9 files changed, 1120 insertions, 0 deletions

diff --git a/src/crypto/ecdsa/ecdsa.go b/src/crypto/ecdsa/ecdsa.go
new file mode 100644
index 0000000..9f9a09a
--- /dev/null
+++ b/src/crypto/ecdsa/ecdsa.go
@@ -0,0 +1,368 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package ecdsa implements the Elliptic Curve Digital Signature Algorithm, as
+// defined in FIPS 186-4 and SEC 1, Version 2.0.
+//
+// Signatures generated by this package are not deterministic, but entropy is
+// mixed with the private key and the message, achieving the same level of
+// security in case of randomness source failure.
+package ecdsa
+
+// [FIPS 186-4] references ANSI X9.62-2005 for the bulk of the ECDSA algorithm.
+// That standard is not freely available, which is a problem in an open source
+// implementation, because not only the implementer, but also any maintainer,
+// contributor, reviewer, auditor, and learner needs access to it. Instead, this
+// package references and follows the equivalent [SEC 1, Version 2.0].
+//
+// [FIPS 186-4]: https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.186-4.pdf
+// [SEC 1, Version 2.0]: https://www.secg.org/sec1-v2.pdf
+
+import (
+	"crypto"
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/elliptic"
+	"crypto/internal/randutil"
+	"crypto/sha512"
+	"errors"
+	"io"
+	"math/big"
+
+	"golang.org/x/crypto/cryptobyte"
+	"golang.org/x/crypto/cryptobyte/asn1"
+)
+
+// A invertible implements fast inverse in GF(N).
+type invertible interface {
+	// Inverse returns the inverse of k mod Params().N.
+	Inverse(k *big.Int) *big.Int
+}
+
+// A combinedMult implements fast combined multiplication for verification.
+type combinedMult interface {
+	// CombinedMult returns [s1]G + [s2]P where G is the generator.
+	CombinedMult(Px, Py *big.Int, s1, s2 []byte) (x, y *big.Int)
+}
+
+const (
+	aesIV = "IV for ECDSA CTR"
+)
+
+// PublicKey represents an ECDSA public key.
+type PublicKey struct {
+	elliptic.Curve
+	X, Y *big.Int
+}
+
+// Any methods implemented on PublicKey might need to also be implemented on
+// PrivateKey, as the latter embeds the former and will expose its methods.
+
+// Equal reports whether pub and x have the same value.
+//
+// Two keys are only considered to have the same value if they have the same Curve value.
+// Note that for example elliptic.P256() and elliptic.P256().Params() are different
+// values, as the latter is a generic not constant time implementation.
+func (pub *PublicKey) Equal(x crypto.PublicKey) bool {
+	xx, ok := x.(*PublicKey)
+	if !ok {
+		return false
+	}
+	return pub.X.Cmp(xx.X) == 0 && pub.Y.Cmp(xx.Y) == 0 &&
+		// Standard library Curve implementations are singletons, so this check
+		// will work for those. Other Curves might be equivalent even if not
+		// singletons, but there is no definitive way to check for that, and
+		// better to err on the side of safety.
+		pub.Curve == xx.Curve
+}
+
+// PrivateKey represents an ECDSA private key.
+type PrivateKey struct {
+	PublicKey
+	D *big.Int
+}
+
+// Public returns the public key corresponding to priv.
+func (priv *PrivateKey) Public() crypto.PublicKey {
+	return &priv.PublicKey
+}
+
+// Equal reports whether priv and x have the same value.
+//
+// See PublicKey.Equal for details on how Curve is compared.
+func (priv *PrivateKey) Equal(x crypto.PrivateKey) bool {
+	xx, ok := x.(*PrivateKey)
+	if !ok {
+		return false
+	}
+	return priv.PublicKey.Equal(&xx.PublicKey) && priv.D.Cmp(xx.D) == 0
+}
+
+// Sign signs digest with priv, reading randomness from rand. The opts argument
+// is not currently used but, in keeping with the crypto.Signer interface,
+// should be the hash function used to digest the message.
+//
+// This method implements crypto.Signer, which is an interface to support keys
+// where the private part is kept in, for example, a hardware module. Common
+// uses can use the SignASN1 function in this package directly.
+func (priv *PrivateKey) Sign(rand io.Reader, digest []byte, opts crypto.SignerOpts) ([]byte, error) {
+	r, s, err := Sign(rand, priv, digest)
+	if err != nil {
+		return nil, err
+	}
+
+	var b cryptobyte.Builder
+	b.AddASN1(asn1.SEQUENCE, func(b *cryptobyte.Builder) {
+		b.AddASN1BigInt(r)
+		b.AddASN1BigInt(s)
+	})
+	return b.Bytes()
+}
+
+var one = new(big.Int).SetInt64(1)
+
+// randFieldElement returns a random element of the order of the given
+// curve using the procedure given in FIPS 186-4, Appendix B.5.1.
