增加飞书webhook监听处理

utils/feishu/decrypt.go

@@ -0,0 +1,44 @@
+package feishu
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/sha256"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// 解密事件消息
+func DecryptFeiShuWebhookMsg(encryptData string, encryptKey string) ([]byte, error) {
+	buf, err := base64.StdEncoding.DecodeString(encryptData)
+	if err != nil {
+		return nil, fmt.Errorf("base64StdEncode Error[%v]", err)
+	}
+	if len(buf) < aes.BlockSize {
+		return nil, errors.New("cipher  too short")
+	}
+	keyBs := sha256.Sum256([]byte(encryptKey))
+	block, err := aes.NewCipher(keyBs[:sha256.Size])
+	if err != nil {
+		return nil, fmt.Errorf("AESNewCipher Error[%v]", err)
+	}
+	iv := buf[:aes.BlockSize]
+	buf = buf[aes.BlockSize:]
+	// CBC mode always works in whole blocks.
+	if len(buf)%aes.BlockSize != 0 {
+		return nil, errors.New("ciphertext is not a multiple of the block size")
+	}
+	mode := cipher.NewCBCDecrypter(block, iv)
+	mode.CryptBlocks(buf, buf)
+	n := strings.Index(string(buf), "{")
+	if n == -1 {
+		n = 0
+	}
+	m := strings.LastIndex(string(buf), "}")
+	if m == -1 {
+		m = len(buf) - 1
+	}
+	return buf[n : m+1], nil
+}

utils/feishu/verify.go

@@ -0,0 +1,22 @@
+package feishu
+
+import (
+	"crypto/sha256"
+	"fmt"
+	"strings"
+)
+
+// 计算签名
+func CalculateFeiShuWebhookSignature(timestamp, nonce, encryptKey string, body []byte) string {
+	var b strings.Builder
+	b.WriteString(timestamp)
+	b.WriteString(nonce)
+	b.WriteString(encryptKey)
+	b.Write(body) //bodystring 指整个请求体，不要在反序列化后再计算
+	bs := []byte(b.String())
+	h := sha256.New()
+	h.Write(bs)
+	bs = h.Sum(nil)
+	sig := fmt.Sprintf("%x", bs)
+	return sig
+}