package ecdh

Import Path
	crypto/ecdh (on go.dev)

Dependency Relation
	imports 11 packages, and imported by 3 packages

Involved Source Files Package ecdh implements Elliptic Curve Diffie-Hellman over NIST curves and Curve25519. nist.go x25519.go
Package-Level Type Names (total 3)
/* sort by: | */
GenerateKey generates a new PrivateKey from rand. NewPrivateKey checks that key is valid and returns a PrivateKey. For NIST curves, this follows SEC 1, Version 2.0, Section 2.3.6, which amounts to decoding the bytes as a fixed length big endian integer and checking that the result is lower than the order of the curve. The zero private key is also rejected, as the encoding of the corresponding public key would be irregular. For X25519, this only checks the scalar length. NewPublicKey checks that key is valid and returns a PublicKey. For NIST curves, this decodes an uncompressed point according to SEC 1, Version 2.0, Section 2.3.4. Compressed encodings and the point at infinity are rejected. For X25519, this only checks the u-coordinate length. Adversarially selected public keys can cause ECDH to return an error. func P256() Curve func P384() Curve func P521() Curve func X25519() Curve func (*PrivateKey).Curve() Curve func (*PublicKey).Curve() Curve
PrivateKey is an ECDH private key, usually kept secret. These keys can be parsed with [crypto/x509.ParsePKCS8PrivateKey] and encoded with [crypto/x509.MarshalPKCS8PrivateKey]. For NIST curves, they then need to be converted with [crypto/ecdsa.PrivateKey.ECDH] after parsing. Bytes returns a copy of the encoding of the private key. (*PrivateKey) Curve() Curve ECDH performs a ECDH exchange and returns the shared secret. For NIST curves, this performs ECDH as specified in SEC 1, Version 2.0, Section 3.3.1, and returns the x-coordinate encoded according to SEC 1, Version 2.0, Section 2.3.5. The result is never the point at infinity. For X25519, this performs ECDH as specified in RFC 7748, Section 6.1. If the result is the all-zero value, ECDH returns an error. Equal returns whether x represents the same private key as k. Note that there can be equivalent private keys with different encodings which would return false from this check but behave the same way as inputs to ECDH. This check is performed in constant time as long as the key types and their curve match. Public implements the implicit interface of all standard library private keys. See the docs of crypto.PrivateKey. (*PrivateKey) PublicKey() *PublicKey func Curve.GenerateKey(rand io.Reader) (*PrivateKey, error) func Curve.NewPrivateKey(key []byte) (*PrivateKey, error) func crypto/ecdsa.(*PrivateKey).ECDH() (*PrivateKey, error)
PublicKey is an ECDH public key, usually a peer's ECDH share sent over the wire. These keys can be parsed with [crypto/x509.ParsePKIXPublicKey] and encoded with [crypto/x509.MarshalPKIXPublicKey]. For NIST curves, they then need to be converted with [crypto/ecdsa.PublicKey.ECDH] after parsing. Bytes returns a copy of the encoding of the public key. (*PublicKey) Curve() Curve Equal returns whether x represents the same public key as k. Note that there can be equivalent public keys with different encodings which would return false from this check but behave the same way as inputs to ECDH. This check is performed in constant time as long as the key types and their curve match. func Curve.NewPublicKey(key []byte) (*PublicKey, error) func (*PrivateKey).PublicKey() *PublicKey func crypto/ecdsa.(*PublicKey).ECDH() (*PublicKey, error) func (*PrivateKey).ECDH(remote *PublicKey) ([]byte, error)
Package-Level Functions (total 4)
P256 returns a Curve which implements NIST P-256 (FIPS 186-3, section D.2.3), also known as secp256r1 or prime256v1. Multiple invocations of this function will return the same value, which can be used for equality checks and switch statements.
P384 returns a Curve which implements NIST P-384 (FIPS 186-3, section D.2.4), also known as secp384r1. Multiple invocations of this function will return the same value, which can be used for equality checks and switch statements.
P521 returns a Curve which implements NIST P-521 (FIPS 186-3, section D.2.5), also known as secp521r1. Multiple invocations of this function will return the same value, which can be used for equality checks and switch statements.
X25519 returns a Curve which implements the X25519 function over Curve25519 (RFC 7748, Section 5). Multiple invocations of this function will return the same value, so it can be used for equality checks and switch statements.