+func randFieldElement(c elliptic.Curve, rand io.Reader) (k *big.Int, err error) {
+	params := c.Params()
+	// Note that for P-521 this will actually be 63 bits more than the order, as
+	// division rounds down, but the extra bit is inconsequential.
+	b := make([]byte, params.BitSize/8+8) // TODO: use params.N.BitLen()
+	_, err = io.ReadFull(rand, b)
+	if err != nil {
+		return
+	}
+
+	k = new(big.Int).SetBytes(b)
+	n := new(big.Int).Sub(params.N, one)
+	k.Mod(k, n)
+	k.Add(k, one)
+	return
+}
+
+// GenerateKey generates a public and private key pair.
+func GenerateKey(c elliptic.Curve, rand io.Reader) (*PrivateKey, error) {
+	k, err := randFieldElement(c, rand)
+	if err != nil {
+		return nil, err
+	}
+
+	priv := new(PrivateKey)
+	priv.PublicKey.Curve = c
+	priv.D = k
+	priv.PublicKey.X, priv.PublicKey.Y = c.ScalarBaseMult(k.Bytes())
+	return priv, nil
+}
+
+// hashToInt converts a hash value to an integer. Per FIPS 186-4, Section 6.4,
+// we use the left-most bits of the hash to match the bit-length of the order of
+// the curve. This also performs Step 5 of SEC 1, Version 2.0, Section 4.1.3.
+func hashToInt(hash []byte, c elliptic.Curve) *big.Int {
+	orderBits := c.Params().N.BitLen()
+	orderBytes := (orderBits + 7) / 8
+	if len(hash) > orderBytes {
+		hash = hash[:orderBytes]
+	}
+
+	ret := new(big.Int).SetBytes(hash)
+	excess := len(hash)*8 - orderBits
+	if excess > 0 {
+		ret.Rsh(ret, uint(excess))
+	}
+	return ret
+}
+
+// fermatInverse calculates the inverse of k in GF(P) using Fermat's method
+// (exponentiation modulo P - 2, per Euler's theorem). This has better
+// constant-time properties than Euclid's method (implemented in
+// math/big.Int.ModInverse and FIPS 186-4, Appendix C.1) although math/big
+// itself isn't strictly constant-time so it's not perfect.
+func fermatInverse(k, N *big.Int) *big.Int {
+	two := big.NewInt(2)
+	nMinus2 := new(big.Int).Sub(N, two)
+	return new(big.Int).Exp(k, nMinus2, N)
+}
+
+var errZeroParam = errors.New("zero parameter")
+
+// Sign signs a hash (which should be the result of hashing a larger message)
+// using the private key, priv. If the hash is longer than the bit-length of the
+// private key's curve order, the hash will be truncated to that length. It
+// returns the signature as a pair of integers. Most applications should use
+// SignASN1 instead of dealing directly with r, s.
+func Sign(rand io.Reader, priv *PrivateKey, hash []byte) (r, s *big.Int, err error) {
+	randutil.MaybeReadByte(rand)
+
+	// This implementation derives the nonce from an AES-CTR CSPRNG keyed by:
+	//
+	//    SHA2-512(priv.D || entropy || hash)[:32]
+	//
+	// The CSPRNG key is indifferentiable from a random oracle as shown in
+	// [Coron], the AES-CTR stream is indifferentiable from a random oracle
+	// under standard cryptographic assumptions (see [Larsson] for examples).
+	//
+	// [Coron]: https://cs.nyu.edu/~dodis/ps/merkle.pdf
+	// [Larsson]: https://web.archive.org/web/20040719170906/https://www.nada.kth.se/kurser/kth/2D1441/semteo03/lecturenotes/assump.pdf
+
+	// Get 256 bits of entropy from rand.
+	entropy := make([]byte, 32)
+	_, err = io.ReadFull(rand, entropy)
+	if err != nil {
+		return
+	}
+
+	// Initialize an SHA-512 hash context; digest...
+	md := sha512.New()
+	md.Write(priv.D.Bytes()) // the private key,
+	md.Write(entropy)        // the entropy,
+	md.Write(hash)           // and the input hash;
+	key := md.Sum(nil)[:32]  // and compute ChopMD-256(SHA-512),
+	// which is an indifferentiable MAC.
+
+	// Create an AES-CTR instance to use as a CSPRNG.
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	// Create a CSPRNG that xors a stream of zeros with
+	// the output of the AES-CTR instance.
