🔗 Binding (WFN ↔ FS / URI)

This module binds a WFN to and from the two CPE serialized forms defined by NISTIR 7695: the 2.3 Formatted String (FS) and the 2.2 URI. Binding converts the logical values * (ANY) and - (NA) plus escaped component values into their wire representation; unbinding reverses it. Conversion helpers between the two forms are also provided.

🔗 BindToFS

func BindToFS(w *WFN) string

Binds a WFN to a CPE 2.3 FS formatted string, per NISTIR 7695. Each attribute is read via Get (so an unset attribute becomes ANY) and escaped with the FS rules. The result has 13 colon-separated parts beginning with cpe:2.3:. A nil WFN returns an empty string.

Parameter	Type	Description
w	*WFN	The WFN to bind

Return	Type	Description
#1	string	The CPE 2.3 FS string, or "" if w is nil

wfn := &cpeskills.WFN{Part: "a", Vendor: "microsoft", Product: "windows", Version: "10"}
fmt.Println(cpeskills.BindToFS(wfn)) // cpe:2.3:a:microsoft:windows:10:*:*:*:*:*:*:*

✂️ UnbindFS

func UnbindFS(fs string) (*WFN, error)

Unbinds a CPE 2.3 FS string back into a WFN. The input must start with cpe:2.3: and contain exactly 13 colon-separated components; each component is unescaped per the FS rules.

Parameter	Type	Description
fs	string	CPE 2.3 FS formatted string

Return	Type	Description
#1	*WFN	The unbound WFN, nil on error
#2	error	nil on success, otherwise a format error

wfn, err := cpeskills.UnbindFS("cpe:2.3:a:microsoft:windows:10:*:*:*:*:*:*:*")
if err != nil {
    panic(err)
}
fmt.Println(wfn.Vendor, wfn.Product) // microsoft windows

🔗 BindToURI

func BindToURI(w *WFN) string

Binds a WFN to a CPE 2.2 URI formatted string, per NISTIR 7695. The five main fields (part, vendor, product, version, update) are colon-separated after the cpe:/ prefix; extended attributes are packed with ~ and appended. A nil WFN returns an empty string.

Parameter	Type	Description
w	*WFN	The WFN to bind

Return	Type	Description
#1	string	The CPE 2.2 URI string, or "" if w is nil

wfn := &cpeskills.WFN{Part: "a", Vendor: "microsoft", Product: "windows", Version: "10"}
fmt.Println(cpeskills.BindToURI(wfn)) // cpe:/a:microsoft:windows:10

✂️ UnbindURI

func UnbindURI(uri string) (*WFN, error)

Unbinds a CPE 2.2 URI string back into a WFN. The input must start with cpe:/. The main fields are read positionally; an extended-attributes segment (containing ~) is unpacked into edition, language, sw_edition, target_sw, target_hw, and other.

Parameter	Type	Description
uri	string	CPE 2.2 URI formatted string

Return	Type	Description
#1	*WFN	The unbound WFN, nil on error
#2	error	nil on success, otherwise a format error

wfn, err := cpeskills.UnbindURI("cpe:/a:microsoft:windows:10")
if err != nil {
    panic(err)
}
fmt.Println(wfn.Part, wfn.Vendor, wfn.Product, wfn.Version) // a microsoft windows 10

🔁 ConvertURIToFS

func ConvertURIToFS(uri string) (string, error)

Converts a CPE 2.2 URI string into a CPE 2.3 FS string by unbinding to a WFN and then re-binding to FS.

Parameter	Type	Description
uri	string	CPE 2.2 URI formatted string

Return	Type	Description
#1	string	The converted CPE 2.3 FS string
#2	error	nil on success, otherwise the unbind error

fs, err := cpeskills.ConvertURIToFS("cpe:/a:microsoft:windows:10")
if err != nil {
    panic(err)
}
fmt.Println(fs) // cpe:2.3:a:microsoft:windows:10:*:*:*:*:*:*:*

🔁 ConvertFSToURI

func ConvertFSToURI(fs string) (string, error)

Converts a CPE 2.3 FS string into a CPE 2.2 URI string by unbinding to a WFN and then re-binding to URI.

Parameter	Type	Description
fs	string	CPE 2.3 FS formatted string

Return	Type	Description
#1	string	The converted CPE 2.2 URI string
#2	error	nil on success, otherwise the unbind error

uri, err := cpeskills.ConvertFSToURI("cpe:2.3:a:microsoft:windows:10:*:*:*:*:*:*:*")
if err != nil {
    panic(err)
}
fmt.Println(uri) // cpe:/a:microsoft:windows:10

📐 Binding Flow Diagram