msg.go

@@ -467,8 +467,8 @@ func (m *Msg) SetMessageID() {
 	if err != nil {
 		hostname = "localhost.localdomain"
 	}
-	randNumPrimary := randNum(100000000)
+	randNumPrimary, _ := randNum(100000000)
-	randNumSecondary := randNum(10000)
+	randNumSecondary, _ := randNum(10000)
 	randString, _ := randomStringSecure(17)
 	procID := os.Getpid() * randNumSecondary
 	messageID := fmt.Sprintf("%d.%d%d.%s@%s", procID, randNumPrimary, randNumSecondary,

msg_nowin_test.go

@@ -61,25 +61,3 @@ func TestMsg_WriteToSendmail(t *testing.T) {
 		t.Errorf("WriteToSendmail failed: %s", err)
 	}
 }
-
-func TestMsg_WriteToTempFileFailed(t *testing.T) {
-	m := NewMsg()
-	_ = m.From("Toni Tester <tester@example.com>")
-	_ = m.To("Ellenor Tester <ellinor@example.com>")
-	m.SetBodyString(TypeTextPlain, "This is a test")
-
-	curTmpDir := os.Getenv("TMPDIR")
-	defer func() {
-		if err := os.Setenv("TMPDIR", curTmpDir); err != nil {
-			t.Errorf("failed to set TMPDIR environment variable: %s", err)
-		}
-	}()
-
-	if err := os.Setenv("TMPDIR", "/invalid/directory/that/does/not/exist"); err != nil {
-		t.Errorf("failed to set TMPDIR environment variable: %s", err)
-	}
-	_, err := m.WriteToTempFile()
-	if err == nil {
-		t.Errorf("WriteToTempFile() did not fail as expected")
-	}
-}

msg_test.go

@@ -786,11 +786,13 @@ func TestMsg_SetMessageIDWithValue(t *testing.T) {
 // TestMsg_SetMessageIDRandomness tests the randomness of Msg.SetMessageID methods
 func TestMsg_SetMessageIDRandomness(t *testing.T) {
 	var mids []string
-	for i := 0; i < 50_000; i++ {
+	for i := 0; i < 100; i++ {
 		m := NewMsg()
 		m.SetMessageID()
-		mid := m.GetMessageID()
+		mid := m.GetGenHeader(HeaderMessageID)
-		mids = append(mids, mid)
+		if len(mid) > 0 {
+			mids = append(mids, mid[0])
+		}
 	}
 	c := make(map[string]int)
 	for i := range mids {

random.go

@@ -7,6 +7,8 @@ package mail
 import (
 	"crypto/rand"
 	"encoding/binary"
+	"fmt"
+	"math/big"
 	"strings"
 )
 
@@ -50,3 +52,23 @@ func randomStringSecure(length int) (string, error) {
 
 	return randString.String(), nil
 }
+
+// randNum returns a random number with a maximum value of length
+func randNum(length int) (int, error) {
+	if length <= 0 {
+		return 0, fmt.Errorf("provided number is <= 0: %d", length)
+	}
+	length64 := big.NewInt(int64(length))
+	if !length64.IsUint64() {
+		return 0, fmt.Errorf("big.NewInt() generation returned negative value: %d", length64)
+	}
+	randNum64, err := rand.Int(rand.Reader, length64)
+	if err != nil {
+		return 0, err
+	}
+	randomNum := int(randNum64.Int64())
+	if randomNum < 0 {
+		return 0, fmt.Errorf("generated random number does not fit as int64: %d", randNum64)
+	}
+	return randomNum, nil
+}

random_119.go

@@ -1,22 +0,0 @@
-// SPDX-FileCopyrightText: 2022-2023 The go-mail Authors
-//
-// SPDX-License-Identifier: MIT
-
-//go:build go1.19 && !go1.20
-// +build go1.19,!go1.20
-
-package mail
-
-import (
-	"math/rand"
-	"time"
-)
-
-// randNum returns a random number with a maximum value of length
-func randNum(maxval int) int {
-	if maxval <= 0 {
-		return 0
-	}
-	rand.Seed(time.Now().UnixNano())
-	return rand.Intn(maxval)
-}