+	csprng := cipher.StreamReader{
+		R: zeroReader,
+		S: cipher.NewCTR(block, []byte(aesIV)),
+	}
+
+	c := priv.PublicKey.Curve
+	return sign(priv, &csprng, c, hash)
+}
+
+func signGeneric(priv *PrivateKey, csprng *cipher.StreamReader, c elliptic.Curve, hash []byte) (r, s *big.Int, err error) {
+	// SEC 1, Version 2.0, Section 4.1.3
+	N := c.Params().N
+	if N.Sign() == 0 {
+		return nil, nil, errZeroParam
+	}
+	var k, kInv *big.Int
+	for {
+		for {
+			k, err = randFieldElement(c, *csprng)
+			if err != nil {
+				r = nil
+				return
+			}
+
+			if in, ok := priv.Curve.(invertible); ok {
+				kInv = in.Inverse(k)
+			} else {
+				kInv = fermatInverse(k, N) // N != 0
+			}
+
+			r, _ = priv.Curve.ScalarBaseMult(k.Bytes())
+			r.Mod(r, N)
+			if r.Sign() != 0 {
+				break
+			}
+		}
+
+		e := hashToInt(hash, c)
+		s = new(big.Int).Mul(priv.D, r)
+		s.Add(s, e)
+		s.Mul(s, kInv)
+		s.Mod(s, N) // N != 0
+		if s.Sign() != 0 {
+			break
+		}
+	}
+
+	return
+}
+
+// SignASN1 signs a hash (which should be the result of hashing a larger message)
+// using the private key, priv. If the hash is longer than the bit-length of the
+// private key's curve order, the hash will be truncated to that length. It
+// returns the ASN.1 encoded signature.
+func SignASN1(rand io.Reader, priv *PrivateKey, hash []byte) ([]byte, error) {
+	return priv.Sign(rand, hash, nil)
+}
+
+// Verify verifies the signature in r, s of hash using the public key, pub. Its
+// return value records whether the signature is valid. Most applications should
+// use VerifyASN1 instead of dealing directly with r, s.
+func Verify(pub *PublicKey, hash []byte, r, s *big.Int) bool {
+	c := pub.Curve
+	N := c.Params().N
+
+	if r.Sign() <= 0 || s.Sign() <= 0 {
+		return false
+	}
+	if r.Cmp(N) >= 0 || s.Cmp(N) >= 0 {
+		return false
+	}
+	return verify(pub, c, hash, r, s)
+}
+
+func verifyGeneric(pub *PublicKey, c elliptic.Curve, hash []byte, r, s *big.Int) bool {
+	// SEC 1, Version 2.0, Section 4.1.4
+	e := hashToInt(hash, c)
+	var w *big.Int
+	N := c.Params().N
+	if in, ok := c.(invertible); ok {
+		w = in.Inverse(s)
+	} else {
+		w = new(big.Int).ModInverse(s, N)
+	}
+
+	u1 := e.Mul(e, w)
+	u1.Mod(u1, N)
+	u2 := w.Mul(r, w)
+	u2.Mod(u2, N)
+
+	// Check if implements S1*g + S2*p
+	var x, y *big.Int
+	if opt, ok := c.(combinedMult); ok {
+		x, y = opt.CombinedMult(pub.X, pub.Y, u1.Bytes(), u2.Bytes())
+	} else {
+		x1, y1 := c.ScalarBaseMult(u1.Bytes())
+		x2, y2 := c.ScalarMult(pub.X, pub.Y, u2.Bytes())
+		x, y = c.Add(x1, y1, x2, y2)
+	}
+
+	if x.Sign() == 0 && y.Sign() == 0 {
+		return false
+	}
+	x.Mod(x, N)
+	return x.Cmp(r) == 0
+}
+
+// VerifyASN1 verifies the ASN.1 encoded signature, sig, of hash using the
+// public key, pub. Its return value records whether the signature is valid.
+func VerifyASN1(pub *PublicKey, hash, sig []byte) bool {
+	var (
+		r, s  = &big.Int{}, &big.Int{}
+		inner cryptobyte.String
+	)
+	input := cryptobyte.String(sig)
+	if !input.ReadASN1(&inner, asn1.SEQUENCE) ||
+		!input.Empty() ||
+		!inner.ReadASN1Integer(r) ||
+		!inner.ReadASN1Integer(s) ||
+		!inner.Empty() {
+		return false
+	}
+	return Verify(pub, hash, r, s)
+}
+
+type zr struct {
+	io.Reader
+}
+
+// Read replaces the contents of dst with zeros.
+func (z *zr) Read(dst []byte) (n int, err error) {
+	for i := range dst {
+		dst[i] = 0
+	}
+	return len(dst), nil
+}
+
+var zeroReader = &zr{}
diff --git a/src/crypto/ecdsa/ecdsa_noasm.go b/src/crypto/ecdsa/ecdsa_noasm.go
new file mode 100644
index 0000000..7fbca10
--- /dev/null
+++ b/src/crypto/ecdsa/ecdsa_noasm.go
@@ -0,0 +1,21 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !s390x
+
+package ecdsa
+
+import (
+	"crypto/cipher"
+	"crypto/elliptic"
+	"math/big"
+)
+
+func sign(priv *PrivateKey, csprng *cipher.StreamReader, c elliptic.Curve, hash []byte) (r, s *big.Int, err error) {
+	return signGeneric(priv, csprng, c, hash)
+}
+
+func verify(pub *PublicKey, c elliptic.Curve, hash []byte, r, s *big.Int) bool {
+	return verifyGeneric(pub, c, hash, r, s)
+}
diff --git a/src/crypto/ecdsa/ecdsa_s390x.go b/src/crypto/ecdsa/ecdsa_s390x.go
new file mode 100644
index 0000000..1480d1b
--- /dev/null
+++ b/src/crypto/ecdsa/ecdsa_s390x.go
@@ -0,0 +1,163 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ecdsa
+
+import (
+	"crypto/cipher"
+	"crypto/elliptic"
+	"internal/cpu"
+	"math/big"
+)
+
+// kdsa invokes the "compute digital signature authentication"
+// instruction with the given function code and 4096 byte
+// parameter block.
