Documentation
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Overview ¶
Package crypto implements the Bitwarden client-side encryption primitives. It covers key derivation (PBKDF2, Argon2id), key stretching (HKDF), AES-256-CBC + HMAC-SHA256 encryption, RSA-OAEP key exchange, the Bitwarden EncString format, and Send key derivation.
Index ¶
- Constants
- func Decrypt(iv, ct, mac, encKey, macKey []byte) ([]byte, error)
- func DecryptPrivateKey(encPrivateKey EncString, symKey *SymmetricKey) ([]byte, error)
- func DeriveKey(password, salt []byte, kdfType, iterations int, memory, parallelism *int) ([]byte, error)
- func EncodeSendSecret(secret []byte) string
- func Encrypt(data, encKey, macKey []byte) (iv, ct, mac []byte, err error)
- func EncryptOrgKeyForMember(orgKey *SymmetricKey, memberPublicKeyDER []byte) (string, error)
- func GenerateRSAKeyPair() (publicKeyDER, privateKeyDER []byte, err error)
- func GenerateSendSecret() ([]byte, error)
- func HashPassword(password string, masterKey []byte) string
- func PublicKeyFromPrivate(privateKeyDER []byte) ([]byte, error)
- func RSADecrypt(data, privateKeyDER []byte) ([]byte, error)
- func RSADecryptEncString(enc EncString, privateKeyDER []byte) ([]byte, error)
- func RSAEncrypt(data, publicKeyDER []byte) ([]byte, error)
- func StretchKey(masterKey []byte) ([]byte, error)
- type EncString
- type SymmetricKey
- func DecryptSymmetricKey(protectedKey EncString, stretchedKey []byte) (*SymmetricKey, error)
- func DeriveSendKey(secret []byte) (*SymmetricKey, error)
- func GenerateSymmetricKey() (*SymmetricKey, error)
- func MakeSymmetricKey(stretched []byte) (*SymmetricKey, error)
- func SendKeyFromAccessURL(urlFragment string) (*SymmetricKey, error)
Constants ¶
const ( KdfTypePBKDF2 = 0 KdfTypeArgon2 = 1 )
KDF type constants matching the Bitwarden API.
const RSAKeySize = 2048
RSAKeySize is the key size used by Bitwarden for RSA key pairs.
const SendSecretSize = 16
SendSecretSize is the size in bytes of the random secret generated for each Bitwarden Send (128 bits).
Variables ¶
This section is empty.
Functions ¶
func Decrypt ¶
Decrypt verifies the HMAC-SHA256 MAC and then decrypts AES-256-CBC ciphertext, removing PKCS7 padding.
func DecryptPrivateKey ¶
func DecryptPrivateKey(encPrivateKey EncString, symKey *SymmetricKey) ([]byte, error)
DecryptPrivateKey decrypts an RSA private key that is stored encrypted in the vault (as a type 2 EncString).
func DeriveKey ¶
func DeriveKey(password, salt []byte, kdfType, iterations int, memory, parallelism *int) ([]byte, error)
DeriveKey derives a 32-byte master key from a password and salt using the specified KDF algorithm. For PBKDF2 the salt is typically the user's email (lowercased). For Argon2id the salt is a raw 32-byte value returned by the server.
func EncodeSendSecret ¶
EncodeSendSecret encodes a Send secret as a base64url string suitable for use in a Send access URL fragment.
func Encrypt ¶
Encrypt encrypts data using AES-256-CBC with PKCS7 padding and produces an HMAC-SHA256 MAC over (iv || ciphertext).
func EncryptOrgKeyForMember ¶
func EncryptOrgKeyForMember(orgKey *SymmetricKey, memberPublicKeyDER []byte) (string, error)
EncryptOrgKeyForMember RSA-encrypts an organization's symmetric key using a member's public key. Returns the encrypted key as a type 4 EncString in its string form.
