Struct sequoia_openpgp::Cert

pub struct Cert { /* fields omitted */ }

A collection of components and their associated signatures.

The Cert data structure mirrors the TPK and TSK data structures defined in RFC 4880. Specifically, it contains components (Keys, UserIDs, and UserAttributes), their associated self signatures, self revocations, third-party signatures, and third-party revocations, as well as useful methods.

Certs are canonicalized in the sense that their Components are deduplicated, and their signatures and revocations are deduplicated and checked for validity. The canonicalization routine does not throw away components that have no self signatures. These are returned as usual by, e.g., Cert::userids.

Keys are deduplicated by comparing their public bits using Key::public_cmp. If two keys are considered equal, and only one of them has secret key material, the key with the secret key material is preferred. If both keys have secret material, then one of them is chosen in a deterministic, but undefined manner, which is subject to change. Note: the secret key material is not integrity checked. Hence when updating a certificate with secret key material, it is essential to first strip the secret key material from copies that came from an untrusted source.

Signatures are deduplicated using their Eq implementation, which compares the data that is hashed and the MPIs. That is, it does not compare the unhashed data, the digest prefix and the unhashed subpacket area. If two signatures are considered equal, but have different unhashed data, the unhashed data are merged in a deterministic, but undefined manner, which is subject to change. This policy prevents an attacker from flooding a certificate with valid signatures that only differ in their unhashed data.

Self signatures and self revocations are checked for validity by making sure that the signature is mathematically correct. At this point, the signature is not checked against a Policy.

Third-party signatures and revocations are checked for validity by making sure the computed digest matches the digest prefix stored in the signature packet. This is not an integrity check and is easily spoofed. Unfortunately, at the time of canonicalization, the actual signatures cannot be checked, because the public keys are not available. If you rely on these signatures, it is up to you to check their validity by using an appropriate signature verification method, e.g., Signature::verify_userid_binding or Signature::verify_userid_revocation.

If a signature or a revocation is not valid, we check to see whether it is simply out of place (i.e., belongs to a different component) and, if so, we reorder it. If not, it is added to a list of bad signatures. These can be retrieved using Cert::bad_signatures.

Signatures and revocations are sorted so that the newest signature comes first. Components are sorted, but in an undefined manner (i.e., when parsing the same certificate multiple times, the components will be in the same order, but we reserve the right to change the sort function between versions).

Secret Keys

Any key in a certificate may include secret key material. To protect secret key material from being leaked, secret keys are not written out when a Cert is serialized. To also serialize secret key material, you need to serialize the object returned by Cert::as_tsk().

Secret key material may be protected with a password. In such cases, it needs to be decrypted before it can be used to decrypt data or generate a signature. Refer to Key::decrypt_secret for details.

Filtering Certificates

Component-wise filtering of userids, user attributes, and subkeys can be done with Cert::retain_userids, Cert::retain_user_attributes, and Cert::retain_subkeys.

If you need even more control, iterate over all components, clone what you want to keep, and then reassemble the certificate. The following example simply copies all the packets, and can be adapted to suit your policy:

use std::convert::TryFrom;
use openpgp::cert::prelude::*;

fn identity_filter(cert: &Cert) -> Result<Cert> {
    // Iterate over all of the Cert components, pushing packets we
    // want to keep into the accumulator.
    let mut acc = Vec::new();

    // Primary key and related signatures.
    let c = cert.primary_key();
    acc.push(c.key().clone().into());
    for s in c.self_signatures()   { acc.push(s.clone().into()) }
    for s in c.certifications()    { acc.push(s.clone().into()) }
    for s in c.self_revocations()  { acc.push(s.clone().into()) }
    for s in c.other_revocations() { acc.push(s.clone().into()) }

    // UserIDs and related signatures.
    for c in cert.userids() {
        acc.push(c.userid().clone().into());
        for s in c.self_signatures()   { acc.push(s.clone().into()) }
        for s in c.attestations()      { acc.push(s.clone().into()) }
        for s in c.certifications()    { acc.push(s.clone().into()) }
        for s in c.self_revocations()  { acc.push(s.clone().into()) }
        for s in c.other_revocations() { acc.push(s.clone().into()) }
    }

