Wrap errors from external libraries to prevent leaking sensitive information

encoding/ascii.go

@@ -2,6 +2,8 @@ package encoding
 
 import (
 	"fmt"
+
+	"github.com/moov-io/iso8583/utils"
 )
 
 var ASCII Encoder = &asciiEncoder{}
@@ -12,7 +14,7 @@ func (e asciiEncoder) Encode(data []byte) ([]byte, error) {
 	var out []byte
 	for _, r := range data {
 		if r > 127 {
-			return nil, fmt.Errorf("invalid ASCII char: '%s'", string(r))
+			return nil, utils.NewSafeError(fmt.Errorf("invalid ASCII char: '%s'", string(r)), "failed to perform ASCII encoding")
 		}
 		out = append(out, r)
 	}
@@ -29,7 +31,7 @@ func (e asciiEncoder) Decode(data []byte, length int) ([]byte, int, error) {
 	var out []byte
 	for _, r := range data {
 		if r > 127 {
-			return nil, 0, fmt.Errorf("invalid ASCII char: '%s'", string(r))
+			return nil, 0, utils.NewSafeError(fmt.Errorf("invalid ASCII char: '%s'", string(r)), "failed to perform ASCII decoding")
 		}
 		out = append(out, r)
 	}

encoding/ascii_test.go

@@ -18,6 +18,7 @@ func TestASCII(t *testing.T) {
 
 		_, _, err = enc.Decode([]byte("hello, 世界!"), 10)
 		require.Error(t, err)
+		require.EqualError(t, err, "failed to perform ASCII decoding")
 
 		_, _, err = enc.Decode([]byte("hello"), 6)
 		require.Error(t, err)
@@ -36,5 +37,6 @@ func TestASCII(t *testing.T) {
 
 		_, err = enc.Encode([]byte("hello, 世界!"))
 		require.Error(t, err)
+		require.EqualError(t, err, "failed to perform ASCII encoding")
 	})
 }

encoding/bcd.go

@@ -3,6 +3,7 @@ package encoding
 import (
 	"fmt"
 
+	"github.com/moov-io/iso8583/utils"
 	"github.com/yerden/go-util/bcd"
 )
 
@@ -19,7 +20,7 @@ func (e *bcdEncoder) Encode(src []byte) ([]byte, error) {
 	dst := make([]byte, bcd.EncodedLen(len(src)))
 	n, err := enc.Encode(dst, src)
 	if err != nil {
-		return nil, err
+		return nil, utils.NewSafeError(err, "failed to perform BCD encoding")
 	}
 
 	return dst[:n], nil
@@ -43,7 +44,7 @@ func (e *bcdEncoder) Decode(src []byte, length int) ([]byte, int, error) {
 	dst := make([]byte, decodedLen)
 	_, err := dec.Decode(dst, src[:read])
 	if err != nil {
-		return nil, 0, err
+		return nil, 0, utils.NewSafeError(err, "failed to perform BCD decoding")
 	}
 
 	// becase BCD is right aligned, we skip first bytes and

encoding/bcd_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
+	"github.com/yerden/go-util/bcd"
 )
 
 func TestBCD(t *testing.T) {
@@ -45,18 +46,26 @@ func TestBCD(t *testing.T) {
 		_, _, err = BCD.Decode(nil, 6)
 		require.Error(t, err)
 		require.EqualError(t, err, "not enough data to decode. expected len 3, got 0")
+
+		_, _, err = BCD.Decode([]byte{0xAB, 0xCD}, 4)
+		require.Error(t, err)
+		require.EqualError(t, err, "failed to perform BCD decoding")
+		require.ErrorIs(t, err, bcd.ErrBadBCD)
 	})
 
 	t.Run("Encode", func(t *testing.T) {
 		res, err := BCD.Encode([]byte("0110"))
-
 		require.NoError(t, err)
 		require.Equal(t, []byte{0x01, 0x10}, res)
 