+//
+// The return value corresponds to the condition code set by the
+// instruction. Interrupted invocations are handled by the
+// function.
+//go:noescape
+func kdsa(fc uint64, params *[4096]byte) (errn uint64)
+
+// testingDisableKDSA forces the generic fallback path. It must only be set in tests.
+var testingDisableKDSA bool
+
+// canUseKDSA checks if KDSA instruction is available, and if it is, it checks
+// the name of the curve to see if it matches the curves supported(P-256, P-384, P-521).
+// Then, based on the curve name, a function code and a block size will be assigned.
+// If KDSA instruction is not available or if the curve is not supported, canUseKDSA
+// will set ok to false.
+func canUseKDSA(c elliptic.Curve) (functionCode uint64, blockSize int, ok bool) {
+	if testingDisableKDSA {
+		return 0, 0, false
+	}
+	if !cpu.S390X.HasECDSA {
+		return 0, 0, false
+	}
+	switch c.Params().Name {
+	case "P-256":
+		return 1, 32, true
+	case "P-384":
+		return 2, 48, true
+	case "P-521":
+		return 3, 80, true
+	}
+	return 0, 0, false // A mismatch
+}
+
+func hashToBytes(dst, hash []byte, c elliptic.Curve) {
+	l := len(dst)
+	if n := c.Params().N.BitLen(); n == l*8 {
+		// allocation free path for curves with a length that is a whole number of bytes
+		if len(hash) >= l {
+			// truncate hash
+			copy(dst, hash[:l])
+			return
+		}
+		// pad hash with leading zeros
+		p := l - len(hash)
+		for i := 0; i < p; i++ {
+			dst[i] = 0
+		}
+		copy(dst[p:], hash)
+		return
+	}
+	// TODO(mundaym): avoid hashToInt call here
+	hashToInt(hash, c).FillBytes(dst)
+}
+
+func sign(priv *PrivateKey, csprng *cipher.StreamReader, c elliptic.Curve, hash []byte) (r, s *big.Int, err error) {
+	if functionCode, blockSize, ok := canUseKDSA(c); ok {
+		for {
+			var k *big.Int
+			k, err = randFieldElement(c, *csprng)
+			if err != nil {
+				return nil, nil, err
+			}
+
+			// The parameter block looks like the following for sign.
+			// 	+---------------------+
+			// 	|   Signature(R)      |
+			//	+---------------------+
+			//	|   Signature(S)      |
+			//	+---------------------+
+			//	|   Hashed Message    |
+			//	+---------------------+
+			//	|   Private Key       |
+			//	+---------------------+
+			//	|   Random Number     |
+			//	+---------------------+
+			//	|                     |
+			//	|        ...          |
+			//	|                     |
+			//	+---------------------+
+			// The common components(signatureR, signatureS, hashedMessage, privateKey and
+			// random number) each takes block size of bytes. The block size is different for
+			// different curves and is set by canUseKDSA function.
+			var params [4096]byte
+
+			// Copy content into the parameter block. In the sign case,
+			// we copy hashed message, private key and random number into
+			// the parameter block.
+			hashToBytes(params[2*blockSize:3*blockSize], hash, c)
+			priv.D.FillBytes(params[3*blockSize : 4*blockSize])
+			k.FillBytes(params[4*blockSize : 5*blockSize])
+			// Convert verify function code into a sign function code by adding 8.
+			// We also need to set the 'deterministic' bit in the function code, by
+			// adding 128, in order to stop the instruction using its own random number
+			// generator in addition to the random number we supply.
+			switch kdsa(functionCode+136, &params) {
+			case 0: // success
+				r = new(big.Int)
+				r.SetBytes(params[:blockSize])
+				s = new(big.Int)
+				s.SetBytes(params[blockSize : 2*blockSize])
+				return
+			case 1: // error
+				return nil, nil, errZeroParam
+			case 2: // retry
+				continue
+			}
+			panic("unreachable")
+		}
+	}
+	return signGeneric(priv, csprng, c, hash)
+}
+
+func verify(pub *PublicKey, c elliptic.Curve, hash []byte, r, s *big.Int) bool {
+	if functionCode, blockSize, ok := canUseKDSA(c); ok {
+		// The parameter block looks like the following for verify:
+		// 	+---------------------+
+		// 	|   Signature(R)      |
+		//	+---------------------+
+		//	|   Signature(S)      |
+		//	+---------------------+
+		//	|   Hashed Message    |
+		//	+---------------------+
+		//	|   Public Key X      |
+		//	+---------------------+
+		//	|   Public Key Y      |
+		//	+---------------------+
+		//	|                     |
+		//	|        ...          |
+		//	|                     |
+		//	+---------------------+
+		// The common components(signatureR, signatureS, hashed message, public key X,
+		// and public key Y) each takes block size of bytes. The block size is different for
+		// different curves and is set by canUseKDSA function.
