gost3410.Public/Private keys BE/LE marshalling

diff --git a/gogost.go b/gogost.go
index 496885e37b1a4f0908b69f0d3190d99d9f7ce974..b7d04d9692dc67496d71f12904ccdc1b0fae3fa9 100644 (file)
--- a/gogost.go
+++ b/gogost.go
@@ -1,4 +1,4 @@
 // Pure Go GOST cryptographic functions library.
 package gogost
 
-const Version = "5.12.0"
+const Version = "5.13.0"

diff --git a/gost3410/private.go b/gost3410/private.go
index 983d8d2849399c80a5617e8a5917180f9b96eb75..18549a29cf1f0f8718af45fef3059ba0183c7977 100644 (file)
--- a/gost3410/private.go
+++ b/gost3410/private.go
@@ -29,7 +29,7 @@ type PrivateKey struct {
 }
 
 // Unmarshal little-endian private key. "raw" must be c.PointSize() length.
-func NewPrivateKey(c *Curve, raw []byte) (*PrivateKey, error) {
+func NewPrivateKeyLE(c *Curve, raw []byte) (*PrivateKey, error) {
        pointSize := c.PointSize()
        if len(raw) != pointSize {
                return nil, fmt.Errorf("gogost/gost3410: len(key)=%d != %d", len(raw), pointSize)
@@ -45,6 +45,24 @@ func NewPrivateKey(c *Curve, raw []byte) (*PrivateKey, error) {
        return &PrivateKey{c, k.Mod(k, c.Q)}, nil
 }
 
+// Unmarshal big-endian private key. "raw" must be c.PointSize() length.
+func NewPrivateKeyBE(c *Curve, raw []byte) (*PrivateKey, error) {
+       pointSize := c.PointSize()
+       if len(raw) != pointSize {
+               return nil, fmt.Errorf("gogost/gost3410: len(key)=%d != %d", len(raw), pointSize)
+       }
+       k := bytes2big(raw)
+       if k.Cmp(zero) == 0 {
+               return nil, errors.New("gogost/gost3410: zero private key")
+       }
+       return &PrivateKey{c, k.Mod(k, c.Q)}, nil
+}
+
+// This is an alias for NewPrivateKeyLE().
+func NewPrivateKey(c *Curve, raw []byte) (*PrivateKey, error) {
+       return NewPrivateKeyLE(c, raw)
+}
+
 func GenPrivateKey(c *Curve, rand io.Reader) (*PrivateKey, error) {
        raw := make([]byte, c.PointSize())
        if _, err := io.ReadFull(rand, raw); err != nil {
@@ -54,12 +72,22 @@ func GenPrivateKey(c *Curve, rand io.Reader) (*PrivateKey, error) {
 }
 
 // Marshal little-endian private key. raw will be prv.C.PointSize() length.
-func (prv *PrivateKey) Raw() (raw []byte) {
+func (prv *PrivateKey) RawLE() (raw []byte) {
        raw = pad(prv.Key.Bytes(), prv.C.PointSize())
        reverse(raw)
        return raw
 }
 
+// Marshal big-endian private key. raw will be prv.C.PointSize() length.
+func (prv *PrivateKey) RawBE() (raw []byte) {
+       return pad(prv.Key.Bytes(), prv.C.PointSize())
+}
+
+// This is an alias for RawLE().
+func (prv *PrivateKey) Raw() []byte {
+       return prv.RawLE()
+}
+
 func (prv *PrivateKey) PublicKey() (*PublicKey, error) {
        x, y, err := prv.C.Exp(prv.Key, prv.C.X, prv.C.Y)
        if err != nil {

diff --git a/gost3410/public.go b/gost3410/public.go
index d2c01bc67acbd2990378f3bd3d1e578617a05e2b..ef5926bc336a03705ef44eaceb00f4656cc574bb 100644 (file)
--- a/gost3410/public.go
+++ b/gost3410/public.go
@@ -23,12 +23,11 @@ import (
 
 type PublicKey struct {
        C *Curve
-       X *big.Int
-       Y *big.Int
+       X, Y *big.Int
 }
 
 // Unmarshal LE(X)||LE(Y) public key. "raw" must be 2*c.PointSize() length.
-func NewPublicKey(c *Curve, raw []byte) (*PublicKey, error) {
+func NewPublicKeyLE(c *Curve, raw []byte) (*PublicKey, error) {
        pointSize := c.PointSize()
        key := make([]byte, 2*pointSize)
        if len(raw) != len(key) {
@@ -44,10 +43,28 @@ func NewPublicKey(c *Curve, raw []byte) (*PublicKey, error) {
        }, nil
 }
 
+// Unmarshal BE(X)||BE(Y) public key. "raw" must be 2*c.PointSize() length.
+func NewPublicKeyBE(c *Curve, raw []byte) (*PublicKey, error) {
+       pointSize := c.PointSize()
+       if len(raw) != 2*pointSize {
+               return nil, fmt.Errorf("gogost/gost3410: len(key) != %d", 2*pointSize)
+       }
+       return &PublicKey{
+               c,
+               bytes2big(raw[:pointSize]),
+               bytes2big(raw[pointSize:]),
+       }, nil
+}
+
+// This is an alias for NewPublicKeyLE().
+func NewPublicKey(c *Curve, raw []byte) (*PublicKey, error) {
+       return NewPublicKeyLE(c, raw)
+}
+
 // Marshal LE(X)||LE(Y) public key. raw will be 2*pub.C.PointSize() length.
-func (pub *PublicKey) Raw() (raw []byte) {
+func (pub *PublicKey) RawLE() []byte {
        pointSize := pub.C.PointSize()
-       raw = append(
+       raw := append(
                pad(pub.Y.Bytes(), pointSize),
                pad(pub.X.Bytes(), pointSize)...,
        )
@@ -55,6 +72,20 @@ func (pub *PublicKey) Raw() (raw []byte) {
        return raw
 }
 
+// Marshal BE(X)||BE(Y) public key. raw will be 2*pub.C.PointSize() length.
+func (pub *PublicKey) RawBE() []byte {
+       pointSize := pub.C.PointSize()
+       return append(
+               pad(pub.X.Bytes(), pointSize),
+               pad(pub.Y.Bytes(), pointSize)...,
+       )
+}
+
+// This is an alias for RawLE().
+func (pub *PublicKey) Raw() []byte {
+       return pub.RawLE()
+}
+
 func (pub *PublicKey) VerifyDigest(digest, signature []byte) (bool, error) {
        pointSize := pub.C.PointSize()
        if len(signature) != 2*pointSize {

diff --git a/news.texi b/news.texi
index 01a789a69f0e0cd85f146585cf568a543827d6ab..022b9a60c95fe610aca49f75d931d86b359fab14 100644 (file)
--- a/news.texi
+++ b/news.texi
@@ -3,6 +3,18 @@
 
 @table @strong
 
+@anchor{Release 5.13.0}
+@item 5.13.0
+    @itemize
+    @item
+        @code{gost3410.NewPublicKeyLE}, @code{gost3410.PublicKey.RawLE},
+        @code{gost3410.NewPublicKeyBE}, @code{gost3410.PublicKey.RawBE},
+        @code{gost3410.NewPrivateKeyLE}, @code{gost3410.PrivateKey.RawLE},
+        @code{gost3410.NewPrivateKeyBE}, @code{gost3410.PrivateKey.RawBE},
+        functions appeared, to simplify dealing with different endianness
+        keys serialisation
+    @end itemize
+
 @anchor{Release 5.12.0}
 @item 5.12.0
 Updated dependencies.