 		// right justified by default
 		res, err = BCD.Encode([]byte("123"))
-
 		require.NoError(t, err)
 		require.Equal(t, []byte{0x01, 0x23}, res)
+
+		_, err = BCD.Encode([]byte("abc"))
+		require.Error(t, err)
+		require.EqualError(t, err, "failed to perform BCD encoding")
+		require.ErrorIs(t, err, bcd.ErrBadInput)
 	})
 }

encoding/bertlv.go

@@ -2,8 +2,9 @@ package encoding
 
 import (
 	"bytes"
-	"fmt"
 	"math/bits"
+
+	"github.com/moov-io/iso8583/utils"
 )
 
 // BER-TLV Tag encoder
@@ -34,7 +35,7 @@ func (berTLVEncoderTag) Decode(data []byte, length int) ([]byte, int, error) {
 
 	firstByte, err := r.ReadByte()
 	if err != nil {
-		return nil, 0, err
+		return nil, 0, utils.NewSafeError(err, "failed to read byte")
 	}
 	tagLenBytes := 1
 
@@ -46,7 +47,7 @@ func (berTLVEncoderTag) Decode(data []byte, length int) ([]byte, int, error) {
 	for shouldReadSubsequentByte {
 		b, err := r.ReadByte()
 		if err != nil {
-			return nil, tagLenBytes, fmt.Errorf("failed to decode TLV tag: %w", err)
+			return nil, tagLenBytes, utils.NewSafeError(err, "failed to decode TLV tag")
 		}
 		tagLenBytes++
 		// We read subsequent bytes to extract the tag by checking if

encoding/bertlv_test.go

@@ -1,6 +1,7 @@
 package encoding
 
 import (
+	"io"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -41,13 +42,27 @@ func TestBerTLVTag(t *testing.T) {
 }
 
 func TestBerTLVTag_DecodeOnInvalidInput(t *testing.T) {
+	t.Run("when bytes are nil", func(t *testing.T) {
+		_, _, err := BerTLVTag.Decode(nil, 0)
+		require.EqualError(t, err, "failed to read byte")
+		require.ErrorIs(t, err, io.EOF)
+	})
+
+	t.Run("when bytes are empty", func(t *testing.T) {
+		_, _, err := BerTLVTag.Decode([]byte{}, 0)
+		require.EqualError(t, err, "failed to read byte")
+		require.ErrorIs(t, err, io.EOF)
+	})
+
 	t.Run("when bits 5-1 of first byte set but 2nd byte does not exist", func(t *testing.T) {
 		_, _, err := BerTLVTag.Decode([]byte{0x5F}, 0)
-		require.EqualError(t, err, "failed to decode TLV tag: EOF")
+		require.EqualError(t, err, "failed to decode TLV tag")
+		require.ErrorIs(t, err, io.EOF)
 	})
 
 	t.Run("when MSB of 2nd byte set but 3nd byte does not exist", func(t *testing.T) {
 		_, _, err := BerTLVTag.Decode([]byte{0x5F, 0xA8}, 0)
-		require.EqualError(t, err, "failed to decode TLV tag: EOF")
+		require.EqualError(t, err, "failed to decode TLV tag")
+		require.ErrorIs(t, err, io.EOF)
 	})
 }

encoding/hex.go

@@ -2,8 +2,10 @@ package encoding
 
 import (
 	"encoding/hex"
-	"fmt"
+	"errors"
 	"strings"
+
+	"github.com/moov-io/iso8583/utils"
 )
 
 // HEX to ASCII encoder
@@ -31,14 +33,14 @@ func (e hexToASCIIEncoder) Decode(data []byte, length int) ([]byte, int, error)
 	// to read 8 HEX digits we have to read 16 ASCII chars (bytes)
 	read := hex.EncodedLen(length)
 	if read > len(data) {
-		return nil, 0, fmt.Errorf("not enough data to read")
+		return nil, 0, errors.New("not enough data to read")
 	}
 
 	out := make([]byte, length)
 
 	_, err := hex.Decode(out, data[:read])
 	if err != nil {
-		return nil, 0, err
+		return nil, 0, utils.NewSafeError(err, "failed to perform hex decoding")
 	}
 
 	return out, read, nil
@@ -56,7 +58,7 @@ func (e asciiToHexEncoder) Encode(data []byte) ([]byte, error) {
 