+		var params [4096]byte
+
+		// Copy content into the parameter block. In the verify case,
+		// we copy signature (r), signature(s), hashed message, public key x component,
+		// and public key y component into the parameter block.
+		r.FillBytes(params[0*blockSize : 1*blockSize])
+		s.FillBytes(params[1*blockSize : 2*blockSize])
+		hashToBytes(params[2*blockSize:3*blockSize], hash, c)
+		pub.X.FillBytes(params[3*blockSize : 4*blockSize])
+		pub.Y.FillBytes(params[4*blockSize : 5*blockSize])
+		return kdsa(functionCode, &params) == 0
+	}
+	return verifyGeneric(pub, c, hash, r, s)
+}
diff --git a/src/crypto/ecdsa/ecdsa_s390x.s b/src/crypto/ecdsa/ecdsa_s390x.s
new file mode 100644
index 0000000..ba5b3bf
--- /dev/null
+++ b/src/crypto/ecdsa/ecdsa_s390x.s
@@ -0,0 +1,28 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include "textflag.h"
+
+// func kdsa(fc uint64, params *[4096]byte) (errn uint64)
+TEXT ·kdsa(SB), NOSPLIT|NOFRAME, $0-24
+	MOVD fc+0(FP), R0     // function code
+	MOVD params+8(FP), R1 // address parameter block
+
+loop:
+	WORD $0xB93A0008 // compute digital signature authentication
+	BVS  loop        // branch back if interrupted
+	BGT  retry       // signing unsuccessful, but retry with new CSPRN
+	BLT  error       // condition code of 1 indicates a failure
+
+success:
+	MOVD $0, errn+16(FP) // return 0 - sign/verify was successful
+	RET
+
+error:
+	MOVD $1, errn+16(FP) // return 1 - sign/verify failed
+	RET
+
+retry:
+	MOVD $2, errn+16(FP) // return 2 - sign/verify was unsuccessful -- if sign, retry with new RN
+	RET
diff --git a/src/crypto/ecdsa/ecdsa_s390x_test.go b/src/crypto/ecdsa/ecdsa_s390x_test.go
new file mode 100644
index 0000000..fd1dc7c
--- /dev/null
+++ b/src/crypto/ecdsa/ecdsa_s390x_test.go
@@ -0,0 +1,32 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build s390x
+
+package ecdsa
+
+import (
+	"crypto/elliptic"
+	"testing"
+)
+
+func TestNoAsm(t *testing.T) {
+	testingDisableKDSA = true
+	defer func() { testingDisableKDSA = false }()
+
+	curves := [...]elliptic.Curve{
+		elliptic.P256(),
+		elliptic.P384(),
+		elliptic.P521(),
+	}
+
+	for _, curve := range curves {
+		name := curve.Params().Name
+		t.Run(name, func(t *testing.T) { testKeyGeneration(t, curve) })
+		t.Run(name, func(t *testing.T) { testSignAndVerify(t, curve) })
+		t.Run(name, func(t *testing.T) { testNonceSafety(t, curve) })
+		t.Run(name, func(t *testing.T) { testINDCCA(t, curve) })
+		t.Run(name, func(t *testing.T) { testNegativeInputs(t, curve) })
+	}
+}
diff --git a/src/crypto/ecdsa/ecdsa_test.go b/src/crypto/ecdsa/ecdsa_test.go
new file mode 100644
index 0000000..c8390b2
--- /dev/null
+++ b/src/crypto/ecdsa/ecdsa_test.go
@@ -0,0 +1,401 @@
+// Copyright 2011 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ecdsa
+
+import (
+	"bufio"
+	"compress/bzip2"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/sha1"
+	"crypto/sha256"
+	"crypto/sha512"
+	"encoding/hex"
+	"hash"
+	"io"
+	"math/big"
+	"os"
+	"strings"
+	"testing"
+)
+
+func testAllCurves(t *testing.T, f func(*testing.T, elliptic.Curve)) {
+	tests := []struct {
+		name  string
+		curve elliptic.Curve
+	}{
+		{"P256", elliptic.P256()},
+		{"P224", elliptic.P224()},
+		{"P384", elliptic.P384()},
+		{"P521", elliptic.P521()},
+	}
+	if testing.Short() {
+		tests = tests[:1]
+	}
+	for _, test := range tests {
+		curve := test.curve
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+			f(t, curve)
+		})
+	}
+}
+
+func TestKeyGeneration(t *testing.T) {
+	testAllCurves(t, testKeyGeneration)
+}
+
+func testKeyGeneration(t *testing.T, c elliptic.Curve) {
+	priv, err := GenerateKey(c, rand.Reader)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !c.IsOnCurve(priv.PublicKey.X, priv.PublicKey.Y) {
+		t.Errorf("public key invalid: %s", err)
+	}
+}
+
+func TestSignAndVerify(t *testing.T) {
+	testAllCurves(t, testSignAndVerify)
+}
+
+func testSignAndVerify(t *testing.T, c elliptic.Curve) {
+	priv, _ := GenerateKey(c, rand.Reader)
+
+	hashed := []byte("testing")
+	r, s, err := Sign(rand.Reader, priv, hashed)
+	if err != nil {
+		t.Errorf("error signing: %s", err)
+		return
+	}
+
+	if !Verify(&priv.PublicKey, hashed, r, s) {
+		t.Errorf("Verify failed")
+	}
+
+	hashed[0] ^= 0xff
+	if Verify(&priv.PublicKey, hashed, r, s) {
+		t.Errorf("Verify always works!")
