Remove pkg/errors dependency

Everything we used it for is provided by stdlib

context.go

@@ -6,9 +6,8 @@ import (
 	"crypto/hmac"
 	"crypto/sha1" // #nosec
 	"encoding/binary"
+	"fmt"
 	"hash"
-
-	"github.com/pkg/errors"
 )
 
 // ProtectionProfile specifies Cipher and AuthTag details, similar to TLS cipher suite
@@ -71,9 +70,9 @@ type Context struct {
 // CreateContext creates a new SRTP Context
 func CreateContext(masterKey, masterSalt []byte, profile ProtectionProfile) (c *Context, err error) {
 	if masterKeyLen := len(masterKey); masterKeyLen != keyLen {
-		return c, errors.Errorf("SRTP Master Key must be len %d, got %d", masterKey, keyLen)
+		return c, fmt.Errorf("SRTP Master Key must be len %d, got %d", masterKey, keyLen)
 	} else if masterSaltLen := len(masterSalt); masterSaltLen != saltLen {
-		return c, errors.Errorf("SRTP Salt must be len %d, got %d", saltLen, masterSaltLen)
+		return c, fmt.Errorf("SRTP Salt must be len %d, got %d", saltLen, masterSaltLen)
 	}
 
 	c = &Context{

go.mod

@@ -8,6 +8,5 @@ require (
 	github.com/pion/rtcp v1.2.1
 	github.com/pion/rtp v1.1.3
 	github.com/pion/transport v0.6.0
-	github.com/pkg/errors v0.8.1
 	github.com/stretchr/testify v1.3.0
 )

go.sum

@@ -10,8 +10,6 @@ github.com/pion/rtp v1.1.3 h1:GTYSTsSLF5vH+UqShGYQEBdoYasWjTTC9UeYglnUO+o=
 github.com/pion/rtp v1.1.3/go.mod h1:/l4cvcKd0D3u9JLs2xSVI95YkfXW87a3br3nqmVtSlE=
 github.com/pion/transport v0.6.0 h1:WAoyJg/6OI8dhCVFl/0JHTMd1iu2iHgGUXevptMtJ3U=
 github.com/pion/transport v0.6.0/go.mod h1:iWZ07doqOosSLMhZ+FXUTq+TamDoXSllxpbGcfkCmbE=
-github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
-github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=

srtcp_test.go

@@ -5,7 +5,6 @@ import (
 	"testing"
 
 	"github.com/pion/rtcp"
-	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -21,12 +20,12 @@ func TestRTCPLifecycle(t *testing.T) {
 	assert := assert.New(t)
 	encryptContext, err := CreateContext(rtcpTestMasterKey, rtcpTestMasterSalt, cipherContextAlgo)
 	if err != nil {
-		t.Error(errors.Wrap(err, "CreateContext failed"))
+		t.Errorf("CreateContext failed: %v", err)
 	}
 
 	decryptContext, err := CreateContext(rtcpTestMasterKey, rtcpTestMasterSalt, cipherContextAlgo)
 	if err != nil {
-		t.Error(errors.Wrap(err, "CreateContext failed"))
+		t.Errorf("CreateContext failed: %v", err)
 	}
 
 	decryptResult, err := decryptContext.DecryptRTCP(nil, rtcpTestEncrypted, nil)
@@ -48,13 +47,13 @@ func TestRTCPLifecycleInPlace(t *testing.T) {
 	encryptHeader := &rtcp.Header{}
 	encryptContext, err := CreateContext(rtcpTestMasterKey, rtcpTestMasterSalt, cipherContextAlgo)
 	if err != nil {
-		t.Error(errors.Wrap(err, "CreateContext failed"))
+		t.Errorf("CreateContext failed: %v", err)
 	}
 
 	decryptHeader := &rtcp.Header{}
 	decryptContext, err := CreateContext(rtcpTestMasterKey, rtcpTestMasterSalt, cipherContextAlgo)
 	if err != nil {
-		t.Error(errors.Wrap(err, "CreateContext failed"))
+		t.Errorf("CreateContext failed: %v", err)
 	}
 
 	// Copy packet, asserts that everything was done in place
@@ -93,13 +92,13 @@ func TestRTCPLifecyclePartialAllocation(t *testing.T) {
 	encryptHeader := &rtcp.Header{}
 	encryptContext, err := CreateContext(rtcpTestMasterKey, rtcpTestMasterSalt, cipherContextAlgo)
 	if err != nil {
-		t.Error(errors.Wrap(err, "CreateContext failed"))
+		t.Errorf("CreateContext failed: %v", err)
 	}
 
 	decryptHeader := &rtcp.Header{}
 	decryptContext, err := CreateContext(rtcpTestMasterKey, rtcpTestMasterSalt, cipherContextAlgo)
 	if err != nil {
-		t.Error(errors.Wrap(err, "CreateContext failed"))
+		t.Errorf("CreateContext failed: %v", err)
 	}
 