 	_, err := hex.Decode(out, data)
 	if err != nil {
-		return nil, err
+		return nil, utils.NewSafeError(err, "failed to perform hex decoding")
 	}
 
 	return out, nil
@@ -68,7 +70,7 @@ func (e asciiToHexEncoder) Encode(data []byte) ([]byte, error) {
 // 0x2A} would be converted to []byte("5F2A")
 func (e asciiToHexEncoder) Decode(data []byte, length int) ([]byte, int, error) {
 	if length > len(data) {
-		return nil, 0, fmt.Errorf("not enough data to read")
+		return nil, 0, errors.New("not enough data to read")
 	}
 
 	out := make([]byte, hex.EncodedLen(length))

encoding/hex_test.go

@@ -18,6 +18,10 @@ func TestHexToASCIIEncoder(t *testing.T) {
 	require.Error(t, err)
 	require.EqualError(t, err, "not enough data to read")
 
+	_, _, err = enc.Decode([]byte("nothex"), 3)
+	require.Error(t, err)
+	require.EqualError(t, err, "failed to perform hex decoding")
+
 	got, err = enc.Encode([]byte{0xAA, 0xBB, 0xCC})
 	require.NoError(t, err)
 	require.Equal(t, []byte("AABBCC"), got)
@@ -34,4 +38,8 @@ func TestASCIIToHexEncoder(t *testing.T) {
 	got, err = enc.Encode([]byte("aabbcc"))
 	require.NoError(t, err)
 	require.Equal(t, []byte{0xAA, 0xBB, 0xCC}, got)
+
+	_, err = enc.Encode([]byte("nothex"))
+	require.Error(t, err)
+	require.EqualError(t, err, "failed to perform hex decoding")
 }

encoding/lbcd.go

@@ -3,6 +3,7 @@ package encoding
 import (
 	"fmt"
 
+	"github.com/moov-io/iso8583/utils"
 	"github.com/yerden/go-util/bcd"
 )
 
@@ -19,7 +20,7 @@ func (e *lBCDEncoder) Encode(src []byte) ([]byte, error) {
 	dst := make([]byte, bcd.EncodedLen(len(src)))
 	n, err := enc.Encode(dst, src)
 	if err != nil {
-		return nil, err
+		return nil, utils.NewSafeError(err, "failed to perform BCD encoding")
 	}
 
 	return dst[:n], nil
@@ -42,7 +43,7 @@ func (e *lBCDEncoder) Decode(src []byte, length int) ([]byte, int, error) {
 
 	_, err := dec.Decode(dst, src)
 	if err != nil {
-		return nil, 0, err
+		return nil, 0, utils.NewSafeError(err, "failed to perform BCD decoding")
 	}
 
 	// because it's left aligned, we return data from

encoding/lbcd_test.go

@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/require"
+	"github.com/yerden/go-util/bcd"
 )
 
 func TestLBCD(t *testing.T) {
@@ -27,12 +28,21 @@ func TestLBCD(t *testing.T) {
 		_, _, err = LBCD.Decode(nil, 5)
 		require.Error(t, err)
 		require.EqualError(t, err, "not enough data to decode. expected len 3, got 0")
+
+		_, _, err = LBCD.Decode([]byte{0xAB, 0xCD}, 4)
+		require.Error(t, err)
+		require.EqualError(t, err, "failed to perform BCD decoding")
+		require.ErrorIs(t, err, bcd.ErrBadBCD)
 	})
 
 	t.Run("Encode", func(t *testing.T) {
 		res, err := LBCD.Encode([]byte("123"))
-
 		require.NoError(t, err)
 		require.Equal(t, []byte{0x12, 0x30}, res)
+
+		_, err = LBCD.Encode([]byte("abc"))
+		require.Error(t, err)
+		require.EqualError(t, err, "failed to perform BCD encoding")
+		require.ErrorIs(t, err, bcd.ErrBadInput)
 	})
 }