func GenerateRSAKeyPair ¶
GenerateRSAKeyPair generates a new RSA-2048 key pair and returns the public key in PKIX DER format and private key in PKCS8 DER format.
func GenerateSendSecret ¶
GenerateSendSecret generates a 16-byte (128-bit) cryptographically random secret for a new Send.
func HashPassword ¶
HashPassword produces the master password hash sent to the server for authentication. It computes PBKDF2-SHA256(masterKey, password, 1) and returns the base64-encoded result.
func PublicKeyFromPrivate ¶
PublicKeyFromPrivate extracts the public key in DER format from a private key DER.
func RSADecrypt ¶
RSADecrypt decrypts data using RSA-OAEP with SHA-1.
func RSADecryptEncString ¶
RSADecryptEncString decrypts a type 4 EncString using an RSA private key.
func RSAEncrypt ¶
RSAEncrypt encrypts data using RSA-OAEP with SHA-1 (as Bitwarden uses).
func StretchKey ¶
StretchKey stretches a 32-byte master key into a 64-byte key using HKDF-SHA256. The first 32 bytes are the encryption key ("enc"), the second 32 bytes are the MAC key ("mac").
Types ¶
type EncString ¶
type EncString struct {
Type int
IV []byte // only for type 2
CT []byte
MAC []byte // only for type 2
}
EncString represents a Bitwarden encrypted string.
Format:
- Type 2 (AES-CBC-256 + HMAC): "2.base64(iv)|base64(ct)|base64(mac)"
- Type 4 (RSA-OAEP-SHA1): "4.base64(rsaEncryptedData)"
func EncryptToEncString ¶
func EncryptToEncString(plaintext []byte, key *SymmetricKey) (EncString, error)
EncryptToEncString encrypts plaintext and returns a type 2 EncString.
func ParseEncBytes ¶
ParseEncBytes parses a Bitwarden encrypted string from its binary format.
func ParseEncString ¶
ParseEncString parses a Bitwarden encrypted string into its components.
func (EncString) Decrypt ¶
func (e EncString) Decrypt(key *SymmetricKey) ([]byte, error)
Decrypt decrypts a type 2 EncString using the given SymmetricKey. For type 4 (RSA), use RSADecryptEncString instead.
type SymmetricKey ¶
type SymmetricKey struct {
EncKey []byte // 32 bytes – AES-256 key
MacKey []byte // 32 bytes – HMAC-SHA256 key
}
SymmetricKey holds a 64-byte key split into a 32-byte encryption key and a 32-byte MAC key. This is used for both the user's vault encryption key and organization keys.
func DecryptSymmetricKey ¶
func DecryptSymmetricKey(protectedKey EncString, stretchedKey []byte) (*SymmetricKey, error)
DecryptSymmetricKey decrypts the server-stored protected symmetric key using the stretched master key.
func DeriveSendKey ¶
func DeriveSendKey(secret []byte) (*SymmetricKey, error)
DeriveSendKey derives a 64-byte SymmetricKey from a 16-byte Send secret using HKDF-SHA256 with "bitwarden-send" as the salt and "send" as the info parameter. The first 32 bytes are the encryption key, the second 32 bytes the MAC key.
func GenerateSymmetricKey ¶
func GenerateSymmetricKey() (*SymmetricKey, error)
GenerateSymmetricKey creates a new random 64-byte symmetric key using a cryptographically secure random number generator.
func MakeSymmetricKey ¶
func MakeSymmetricKey(stretched []byte) (*SymmetricKey, error)
MakeSymmetricKey creates a SymmetricKey from a 64-byte stretched key.
func SendKeyFromAccessURL ¶
func SendKeyFromAccessURL(urlFragment string) (*SymmetricKey, error)
SendKeyFromAccessURL decodes a base64url-encoded secret from a Send access URL fragment and derives the Send encryption key.
func (*SymmetricKey) Bytes ¶
func (sk *SymmetricKey) Bytes() []byte
Bytes returns the full 64-byte key (enc + mac concatenated).
Source Files