Fedora/RedHat distros comply with US patent law and remove this curve, which makes it impossible to run ethereum with distro provided Golang. File crypto/ecies/README claims it is unsupported anyway.
		
			
				
	
	
		
			578 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			578 lines
		
	
	
		
			14 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
// Copyright (c) 2013 Kyle Isom <kyle@tyrfingr.is>
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// Copyright (c) 2012 The Go Authors. All rights reserved.
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//
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// Redistribution and use in source and binary forms, with or without
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// modification, are permitted provided that the following conditions are
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// met:
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//
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//    * Redistributions of source code must retain the above copyright
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// notice, this list of conditions and the following disclaimer.
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//    * Redistributions in binary form must reproduce the above
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// copyright notice, this list of conditions and the following disclaimer
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// in the documentation and/or other materials provided with the
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// distribution.
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//    * Neither the name of Google Inc. nor the names of its
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// contributors may be used to endorse or promote products derived from
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// this software without specific prior written permission.
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//
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// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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package ecies
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import (
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	"bytes"
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	"crypto"
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	"crypto/elliptic"
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	"crypto/sha1"
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	"crypto/sha256"
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	"crypto/sha512"
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	"encoding/asn1"
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	"encoding/pem"
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	"fmt"
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	"hash"
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	"math/big"
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)
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var (
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	secgScheme     = []int{1, 3, 132, 1}
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	shaScheme      = []int{2, 16, 840, 1, 101, 3, 4, 2}
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	ansiX962Scheme = []int{1, 2, 840, 10045}
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	x963Scheme     = []int{1, 2, 840, 63, 0}
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)
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var ErrInvalidPrivateKey = fmt.Errorf("ecies: invalid private key")
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func doScheme(base, v []int) asn1.ObjectIdentifier {
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	var oidInts asn1.ObjectIdentifier
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	oidInts = append(oidInts, base...)
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	return append(oidInts, v...)
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}
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// curve OID code taken from crypto/x509, including
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//	- oidNameCurve*
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//	- namedCurveFromOID
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//	- oidFromNamedCurve
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// RFC 5480, 2.1.1.1. Named Curve
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//
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// secp224r1 OBJECT IDENTIFIER ::= {
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//   iso(1) identified-organization(3) certicom(132) curve(0) 33 }
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//
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// secp256r1 OBJECT IDENTIFIER ::= {
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//   iso(1) member-body(2) us(840) ansi-X9-62(10045) curves(3)
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//   prime(1) 7 }
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//
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// secp384r1 OBJECT IDENTIFIER ::= {
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//   iso(1) identified-organization(3) certicom(132) curve(0) 34 }
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//
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// secp521r1 OBJECT IDENTIFIER ::= {
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//   iso(1) identified-organization(3) certicom(132) curve(0) 35 }
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//
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// NB: secp256r1 is equivalent to prime256v1
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type secgNamedCurve asn1.ObjectIdentifier
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var (
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	secgNamedCurveP256 = secgNamedCurve{1, 2, 840, 10045, 3, 1, 7}
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	secgNamedCurveP384 = secgNamedCurve{1, 3, 132, 0, 34}
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	secgNamedCurveP521 = secgNamedCurve{1, 3, 132, 0, 35}
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	rawCurveP256       = []byte{6, 8, 4, 2, 1, 3, 4, 7, 2, 2, 0, 6, 6, 1, 3, 1, 7}
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	rawCurveP384       = []byte{6, 5, 4, 3, 1, 2, 9, 4, 0, 3, 4}
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	rawCurveP521       = []byte{6, 5, 4, 3, 1, 2, 9, 4, 0, 3, 5}
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)
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func rawCurve(curve elliptic.Curve) []byte {
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	switch curve {
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	case elliptic.P256():
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		return rawCurveP256
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	case elliptic.P384():
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		return rawCurveP384
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	case elliptic.P521():
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		return rawCurveP521
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	default:
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		return nil
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	}
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}
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func (curve secgNamedCurve) Equal(curve2 secgNamedCurve) bool {
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	if len(curve) != len(curve2) {
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		return false
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	}
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	for i, _ := range curve {
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		if curve[i] != curve2[i] {
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			return false
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		}
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	}
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	return true
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}
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func namedCurveFromOID(curve secgNamedCurve) elliptic.Curve {
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	switch {
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	case curve.Equal(secgNamedCurveP256):
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		return elliptic.P256()
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	case curve.Equal(secgNamedCurveP384):
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		return elliptic.P384()
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	case curve.Equal(secgNamedCurveP521):
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		return elliptic.P521()
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	}
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	return nil
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}
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func oidFromNamedCurve(curve elliptic.Curve) (secgNamedCurve, bool) {
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	switch curve {
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	case elliptic.P256():
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		return secgNamedCurveP256, true
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	case elliptic.P384():
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		return secgNamedCurveP384, true
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	case elliptic.P521():
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		return secgNamedCurveP521, true
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	}
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	return nil, false
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}
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// asnAlgorithmIdentifier represents the ASN.1 structure of the same name. See RFC
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// 5280, section 4.1.1.2.
