Finite Field Arithmetic · sodium-native

Bindings for the crypto_scalarmult_ed25519 and crypto_core_ed25519 API. See the libsodium docs for more information.

Constants

Buffer lengths (integer)

crypto_scalarmult_ed25519_BYTES
crypto_scalarmult_ed25519_SCALARBYTES
crypto_core_ed25519_BYTES
crypto_core_ed25519_UNIFORMBYTES
crypto_core_ed25519_SCALARBYTES
crypto_core_ed25519_NONREDUCEDSCALARBYTES
crypto_core_ed25519_UNIFORMBYTES

String constants (string)

crypto_scalarmult_PRIMITIVE

`crypto_core_ed25519_is_valid_point`

var bool = sodium.crypto_core_ed25519_is_valid_point(p)

Checks that p represents a point on the edwards25519 curve, in canonical form, on the main subgroup, and that the point does not have a small order.

p must be a buffer of at least crypto_core_ed25519_BYTES bytes

Returns true or false.

`crypto_core_ed25519_from_uniform`

sodium.crypto_core_ed25519_from_uniform(p, r)

Maps a crypto_core_ed25519_UNIFORMBYTES bytes vector (usually the output of a hash function) to a valid curve point and stores its compressed representation in p.

The point is guaranteed to be on the main subgroup.

p must be a buffer of at least crypto_core_ed25519_BYTES bytes
r must be a buffer of at least crypto_core_ed25519_UNIFORMBYTES bytes

`crypto_scalarmult_ed25519`

sodium.crypto_scalarmult_ed25519(q, n, p)

Multiplies point p by scalar n and stores its compressed representation in q.

q must be a buffer of at least crypto_scalarmult_ed25519_BYTES bytes
n must be a buffer of at least crypto_scalarmult_ed25519_SCALARBYTES bytes
p must be a buffer of at least crypto_scalarmult_ed25519_BYTES bytes

Note this function will throw, if n is zero or p is an invalid curve point.

`crypto_scalarmult_ed25519_base`

sodium.crypto_scalarmult_ed25519_base(q, n)

Multiplies the base point by scalar n and stores its compressed representation in q. Note that n will be clamped.

q must be a buffer of at least crypto_scalarmult_ed25519_BYTES bytes
n must be a buffer of at least crypto_scalarmult_ed25519_SCALARBYTES bytes

Note this function will throw if n is zero.

`crypto_scalarmult_ed25519_noclamp`

sodium.crypto_scalarmult_ed25519_noclamp(q, n, p)

Multiplies point p by scalar n and stores its compressed representation in q. This version does not clamp.

q must be a buffer of at least crypto_scalarmult_ed25519_BYTES bytes
n must be a buffer of at least crypto_scalarmult_ed25519_SCALARBYTES bytes
p must be a buffer of at least crypto_scalarmult_ed25519_BYTES bytes

Note this function will throw, if n is zero or p is an invalid curve point.

`crypto_scalarmult_ed25519_base_noclamp`

sodium.crypto_scalarmult_ed25519_base_noclamp(q, n)

Multiplies the base point by scalar n and stores its compressed representation in q. This version does not clamp.

q must be a buffer of at least crypto_scalarmult_ed25519_BYTES bytes
n must be a buffer of at least crypto_scalarmult_ed25519_SCALARBYTES bytes

Note this function will throw, if n is zero.

`crypto_core_ed25519_add`

sodium.crypto_core_ed25519_add(r, p, q)

Adds point q to p and stores the result in r.

r must be a buffer of at least crypto_core_ed25519_BYTES bytes
p must be a buffer of at least crypto_core_ed25519_BYTES bytes
q must be a buffer of at least crypto_core_ed25519_BYTES bytes

Note this function will throw, if p, q are not valid curve points

`crypto_core_ed25519_sub`

sodium.crypto_core_ed25519_sub(r, p, q)

Subtracts point q to p and stores the result in r.

r must be a buffer of at least crypto_core_ed25519_BYTES bytes
p must be a buffer of at least crypto_core_ed25519_BYTES bytes
q must be a buffer of at least crypto_core_ed25519_BYTES bytes

Note this function will throw, if p, q are not valid curve points.

`crypto_core_ed25519_scalar_random`

sodium.crypto_core_ed25519_scalar_random(r)

Generates random scalar in ]0..L[ and stores the result in r.

r must be a buffer of at least crypto_core_ed25519_SCALARBYTES bytes

`crypto_core_ed25519_scalar_reduce`

sodium.crypto_core_ed25519_scalar_reduce(r, s)

Reduces s mod L and stores the result in r.

r must be a buffer of at least crypto_core_ed25519_SCALARBYTES bytes
s must be a buffer of at least crypto_core_ed25519_NONREDUCEDSCALARBYTES bytes

`crypto_core_ed25519_scalar_invert`

sodium.crypto_core_ed25519_scalar_invert(recip, s)

Finds recip such that s * recip = 1 (mod L) and stores the result in recip.

recip must be a buffer of at least crypto_core_ed25519_SCALARBYTES bytes
s must be a buffer of at least crypto_core_ed25519_SCALARBYTES bytes

`crypto_core_ed25519_scalar_negate`

sodium.crypto_core_ed25519_scalar_negate(neg, s)

Finds neg such that s + neg = 0 (mod L) and stores the result in neg.

neg must be a buffer of at least crypto_core_ed25519_SCALARBYTES bytes
s must be a buffer of at least crypto_core_ed25519_SCALARBYTES bytes

`crypto_core_ed25519_scalar_complement`

sodium.crypto_core_ed25519_scalar_complement(comp, s)

Finds comp such that s + comp = 1 (mod L) and stores the result in recip.

comp must be a buffer of at least crypto_core_ed25519_SCALARBYTES bytes
s must be a buffer of at least crypto_core_ed25519_SCALARBYTES bytes

`crypto_core_ed25519_scalar_add`

sodium.crypto_core_ed25519_scalar_add(z, x, y)

Adds x and y such that x + y = z (mod L) and stores the result in z.

x must be a buffer of at least crypto_core_ed25519_SCALARBYTES bytes
y must be a buffer of at least crypto_core_ed25519_SCALARBYTES bytes
z must be a buffer of at least crypto_core_ed25519_SCALARBYTES bytes

`crypto_core_ed25519_scalar_sub`

sodium.crypto_core_ed25519_scalar_sub(z, x, y)

Subtracts x and y such that x - y = z (mod L) and stores the result in z.

x must be a buffer of at least crypto_core_ed25519_SCALARBYTES bytes
y must be a buffer of at least crypto_core_ed25519_SCALARBYTES bytes
z must be a buffer of at least crypto_core_ed25519_SCALARBYTES bytes