    // UserAttributes and related signatures.
    for c in cert.user_attributes() {
        acc.push(c.user_attribute().clone().into());
        for s in c.self_signatures()   { acc.push(s.clone().into()) }
        for s in c.attestations()      { acc.push(s.clone().into()) }
        for s in c.certifications()    { acc.push(s.clone().into()) }
        for s in c.self_revocations()  { acc.push(s.clone().into()) }
        for s in c.other_revocations() { acc.push(s.clone().into()) }
    }

    // Subkeys and related signatures.
    for c in cert.keys().subkeys() {
        acc.push(c.key().clone().into());
        for s in c.self_signatures()   { acc.push(s.clone().into()) }
        for s in c.certifications()    { acc.push(s.clone().into()) }
        for s in c.self_revocations()  { acc.push(s.clone().into()) }
        for s in c.other_revocations() { acc.push(s.clone().into()) }
    }

    // Unknown components and related signatures.
    for c in cert.unknowns() {
        acc.push(c.unknown().clone().into());
        for s in c.self_signatures()   { acc.push(s.clone().into()) }
        for s in c.certifications()    { acc.push(s.clone().into()) }
        for s in c.self_revocations()  { acc.push(s.clone().into()) }
        for s in c.other_revocations() { acc.push(s.clone().into()) }
    }

    // Any signatures that we could not associate with a component.
    for s in cert.bad_signatures()     { acc.push(s.clone().into()) }

    // Finally, parse into Cert.
    Cert::try_from(acc)
}

let (cert, _) =
    CertBuilder::general_purpose(None, Some("alice@example.org"))
    .generate()?;
assert_eq!(cert, identity_filter(&cert)?);

Examples

Parse a certificate:

use std::convert::TryFrom;
use sequoia_openpgp as openpgp;
use openpgp::Cert;

match Cert::try_from(ppr) {
    Ok(cert) => {
        println!("Key: {}", cert.fingerprint());
        for uid in cert.userids() {
            println!("User ID: {}", uid.userid());
        }
    }
    Err(err) => {
        eprintln!("Error parsing Cert: {}", err);
    }
}

Implementations

impl Cert

pub fn primary_key(&self) -> PrimaryKeyAmalgamation<'_, PublicParts>

Returns the primary key.

Unlike getting the certificate’s primary key using the Cert::keys method, this method does not erase the key’s role.

A key’s secret key material may be protected with a password. In such cases, it needs to be decrypted before it can be used to decrypt data or generate a signature. Refer to Key::decrypt_secret for details.

Examples

The first key returned by Cert::keys is the primary key, but its role has been erased:

assert_eq!(cert.primary_key().key().role_as_unspecified(),
           cert.keys().nth(0).unwrap().key());

pub fn revocation_status<T>(
    &self,
    policy: &dyn Policy,
    t: T
) -> RevocationStatus<'_> where
    T: Into<Option<SystemTime>>, 

Returns the certificate’s revocation status.

Normally, methods that take a policy and a reference time are only provided by ValidCert. This method is provided here because there are two revocation criteria, and one of them is independent of the reference time. That is, even if it is not possible to turn a Cert into a ValidCert at time t, it may still be considered revoked at time t.

A certificate is considered revoked at time t if:

• There is a valid and live revocation at time t that is newer than all valid and live self signatures at time t, or

• There is a valid hard revocation (even if it is not live at time t, and even if there is a newer self signature).

Note: certificates and subkeys have different revocation criteria from User IDs and User Attributes.

Examples

use sequoia_openpgp as openpgp;
use openpgp::cert::prelude::*;
use openpgp::types::RevocationStatus;
use openpgp::policy::StandardPolicy;

let p = &StandardPolicy::new();

let (cert, rev) =
    CertBuilder::general_purpose(None, Some("alice@example.org"))
    .generate()?;

assert_eq!(cert.revocation_status(p, None), RevocationStatus::NotAsFarAsWeKnow);

// Merge the revocation certificate.  `cert` is now considered
// to be revoked.
let cert = cert.insert_packets(rev.clone())?;
assert_eq!(cert.revocation_status(p, None),
           RevocationStatus::Revoked(vec![&rev.into()]));

pub fn revoke(
    &self,
    primary_signer: &mut dyn Signer,
    code: ReasonForRevocation,
    reason: &[u8]
) -> Result<Signature>

Revokes the certificate in place.

This is a convenience function around CertRevocationBuilder to generate a revocation certificate.

If you want to revoke an individual component, use SubkeyRevocationBuilder, UserIDRevocationBuilder, or UserAttributeRevocationBuilder, as appropriate.