+	}
+}
+
+func TestSignAndVerifyASN1(t *testing.T) {
+	testAllCurves(t, testSignAndVerifyASN1)
+}
+
+func testSignAndVerifyASN1(t *testing.T, c elliptic.Curve) {
+	priv, _ := GenerateKey(c, rand.Reader)
+
+	hashed := []byte("testing")
+	sig, err := SignASN1(rand.Reader, priv, hashed)
+	if err != nil {
+		t.Errorf("error signing: %s", err)
+		return
+	}
+
+	if !VerifyASN1(&priv.PublicKey, hashed, sig) {
+		t.Errorf("VerifyASN1 failed")
+	}
+
+	hashed[0] ^= 0xff
+	if VerifyASN1(&priv.PublicKey, hashed, sig) {
+		t.Errorf("VerifyASN1 always works!")
+	}
+}
+
+func TestNonceSafety(t *testing.T) {
+	testAllCurves(t, testNonceSafety)
+}
+
+func testNonceSafety(t *testing.T, c elliptic.Curve) {
+	priv, _ := GenerateKey(c, rand.Reader)
+
+	hashed := []byte("testing")
+	r0, s0, err := Sign(zeroReader, priv, hashed)
+	if err != nil {
+		t.Errorf("error signing: %s", err)
+		return
+	}
+
+	hashed = []byte("testing...")
+	r1, s1, err := Sign(zeroReader, priv, hashed)
+	if err != nil {
+		t.Errorf("error signing: %s", err)
+		return
+	}
+
+	if s0.Cmp(s1) == 0 {
+		// This should never happen.
+		t.Errorf("the signatures on two different messages were the same")
+	}
+
+	if r0.Cmp(r1) == 0 {
+		t.Errorf("the nonce used for two different messages was the same")
+	}
+}
+
+func TestINDCCA(t *testing.T) {
+	testAllCurves(t, testINDCCA)
+}
+
+func testINDCCA(t *testing.T, c elliptic.Curve) {
+	priv, _ := GenerateKey(c, rand.Reader)
+
+	hashed := []byte("testing")
+	r0, s0, err := Sign(rand.Reader, priv, hashed)
+	if err != nil {
+		t.Errorf("error signing: %s", err)
+		return
+	}
+
+	r1, s1, err := Sign(rand.Reader, priv, hashed)
+	if err != nil {
+		t.Errorf("error signing: %s", err)
+		return
+	}
+
+	if s0.Cmp(s1) == 0 {
+		t.Errorf("two signatures of the same message produced the same result")
+	}
+
+	if r0.Cmp(r1) == 0 {
+		t.Errorf("two signatures of the same message produced the same nonce")
+	}
+}
+
+func fromHex(s string) *big.Int {
+	r, ok := new(big.Int).SetString(s, 16)
+	if !ok {
+		panic("bad hex")
+	}
+	return r
+}
+
+func TestVectors(t *testing.T) {
+	// This test runs the full set of NIST test vectors from
+	// https://csrc.nist.gov/groups/STM/cavp/documents/dss/186-3ecdsatestvectors.zip
+	//
+	// The SigVer.rsp file has been edited to remove test vectors for
+	// unsupported algorithms and has been compressed.
+
+	if testing.Short() {
+		return
+	}
+
+	f, err := os.Open("testdata/SigVer.rsp.bz2")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	buf := bufio.NewReader(bzip2.NewReader(f))
+
+	lineNo := 1
+	var h hash.Hash
+	var msg []byte
+	var hashed []byte
+	var r, s *big.Int
+	pub := new(PublicKey)
+
+	for {
+		line, err := buf.ReadString('\n')
+		if len(line) == 0 {
+			if err == io.EOF {
+				break
+			}
+			t.Fatalf("error reading from input: %s", err)
+		}
+		lineNo++
+		// Need to remove \r\n from the end of the line.