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type asnAlgorithmIdentifier struct {
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	Algorithm  asn1.ObjectIdentifier
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	Parameters asn1.RawValue `asn1:"optional"`
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}
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func (a asnAlgorithmIdentifier) Cmp(b asnAlgorithmIdentifier) bool {
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	if len(a.Algorithm) != len(b.Algorithm) {
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		return false
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	}
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	for i, _ := range a.Algorithm {
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		if a.Algorithm[i] != b.Algorithm[i] {
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			return false
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		}
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	}
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	return true
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}
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type asnHashFunction asnAlgorithmIdentifier
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var (
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	oidSHA1   = asn1.ObjectIdentifier{1, 3, 14, 3, 2, 26}
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	oidSHA224 = doScheme(shaScheme, []int{4})
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	oidSHA256 = doScheme(shaScheme, []int{1})
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	oidSHA384 = doScheme(shaScheme, []int{2})
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	oidSHA512 = doScheme(shaScheme, []int{3})
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)
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func hashFromOID(oid asn1.ObjectIdentifier) func() hash.Hash {
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	switch {
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	case oid.Equal(oidSHA1):
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		return sha1.New
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	case oid.Equal(oidSHA224):
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		return sha256.New224
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	case oid.Equal(oidSHA256):
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		return sha256.New
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	case oid.Equal(oidSHA384):
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		return sha512.New384
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	case oid.Equal(oidSHA512):
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		return sha512.New
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	}
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	return nil
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}
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func oidFromHash(hash crypto.Hash) (asn1.ObjectIdentifier, bool) {
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	switch hash {
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	case crypto.SHA1:
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		return oidSHA1, true
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	case crypto.SHA224:
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		return oidSHA224, true
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	case crypto.SHA256:
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		return oidSHA256, true
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	case crypto.SHA384:
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		return oidSHA384, true
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	case crypto.SHA512:
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		return oidSHA512, true
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	default:
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		return nil, false
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	}
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}
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var (
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	asnAlgoSHA1 = asnHashFunction{
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		Algorithm: oidSHA1,
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	}
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	asnAlgoSHA224 = asnHashFunction{
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		Algorithm: oidSHA224,
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	}
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	asnAlgoSHA256 = asnHashFunction{
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		Algorithm: oidSHA256,
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	}
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	asnAlgoSHA384 = asnHashFunction{
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		Algorithm: oidSHA384,
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	}
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	asnAlgoSHA512 = asnHashFunction{
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		Algorithm: oidSHA512,
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	}
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)
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// type ASNasnSubjectPublicKeyInfo struct {
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//
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// }
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//
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type asnSubjectPublicKeyInfo struct {
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	Algorithm   asn1.ObjectIdentifier
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	PublicKey   asn1.BitString
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	Supplements ecpksSupplements `asn1:"optional"`
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}
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type asnECPKAlgorithms struct {
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	Type asn1.ObjectIdentifier
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}
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var idPublicKeyType = doScheme(ansiX962Scheme, []int{2})
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var idEcPublicKey = doScheme(idPublicKeyType, []int{1})
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var idEcPublicKeySupplemented = doScheme(idPublicKeyType, []int{0})
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func curveToRaw(curve elliptic.Curve) (rv asn1.RawValue, ok bool) {
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	switch curve {
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	case elliptic.P256(), elliptic.P384(), elliptic.P521():
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		raw := rawCurve(curve)
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		return asn1.RawValue{
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			Tag:       30,
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			Bytes:     raw[2:],
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			FullBytes: raw,
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		}, true
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	default:
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		return rv, false
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	}
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}
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func asnECPublicKeyType(curve elliptic.Curve) (algo asnAlgorithmIdentifier, ok bool) {
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	raw, ok := curveToRaw(curve)
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	if !ok {
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		return
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	} else {
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		return asnAlgorithmIdentifier{Algorithm: idEcPublicKey,
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			Parameters: raw}, true
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	}
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}
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type asnECPrivKeyVer int
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var asnECPrivKeyVer1 asnECPrivKeyVer = 1
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type asnPrivateKey struct {
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	Version asnECPrivKeyVer
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	Private []byte
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	Curve   secgNamedCurve `asn1:"optional"`
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	Public  asn1.BitString
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}
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var asnECDH = doScheme(secgScheme, []int{12})
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type asnECDHAlgorithm asnAlgorithmIdentifier
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var (
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	dhSinglePass_stdDH_sha1kdf = asnECDHAlgorithm{
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		Algorithm: doScheme(x963Scheme, []int{2}),
