Encode and decode TCString

decode.go

@@ -0,0 +1,203 @@
+package iabtcf
+
+import (
+	"encoding/base64"
+	"fmt"
+	"strings"
+)
+
+func DecodeSegmentType(s string) int {
+	b, err := base64.RawURLEncoding.DecodeString(s)
+	if err != nil {
+		return 0
+	}
+
+	var e = NewTCEncoder(b)
+	return e.ReadInt(3)
+}
+
+func Decode(s string) (t *TCData, err error) {
+	t = &TCData{}
+	for _, v := range strings.Split(s, ".") {
+		segmentType := DecodeSegmentType(v)
+		if segmentType == 1 {
+			segment, err := DecodeDisclosedVendors(v)
+			if err == nil {
+				t.DisclosedVendors = segment
+			}
+		} else if segmentType == 2 {
+			segment, err := DecodeAllowedVendors(v)
+			if err == nil {
+				t.AllowedVendors = segment
+			}
+		} else if segmentType == 3 {
+			segment, err := DecodePubllisherTC(v)
+			if err == nil {
+				t.PublisherTC = segment
+			}
+		} else {
+			segment, err := DecodeCoreString(v)
+			if err == nil {
+				t.CoreString = segment
+			}
+		}
+	}
+
+	if t.CoreString == nil {
+		return nil, fmt.Errorf("invalid TC string")
+	}
+
+	return t, nil
+}
+
+func DecodeCoreString(s string) (c *CoreString, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = fmt.Errorf("%v", r)
+		}
+	}()
+
+	b, err := base64.RawURLEncoding.DecodeString(s)
+	if err != nil {
+		return nil, err
+	}
+
+	var e = NewTCEncoder(b)
+
+	c = &CoreString{}
+	c.Version = e.ReadInt(6)
+	c.Created = e.ReadTime()
+	c.LastUpdated = e.ReadTime()
+	c.CmpId = e.ReadInt(12)
+	c.CmpVersion = e.ReadInt(12)
+	c.ConsentScreen = e.ReadInt(6)
+	c.ConsentLanguage = e.ReadIsoCode()
+	c.VendorListVersion = e.ReadInt(12)
+	c.TcfPolicyVersion = e.ReadInt(6)
+	c.IsServiceSpecific = e.ReadBool()
+	c.UseNonStandardStacks = e.ReadBool()
+	c.SpecialFeatureOptIns = e.ReadBitField(12)
+	c.PurposesConsent = e.ReadBitField(24)
+	c.PurposesLITransparency = e.ReadBitField(24)
+	c.PurposeOneTreatment = e.ReadBool()
+	c.PublisherCC = e.ReadIsoCode()
+
+	c.MaxVendorId = e.ReadInt(16)
+	c.IsRangeEncoding = e.ReadBool()
+	if c.IsRangeEncoding {
+		c.NumEntries = e.ReadInt(12)
+		c.RangeEntries = e.ReadRangeEntries(uint(c.NumEntries))
+	} else {
+		c.VendorsConsent = e.ReadBitField(uint(c.MaxVendorId))
+	}
+
+	c.MaxVendorIdLI = e.ReadInt(16)
+	c.IsRangeEncodingLI = e.ReadBool()
+	if c.IsRangeEncodingLI {
+		c.NumEntriesLI = e.ReadInt(12)
+		c.RangeEntriesLI = e.ReadRangeEntries(uint(c.NumEntriesLI))
+	} else {
+		c.VendorsLITransparency = e.ReadBitField(uint(c.MaxVendorIdLI))
+	}
+
+	c.NumPubRestrictions = e.ReadInt(12)
+	c.PubRestrictions = e.ReadPubRestrictions(uint(c.NumPubRestrictions))
+
+	return c, nil
+}
+
+func DecodeDisclosedVendors(s string) (d *DisclosedVendors, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = fmt.Errorf("%v", r)
+		}
+	}()
+
+	b, err := base64.RawURLEncoding.DecodeString(s)
+	if err != nil {
+		return nil, err
+	}
+
+	var e = NewTCEncoder(b)
+
+	d = &DisclosedVendors{}
+	d.SegmentType = e.ReadInt(3)
+	d.MaxVendorId = e.ReadInt(16)
+	d.IsRangeEncoding = e.ReadBool()
+	if d.IsRangeEncoding {
+		d.NumEntries = e.ReadInt(12)
+		d.RangeEntries = e.ReadRangeEntries(uint(d.NumEntries))
+	} else {
+		d.DisclosedVendors = e.ReadBitField(uint(d.MaxVendorId))
+	}
+
+	if d.SegmentType != 1 {
+		err = fmt.Errorf("disclosed vendors segment type must be 1")
+		return nil, err
+	}
+
+	return d, nil
+}
+
+func DecodeAllowedVendors(s string) (a *AllowedVendors, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = fmt.Errorf("%v", r)
+		}
+	}()
+
+	b, err := base64.RawURLEncoding.DecodeString(s)
+	if err != nil {
+		return nil, err
+	}
+
+	var e = NewTCEncoder(b)
+
+	a = &AllowedVendors{}
+	a.SegmentType = e.ReadInt(3)
+	a.MaxVendorId = e.ReadInt(16)
+	a.IsRangeEncoding = e.ReadBool()
+	if a.IsRangeEncoding {
+		a.NumEntries = e.ReadInt(12)
+		a.RangeEntries = e.ReadRangeEntries(uint(a.NumEntries))
+	} else {
+		a.AllowedVendors = e.ReadBitField(uint(a.MaxVendorId))
+	}
+
+	if a.SegmentType != 2 {
+		err = fmt.Errorf("allowed vendors segment type must be 2")
+		return nil, err
+	}
+
+	return a, nil
+}
+
+func DecodePubllisherTC(s string) (p *PublisherTC, err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = fmt.Errorf("%v", r)
+		}
+	}()
+
+	b, err := base64.RawURLEncoding.DecodeString(s)
+	if err != nil {
+		return nil, err
+	}
+
+	var e = NewTCEncoder(b)
+
+	p = &PublisherTC{}
+	p.SegmentType = e.ReadInt(3)
+	p.PubPurposesConsent = e.ReadBitField(24)
+	p.PubPurposesLITransparency = e.ReadBitField(24)
+	p.NumCustomPurposes = e.ReadInt(6)
+	p.CustomPurposesConsent = e.ReadBitField(uint(p.NumCustomPurposes))
+	p.CustomPurposesLITransparency = e.ReadBitField(uint(p.NumCustomPurposes))
+
+	if p.SegmentType != 3 {
+		err = fmt.Errorf("allowed vendors segment type must be 3")
+		return nil, err
+	}
+
+	return p, nil
+}