Examples

use sequoia_openpgp as openpgp;
use openpgp::types::{ReasonForRevocation, RevocationStatus, SignatureType};
use openpgp::cert::prelude::*;
use openpgp::crypto::KeyPair;
use openpgp::parse::Parse;
use openpgp::policy::StandardPolicy;

let p = &StandardPolicy::new();

let (cert, rev) = CertBuilder::new()
    .set_cipher_suite(CipherSuite::Cv25519)
    .generate()?;

// A new certificate is not revoked.
assert_eq!(cert.revocation_status(p, None),
           RevocationStatus::NotAsFarAsWeKnow);

// The default revocation certificate is a generic
// revocation.
assert_eq!(rev.reason_for_revocation().unwrap().0,
           ReasonForRevocation::Unspecified);

// Create a revocation to explain what *really* happened.
let mut keypair = cert.primary_key()
    .key().clone().parts_into_secret()?.into_keypair()?;
let rev = cert.revoke(&mut keypair,
                      ReasonForRevocation::KeyCompromised,
                      b"It was the maid :/")?;
let cert = cert.insert_packets(rev)?;
if let RevocationStatus::Revoked(revs) = cert.revocation_status(p, None) {
    assert_eq!(revs.len(), 1);
    let rev = revs[0];

    assert_eq!(rev.typ(), SignatureType::KeyRevocation);
    assert_eq!(rev.reason_for_revocation(),
               Some((ReasonForRevocation::KeyCompromised,
                     "It was the maid :/".as_bytes())));
} else {
    unreachable!()
}

pub fn set_expiration_time<T>(
    &self,
    policy: &dyn Policy,
    t: T,
    primary_signer: &mut dyn Signer,
    expiration: Option<SystemTime>
) -> Result<Vec<Signature>> where
    T: Into<Option<SystemTime>>, 

Sets the certificate to expire at the specified time.

If no time (None) is specified, then the certificate is set to not expire.

This function creates new binding signatures that cause the certificate to expire at the specified time. Specifically, it updates the current binding signature on each of the valid, non-revoked User IDs, and the direct key signature, if any. This is necessary, because the primary User ID is first consulted when determining the certificate’s expiration time, and certificates can be distributed with a possibly empty subset of User IDs.

A policy is needed, because the expiration is updated by updating the current binding signatures.

Examples

use std::time;
use sequoia_openpgp as openpgp;
use openpgp::cert::prelude::*;
use openpgp::crypto::KeyPair;
use openpgp::policy::StandardPolicy;

let p = &StandardPolicy::new();

// The certificate is alive (not expired).
assert!(cert.with_policy(p, None)?.alive().is_ok());

// Make cert expire now.
let mut keypair = cert.primary_key()
    .key().clone().parts_into_secret()?.into_keypair()?;
let sigs = cert.set_expiration_time(p, None, &mut keypair,
                                    Some(time::SystemTime::now()))?;

let cert = cert.insert_packets(sigs)?;
assert!(cert.with_policy(p, None)?.alive().is_err());

pub fn userids(&self) -> UserIDAmalgamationIter<'_>

Returns an iterator over the certificate’s User IDs.

This returns all User IDs, even those without a binding signature.

Examples

println!("{}'s User IDs:", cert.fingerprint());
for ua in cert.userids() {
    println!("  {}", String::from_utf8_lossy(ua.value()));
}

pub fn user_attributes(&self) -> UserAttributeAmalgamationIter<'_>

Returns an iterator over the certificate’s User Attributes.

This returns all User Attributes, even those without a binding signature.

Examples

println!("{}'s has {} User Attributes.",
         cert.fingerprint(),
         cert.user_attributes().count());

pub fn keys(&self) -> KeyAmalgamationIter<'_, PublicParts, UnspecifiedRole>

Returns an iterator over the certificate’s keys.

That is, this returns an iterator over the primary key and any subkeys. It returns all keys, even those without a binding signature.

By necessity, this function erases the returned keys’ roles. If you are only interested in the primary key, use Cert::primary_key. If you are only interested in the subkeys, use KeyAmalgamationIter::subkeys. These functions preserve the keys’ role in the type system.

A key’s secret secret key material may be protected with a password. In such cases, it needs to be decrypted before it can be used to decrypt data or generate a signature. Refer to Key::decrypt_secret for details.