 	// Copy packet, asserts that partial buffers can be used

srtp.go

@@ -3,9 +3,9 @@ package srtp
 import (
 	"crypto/cipher"
 	"crypto/subtle"
+	"fmt"
 
 	"github.com/pion/rtp"
-	"github.com/pkg/errors"
 )
 
 func (c *Context) decryptRTP(dst []byte, ciphertext []byte, header *rtp.Header) ([]byte, error) {
@@ -27,7 +27,7 @@ func (c *Context) decryptRTP(dst []byte, ciphertext []byte, header *rtp.Header)
 	// See if the auth tag actually matches.
 	// We use a constant time comparison to prevent timing attacks.
 	if subtle.ConstantTimeCompare(actualTag, expectedTag) != 1 {
-		return nil, errors.Errorf("failed to verify auth tag")
+		return nil, fmt.Errorf("failed to verify auth tag")
 	}
 
 	// Write the plaintext header to the destination buffer.

srtp_test.go

@@ -5,7 +5,6 @@ import (
 	"testing"
 
 	"github.com/pion/rtp"
-	"github.com/pkg/errors"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -27,7 +26,7 @@ func TestKeyLen(t *testing.T) {
 	}
 
 	if _, err := CreateContext(make([]byte, keyLen), make([]byte, saltLen), cipherContextAlgo); err != nil {
-		t.Error(errors.Wrap(err, "CreateContext failed with a valid length key and salt"))
+		t.Errorf("CreateContext failed with a valid length key and salt: %v", err)
 	}
 }
 
@@ -41,26 +40,27 @@ func TestValidSessionKeys(t *testing.T) {
 
 	c, err := CreateContext(masterKey, masterSalt, cipherContextAlgo)
 	if err != nil {
-		t.Error(errors.Wrap(err, "CreateContext failed"))
+		t.Errorf("CreateContext failed: %v", err)
 	}
 
 	sessionKey, err := c.generateSessionKey(labelSRTPEncryption)
 	if err != nil {
-		t.Error(errors.Wrap(err, "generateSessionKey failed"))
+		t.Errorf("generateSessionKey failed: %v", err)
+
 	} else if !bytes.Equal(sessionKey, expectedSessionKey) {
 		t.Errorf("Session Key % 02x does not match expected % 02x", sessionKey, expectedSessionKey)
 	}
 
 	sessionSalt, err := c.generateSessionSalt(labelSRTPSalt)
 	if err != nil {
-		t.Error(errors.Wrap(err, "generateSessionSalt failed"))
+		t.Errorf("generateSessionSalt failed: %v", err)
 	} else if !bytes.Equal(sessionSalt, expectedSessionSalt) {
 		t.Errorf("Session Salt % 02x does not match expected % 02x", sessionSalt, expectedSessionSalt)
 	}
 
 	sessionAuthTag, err := c.generateSessionAuthTag(labelSRTPAuthenticationTag)
 	if err != nil {
-		t.Error(errors.Wrap(err, "generateSessionAuthTag failed"))
+		t.Errorf("generateSessionAuthTag failed: %v", err)
 	} else if !bytes.Equal(sessionAuthTag, expectedSessionAuthTag) {
 		t.Errorf("Session Auth Tag % 02x does not match expected % 02x", sessionAuthTag, expectedSessionAuthTag)
 	}
@@ -73,7 +73,7 @@ func TestValidPacketCounter(t *testing.T) {
 
 	c, err := CreateContext(masterKey, masterSalt, cipherContextAlgo)
 	if err != nil {
-		t.Error(errors.Wrap(err, "CreateContext failed"))
+		t.Errorf("CreateContext failed: %v", err)
 	}
 
 	s := &ssrcState{ssrc: 4160032510}
@@ -90,7 +90,7 @@ func TestRolloverCount(t *testing.T) {
 
 	c, err := CreateContext(masterKey, masterSalt, cipherContextAlgo)
 	if err != nil {
-		t.Error(errors.Wrap(err, "CreateContext failed"))
+		t.Errorf("CreateContext failed: %v", err)
 	}
 
 	s := &ssrcState{ssrc: defaultSsrc}
@@ -140,7 +140,7 @@ func TestRTPInvalidAuth(t *testing.T) {
 
 	invalidContext, err := CreateContext(masterKey, invalidSalt, cipherContextAlgo)
 	if err != nil {
-		t.Fatal(errors.Wrap(err, "CreateContext failed"))
+		t.Errorf("CreateContext failed: %v", err)
 	}
 
 	for _, testCase := range rtpTestCases {