go-encrypted-config-value

README

go-encrypted-config-value

go-encrypted-config-value is a Go implementation of the encrypted-config-value library. It provides a simple mechanism to encrypt and decrypt values stored in configuration on disk.

Overview

The encryption package provides primitives such as Key and Cipher. It provides implementations of an AES-GCM cipher with configurable nonce and tag sizes and an RSA-OAEP cipher with configurable hash algorithms for OAEP and MDF1. It also provides functions for creating and serializing AES and RSA keys.

The encryptedconfigvalue package provides functionality for creating, decrypting and serializing/deserializing encrypted config values.

Usage

AES:

keyPair, err := encryptedconfigvalue.AES.GenerateKeyPair()
encryptedVal, err := encryptedconfigvalue.AES.Encrypter().Encrypt("secret text", keyPair.EncryptionKey)

serializedKey := keyPair.EncryptionKey.ToSerializable()
serializedValue, err := encryptedVal.ToSerializable()

rehydratedKey, err := encryptedconfigvalue.NewKeyWithType(serializedKey)
rehydratedValue, err := encryptedconfigvalue.NewEncryptedValue(serializedValue)

plaintext, err := rehydratedValue.Decrypt(rehydratedKey)

RSA:

keyPair, err := encryptedconfigvalue.RSA.GenerateKeyPair()
encryptedVal, err := encryptedconfigvalue.RSA.Encrypter().Encrypt("secret text", keyPair.EncryptionKey)

serializedPublicKey := keyPair.EncryptionKey.ToSerializable()
serializedPrivateKey := keyPair.DecryptionKey.ToSerializable()
serializedValue, err := encryptedVal.ToSerializable()

rehydratedDecryptionKey, err := encryptedconfigvalue.NewKeyWithType(serializedKey)
rehydratedValue, err := encryptedconfigvalue.NewEncryptedValue(serializedValue)

plaintext, err := rehydratedValue.Decrypt(rehydratedDecryptionKey)

Values in Configuration:

• encryptedconfigvalue.ContainsEncryptedConfigValueStringVars returns true if the provided input contains any entries values of the form "${enc:...}"
• encryptedconfigvalue.DecryptAllEncryptedValueStringVars returns a version of the provided input where all string values of the form "${enc:...}" are replaced with the result of decrypting the values using the provided key
• encryptedconfigvalue.DecryptEncryptedStringVariables recusrively finds all occurrences of string values of the form "${enc:...}" in the exported fields of an object and replaces them with the result of decrypting the values using the provided key

Backwards Compatibility

This library supports reading encryption keys and encrypted values that are stored in the legacy format. The encryptedconfigvalue.NewKeyWithType and encryptedconfigvalue.NewEncryptedValue will both accept valid values in the legacy format.

This library can generate EncryptedValue objects that serialize using legacy encrypters that are provided as part of the library.

AES: encryptedVal, err := encryptedconfigvalue.LegacyAESGCMEncrypter().Encrypt("secret text", keyPair.EncryptionKey) RSA: encryptedVal, err := encryptedconfigvalue.LegacyRSAOAEPEncrypter().Encrypt("secret text", keyPair.EncryptionKey)

The ToSerializable function for these legacy values will return a string that encodes the values using the legacy format.

The format for AES keys did not change between the legacy and new format.

The format for RSA keys did change, but because the legacy format for RSA keys was not widely used and had deficiencies (it was not able to differentiate between a public and private key based on the serialized format), writing such values is not supported by this library.

License

This project is made available under the BSD 3-Clause License.