Examples

println!("{}'s has {} keys.",
         cert.fingerprint(),
         cert.keys().count());

pub fn unknowns(&self) -> UnknownComponentAmalgamationIter<'_>

Returns an iterator over the certificate’s unknown components.

This function returns all unknown components even those without a binding signature.

Examples

println!("{}'s has {} unknown components.",
         cert.fingerprint(),
         cert.unknowns().count());
for ua in cert.unknowns() {
    println!("  Unknown component with tag {} ({}), error: {}",
             ua.tag(), u8::from(ua.tag()), ua.error());
}

pub fn bad_signatures(&self) -> impl Iterator<Item = &Signature> + Send + Sync

Returns a slice containing the bad signatures.

Bad signatures are signatures and revocations that we could not associate with one of the certificate’s components.

For self signatures and self revocations, we check that the signature is correct. For third-party signatures and third-party revocations, we only check that the digest prefix is correct, because third-party keys are not available. Checking the digest prefix is not an integrity check; third party-signatures and third-party revocations may be invalid and must still be checked for validity before use.

Examples

println!("{}'s has {} bad signatures.",
         cert.fingerprint(),
         cert.bad_signatures().count());

pub fn revocation_keys<'a>(
    &'a self,
    policy: &dyn Policy
) -> Box<dyn Iterator<Item = &'a RevocationKey> + 'a>

Returns a list of any designated revokers for this certificate.

This function returns the designated revokers listed on the primary key’s binding signatures and the certificate’s direct key signatures.

Note: the returned list is deduplicated.

Examples

use sequoia_openpgp as openpgp;
use openpgp::cert::prelude::*;
use openpgp::policy::StandardPolicy;
use openpgp::types::RevocationKey;

let p = &StandardPolicy::new();

let (alice, _) =
    CertBuilder::general_purpose(None, Some("alice@example.org"))
    .generate()?;
// Make Alice a designated revoker for Bob.
let (bob, _) =
    CertBuilder::general_purpose(None, Some("bob@example.org"))
    .set_revocation_keys(vec![(&alice).into()])
    .generate()?;

// Make sure Alice is listed as a designated revoker for Bob.
assert_eq!(bob.revocation_keys(p).collect::<Vec<&RevocationKey>>(),
           vec![&(&alice).into()]);

pub fn into_packets(self) -> impl Iterator<Item = Packet> + Send + Sync

Converts the certificate into an iterator over a sequence of packets.

WARNING: When serializing a Cert, any secret key material is dropped. In order to serialize the secret key material, it is first necessary to convert the Cert into a TSK and serialize that. This behavior makes it harder to accidentally leak secret key material. This function is different. If a key contains secret key material, it is exported as a SecretKey or SecretSubkey, as appropriate. This means that if you serialize the resulting packets, the secret key material will be serialized too.

Examples

println!("Cert contains {} packets",
         cert.into_packets().count());

pub fn from_packets(
    p: impl Iterator<Item = Packet> + Send + Sync
) -> Result<Self>

Returns the first certificate found in the sequence of packets.

If the sequence of packets does not start with a certificate (specifically, if it does not start with a primary key packet), then this fails.

If the sequence contains multiple certificates (i.e., it is a keyring), or the certificate is followed by an invalid packet this function will fail. To parse keyrings, use CertParser instead of this function.

Examples

use sequoia_openpgp as openpgp;
use openpgp::cert::prelude::*;
use openpgp::packet::prelude::*;
use openpgp::PacketPile;

let (cert, rev) =
    CertBuilder::general_purpose(None, Some("alice@example.org"))
    .generate()?;

// We should be able to turn a certificate into a PacketPile
// and back.
assert!(Cert::from_packets(cert.into_packets()).is_ok());

// But a revocation certificate is not a certificate, so this
// will fail.
let p : Vec<Packet> = vec![rev.into()];
assert!(Cert::from_packets(p.into_iter()).is_err());

pub fn into_packet_pile(self) -> PacketPile

Converts the certificate into a PacketPile.

Examples

let pp = cert.into_packet_pile();

pub fn key_handle(&self) -> KeyHandle

Returns the certificate’s fingerprint as a KeyHandle.

Examples

println!("{}", cert.key_handle());

// This always returns a fingerprint.
match cert.key_handle() {
    KeyHandle::Fingerprint(_) => (),
    KeyHandle::KeyID(_) => unreachable!(),
}

pub fn fingerprint(&self) -> Fingerprint

Returns the certificate’s fingerprint.

