init: v1.0.0

sm/sm4/cipher.go

@@ -0,0 +1,75 @@
+///
+/// Copyright (c) 2018 xdx. All rights reserved.
+///
+/// \file: cipher.go
+///
+/// \brief: SM4's Block interface and its implements
+///
+/// \author: xdx
+///
+
+package sm4
+
+import (
+	"crypto/cipher"
+
+	"xdx.jelly/xgcl/gerrors"
+)
+
+// BlockSize is the SM4 block size in bytes.
+const BlockSize = 16
+
+// NewCipher creates and returns a new cipher.Block.
+// it call the newCipher of each platform
+func NewCipher(key []byte) (cipher.Block, error) {
+	if len(key) < BlockSize {
+		return nil, gerrors.WithAnnotatingf(ErrInvalidInput, "input key size is %d, want %d", len(key), BlockSize)
+	}
+	// newCipher is defined on different arch.
+	return newCipher(key)
+}
+
+// newCipherGeneric creates and returns a new cipher.Block.
+func newCipherGeneric(key []byte) (cipher.Block, error) {
+	cp := new(sm4Cipher)
+	// gen keys
+	expandKey(key, cp.encKey[:], cp.decKey[:])
+	return cp, nil
+}
+
+// sm4Cipher is an instance of cipher.Block interface
+type sm4Cipher struct {
+	encKey [32]uint32
+	decKey [32]uint32
+}
+
+// Clear implements the Clearable interface
+func (c *sm4Cipher) Clear() {
+	for i := 0; i < len(c.decKey); i++ {
+		c.decKey[i] = 0
+		c.encKey[i] = 0
+	}
+}
+
+func (c *sm4Cipher) BlockSize() int { return BlockSize }
+
+// 调用前应保证输入一个block
+func (c *sm4Cipher) Encrypt(dst, src []byte) {
+	if len(src) < BlockSize {
+		panic("xdx.jelly/xgcl/sm/sm4/Encrypt: input not full block")
+	}
+	if len(dst) < BlockSize {
+		panic("xdx.jelly/xgcl/sm/sm4/Encrypt: output not full block")
+	}
+	encryptBlockGo(c.encKey[:], dst, src)
+}
+
+func (c *sm4Cipher) Decrypt(dst, src []byte) {
+	if len(src) < BlockSize {
+		panic("xdx.jelly/xgcl/sm/sm4/Decrypt: input not full block")
+	}
+	if len(dst) < BlockSize {
+		panic("xdx.jelly/xgcl/sm/sm4/Decrypt: output not full block")
+	}
+	decryptBlockGo(c.decKey[:], dst, src)
+}