Struct SecretKey 

pub struct SecretKey<C: Curve> {
    inner: ScalarValue<C>,
}

Elliptic curve secret keys.

This type wraps a secret scalar value, helping to prevent accidental exposure and securely erasing the value from memory when dropped.

Generating secret keys

SecretKeys can be generated using the Generate trait.

Parsing PKCS#8 Keys

PKCS#8 is a commonly used format for encoding secret keys (especially ones generated by OpenSSL).

Keys in PKCS#8 format are either binary (ASN.1 BER/DER), or PEM encoded (ASCII) and begin with the following:

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

To decode an elliptic curve private key from PKCS#8, enable the pkcs8 feature of this crate (or the pkcs8 feature of a specific RustCrypto elliptic curve crate) and use the DecodePrivateKey trait to parse it.

When the pem feature of this crate (or a specific RustCrypto elliptic curve crate) is enabled, a FromStr impl is also available.

Fields

inner: ScalarValue<C>

Scalar value

Implementations

impl<C> SecretKey<C>

where C: Curve,

pub const MIN_SIZE: usize = 24

Minimum allowed size of an elliptic curve secret key in bytes.

This provides the equivalent of 96-bits of symmetric security.

pub fn from_scalar(scalar: impl Into<ScalarValue<C>>) -> CtOption<Self>

Create a new secret key from a scalar value.

Returns

This will return a none if the scalar is all-zero.

pub fn as_scalar_value(&self) -> &ScalarValue<C>

Borrow the inner secret ScalarValue value.

Security Warning

This value is key material. Please treat it with the care it deserves!

pub fn to_nonzero_scalar(&self) -> NonZeroScalar<C>

where C: CurveArithmetic,

Get the secret NonZeroScalar value for this key.

Security Warning

This value is key material. Please treat it with the care it deserves!

pub fn public_key(&self) -> PublicKey<C>

where C: CurveArithmetic,

Get the PublicKey which corresponds to this secret key

pub fn from_bytes(bytes: &FieldBytes<C>) -> Result<Self>

Deserialize secret key from an encoded secret scalar.

Errors

Returns Error if bytes overflows the scalar modulus.

pub fn from_slice(slice: &[u8]) -> Result<Self>

Deserialize secret key from an encoded secret scalar passed as a byte slice.

The slice is expected to be a minimum of 24-bytes (192-bytes) and at most C::FieldBytesSize bytes in length.

Byte slices shorter than the field size are handled by zero padding the input.

NOTE: this function is variable-time with respect to the input length. To avoid a timing sidechannel, always ensure that the input has been pre-padded to C::FieldBytesSize.

Errors

• if slice is shorter than Self::MIN_SIZE.
• if slice is not sized appropriately for the scalar modulus.
• if the decoded scalar field element overflows the scalar modulus.

pub fn to_bytes(&self) -> FieldBytes<C>

Serialize raw secret scalar as a big endian integer.

pub fn diffie_hellman(&self, public_key: &PublicKey<C>) -> SharedSecret<C>

where C: CurveArithmetic,

Perform Elliptic Curve Diffie-Hellman with the given public key, returning a shared secret.

See the documentation in the ecdh module for more information.

pub fn from_der(der_bytes: &[u8]) -> DecodeResult<Self>

where C: AssociatedOid + Curve + ValidatePublicKey, FieldBytesSize<C>: ModulusSize,

Decode SecretKey from DER-encoded private key.

Supported formats

• PKCS#8: requires pkcs8 feature
• SEC1: requires sec1 feature

If you are expecting one format over the other, it’s better to use a more specific method:

• PKCS#8: ::pkcs8::DecodePrivateKey::from_pkcs8_der
• SEC1: ::sec1::DecodeEcPrivateKey::from_sec1_der

Errors

• Returns DecodeError::Pkcs8 if PKCS#8 key could not be decoded
• Returns DecodeError::Sec1 if SEC1 key could not be decoded

pub fn from_pem(pem: &str) -> DecodeResult<Self>

where C: AssociatedOid + Curve + ValidatePublicKey, FieldBytesSize<C>: ModulusSize,

Decode SecretKey from PEM-encoded private key.

If you are expecting one format over the other, it’s better to use a more specific method:

• PKCS#8: ::pkcs8::DecodePrivateKey::from_pkcs8_pem
• SEC1: ::sec1::DecodeEcPrivateKey::from_sec1_pem

Errors

• Returns DecodeError::Pem if PEM label is invalid or otherwise malformed
• Returns DecodeError::Pkcs8 if PKCS#8 key detected but could not be decoded
• Returns DecodeError::Sec1 if SEC1 key detected but could not be decoded

pub fn from_sec1_der(der_bytes: &[u8]) -> DecodeResult<Self>

where C: AssociatedOid + Curve + ValidatePublicKey, FieldBytesSize<C>: ModulusSize,

Deserialize secret key encoded in the SEC1 ASN.1 DER ECPrivateKey format.