Examples

println!("{}", cert.fingerprint());

pub fn keyid(&self) -> KeyID

Returns the certificate’s Key ID.

As a general rule of thumb, you should prefer the fingerprint as it is possible to create keys with a colliding Key ID using a birthday attack.

Examples

println!("{}", cert.keyid());

pub fn merge_public(self, other: Cert) -> Result<Self>

Merges other into self, ignoring secret key material in other.

If other is a different certificate, then an error is returned.

This routine merges duplicate packets. This is different from Cert::insert_packets, which prefers keys in the packets that are being merged into the certificate.

This function is appropriate to merge certificate material from untrusted sources like keyservers. If other contains secret key material, it is ignored. See Cert::merge_public_and_secret on how to merge certificates containing secret key material from trusted sources.

Examples

// Merge the local version with the version from the keyserver.
let cert = local.merge_public(keyserver)?;

pub fn merge_public_and_secret(self, other: Cert) -> Result<Self>

Merges other into self, including secret key material.

If other is a different certificate, then an error is returned.

This routine merges duplicate packets. This is different from Cert::insert_packets, which prefers keys in the packets that are being merged into the certificate.

It is important to only merge key material from trusted sources using this function, because it may be used to import secret key material. Secret key material is not authenticated by OpenPGP, and there are plausible attack scenarios where a malicious actor injects secret key material.

Examples

// Merge the local version with the version from your other device.
let cert = local.merge_public_and_secret(other_device)?;

pub fn insert_packets<I>(self, packets: I) -> Result<Self> where
    I: IntoIterator,
    I::Item: Into<Packet>, 

Adds packets to the certificate.

This function turns the certificate into a sequence of packets, appends the packets to the end of it, and canonicalizes the result. Known packets that don’t belong in a TPK or TSK cause this function to return an error. Unknown packets are retained and added to the list of unknown components. The goal is to provide some future compatibility.

If a key is merged that already exists in the certificate, it replaces the existing key. This way, secret key material can be added, removed, encrypted, or decrypted.

Similarly, if a signature is merged that already exists in the certificate, it replaces the existing signature. This way, the unhashed subpacket area can be updated.

Examples

use sequoia_openpgp as openpgp;
use openpgp::cert::prelude::*;
use openpgp::packet::prelude::*;
use openpgp::serialize::Serialize;
use openpgp::parse::Parse;
use openpgp::types::DataFormat;

// Create a new key.
let (cert, rev) =
      CertBuilder::general_purpose(None, Some("alice@example.org"))
      .generate()?;
assert!(cert.is_tsk());


// Merge in the revocation certificate.
assert_eq!(cert.primary_key().self_revocations().count(), 0);
let cert = cert.insert_packets(rev)?;
assert_eq!(cert.primary_key().self_revocations().count(), 1);


// Add an unknown packet.
let tag = Tag::Private(61.into());
let unknown = Unknown::new(tag,
    openpgp::Error::UnsupportedPacketType(tag).into());

// It shows up as an unknown component.
let cert = cert.insert_packets(unknown)?;
assert_eq!(cert.unknowns().count(), 1);
for p in cert.unknowns() {
    assert_eq!(p.tag(), tag);
}


// Try and merge a literal data packet.
let mut lit = Literal::new(DataFormat::Text);
lit.set_body(b"test".to_vec());

// Merging packets that are known to not belong to a
// certificate result in an error.
assert!(cert.insert_packets(lit).is_err());

Remove secret key material:

use sequoia_openpgp as openpgp;
use openpgp::cert::prelude::*;
use openpgp::packet::prelude::*;

// Create a new key.
let (cert, _) =
      CertBuilder::general_purpose(None, Some("alice@example.org"))
      .generate()?;
assert!(cert.is_tsk());

// We just created the key, so all of the keys have secret key
// material.
let mut pk = cert.primary_key().key().clone();

// Split off the secret key material.
let (pk, sk) = pk.take_secret();
assert!(sk.is_some());
assert!(! pk.has_secret());

// Merge in the public key.  Recall: the packets that are
// being merged into the certificate take precedence.
let cert = cert.insert_packets(pk)?;

// The secret key material is stripped.
assert!(! cert.primary_key().has_secret());

Update a binding signature’s unhashed subpacket area:

use sequoia_openpgp as openpgp;
use openpgp::cert::prelude::*;
use openpgp::packet::prelude::*;
use openpgp::packet::signature::subpacket::*;

