91 lines
2.7 KiB
Go
91 lines
2.7 KiB
Go
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package crypt
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import (
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core "github.com/host-uk/core/pkg/framework/core"
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)
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// Encrypt encrypts data with a passphrase using ChaCha20-Poly1305.
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// A random salt is generated and prepended to the output.
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// Format: salt (16 bytes) + nonce (24 bytes) + ciphertext.
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func Encrypt(plaintext, passphrase []byte) ([]byte, error) {
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salt, err := generateSalt(argon2SaltLen)
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if err != nil {
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return nil, core.E("crypt.Encrypt", "failed to generate salt", err)
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}
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key := DeriveKey(passphrase, salt, argon2KeyLen)
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encrypted, err := ChaCha20Encrypt(plaintext, key)
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if err != nil {
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return nil, core.E("crypt.Encrypt", "failed to encrypt", err)
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}
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// Prepend salt to the encrypted data (which already has nonce prepended)
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result := make([]byte, 0, len(salt)+len(encrypted))
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result = append(result, salt...)
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result = append(result, encrypted...)
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return result, nil
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}
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// Decrypt decrypts data encrypted with Encrypt.
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// Expects format: salt (16 bytes) + nonce (24 bytes) + ciphertext.
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func Decrypt(ciphertext, passphrase []byte) ([]byte, error) {
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if len(ciphertext) < argon2SaltLen {
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return nil, core.E("crypt.Decrypt", "ciphertext too short", nil)
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}
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salt := ciphertext[:argon2SaltLen]
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encrypted := ciphertext[argon2SaltLen:]
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key := DeriveKey(passphrase, salt, argon2KeyLen)
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plaintext, err := ChaCha20Decrypt(encrypted, key)
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if err != nil {
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return nil, core.E("crypt.Decrypt", "failed to decrypt", err)
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}
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return plaintext, nil
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}
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// EncryptAES encrypts data using AES-256-GCM with a passphrase.
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// A random salt is generated and prepended to the output.
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// Format: salt (16 bytes) + nonce (12 bytes) + ciphertext.
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func EncryptAES(plaintext, passphrase []byte) ([]byte, error) {
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salt, err := generateSalt(argon2SaltLen)
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if err != nil {
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return nil, core.E("crypt.EncryptAES", "failed to generate salt", err)
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}
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key := DeriveKey(passphrase, salt, argon2KeyLen)
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encrypted, err := AESGCMEncrypt(plaintext, key)
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if err != nil {
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return nil, core.E("crypt.EncryptAES", "failed to encrypt", err)
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}
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result := make([]byte, 0, len(salt)+len(encrypted))
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result = append(result, salt...)
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result = append(result, encrypted...)
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return result, nil
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}
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// DecryptAES decrypts data encrypted with EncryptAES.
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// Expects format: salt (16 bytes) + nonce (12 bytes) + ciphertext.
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func DecryptAES(ciphertext, passphrase []byte) ([]byte, error) {
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if len(ciphertext) < argon2SaltLen {
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return nil, core.E("crypt.DecryptAES", "ciphertext too short", nil)
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}
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salt := ciphertext[:argon2SaltLen]
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encrypted := ciphertext[argon2SaltLen:]
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key := DeriveKey(passphrase, salt, argon2KeyLen)
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plaintext, err := AESGCMDecrypt(encrypted, key)
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if err != nil {
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return nil, core.E("crypt.DecryptAES", "failed to decrypt", err)
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}
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return plaintext, nil
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}
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