Errors

• if der_bytes does not encode a valid SEC1 private key
• if the contained document does not encode a valid key for this curve

pub fn to_sec1_der(&self) -> Result<Zeroizing<Vec<u8>>>

where C: AssociatedOid + CurveArithmetic, AffinePoint<C>: FromSec1Point<C> + ToSec1Point<C>, FieldBytesSize<C>: ModulusSize,

Serialize secret key in the SEC1 ASN.1 DER ECPrivateKey format.

Errors

If an internal error occurs encoding this key.

pub fn from_sec1_pem(s: &str) -> DecodeResult<Self>

where C: AssociatedOid + Curve + ValidatePublicKey, FieldBytesSize<C>: ModulusSize,

Parse SecretKey from PEM-encoded SEC1 ECPrivateKey format.

PEM-encoded SEC1 keys can be identified by the leading delimiter:

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

Errors

• if the document cannot be decoded as PEM
• if the PEM document does not encode a valid private key for this curve

pub fn to_sec1_pem(&self, line_ending: LineEnding) -> Result<Zeroizing<String>>

where C: AssociatedOid + CurveArithmetic, AffinePoint<C>: FromSec1Point<C> + ToSec1Point<C>, FieldBytesSize<C>: ModulusSize,

Serialize private key as self-zeroizing PEM-encoded SEC1 ECPrivateKey with the given pem::LineEnding.

Pass Default::default() to use the OS’s native line endings.

Errors

If an internal error occurs encoding this key.

pub fn random<R: CryptoRng + ?Sized>(rng: &mut R) -> Self

👎Deprecated since 0.14.0: use the Generate trait instead

Deprecated: Generate a random SecretKey.

Trait Implementations

impl<C> AssociatedAlgorithmIdentifier for SecretKey<C>

where C: AssociatedOid + Curve,

const ALGORITHM_IDENTIFIER: AlgorithmIdentifier<ObjectIdentifier>

AlgorithmIdentifier for this structure.

type Params = ObjectIdentifier

Algorithm parameters.

impl<C: Clone + Curve> Clone for SecretKey<C>

fn clone(&self) -> SecretKey<C>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<C> ConstantTimeEq for SecretKey<C>

where C: Curve,

fn ct_eq(&self, other: &Self) -> Choice

Determine if two items are equal.

fn ct_ne(&self, other: &Self) -> Choice

Determine if two items are NOT equal.

impl<C> Debug for SecretKey<C>

where C: Curve,

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

Formats the value using the given formatter.

impl<C> DecodeEcPrivateKey for SecretKey<C>

where C: AssociatedOid + Curve + ValidatePublicKey, FieldBytesSize<C>: ModulusSize,

Available on crate feature sec1 only.

fn from_sec1_der(bytes: &[u8]) -> Result<Self>

Deserialize SEC1 private key from ASN.1 DER-encoded data (binary format).

fn from_sec1_pem(s: &str) -> Result<Self, Error>

Deserialize SEC1-encoded private key from PEM.

fn read_sec1_der_file(path: impl AsRef<Path>) -> Result<Self, Error>

Load SEC1 private key from an ASN.1 DER-encoded file on the local filesystem (binary format).

fn read_sec1_pem_file(path: impl AsRef<Path>) -> Result<Self, Error>

Load SEC1 private key from a PEM-encoded file on the local filesystem.

impl<C> Drop for SecretKey<C>

where C: Curve,

fn drop(&mut self)

Executes the destructor for this type.

impl<C> EncodeEcPrivateKey for SecretKey<C>

where C: AssociatedOid + CurveArithmetic, AffinePoint<C>: FromSec1Point<C> + ToSec1Point<C>, FieldBytesSize<C>: ModulusSize,

Available on crate features alloc and arithmetic and sec1 only.

fn to_sec1_der(&self) -> Result<SecretDocument>

Serialize a SecretDocument containing a SEC1-encoded private key.

fn to_sec1_pem( &self, line_ending: LineEnding, ) -> Result<Zeroizing<String>, Error>

Serialize this private key as PEM-encoded SEC1 with the given LineEnding.

fn write_sec1_der_file(&self, path: impl AsRef<Path>) -> Result<(), Error>

Write ASN.1 DER-encoded SEC1 private key to the given path.

fn write_sec1_pem_file( &self, path: impl AsRef<Path>, line_ending: LineEnding, ) -> Result<(), Error>

Write ASN.1 PEM-encoded SEC1 private key to the given path.