// Create a new key.
let (cert, _) =
      CertBuilder::general_purpose(None, Some("alice@example.org"))
      .generate()?;
assert_eq!(cert.userids().nth(0).unwrap().self_signatures().count(), 1);

// Grab the binding signature so that we can modify it.
let mut sig =
    cert.userids().nth(0).unwrap().self_signatures().nth(0)
    .unwrap().clone();

// Add a notation subpacket.  Note that the information is not
// authenticated, therefore it may only be trusted if the
// certificate with the signature is placed in a trusted store.
let notation = NotationData::new("retrieved-from@example.org",
                                 "generated-locally",
                                 NotationDataFlags::empty()
                                     .set_human_readable());
sig.unhashed_area_mut().add(
    Subpacket::new(SubpacketValue::NotationData(notation), false)?)?;

// Merge in the signature.  Recall: the packets that are
// being merged into the certificate take precedence.
let cert = cert.insert_packets(sig)?;

// The old binding signature is replaced.
assert_eq!(cert.userids().nth(0).unwrap().self_signatures().count(), 1);
assert_eq!(cert.userids().nth(0).unwrap().self_signatures().nth(0)
               .unwrap()
               .unhashed_area()
               .subpackets(SubpacketTag::NotationData).count(), 1);

pub fn is_tsk(&self) -> bool

Returns whether at least one of the keys includes secret key material.

This returns true if either the primary key or at least one of the subkeys includes secret key material.

Examples

use sequoia_openpgp as openpgp;
use openpgp::cert::prelude::*;
use openpgp::policy::StandardPolicy;
use openpgp::serialize::Serialize;
use openpgp::parse::Parse;

let p = &StandardPolicy::new();

// Create a new key.
let (cert, _) =
      CertBuilder::general_purpose(None, Some("alice@example.org"))
      .generate()?;
assert!(cert.is_tsk());

// If we serialize the certificate, the secret key material is
// stripped, unless we first convert it to a TSK.

let mut buffer = Vec::new();
cert.as_tsk().serialize(&mut buffer);
let cert = Cert::from_bytes(&buffer)?;
assert!(cert.is_tsk());

// Now round trip it without first converting it to a TSK.  This
// drops the secret key material.
let mut buffer = Vec::new();
cert.serialize(&mut buffer);
let cert = Cert::from_bytes(&buffer)?;
assert!(!cert.is_tsk());

pub fn strip_secret_key_material(self) -> Cert

Strips any secret key material.

Examples

use sequoia_openpgp as openpgp;
use openpgp::cert::prelude::*;


// Create a new key.
let (cert, _) =
      CertBuilder::general_purpose(None, Some("alice@example.org"))
      .generate()?;
assert!(cert.is_tsk());

let cert = cert.strip_secret_key_material();
assert!(! cert.is_tsk());

pub fn retain_userids<P>(self, predicate: P) -> Cert where
    P: FnMut(UserIDAmalgamation<'_>) -> bool, 

Retains only the userids specified by the predicate.

Removes all the userids for which the given predicate returns false.

Warning

Because userid binding signatures are traditionally used to provide additional information like the certificate holder’s algorithm preferences (see Preferences) and primary key flags (see ValidKeyAmalgamation::key_flags). Removing a userid may inadvertently change this information.

Examples

use sequoia_openpgp as openpgp;
use openpgp::cert::prelude::*;

// Create a new key.
let (cert, _) =
      CertBuilder::general_purpose(None, Some("alice@example.org"))
      .add_userid("Alice Lovelace <alice@lovelace.name>")
      .generate()?;
assert_eq!(cert.userids().count(), 2);

let cert = cert.retain_userids(|ua| {
    if let Ok(Some(address)) = ua.email() {
        address == "alice@example.org" // Only keep this one.
    } else {
        false                          // Drop malformed userids.
    }
});
assert_eq!(cert.userids().count(), 1);
assert_eq!(cert.userids().nth(0).unwrap().email()?.unwrap(),
           "alice@example.org");

pub fn retain_user_attributes<P>(self, predicate: P) -> Cert where
    P: FnMut(UserAttributeAmalgamation<'_>) -> bool, 

Retains only the user attributes specified by the predicate.

Removes all the user attributes for which the given predicate returns false.