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	}
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	dhSinglePass_stdDH_sha256kdf = asnECDHAlgorithm{
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		Algorithm: doScheme(secgScheme, []int{11, 1}),
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	}
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	dhSinglePass_stdDH_sha384kdf = asnECDHAlgorithm{
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		Algorithm: doScheme(secgScheme, []int{11, 2}),
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	}
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	dhSinglePass_stdDH_sha224kdf = asnECDHAlgorithm{
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		Algorithm: doScheme(secgScheme, []int{11, 0}),
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	}
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	dhSinglePass_stdDH_sha512kdf = asnECDHAlgorithm{
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		Algorithm: doScheme(secgScheme, []int{11, 3}),
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	}
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)
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func (a asnECDHAlgorithm) Cmp(b asnECDHAlgorithm) bool {
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	if len(a.Algorithm) != len(b.Algorithm) {
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		return false
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	}
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	for i, _ := range a.Algorithm {
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		if a.Algorithm[i] != b.Algorithm[i] {
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			return false
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		}
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	}
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	return true
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}
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// asnNISTConcatenation is the only supported KDF at this time.
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type asnKeyDerivationFunction asnAlgorithmIdentifier
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var asnNISTConcatenationKDF = asnKeyDerivationFunction{
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	Algorithm: doScheme(secgScheme, []int{17, 1}),
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}
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func (a asnKeyDerivationFunction) Cmp(b asnKeyDerivationFunction) bool {
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	if len(a.Algorithm) != len(b.Algorithm) {
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		return false
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	}
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	for i, _ := range a.Algorithm {
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		if a.Algorithm[i] != b.Algorithm[i] {
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			return false
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		}
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	}
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	return true
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}
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var eciesRecommendedParameters = doScheme(secgScheme, []int{7})
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var eciesSpecifiedParameters = doScheme(secgScheme, []int{8})
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type asnECIESParameters struct {
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	KDF asnKeyDerivationFunction     `asn1:"optional"`
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	Sym asnSymmetricEncryption       `asn1:"optional"`
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	MAC asnMessageAuthenticationCode `asn1:"optional"`
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}
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type asnSymmetricEncryption asnAlgorithmIdentifier
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var (
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	aes128CTRinECIES = asnSymmetricEncryption{
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		Algorithm: doScheme(secgScheme, []int{21, 0}),
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	}
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	aes192CTRinECIES = asnSymmetricEncryption{
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		Algorithm: doScheme(secgScheme, []int{21, 1}),
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	}
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	aes256CTRinECIES = asnSymmetricEncryption{
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		Algorithm: doScheme(secgScheme, []int{21, 2}),
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	}
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)
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func (a asnSymmetricEncryption) Cmp(b asnSymmetricEncryption) bool {
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	if len(a.Algorithm) != len(b.Algorithm) {
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		return false
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	}
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	for i, _ := range a.Algorithm {
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		if a.Algorithm[i] != b.Algorithm[i] {
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			return false
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		}
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	}
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	return true
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}
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type asnMessageAuthenticationCode asnAlgorithmIdentifier
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var (
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	hmacFull = asnMessageAuthenticationCode{
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		Algorithm: doScheme(secgScheme, []int{22}),
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	}
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)
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func (a asnMessageAuthenticationCode) Cmp(b asnMessageAuthenticationCode) bool {
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						|
	if len(a.Algorithm) != len(b.Algorithm) {
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		return false
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						|
	}
 | 
						|
	for i, _ := range a.Algorithm {
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						|
		if a.Algorithm[i] != b.Algorithm[i] {
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			return false
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						|
		}
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	}
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	return true
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}
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type ecpksSupplements struct {
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	ECDomain      secgNamedCurve
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						|
	ECCAlgorithms eccAlgorithmSet
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}
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						|
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type eccAlgorithmSet struct {
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	ECDH  asnECDHAlgorithm   `asn1:"optional"`
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	ECIES asnECIESParameters `asn1:"optional"`
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}
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func marshalSubjectPublicKeyInfo(pub *PublicKey) (subj asnSubjectPublicKeyInfo, err error) {
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	subj.Algorithm = idEcPublicKeySupplemented
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	curve, ok := oidFromNamedCurve(pub.Curve)
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						|
	if !ok {
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						|
		err = ErrInvalidPublicKey
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						|
		return
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						|
	}
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	subj.Supplements.ECDomain = curve
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						|
	if pub.Params != nil {
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						|
		subj.Supplements.ECCAlgorithms.ECDH = paramsToASNECDH(pub.Params)
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						|
		subj.Supplements.ECCAlgorithms.ECIES = paramsToASNECIES(pub.Params)
 | 
						|
	}
 | 
						|
	pubkey := elliptic.Marshal(pub.Curve, pub.X, pub.Y)
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						|
	subj.PublicKey = asn1.BitString{
 | 
						|
		BitLength: len(pubkey) * 8,
 | 
						|
		Bytes:     pubkey,
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						|
	}
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						|
	return
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						|
}
 | 
						|
 | 
						|
// Encode a public key to DER format.
