585 lines
14 KiB
Go
585 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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"github.com/ethereum/go-ethereum/crypto/secp256k1"
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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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secgNamedCurveS256 = secgNamedCurve{1, 3, 132, 0, 10}
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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(secgNamedCurveS256):
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return secp256k1.S256()
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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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case secp256k1.S256():
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return secgNamedCurveS256, 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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}
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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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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)
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}
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pubkey := elliptic.Marshal(pub.Curve, pub.X, pub.Y)
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subj.PublicKey = asn1.BitString{
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BitLength: len(pubkey) * 8,
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Bytes: pubkey,
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}
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return
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}
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// Encode a public key to DER format.
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func MarshalPublic(pub *PublicKey) ([]byte, error) {
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subj, err := marshalSubjectPublicKeyInfo(pub)
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if err != nil {
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return nil, err
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}
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return asn1.Marshal(subj)
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}
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// Decode a DER-encoded public key.
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func UnmarshalPublic(in []byte) (pub *PublicKey, err error) {
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var subj asnSubjectPublicKeyInfo
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if _, err = asn1.Unmarshal(in, &subj); err != nil {
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return
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}
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if !subj.Algorithm.Equal(idEcPublicKeySupplemented) {
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err = ErrInvalidPublicKey
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return
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}
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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 {
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err = ErrInvalidPublicKey
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return
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}
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pub.X = x
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pub.Y = y
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pub.Params = new(ECIESParams)
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asnECIEStoParams(subj.Supplements.ECCAlgorithms.ECIES, pub.Params)
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asnECDHtoParams(subj.Supplements.ECCAlgorithms.ECDH, pub.Params)
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if pub.Params == nil {
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if pub.Params = ParamsFromCurve(pub.Curve); pub.Params == nil {
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err = ErrInvalidPublicKey
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}
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}
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return
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}
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func marshalPrivateKey(prv *PrivateKey) (ecprv asnPrivateKey, err error) {
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ecprv.Version = asnECPrivKeyVer1
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ecprv.Private = prv.D.Bytes()
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var ok bool
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ecprv.Curve, ok = oidFromNamedCurve(prv.PublicKey.Curve)
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if !ok {
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err = ErrInvalidPrivateKey
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return
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}
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var pub []byte
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if pub, err = MarshalPublic(&prv.PublicKey); err != nil {
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return
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} else {
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ecprv.Public = asn1.BitString{
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BitLength: len(pub) * 8,
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Bytes: pub,
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}
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}
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return
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}
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// Encode a private key to DER format.
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func MarshalPrivate(prv *PrivateKey) ([]byte, error) {
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ecprv, err := marshalPrivateKey(prv)
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if err != nil {
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return nil, err
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}
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return asn1.Marshal(ecprv)
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}
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// Decode a private key from a DER-encoded format.
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func UnmarshalPrivate(in []byte) (prv *PrivateKey, err error) {
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var ecprv asnPrivateKey
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if _, err = asn1.Unmarshal(in, &ecprv); err != nil {
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return
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} else if ecprv.Version != asnECPrivKeyVer1 {
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err = ErrInvalidPrivateKey
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return
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}
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privateCurve := namedCurveFromOID(ecprv.Curve)
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if privateCurve == nil {
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err = ErrInvalidPrivateKey
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return
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}
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prv = new(PrivateKey)
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prv.D = new(big.Int).SetBytes(ecprv.Private)
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if pub, err := UnmarshalPublic(ecprv.Public.Bytes); err != nil {
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return nil, err
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} else {
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prv.PublicKey = *pub
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}
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return
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}
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// Export a public key to PEM format.
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func ExportPublicPEM(pub *PublicKey) (out []byte, err error) {
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der, err := MarshalPublic(pub)
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if err != nil {
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return
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}
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var block pem.Block
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block.Type = "ELLIPTIC CURVE PUBLIC KEY"
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block.Bytes = der
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|
|
|
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
|
|
}
|