init

Author: CC11001100

Diff for: .gitignore

@@ -0,0 +1 @@
+.idea

Diff for: atbash_cipher.go

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+package atbash_cipher
+
+import "unicode/utf8"
+
+// 因为是对称的，所以只需要做一张映射表就可以了，映射表是固定的
+var mappingTable = make(map[rune]rune, 0)
+
+func init() {
+	for index := 0; index < 26; index++ {
+		fromCharacter := rune('A' + index)
+		toCharacter := rune('A' + 25 - index)
+		// 同时做一个大小写的映射，通过空间换时间避免掉判断大小写
+		mappingTable[fromCharacter] = toCharacter
+		mappingTable[fromCharacter+32] = toCharacter + 32
+	}
+}
+
+// Encrypt 对明文进行atbash加密，英文字符会进行映射，其它字符会保持原样
+func Encrypt(plaintext string) string {
+	runeSlice := make([]rune, utf8.RuneCountInString(plaintext))
+	for index, character := range plaintext {
+		mappingToCharacter, exists := mappingTable[character]
+		if exists {
+			runeSlice[index] = mappingToCharacter
+		} else {
+			runeSlice[index] = character
+		}
+	}
+	return string(runeSlice)
+}
+
+// Decrypt 解密
+func Decrypt(ciphertext string) string {
+	return Encrypt(ciphertext)
+}

Diff for: atbash_cipher_test.go

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+package atbash_cipher
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestDecrypt(t *testing.T) {
+	plaintext := "abcdefg"
+	encryptResult := Encrypt(plaintext)
+	fmt.Println(encryptResult)
+	decryptResult := Decrypt(encryptResult)
+	fmt.Println(decryptResult)
+}

Diff for: go.mod

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+module github.com/cryptography-research-lab/go-atbash-cipher
+
+go 1.18