 | 
						|
func MarshalPublic(pub *PublicKey) ([]byte, error) {
 | 
						|
	subj, err := marshalSubjectPublicKeyInfo(pub)
 | 
						|
	if err != nil {
 | 
						|
		return nil, err
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						|
	}
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						|
	return asn1.Marshal(subj)
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						|
}
 | 
						|
 | 
						|
// Decode a DER-encoded public key.
 | 
						|
func UnmarshalPublic(in []byte) (pub *PublicKey, err error) {
 | 
						|
	var subj asnSubjectPublicKeyInfo
 | 
						|
 | 
						|
	if _, err = asn1.Unmarshal(in, &subj); err != nil {
 | 
						|
		return
 | 
						|
	}
 | 
						|
	if !subj.Algorithm.Equal(idEcPublicKeySupplemented) {
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						|
		err = ErrInvalidPublicKey
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						|
		return
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						|
	}
 | 
						|
	pub = new(PublicKey)
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						|
	pub.Curve = namedCurveFromOID(subj.Supplements.ECDomain)
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						|
	x, y := elliptic.Unmarshal(pub.Curve, subj.PublicKey.Bytes)
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						|
	if x == nil {
 | 
						|
		err = ErrInvalidPublicKey
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						|
		return
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						|
	}
 | 
						|
	pub.X = x
 | 
						|
	pub.Y = y
 | 
						|
	pub.Params = new(ECIESParams)
 | 
						|
	asnECIEStoParams(subj.Supplements.ECCAlgorithms.ECIES, pub.Params)
 | 
						|
	asnECDHtoParams(subj.Supplements.ECCAlgorithms.ECDH, pub.Params)
 | 
						|
	if pub.Params == nil {
 | 
						|
		if pub.Params = ParamsFromCurve(pub.Curve); pub.Params == nil {
 | 
						|
			err = ErrInvalidPublicKey
 | 
						|
		}
 | 
						|
	}
 | 
						|
	return
 | 
						|
}
 | 
						|
 | 
						|
func marshalPrivateKey(prv *PrivateKey) (ecprv asnPrivateKey, err error) {
 | 
						|
	ecprv.Version = asnECPrivKeyVer1
 | 
						|
	ecprv.Private = prv.D.Bytes()
 | 
						|
 | 
						|
	var ok bool
 | 
						|
	ecprv.Curve, ok = oidFromNamedCurve(prv.PublicKey.Curve)
 | 
						|
	if !ok {
 | 
						|
		err = ErrInvalidPrivateKey
 | 
						|
		return
 | 
						|
	}
 | 
						|
 | 
						|
	var pub []byte
 | 
						|
	if pub, err = MarshalPublic(&prv.PublicKey); err != nil {
 | 
						|
		return
 | 
						|
	} else {
 | 
						|
		ecprv.Public = asn1.BitString{
 | 
						|
			BitLength: len(pub) * 8,
 | 
						|
			Bytes:     pub,
 | 
						|
		}
 | 
						|
	}
 | 
						|
	return
 | 
						|
}
 | 
						|
 | 
						|
// Encode a private key to DER format.