Examples

use sequoia_openpgp as openpgp;
use openpgp::cert::prelude::*;

// Create a new key.
let (cert, _) =
      CertBuilder::general_purpose(None, Some("alice@example.org"))
      // Add nonsensical user attribute.
      .add_user_attribute(vec![0, 1, 2])
      .generate()?;
assert_eq!(cert.user_attributes().count(), 1);

// Strip all user attributes
let cert = cert.retain_user_attributes(|_| false);
assert_eq!(cert.user_attributes().count(), 0);

pub fn retain_subkeys<P>(self, predicate: P) -> Cert where
    P: FnMut(SubordinateKeyAmalgamation<'_, PublicParts>) -> bool, 

Retains only the subkeys specified by the predicate.

Removes all the subkeys for which the given predicate returns false.

Examples

use sequoia_openpgp as openpgp;
use openpgp::policy::StandardPolicy;
use openpgp::cert::prelude::*;

// Create a new key.
let (cert, _) =
      CertBuilder::new()
      .add_userid("Alice Lovelace <alice@lovelace.name>")
      .add_transport_encryption_subkey()
      .add_storage_encryption_subkey()
      .generate()?;
assert_eq!(cert.keys().subkeys().count(), 2);

// Retain only the transport encryption subkey.  For that, we
// need to examine the key flags, therefore we need to turn
// the `KeyAmalgamation` into a `ValidKeyAmalgamation` under a
// policy.
let p = &StandardPolicy::new();
let cert = cert.retain_subkeys(|ka| {
    if let Ok(vka) = ka.with_policy(p, None) {
        vka.key_flags().map(|flags| flags.for_transport_encryption())
            .unwrap_or(false)      // Keep transport encryption keys.
    } else {
        false                      // Drop unbound keys.
    }
});
assert_eq!(cert.keys().subkeys().count(), 1);
assert!(cert.with_policy(p, None)?.keys().subkeys().nth(0).unwrap()
            .key_flags().unwrap().for_transport_encryption());

pub fn with_policy<'a, T>(
    &'a self,
    policy: &'a dyn Policy,
    time: T
) -> Result<ValidCert<'a>> where
    T: Into<Option<SystemTime>>, 

Associates a policy and a reference time with the certificate.

This is used to turn a Cert into a ValidCert. (See also ValidateAmalgamation, which does the same for component amalgamations.)

A certificate is considered valid if:

• It has a self signature that is live at time t.

• The policy considers it acceptable.

This doesn’t say anything about whether the certificate itself is alive (see ValidCert::alive) or revoked (see ValidCert::revoked).

Examples

use sequoia_openpgp as openpgp;
use openpgp::policy::StandardPolicy;

let p = &StandardPolicy::new();

let vc = cert.with_policy(p, None)?;

impl Cert

pub fn as_tsk<'a>(&'a self) -> TSK<'a>

Derive a TSK object from this key.

This object writes out secret keys during serialization.

impl Cert

pub fn armor_headers(&self) -> Vec<String>

Creates descriptive armor headers.

Returns armor headers that describe this Cert. The Cert’s primary fingerprint and valid userids (according to the default policy) are included as comments, so that it is easier to identify the Cert when looking at the armored data.

pub fn armored<'a>(&'a self) -> impl Serialize + SerializeInto + 'a

Wraps this Cert in an armor structure when serialized.

Derives an object from this Cert that adds an armor structure to the serialized Cert when it is serialized. Additionally, the Cert’s User IDs are added as comments, so that it is easier to identify the Cert when looking at the armored data.

Examples

use sequoia_openpgp as openpgp;
use openpgp::cert::prelude::*;
use openpgp::serialize::SerializeInto;

let (cert, _) =
    CertBuilder::general_purpose(None, Some("Mr. Pink ☮☮☮"))
    .generate()?;
let armored = String::from_utf8(cert.armored().to_vec()?)?;

assert!(armored.starts_with("-----BEGIN PGP PUBLIC KEY BLOCK-----"));
assert!(armored.contains("Mr. Pink ☮☮☮"));

Trait Implementations

impl Clone for Cert

fn clone(&self) -> Cert

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Cert

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Cert

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<&'_ Cert> for RevocationKey

fn from(cert: &Cert) -> Self

Performs the conversion.

impl From<Cert> for Vec<Packet>

fn from(cert: Cert) -> Self

Performs the conversion.

impl From<Cert> for PacketPile

fn from(cert: Cert) -> PacketPile

Converts the Cert into a PacketPile.

