pub struct MPI { /* private fields */ }
Expand description
A Multiprecision Integer.
Implementations§
Source§impl MPI
impl MPI
Sourcepub fn new(value: &[u8]) -> Self
pub fn new(value: &[u8]) -> Self
Creates a new MPI.
This function takes care of removing leading zeros.
Sourcepub fn new_point(x: &[u8], y: &[u8], field_bits: usize) -> Self
pub fn new_point(x: &[u8], y: &[u8], field_bits: usize) -> Self
Creates new MPI encoding an uncompressed EC point.
Encodes the given point on an elliptic curve (see Section 6 of
RFC 6637 for details). This is used to encode public keys
and ciphertexts for the NIST curves (NistP256
, NistP384
,
and NistP521
).
Sourcepub fn new_compressed_point(x: &[u8]) -> Self
pub fn new_compressed_point(x: &[u8]) -> Self
Creates new MPI encoding a compressed EC point using native encoding.
Encodes the given point on an elliptic curve (see Section 13.2
of RFC4880bis for details). This is used to encode public
keys and ciphertexts for the Bernstein curves (currently
X25519
).
Sourcepub fn bits(&self) -> usize
pub fn bits(&self) -> usize
Returns the length of the MPI in bits.
Leading zero-bits are not included in the returned size.
Sourcepub fn value(&self) -> &[u8] ⓘ
pub fn value(&self) -> &[u8] ⓘ
Returns the value of this MPI.
Note that due to stripping of zero-bytes, the returned value may be shorter than expected.
Sourcepub fn value_padded(&self, to: usize) -> Result<Cow<'_, [u8]>>
pub fn value_padded(&self, to: usize) -> Result<Cow<'_, [u8]>>
Returns the value of this MPI zero-padded to the given length.
MPI-encoding strips leading zero-bytes. This function adds
them back, if necessary. If the size exceeds to
, an error
is returned.
Sourcepub fn decode_point(&self, curve: &Curve) -> Result<(&[u8], &[u8])>
pub fn decode_point(&self, curve: &Curve) -> Result<(&[u8], &[u8])>
Decodes an EC point encoded as MPI.
Decodes the MPI into a point on an elliptic curve (see
Section 6 of RFC 6637 and Section 13.2 of RFC4880bis for
details). If the point is not compressed, the function
returns (x, y)
. If it is compressed, y
will be empty.
§Errors
Returns Error::UnsupportedEllipticCurve
if the curve is not
supported, Error::MalformedMPI
if the point is formatted
incorrectly, Error::InvalidOperation
if the given curve is
operating on native octet strings.