go/src/crypto/dsa/dsa.go

type Parameters …

type PublicKey …

type PrivateKey …

var ErrInvalidPublicKey …

type ParameterSizes …

const L1024N160 …

const L2048N224 …

const L2048N256 …

const L3072N256 …

const numMRTests …

// GenerateParameters puts a random, valid set of DSA parameters into params.
// This function can take many seconds, even on fast machines.
func GenerateParameters(params *Parameters, rand io.Reader, sizes ParameterSizes) error { … }

// GenerateKey generates a public&private key pair. The Parameters of the
// [PrivateKey] must already be valid (see [GenerateParameters]).
func GenerateKey(priv *PrivateKey, rand io.Reader) error { … }

// fermatInverse calculates the inverse of k in GF(P) using Fermat's method.
// This has better constant-time properties than Euclid's method (implemented
// in math/big.Int.ModInverse) although math/big itself isn't strictly
// constant-time so it's not perfect.
func fermatInverse(k, P *big.Int) *big.Int { … }

// Sign signs an arbitrary length hash (which should be the result of hashing a
// larger message) using the private key, priv. It returns the signature as a
// pair of integers. The security of the private key depends on the entropy of
// rand.
//
// Note that FIPS 186-3 section 4.6 specifies that the hash should be truncated
// to the byte-length of the subgroup. This function does not perform that
// truncation itself.
//
// Be aware that calling Sign with an attacker-controlled [PrivateKey] may
// require an arbitrary amount of CPU.
func Sign(rand io.Reader, priv *PrivateKey, hash []byte) (r, s *big.Int, err error) { … }

// Verify verifies the signature in r, s of hash using the public key, pub. It
// reports whether the signature is valid.
//
// Note that FIPS 186-3 section 4.6 specifies that the hash should be truncated
// to the byte-length of the subgroup. This function does not perform that
// truncation itself.
func Verify(pub *PublicKey, hash []byte, r, s *big.Int) bool { … }