Crate pkcs8[−][src]

Expand description

RustCrypto: PKCS#8 (Private Keys)

Pure Rust implementation of Public-Key Cryptography Standards (PKCS) #8: Private-Key Information Syntax Specification (RFC 5208).

Documentation

About PKCS#8

PKCS#8 is a format for cryptographic private keys, often containing pairs of private and public keys.

You can identify a PKCS#8 private key encoded as PEM (i.e. text) by the following:

-----BEGIN PRIVATE KEY-----

PKCS#8 private keys can optionally be encrypted under a password using key derivation algorithms like PBKDF2 and scrypt, and encrypted with ciphers like AES-CBC. When a PKCS#8 private key has been encrypted, it starts with the following:

-----BEGIN ENCRYPTED PRIVATE KEY-----

PKCS#8 private keys can also be serialized in an ASN.1-based binary format. The PEM text encoding is a Base64 representation of this format.

Supported Algorithms

This crate is implemented in an algorithm-agnostic manner with the goal of enabling PKCS#8 support for any algorithm.

That said, it has been tested for interoperability against keys generated by OpenSSL for the following algorithms:

ECC (id-ecPublicKey)
Ed25519 (id-Ed25519)
RSA (id-rsaEncryption)
X25519 (id-X25519)

Please open an issue if you encounter trouble using it with a particular algorithm, including the ones listed above or other algorithms.

Minimum Supported Rust Version

This crate requires Rust 1.56 at a minimum.

We may change the MSRV in the future, but it will be accompanied by a minor version bump.

License

Licensed under either of:

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

About this crate

This library provides generalized PKCS#8 support designed to work with a number of different algorithms. It supports no_std platforms including ones without a heap (albeit with reduced functionality).

It supports decoding/encoding the following types:

EncryptedPrivateKeyInfo: (with pkcs5 feature) encrypted key.
PrivateKeyInfo: algorithm identifier and data representing a private key. Optionally also includes public key data for asymmetric keys.
SubjectPublicKeyInfo: algorithm identifier and data representing a public key (re-exported from the spki crate)

When the alloc feature is enabled, the following additional types are available which provide more convenient decoding/encoding support:

EncryptedPrivateKeyDocument: (with pkcs5 feature) heap-backed encrypted key.
PrivateKeyDocument: heap-backed storage for serialized PrivateKeyInfo.
PublicKeyDocument: heap-backed storage for serialized SubjectPublicKeyInfo.

When the pem feature is enabled, it also supports decoding/encoding documents from “PEM encoding” format as defined in RFC 7468.

Encrypted Private Key Support

EncryptedPrivateKeyInfo supports decoding/encoding encrypted PKCS#8 private keys and is gated under the pkcs5 feature. The corresponding EncryptedPrivateKeyDocument type provides heap-backed storage (alloc feature required).

When the encryption feature of this crate is enabled, it provides EncryptedPrivateKeyInfo::decrypt and PrivateKeyInfo::encrypt functions which are able to decrypt/encrypt keys using the following algorithms:

PKCS#5v2 Password Based Encryption Scheme 2 (RFC 8018)
- Key derivation functions:
  - scrypt (RFC 7914)
  - PBKDF2 (RFC 8018)
    - SHA-2 based PRF with HMAC-SHA224, HMAC-SHA256, HMAC-SHA384, or HMAC-SHA512
    - SHA-1 based PRF with HMAC-SHA1, when the sha1 feature of this crate is enabled.
- Symmetric encryption: AES-128-CBC, AES-192-CBC, or AES-256-CBC (best available options for PKCS#5v2)

Legacy DES-CBC and DES-EDE3-CBC (3DES) support (optional)

When the des-insecure and/or 3des features are enabled this crate provides support for private keys encrypted with with DES-CBC and DES-EDE3-CBC (3DES or Triple DES) symmetric encryption, respectively.

⚠️ WARNING ⚠️

DES support (gated behind the des-insecure feature) is implemented to allow for decryption of legacy PKCS#8 files only.

Such PKCS#8 documents should be considered INSECURE due to the short 56-bit key size of DES.

New keys should use AES instead.