impl<C> EncodePrivateKey for SecretKey<C>

where C: AssociatedOid + CurveArithmetic, AffinePoint<C>: FromSec1Point<C> + ToSec1Point<C>, FieldBytesSize<C>: ModulusSize,

Available on crate features alloc and arithmetic only.

fn to_pkcs8_der(&self) -> Result<SecretDocument>

Serialize a SecretDocument containing a PKCS#8-encoded private key.

fn to_pkcs8_pem( &self, line_ending: LineEnding, ) -> Result<Zeroizing<String>, Error>

Serialize this private key as PEM-encoded PKCS#8 with the given LineEnding.

fn write_pkcs8_der_file(&self, path: impl AsRef<Path>) -> Result<(), Error>

Write ASN.1 DER-encoded PKCS#8 private key to the given path.

fn write_pkcs8_pem_file( &self, path: impl AsRef<Path>, line_ending: LineEnding, ) -> Result<(), Error>

Write ASN.1 PEM-encoded PKCS#8 private key to the given path.

impl<C> From<&NonZeroScalar<C>> for SecretKey<C>

where C: CurveArithmetic,

Available on crate feature arithmetic only.

fn from(scalar: &NonZeroScalar<C>) -> SecretKey<C>

Converts to this type from the input type.

impl<C> From<&SecretKey<C>> for NonZeroScalar<C>

where C: CurveArithmetic,

fn from(sk: &SecretKey<C>) -> NonZeroScalar<C>

Converts to this type from the input type.

impl<C> From<&SecretKey<C>> for PublicKey<C>

where C: CurveArithmetic,

fn from(secret_key: &SecretKey<C>) -> PublicKey<C>

Converts to this type from the input type.

impl<C> From<NonZeroScalar<C>> for SecretKey<C>

where C: CurveArithmetic,

Available on crate feature arithmetic only.

fn from(scalar: NonZeroScalar<C>) -> SecretKey<C>

Converts to this type from the input type.

impl<C> From<SecretKey<C>> for NonZeroScalar<C>

where C: CurveArithmetic,

fn from(sk: SecretKey<C>) -> NonZeroScalar<C>

Converts to this type from the input type.

impl<C> From<SecretKey<C>> for PublicKey<C>

where C: CurveArithmetic,

fn from(secret_key: SecretKey<C>) -> Self

Converts to this type from the input type.

impl<C> FromStr for SecretKey<C>

where C: Curve + AssociatedOid + ValidatePublicKey, FieldBytesSize<C>: ModulusSize,

Available on crate feature pem only.

type Err = Error

The associated error which can be returned from parsing.

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

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

impl<C> Generate for SecretKey<C>

where C: Curve,

fn try_generate_from_rng<R: TryCryptoRng + ?Sized>( rng: &mut R, ) -> Result<Self, R::Error>

Generate random key using the provided TryCryptoRng.

fn generate_from_rng<R>(rng: &mut R) -> Self

where R: CryptoRng + ?Sized,

Generate random key using the provided CryptoRng.

fn try_generate() -> Result<Self, Error>

Randomly generate a value of this type using the system’s ambient cryptographically secure random number generator.

fn generate() -> Self

Randomly generate a value of this type using the system’s ambient cryptographically secure random number generator.

impl<C> KeySizeUser for SecretKey<C>

where C: Curve,

type KeySize = <C as Curve>::FieldBytesSize

Key size in bytes.

fn key_size() -> usize

Return key size in bytes.

impl<C> PartialEq for SecretKey<C>

where C: Curve,

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<C> TryFrom<EcPrivateKey<'_>> for SecretKey<C>

where C: AssociatedOid + Curve + ValidatePublicKey, FieldBytesSize<C>: ModulusSize,

Available on crate feature sec1 only.

type Error = Error

The type returned in the event of a conversion error.

fn try_from(sec1_private_key: EcPrivateKey<'_>) -> Result<Self>

Performs the conversion.

impl<C> TryFrom<PrivateKeyInfo<AnyRef<'_>, &OctetStringRef, BitStringRef<'_>>> for SecretKey<C>

where C: AssociatedOid + Curve + ValidatePublicKey, FieldBytesSize<C>: ModulusSize,

type Error = Error

The type returned in the event of a conversion error.

fn try_from(private_key_info: PrivateKeyInfoRef<'_>) -> Result<Self>

Performs the conversion.

impl<C> TryKeyInit for SecretKey<C>

where C: Curve,

fn new(key_bytes: &FieldBytes<C>) -> Result<Self, InvalidKey>

Create new value from a fixed-size key.

fn new_from_slice(key: &[u8]) -> Result<Self, InvalidKey>

Create new value from a variable size key.

impl<C: Curve> Eq for SecretKey<C>

impl<C> ZeroizeOnDrop for SecretKey<C>

where C: Curve,