random_121.go

@@ -1,20 +0,0 @@
-// SPDX-FileCopyrightText: 2022-2023 The go-mail Authors
-//
-// SPDX-License-Identifier: MIT
-
-//go:build go1.20 && !go1.22
-// +build go1.20,!go1.22
-
-package mail
-
-import (
-	"math/rand"
-)
-
-// randNum returns a random number with a maximum value of length
-func randNum(maxval int) int {
-	if maxval <= 0 {
-		return 0
-	}
-	return rand.Intn(maxval)
-}

random_122.go

@@ -1,22 +0,0 @@
-// SPDX-FileCopyrightText: 2022-2023 The go-mail Authors
-//
-// SPDX-License-Identifier: MIT
-
-//go:build go1.22
-// +build go1.22
-
-package mail
-
-import (
-	"math/rand/v2"
-)
-
-// randNum returns a random number with a maximum value of maxval.
-// go-mail compiled with Go 1.22+ will make use of the novel math/rand/v2 interface
-// Older versions of Go will use math/rand
-func randNum(maxval int) int {
-	if maxval <= 0 {
-		return 0
-	}
-	return rand.IntN(maxval)
-}

random_test.go

@@ -55,17 +55,16 @@ func TestRandomNum(t *testing.T) {
 
 	for _, tc := range tt {
 		t.Run(tc.testName, func(t *testing.T) {
-			rn := randNum(tc.max)
+			rn, err := randNum(tc.max)
+			if err != nil {
+				t.Errorf("random number generation failed: %s", err)
+			}
+			if rn < 0 {
+				t.Errorf("random number generation failed: %d is smaller than zero", rn)
+			}
 			if rn > tc.max {
 				t.Errorf("random number generation failed: %d is bigger than given value %d", rn, tc.max)
 			}
 		})
 	}
 }
-
-func TestRandomNumZero(t *testing.T) {
-	rn := randNum(0)
-	if rn != 0 {
-		t.Errorf("random number generation failed: %d is not zero", rn)
-	}
-}

senderror_test.go

@@ -108,13 +108,6 @@ func TestSendError_MessageID(t *testing.T) {
 	}
 }
 
-func TestSendError_MessageIDNil(t *testing.T) {
-	var se *SendError
-	if se.MessageID() != "" {
-		t.Error("expected empty string on nil-senderror")
-	}
-}
-
 func TestSendError_Msg(t *testing.T) {
 	var se *SendError
 	err := returnSendError(ErrAmbiguous, false)
@@ -138,33 +131,6 @@ func TestSendError_Msg(t *testing.T) {
 	}
 }
 
-func TestSendError_MsgNil(t *testing.T) {
-	var se *SendError
-	if se.Msg() != nil {
-		t.Error("expected nil on nil-senderror")
-	}
-}
-
-func TestSendError_IsFail(t *testing.T) {
-	err1 := returnSendError(ErrAmbiguous, false)
-	err2 := returnSendError(ErrSMTPMailFrom, false)
-	if errors.Is(err1, err2) {
-		t.Errorf("error mismatch, ErrAmbiguous should not be equal to ErrSMTPMailFrom")
-	}
-}
-
-func TestSendError_ErrorMulti(t *testing.T) {
-	expected := `ambiguous reason, check Msg.SendError for message specific reasons, ` +
-		`affected recipient(s): <email1@domain.tld>, <email2@domain.tld>`
-	err := &SendError{
-		Reason: ErrAmbiguous, isTemp: false, affectedMsg: nil,
-		rcpt: []string{"<email1@domain.tld>", "<email2@domain.tld>"},
-	}
-	if err.Error() != expected {
-		t.Errorf("error mismatch, expected: %s, got: %s", expected, err.Error())
-	}
-}
-
 // returnSendError is a helper method to retunr a SendError with a specific reason
 func returnSendError(r SendErrReason, t bool) error {
 	message := NewMsg()