+		if !strings.HasSuffix(line, "\r\n") {
+			t.Fatalf("bad line ending (expected \\r\\n) on line %d", lineNo)
+		}
+		line = line[:len(line)-2]
+
+		if len(line) == 0 || line[0] == '#' {
+			continue
+		}
+
+		if line[0] == '[' {
+			line = line[1 : len(line)-1]
+			curve, hash, _ := strings.Cut(line, ",")
+
+			switch curve {
+			case "P-224":
+				pub.Curve = elliptic.P224()
+			case "P-256":
+				pub.Curve = elliptic.P256()
+			case "P-384":
+				pub.Curve = elliptic.P384()
+			case "P-521":
+				pub.Curve = elliptic.P521()
+			default:
+				pub.Curve = nil
+			}
+
+			switch hash {
+			case "SHA-1":
+				h = sha1.New()
+			case "SHA-224":
+				h = sha256.New224()
+			case "SHA-256":
+				h = sha256.New()
+			case "SHA-384":
+				h = sha512.New384()
+			case "SHA-512":
+				h = sha512.New()
+			default:
+				h = nil
+			}
+
+			continue
+		}
+
+		if h == nil || pub.Curve == nil {
+			continue
+		}
+
+		switch {
+		case strings.HasPrefix(line, "Msg = "):
+			if msg, err = hex.DecodeString(line[6:]); err != nil {
+				t.Fatalf("failed to decode message on line %d: %s", lineNo, err)
+			}
+		case strings.HasPrefix(line, "Qx = "):
+			pub.X = fromHex(line[5:])
+		case strings.HasPrefix(line, "Qy = "):
+			pub.Y = fromHex(line[5:])
+		case strings.HasPrefix(line, "R = "):
+			r = fromHex(line[4:])
+		case strings.HasPrefix(line, "S = "):
+			s = fromHex(line[4:])
+		case strings.HasPrefix(line, "Result = "):
+			expected := line[9] == 'P'
+			h.Reset()
+			h.Write(msg)
+			hashed := h.Sum(hashed[:0])
+			if Verify(pub, hashed, r, s) != expected {
+				t.Fatalf("incorrect result on line %d", lineNo)
+			}
+		default:
+			t.Fatalf("unknown variable on line %d: %s", lineNo, line)
+		}
+	}
+}
+
+func TestNegativeInputs(t *testing.T) {
+	testAllCurves(t, testNegativeInputs)
+}
+
+func testNegativeInputs(t *testing.T, curve elliptic.Curve) {
+	key, err := GenerateKey(curve, rand.Reader)
+	if err != nil {
+		t.Errorf("failed to generate key")
+	}
+
+	var hash [32]byte
+	r := new(big.Int).SetInt64(1)
+	r.Lsh(r, 550 /* larger than any supported curve */)
+	r.Neg(r)
+
+	if Verify(&key.PublicKey, hash[:], r, r) {
+		t.Errorf("bogus signature accepted")
+	}
+}
+
+func TestZeroHashSignature(t *testing.T) {
+	testAllCurves(t, testZeroHashSignature)
+}
+
+func testZeroHashSignature(t *testing.T, curve elliptic.Curve) {
+	zeroHash := make([]byte, 64)
+
+	privKey, err := GenerateKey(curve, rand.Reader)
+	if err != nil {
+		panic(err)
+	}
+
+	// Sign a hash consisting of all zeros.
+	r, s, err := Sign(rand.Reader, privKey, zeroHash)
+	if err != nil {
+		panic(err)
+	}
+
+	// Confirm that it can be verified.
+	if !Verify(&privKey.PublicKey, zeroHash, r, s) {
+		t.Errorf("zero hash signature verify failed for %T", curve)
+	}
+}
+
+func benchmarkAllCurves(t *testing.B, f func(*testing.B, elliptic.Curve)) {
+	tests := []struct {
+		name  string
+		curve elliptic.Curve
+	}{
+		{"P256", elliptic.P256()},
+		{"P224", elliptic.P224()},
+		{"P384", elliptic.P384()},
+		{"P521", elliptic.P521()},
+	}
+	for _, test := range tests {
+		curve := test.curve
+		t.Run(test.name, func(t *testing.B) {
+			f(t, curve)
+		})
+	}
+}
+
+func BenchmarkSign(b *testing.B) {
+	benchmarkAllCurves(b, func(b *testing.B, curve elliptic.Curve) {
+		priv, err := GenerateKey(curve, rand.Reader)
+		if err != nil {
+			b.Fatal(err)
+		}
+		hashed := []byte("testing")
+
+		b.ReportAllocs()
+		b.ResetTimer()
+		for i := 0; i < b.N; i++ {
+			sig, err := SignASN1(rand.Reader, priv, hashed)
+			if err != nil {
+				b.Fatal(err)
+			}
+			// Prevent the compiler from optimizing out the operation.