 | 
						|
func MarshalPrivate(prv *PrivateKey) ([]byte, error) {
 | 
						|
	ecprv, err := marshalPrivateKey(prv)
 | 
						|
	if err != nil {
 | 
						|
		return nil, err
 | 
						|
	}
 | 
						|
	return asn1.Marshal(ecprv)
 | 
						|
}
 | 
						|
 | 
						|
// Decode a private key from a DER-encoded format.
 | 
						|
func UnmarshalPrivate(in []byte) (prv *PrivateKey, err error) {
 | 
						|
	var ecprv asnPrivateKey
 | 
						|
 | 
						|
	if _, err = asn1.Unmarshal(in, &ecprv); err != nil {
 | 
						|
		return
 | 
						|
	} else if ecprv.Version != asnECPrivKeyVer1 {
 | 
						|
		err = ErrInvalidPrivateKey
 | 
						|
		return
 | 
						|
	}
 | 
						|
 | 
						|
	privateCurve := namedCurveFromOID(ecprv.Curve)
 | 
						|
	if privateCurve == nil {
 | 
						|
		err = ErrInvalidPrivateKey
 | 
						|
		return
 | 
						|
	}
 | 
						|
 | 
						|
	prv = new(PrivateKey)
 | 
						|
	prv.D = new(big.Int).SetBytes(ecprv.Private)
 | 
						|
 | 
						|
	if pub, err := UnmarshalPublic(ecprv.Public.Bytes); err != nil {
 | 
						|
		return nil, err
 | 
						|
	} else {
 | 
						|
		prv.PublicKey = *pub
 | 
						|
	}
 | 
						|
 | 
						|
	return
 | 
						|
}
 | 
						|
 | 
						|
// Export a public key to PEM format.
 | 
						|
func ExportPublicPEM(pub *PublicKey) (out []byte, err error) {
 | 
						|
	der, err := MarshalPublic(pub)
 | 
						|
	if err != nil {
 | 
						|
		return
 | 
						|
	}
 | 
						|
 | 
						|
	var block pem.Block
 | 
						|
	block.Type = "ELLIPTIC CURVE PUBLIC KEY"
 | 
						|
	block.Bytes = der
 | 
						|
 | 
						|
	buf := new(bytes.Buffer)
 | 
						|
	err = pem.Encode(buf, &block)
 | 
						|
	if err != nil {
 | 
						|
		return
 | 
						|
	} else {
 | 
						|
		out = buf.Bytes()
 | 
						|
	}
 | 
						|
	return
 | 
						|
}
 | 
						|
 | 
						|
// Export a private key to PEM format.
 | 
						|
func ExportPrivatePEM(prv *PrivateKey) (out []byte, err error) {
 | 
						|
	der, err := MarshalPrivate(prv)
 | 
						|
	if err != nil {
 | 
						|
		return
 | 
						|
	}
 | 
						|
 | 
						|
	var block pem.Block
 | 
						|
	block.Type = "ELLIPTIC CURVE PRIVATE KEY"
 | 
						|
	block.Bytes = der
 | 
						|
 | 
						|
	buf := new(bytes.Buffer)
 | 
						|
	err = pem.Encode(buf, &block)
 | 
						|
	if err != nil {
 | 
						|
		return
 | 
						|
	} else {
 | 
						|
		out = buf.Bytes()
 | 
						|
	}
 | 
						|
	return
 | 
						|
}
 | 
						|
 | 
						|
// Import a PEM-encoded public key.
 | 
						|
func ImportPublicPEM(in []byte) (pub *PublicKey, err error) {
 | 
						|
	p, _ := pem.Decode(in)
 | 
						|
	if p == nil || p.Type != "ELLIPTIC CURVE PUBLIC KEY" {
 | 
						|
		return nil, ErrInvalidPublicKey
 | 
						|
	}
 | 
						|
 | 
						|
	pub, err = UnmarshalPublic(p.Bytes)
 | 
						|
	return
 | 
						|
}
 | 
						|
 | 
						|
// Import a PEM-encoded private key.
 | 
						|
func ImportPrivatePEM(in []byte) (prv *PrivateKey, err error) {
 | 
						|
	p, _ := pem.Decode(in)
 | 
						|
	if p == nil || p.Type != "ELLIPTIC CURVE PRIVATE KEY" {
 | 
						|
		return nil, ErrInvalidPrivateKey
 | 
						|
	}
 | 
						|
 | 
						|
	prv, err = UnmarshalPrivate(p.Bytes)
 | 
						|
	return
 | 
						|
}
 |