If any packets include secret key material, that secret key material is not dropped, as it is when serializing a Cert.

impl FromStr for Cert

type Err = Error

The associated error which can be returned from parsing.

fn from_str(s: &str) -> Result<Self, Self::Err>

Parses a string s to return a value of this type.

impl IntoIterator for Cert

type Item = Packet

The type of the elements being iterated over.

type IntoIter = IntoIter

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.

impl Marshal for Cert

fn serialize(&self, o: &mut dyn Write) -> Result<()>

Writes a serialized version of the object to o.

fn export(&self, o: &mut dyn Write) -> Result<()>

Exports a serialized version of the object to o.

impl MarshalInto for Cert

fn serialized_len(&self) -> usize

Computes the maximal length of the serialized representation.

fn serialize_into(&self, buf: &mut [u8]) -> Result<usize>

Serializes into the given buffer.

fn export_into(&self, buf: &mut [u8]) -> Result<usize>

Exports into the given buffer.

fn to_vec(&self) -> Result<Vec<u8>>

Serializes the packet to a vector.

fn export_to_vec(&self) -> Result<Vec<u8>>

Exports to a vector.

impl<'a> Parse<'a, Cert> for Cert

fn from_reader<R: Read + Send + Sync>(reader: R) -> Result<Self>

Returns the first Cert encountered in the reader.

fn from_file<P: AsRef<Path>>(path: P) -> Result<Self>

Returns the first Cert encountered in the file.

fn from_bytes<D: AsRef<[u8]> + ?Sized + Send + Sync>(
    data: &'a D
) -> Result<Self>

Returns the first Cert found in buf.

buf must be an OpenPGP-encoded message.

impl PartialEq<Cert> for Cert

fn eq(&self, other: &Cert) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Cert) -> bool

This method tests for !=.

impl Serialize for Cert

fn serialize(&self, o: &mut dyn Write) -> Result<()>

Writes a serialized version of the object to o.

fn export(&self, o: &mut dyn Write) -> Result<()>

Exports a serialized version of the object to o.

impl SerializeInto for Cert

fn serialized_len(&self) -> usize

Computes the maximal length of the serialized representation.

fn serialize_into(&self, buf: &mut [u8]) -> Result<usize>

Serializes into the given buffer.

fn to_vec(&self) -> Result<Vec<u8>>

Serializes the packet to a vector.

fn export_into(&self, buf: &mut [u8]) -> Result<usize>

Exports into the given buffer.

fn export_to_vec(&self) -> Result<Vec<u8>>

Exports to a vector.

impl TryFrom<Packet> for Cert

type Error = Error

The type returned in the event of a conversion error.

fn try_from(p: Packet) -> Result<Self>

Performs the conversion.

impl TryFrom<PacketParserResult<'_>> for Cert

fn try_from(ppr: PacketParserResult<'_>) -> Result<Self>

Returns the Cert found in the packet stream.

If the sequence contains multiple certificates (i.e., it is a keyring), or the certificate is followed by an invalid packet this function will fail. To parse keyrings, use CertParser instead of this function.

type Error = Error

The type returned in the event of a conversion error.

impl TryFrom<PacketPile> for Cert

fn try_from(p: PacketPile) -> Result<Self>

Returns the certificate found in the PacketPile.

If the PacketPile does not start with a certificate (specifically, if it does not start with a primary key packet), then this fails.

If the sequence contains multiple certificates (i.e., it is a keyring), or the certificate is followed by an invalid packet this function will fail. To parse keyrings, use CertParser instead of this function.

Examples

use sequoia_openpgp as openpgp;
use openpgp::cert::prelude::*;
use openpgp::packet::prelude::*;
use openpgp::PacketPile;
use std::convert::TryFrom;

let (cert, rev) =
    CertBuilder::general_purpose(None, Some("alice@example.org"))
    .generate()?;

// We should be able to turn a certificate into a PacketPile
// and back.
let pp : PacketPile = cert.into();
assert!(Cert::try_from(pp).is_ok());

// But a revocation certificate is not a certificate, so this
// will fail.
let pp : PacketPile = Packet::from(rev).into();
assert!(Cert::try_from(pp).is_err());

type Error = Error

The type returned in the event of a conversion error.

impl TryFrom<Vec<Packet, Global>> for Cert

type Error = Error

The type returned in the event of a conversion error.

fn try_from(p: Vec<Packet>) -> Result<Self>

Performs the conversion.

impl StructuralPartialEq for Cert