+			hashed[0] = sig[0]
+		}
+	})
+}
+
+func BenchmarkVerify(b *testing.B) {
+	benchmarkAllCurves(b, func(b *testing.B, curve elliptic.Curve) {
+		priv, err := GenerateKey(curve, rand.Reader)
+		if err != nil {
+			b.Fatal(err)
+		}
+		hashed := []byte("testing")
+		r, s, err := Sign(rand.Reader, priv, hashed)
+		if err != nil {
+			b.Fatal(err)
+		}
+
+		b.ReportAllocs()
+		b.ResetTimer()
+		for i := 0; i < b.N; i++ {
+			if !Verify(&priv.PublicKey, hashed, r, s) {
+				b.Fatal("verify failed")
+			}
+		}
+	})
+}
+
+func BenchmarkGenerateKey(b *testing.B) {
+	benchmarkAllCurves(b, func(b *testing.B, curve elliptic.Curve) {
+		b.ReportAllocs()
+		b.ResetTimer()
+		for i := 0; i < b.N; i++ {
+			if _, err := GenerateKey(curve, rand.Reader); err != nil {
+				b.Fatal(err)
+			}
+		}
+	})
+}
diff --git a/src/crypto/ecdsa/equal_test.go b/src/crypto/ecdsa/equal_test.go
new file mode 100644
index 0000000..53ac850
--- /dev/null
+++ b/src/crypto/ecdsa/equal_test.go
@@ -0,0 +1,75 @@
+// Copyright 2020 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ecdsa_test
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/x509"
+	"testing"
+)
+
+func testEqual(t *testing.T, c elliptic.Curve) {
+	private, _ := ecdsa.GenerateKey(c, rand.Reader)
+	public := &private.PublicKey
+
+	if !public.Equal(public) {
+		t.Errorf("public key is not equal to itself: %v", public)
+	}
+	if !public.Equal(crypto.Signer(private).Public().(*ecdsa.PublicKey)) {
+		t.Errorf("private.Public() is not Equal to public: %q", public)
+	}
+	if !private.Equal(private) {
+		t.Errorf("private key is not equal to itself: %v", private)
+	}
+
+	enc, err := x509.MarshalPKCS8PrivateKey(private)
+	if err != nil {
+		t.Fatal(err)
+	}
+	decoded, err := x509.ParsePKCS8PrivateKey(enc)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !public.Equal(decoded.(crypto.Signer).Public()) {
+		t.Errorf("public key is not equal to itself after decoding: %v", public)
+	}
+	if !private.Equal(decoded) {
+		t.Errorf("private key is not equal to itself after decoding: %v", private)
+	}
+
+	other, _ := ecdsa.GenerateKey(c, rand.Reader)
+	if public.Equal(other.Public()) {
+		t.Errorf("different public keys are Equal")
+	}
+	if private.Equal(other) {
+		t.Errorf("different private keys are Equal")
+	}
+
+	// Ensure that keys with the same coordinates but on different curves
+	// aren't considered Equal.
+	differentCurve := &ecdsa.PublicKey{}
+	*differentCurve = *public // make a copy of the public key
+	if differentCurve.Curve == elliptic.P256() {
+		differentCurve.Curve = elliptic.P224()
+	} else {
+		differentCurve.Curve = elliptic.P256()
+	}
+	if public.Equal(differentCurve) {
+		t.Errorf("public keys with different curves are Equal")
+	}
+}
+
+func TestEqual(t *testing.T) {
+	t.Run("P224", func(t *testing.T) { testEqual(t, elliptic.P224()) })
+	if testing.Short() {
+		return
+	}
+	t.Run("P256", func(t *testing.T) { testEqual(t, elliptic.P256()) })
+	t.Run("P384", func(t *testing.T) { testEqual(t, elliptic.P384()) })
+	t.Run("P521", func(t *testing.T) { testEqual(t, elliptic.P521()) })
+}
diff --git a/src/crypto/ecdsa/example_test.go b/src/crypto/ecdsa/example_test.go
new file mode 100644
index 0000000..652c165
--- /dev/null
+++ b/src/crypto/ecdsa/example_test.go
@@ -0,0 +1,32 @@
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package ecdsa_test
+
+import (
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"crypto/sha256"
+	"fmt"
+)
+
+func Example() {
+	privateKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		panic(err)
+	}
+
+	msg := "hello, world"
+	hash := sha256.Sum256([]byte(msg))
+
+	sig, err := ecdsa.SignASN1(rand.Reader, privateKey, hash[:])
+	if err != nil {
+		panic(err)
+	}
+	fmt.Printf("signature: %x\n", sig)
+
+	valid := ecdsa.VerifyASN1(&privateKey.PublicKey, hash[:], sig)
+	fmt.Println("signature verified:", valid)
+}
diff --git a/src/crypto/ecdsa/testdata/SigVer.rsp.bz2 b/src/crypto/ecdsa/testdata/SigVer.rsp.bz2
new file mode 100644
index 0000000..09fe2b4
--- /dev/null
+++ b/src/crypto/ecdsa/testdata/SigVer.rsp.bz2