field/binary.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 
 	"github.com/moov-io/iso8583/encoding"
+	"github.com/moov-io/iso8583/utils"
 )
 
 var _ Field = (*Binary)(nil)
@@ -118,7 +119,7 @@ func (f *Binary) SetData(data interface{}) error {
 
 	bin, ok := data.(*Binary)
 	if !ok {
-		return fmt.Errorf("data does not match required *Binary type")
+		return errors.New("data does not match required *Binary type")
 	}
 
 	f.data = bin
@@ -137,19 +138,23 @@ func (f *Binary) MarshalJSON() ([]byte, error) {
 	if err != nil {
 		return nil, err
 	}
-	return json.Marshal(str)
+	bytes, err := json.Marshal(str)
+	if err != nil {
+		return nil, utils.NewSafeError(err, "failed to JSON marshal string to bytes")
+	}
+	return bytes, nil
 }
 
 func (f *Binary) UnmarshalJSON(b []byte) error {
 	var v string
 	err := json.Unmarshal(b, &v)
 	if err != nil {
-		return fmt.Errorf("failed to JSON unmarshal bytes to string: %w", err)
+		return utils.NewSafeError(err, "failed to JSON unmarshal bytes to string")
 	}
 
 	hex, err := encoding.ASCIIHexToBytes.Encode([]byte(v))
 	if err != nil {
-		return fmt.Errorf("failed to convert ASCII Hex string to bytes")
+		return utils.NewSafeError(err, "failed to convert ASCII Hex string to bytes")
 	}
 	return f.SetBytes(hex)
 }

field/composite.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/moov-io/iso8583/padding"
 	"github.com/moov-io/iso8583/sort"
+	"github.com/moov-io/iso8583/utils"
 )
 
 var _ Field = (*Composite)(nil)
@@ -304,7 +305,11 @@ func (f *Composite) String() (string, error) {
 // MarshalJSON implements the encoding/json.Marshaler interface.
 func (f *Composite) MarshalJSON() ([]byte, error) {
 	jsonData := OrderedMap(f.getSubfields())
-	return json.Marshal(jsonData)
+	bytes, err := json.Marshal(jsonData)
+	if err != nil {
+		return nil, utils.NewSafeError(err, "failed to JSON marshal map to bytes")
+	}
+	return bytes, nil
 }
 
 // UnmarshalJSON implements the encoding/json.Unmarshaler interface.
@@ -314,7 +319,7 @@ func (f *Composite) UnmarshalJSON(b []byte) error {
 	var data map[string]json.RawMessage
 	err := json.Unmarshal(b, &data)
 	if err != nil {
-		return err
+		return utils.NewSafeError(err, "failed to JSON unmarshal bytes to map")
 	}
 
 	for tag, rawMsg := range data {
@@ -328,7 +333,7 @@ func (f *Composite) UnmarshalJSON(b []byte) error {
 		}
 
 		if err := json.Unmarshal(rawMsg, subfield); err != nil {
-			return fmt.Errorf("failed to unmarshal subfield %v: %w", tag, err)
+			return utils.NewSafeErrorf(err, "failed to unmarshal subfield %v", tag)
 		}
 
 		f.setSubfields[tag] = struct{}{}

field/composite_test.go

@@ -3,6 +3,7 @@ package field
 import (
 	"fmt"
 	"reflect"
+	"strconv"
 	"testing"
 
 	"github.com/moov-io/iso8583/encoding"
@@ -382,7 +383,8 @@ func TestCompositePacking(t *testing.T) {
 		read, err := composite.Unpack([]byte("ABCDEF"))
 		require.Equal(t, 0, read)
 		require.Error(t, err)
-		require.EqualError(t, err, "failed to unpack subfield 3: failed to set bytes: failed to convert into number: strconv.Atoi: parsing \"EF\": invalid syntax")
+		require.EqualError(t, err, "failed to unpack subfield 3: failed to set bytes: failed to convert into number")
+		require.ErrorIs(t, err, strconv.ErrSyntax)
 	})
 
 	t.Run("Unpack returns an error on length of data exceeding max length", func(t *testing.T) {