Add kyc tool library

Signed-off-by: Asai Neko <sugar@sne.moe>

internal/kyc/crypto.go

@@ -0,0 +1,39 @@
+package kyc
+
+import (
+	"encoding/json"
+	"errors"
+	"nixcn-cms/internal/cryptography"
+
+	"github.com/spf13/viper"
+)
+
+func EncodeAES(kyc *KycInfo) (*string, error) {
+	plainJson, err := json.Marshal(kyc)
+	if err != nil {
+		return nil, err
+	}
+
+	aesKey := viper.GetString("secrets.kyc_info_key")
+	encrypted, err := cryptography.AESCBCEncrypt(plainJson, []byte(aesKey))
+	if err != nil {
+		return nil, err
+	}
+
+	return &encrypted, nil
+}
+
+func DecodeAES(cipherStr string) (*KycInfo, error) {
+	aesKey := viper.GetString("secrets.kyc_info_key")
+	plainBytes, err := cryptography.AESCBCDecrypt(cipherStr, []byte(aesKey))
+	if err != nil {
+		return nil, err
+	}
+
+	var kycInfo KycInfo
+	if err := json.Unmarshal(plainBytes, &kycInfo); err != nil {
+		return nil, errors.New("[KYC] invalid decrypted json")
+	}
+
+	return &kycInfo, nil
+}