utils.go raw
1 package utils
2
3 import (
4 "bytes"
5 "crypto"
6 "crypto/hmac"
7 "crypto/md5"
8 "crypto/rand"
9 "crypto/rsa"
10 "crypto/sha1"
11 "crypto/x509"
12 "encoding/base64"
13 "encoding/hex"
14 "fmt"
15 "hash"
16 "io"
17 mathrand "math/rand"
18 "net/url"
19 "os"
20 "runtime"
21 "strconv"
22 "sync/atomic"
23 "time"
24 )
25
26 type uuid [16]byte
27
28 const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
29
30 var hookRead = func(fn func(p []byte) (n int, err error)) func(p []byte) (n int, err error) {
31 return fn
32 }
33
34 var hookRSA = func(fn func(rand io.Reader, priv *rsa.PrivateKey, hash crypto.Hash, hashed []byte) ([]byte, error)) func(rand io.Reader, priv *rsa.PrivateKey, hash crypto.Hash, hashed []byte) ([]byte, error) {
35 return fn
36 }
37
38 // GetUUID returns a uuid
39 func GetUUID() (uuidHex string) {
40 uuid := newUUID()
41 uuidHex = hex.EncodeToString(uuid[:])
42 return
43 }
44
45 // RandStringBytes returns a rand string
46 func RandStringBytes(n int) string {
47 b := make([]byte, n)
48 for i := range b {
49 b[i] = letterBytes[mathrand.Intn(len(letterBytes))]
50 }
51 return string(b)
52 }
53
54 // ShaHmac1 return a string which has been hashed
55 func ShaHmac1(source, secret string) string {
56 key := []byte(secret)
57 hmac := hmac.New(sha1.New, key)
58 hmac.Write([]byte(source))
59 signedBytes := hmac.Sum(nil)
60 signedString := base64.StdEncoding.EncodeToString(signedBytes)
61 return signedString
62 }
63
64 // Sha256WithRsa return a string which has been hashed with Rsa
65 func Sha256WithRsa(source, secret string) string {
66 decodeString, err := base64.StdEncoding.DecodeString(secret)
67 if err != nil {
68 panic(err)
69 }
70 private, err := x509.ParsePKCS8PrivateKey(decodeString)
71 if err != nil {
72 panic(err)
73 }
74
75 h := crypto.Hash.New(crypto.SHA256)
76 h.Write([]byte(source))
77 hashed := h.Sum(nil)
78 signature, err := hookRSA(rsa.SignPKCS1v15)(rand.Reader, private.(*rsa.PrivateKey),
79 crypto.SHA256, hashed)
80 if err != nil {
81 panic(err)
82 }
83
84 return base64.StdEncoding.EncodeToString(signature)
85 }
86
87 // GetMD5Base64 returns a string which has been base64
88 func GetMD5Base64(bytes []byte) (base64Value string) {
89 md5Ctx := md5.New()
90 md5Ctx.Write(bytes)
91 md5Value := md5Ctx.Sum(nil)
92 base64Value = base64.StdEncoding.EncodeToString(md5Value)
93 return
94 }
95
96 // GetTimeInFormatISO8601 returns a time string
97 func GetTimeInFormatISO8601() (timeStr string) {
98 gmt := time.FixedZone("GMT", 0)
99
100 return time.Now().In(gmt).Format("2006-01-02T15:04:05Z")
101 }
102
103 // GetURLFormedMap returns a url encoded string
104 func GetURLFormedMap(source map[string]string) (urlEncoded string) {
105 urlEncoder := url.Values{}
106 for key, value := range source {
107 urlEncoder.Add(key, value)
108 }
109 urlEncoded = urlEncoder.Encode()
110 return
111 }
112
113 func newUUID() uuid {
114 ns := uuid{}
115 safeRandom(ns[:])
116 u := newFromHash(md5.New(), ns, RandStringBytes(16))
117 u[6] = (u[6] & 0x0f) | (byte(2) << 4)
118 u[8] = (u[8]&(0xff>>2) | (0x02 << 6))
119
120 return u
121 }
122
123 func newFromHash(h hash.Hash, ns uuid, name string) uuid {
124 u := uuid{}
125 h.Write(ns[:])
126 h.Write([]byte(name))
127 copy(u[:], h.Sum(nil))
128
129 return u
130 }
131
132 func safeRandom(dest []byte) {
133 if _, err := hookRead(rand.Read)(dest); err != nil {
134 panic(err)
135 }
136 }
137
138 func (u uuid) String() string {
139 buf := make([]byte, 36)
140
141 hex.Encode(buf[0:8], u[0:4])
142 buf[8] = '-'
143 hex.Encode(buf[9:13], u[4:6])
144 buf[13] = '-'
145 hex.Encode(buf[14:18], u[6:8])
146 buf[18] = '-'
147 hex.Encode(buf[19:23], u[8:10])
148 buf[23] = '-'
149 hex.Encode(buf[24:], u[10:])
150
151 return string(buf)
152 }
153
154 var processStartTime int64 = time.Now().UnixNano() / 1e6
155 var seqId int64 = 0
156
157 func getGID() uint64 {
158 // https://blog.sgmansfield.com/2015/12/goroutine-ids/
159 b := make([]byte, 64)
160 b = b[:runtime.Stack(b, false)]
161 b = bytes.TrimPrefix(b, []byte("goroutine "))
162 b = b[:bytes.IndexByte(b, ' ')]
163 n, _ := strconv.ParseUint(string(b), 10, 64)
164 return n
165 }
166
167 func GetNonce() (uuidHex string) {
168 routineId := getGID()
169 currentTime := time.Now().UnixNano() / 1e6
170 seq := atomic.AddInt64(&seqId, 1)
171 randNum := mathrand.Int63()
172 msg := fmt.Sprintf("%d-%d-%d-%d-%d", processStartTime, routineId, currentTime, seq, randNum)
173 h := md5.New()
174 h.Write([]byte(msg))
175 return hex.EncodeToString(h.Sum(nil))
176 }
177
178 // Get first non-empty value
179 func GetDefaultString(values ...string) string {
180 for _, v := range values {
181 if v != "" {
182 return v
183 }
184 }
185
186 return ""
187 }
188
189 // set back the memoried enviroment variables
190 type Rollback func()
191
192 func Memory(keys ...string) Rollback {
193 // remenber enviroment variables
194 m := make(map[string]string)
195 for _, key := range keys {
196 m[key] = os.Getenv(key)
197 }
198
199 return func() {
200 for _, key := range keys {
201 os.Setenv(key, m[key])
202 }
203 }
204 }
205