypted messages and verification of
     inline-signed messages is now considerably faster, as is ASCII
     Armor encoding and decoding.
** New functionality
   - CertRevocationBuilder::add_notation
   - CertRevocationBuilder::set_notation
   - KeyFlags::clear_group_key
   - SubkeyRevocationBuilder::add_notation
   - SubkeyRevocationBuilder::set_notation
   - UserAttributeRevocationBuilder::add_notation
   - UserAttributeRevocationBuilder::set_notation
   - UserIDRevocationBuilder::add_notation
   - UserIDRevocationBuilder::set_notation
* Changes in 1.5.0
** Notable changes
   - This crate is now licensed under the LGPL 2.0 or later.
* Changes in 1.4.0
** New cryptographic backends
   - We added a backend based on the RustCrypto crates.
** New functionality
   - CipherSuite::is_supported
   - MPI::value_padded
   - Preferences::policy_uri
   - ProtectedMPI::value_padded
   - TSK::eq
   - ValidAmalgamation::revocation_keys
   - ValidCert::policy_uri
   - ValidCert::revocation_keys
** Notable fixes
   - Filters set using CertParser::unvalidated_cert_filter are now
     preserved during iterations.
* Changes in 1.3.1
** Notable fixes
   - Fixed a crash resulting from unconstrained, attacker-controlled
     heap allocations.
* Changes in 1.3.0
** New functionality
   - CertBuilder::add_subkey_with
   - CertBuilder::add_user_attribute_with
   - CertBuilder::add_userid_with
   - ComponentBundle::attestations
   - Encryptor::with_session_key
   - Signature::verify_user_attribute_attestation
   - Signature::verify_userid_attestation
   - SignatureBuilder::pre_sign
   - SignatureBuilder::set_attested_certifications
   - SignatureType::AttestationKey
   - SubpacketAreas::MAX_SIZE
   - SubpacketAreas::attested_certifications
   - SubpacketTag::AttestedCertifications
   - SubpacketValue::AttestedCertifications
   - UserAttributeAmalgamation::attest_certifications
   - UserIDAmalgamation::attest_certifications
   - ValidUserAttributeAmalgamation::attest_certifications
   - ValidUserAttributeAmalgamation::attestation_key_signatures
   - ValidUserAttributeAmalgamation::attested_certifications
   - ValidUserIDAmalgamation::attest_certifications
   - ValidUserIDAmalgamation::attestation_key_signatures
   - ValidUserIDAmalgamation::attested_certifications
** Notable fixes
   - Improve Cert::insert_packets runtime from O(n^2) to O(n log n).
   - CertParser returned errors out of order (#699).
* Changes in 1.1.0
** New functionality
   - The new regex module provides regular expression support for
     scoping trust signatures.
   - Sequoia now supports the Cleartext Signature Framework.
   - ComponentAmalgamation::signatures
   - ComponentBundle::signatures
   - Fingerprint::to_spaced_hex
   - HashAlgorithm::text_name
   - KeyHandle now implements FromStr
   - KeyHandle::is_invalid
   - KeyHandle::to_hex
   - KeyHandle::to_spaced_hex
   - KeyID::to_spaced_hex
   - Signature4::hash_for_confirmation
   - Signature::hash_for_confirmation
   - TSK::armored
   - ValidComponentAmalgamation::signatures
** Notable fixes
   - Fixed two crashes related to detached signature verification.
   - Fixed a parsing bug where the parser did not consume all data in
     an compressed data packet.

* Changes in 1.0.0

This is the initial stable release.