Add Aliyun Id2MetaVerify encode impl

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

pkgs/kyc/kyc.go

@@ -1,15 +1,19 @@
 package kyc
 
 import (
+	"crypto/md5"
 	"encoding/base64"
+	"encoding/hex"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"nixcn-cms/internal/cryptography"
+	"unicode/utf8"
 
 	"github.com/spf13/viper"
 )
 
-func EncodeB64Json(b64Json string) (*string, error) {
+func DecodeB64Json(b64Json string) (*KycInfo, error) {
 	rawJson, err := base64.StdEncoding.DecodeString(b64Json)
 	if err != nil {
 		return nil, errors.New("invalid base64 json")
@@ -20,6 +24,10 @@ func EncodeB64Json(b64Json string) (*string, error) {
 		return nil, errors.New("invalid json structure")
 	}
 
+	return &kyc, nil
+}
+
+func EncodeAES(kyc *KycInfo) (*string, error) {
 	plainJson, err := json.Marshal(kyc)
 	if err != nil {
 		return nil, err
@@ -48,3 +56,50 @@ func DecodeAES(cipherStr string) (*KycInfo, error) {
 
 	return &kyc, nil
 }
+
+func MD5AliEnc(kyc *KycInfo) (*MD5Ali, error) {
+	if kyc.Type != "Chinese" {
+		return nil, nil
+	}
+
+	// MD5 Legal Name rule: First Chinese char md5enc, remaining plain, at least 2 Chinese chars
+	if len(kyc.LegalName) < 2 || utf8.RuneCountInString(kyc.LegalName) < 2 {
+		return nil, fmt.Errorf("input string must have at least 2 Chinese characters")
+	}
+
+	lnFirstRune, size := utf8.DecodeRuneInString(kyc.LegalName)
+	if lnFirstRune == utf8.RuneError {
+		return nil, fmt.Errorf("invalid first character")
+	}
+
+	lnHash := md5.New()
+	lnHash.Write([]byte(string(lnFirstRune)))
+	lnFirstHash := hex.EncodeToString(lnHash.Sum(nil))
+
+	lnRemaining := kyc.LegalName[size:]
+
+	ln := lnFirstHash + lnRemaining
+
+	// MD5 Resident Id rule: First 6 char plain, middle birthdate md5enc, last 4 char plain, at least 18 chars
+	if len(kyc.ResidentId) < 18 {
+		return nil, fmt.Errorf("input string must have at least 18 characters")
+	}
+
+	ridPrefix := kyc.ResidentId[:6]
+	ridSuffix := kyc.ResidentId[len(kyc.ResidentId)-4:]
+	ridMiddle := kyc.ResidentId[6 : len(kyc.ResidentId)-4]
+
+	ridHash := md5.New()
+	ridHash.Write([]byte(ridMiddle))
+	ridMiddleHash := hex.EncodeToString(ridHash.Sum(nil))
+
+	rid := ridPrefix + ridMiddleHash + ridSuffix
+
+	// Aliyun Id2MetaVerify API Params
+	var kycAli MD5Ali
+	kycAli.ParamType = "md5"
+	kycAli.UserName = ln
+	kycAli.IdentifyNum = rid
+
+	return &kycAli, nil
+}

pkgs/kyc/types.go

@@ -5,3 +5,9 @@ type KycInfo struct {
 	LegalName  string `json:"legal_name"`
 	ResidentId string `json:"rsident_id"`
 }
+
+type MD5Ali struct {
+	ParamType   string `json:"param_type"`
+	IdentifyNum string `json:"identify_num"`
+	UserName    string `json:"user_name"`
+}