code.pfad.fr/swift ↑

swift package

import "code.pfad.fr/swift"

package swift provides methods to check the validity of an IBAN (and retrieve the BIC for some countries). Play with the demo in the browser, powered by JS+Wasm.

Example 
// SPDX-FileCopyrightText: 2023 Olivier Charvin <git@olivier.pfad.fr>
//
// SPDX-License-Identifier: CC0-1.0

package main

import (
	"fmt"

	"code.pfad.fr/swift"
	"code.pfad.fr/swift/bic"
)

var germanTestIBAN = "DE75512108001245126199"

func main() {
	iban, err := swift.NewIBAN(germanTestIBAN, swift.CountryBelongsToSEPA())
	if err != nil {
		panic(err)
	}
	fmt.Println("IBAN:", iban.MaskedAndSpaced())
	fmt.Println("BIC: ", bic.FromIBAN(iban).String())
}

Output:

IBAN: DE75 512* **** **** ***1 99
BIC:  SOGEDEFFXXX

Index

Examples

Variables

❖ 
var ErrCountryNotInRegistry = errors.New("country is not listed in the IBAN registry")

ErrCountryNotInRegistry is returned when a country is not listed in the iban registry.

❖ 
var ErrCountryOutsideSEPA = errors.New("country is outside the Single Euro Payments Area (SEPA)")

ErrCountryOutsideSEPA is returned when a country does not belong to the Single Euro Payments Area.

type BIC

❖ 
type BIC struct {
	Institution string      // 4 letters
	CountryCode CountryCode // 2 letters (ISO 3166-1 alpha-2 code)
	Location    string      // 2 letters or digits
	Branch      string      // 3 letters or digits (optional)
}

BIC represents the routing information as specified by ISO 9362 (also known as Business Identifier Codes (BIC), SWIFT ID or SWIFT code, and SWIFT-BIC).

func NewBIC

❖ 
func NewBIC(s string) (BIC, error)

NewBIC uppercases a BIC and perform some basic checks (format and length). If the country code is unknown the BIC will be accepted, call CountryCode.BelongsToIBANRegistry or CountryCode.BelongsToSEPA to perform additional validation.

func (BIC) String

❖ 
func (b BIC) String() string

String returns the BIC.

type CheckDigitsError

❖ 
type CheckDigitsError struct {
	Expected      int
	Actual        int
	NationalCheck bool // true if the check failed at the country level (within the BBAN)
}

CheckDigitsError indicates that the checksum did not match the expected check digits.

func (CheckDigitsError) Error

❖ 
func (e CheckDigitsError) Error() string

type CountryCode

❖ 
type CountryCode string

CountryCode is the ISO 3166-1 alpha-2 code of the country (uppercase)

func (CountryCode) BelongsToIBANRegistry

❖ 
func (cc CountryCode) BelongsToIBANRegistry() bool

BelongsToIBANRegistry returns true if the country is listed in the iban registry https://www.swift.com/resource/iban-registry-pdf

func (CountryCode) BelongsToSEPA

❖ 
func (cc CountryCode) BelongsToSEPA() bool

BelongsToSEPA indicates if a country belongs to the Single Euro Payments Area according to https://www.swift.com/resource/iban-registry-pdf

type ExpectedCharType

❖ 
type ExpectedCharType format.ExpectedCharType
❖ 
const (
	ExpectedNoMoreChar         ExpectedCharType = format.NoMoreChar
	ExpectedUppercaseAlphaChar ExpectedCharType = format.UppercaseAlphaChar             // (A-Z)
	ExpectedAlphaChar          ExpectedCharType = format.AlphaChar                               // (a-z, A-Z)
	ExpectedNumericChar        ExpectedCharType = format.ExpectedNumericChar           // (0-9)
	ExpectedAlphaNumericChar   ExpectedCharType = format.ExpectedAlphaNumericChar // (a-z, A-Z, 0-9)
)

type FormatError

❖ 
type FormatError struct {
	Position int              // index in the submitted string where the error occurred
	Expected ExpectedCharType // expected type of character
	Got      string           // submitted character

	Part         string // part of the submitted string considered (all chars should conform to the expected type)
	PartPosition int    // start index of the part above
}

FormatError indicates that an unexpected character type was encountered.

func (FormatError) Error

❖ 
func (e FormatError) Error() string

type IBAN

❖ 
type IBAN struct {
	CountryCode CountryCode
	CheckDigits int
	BBAN        string
}

IBAN represents an International Bank Account Number

func NewIBAN

❖ 
func NewIBAN(s string, additionalRules ...IBANValidator) (IBAN, error)

NewIBAN sanitizes, parses and checks an IBAN (length, format, check digit sum). See CountryBelongsToIBANRegistry and CountryBelongsToSEPA to perform country code validation. See NationalFormatCheck to additionnally verify the national format.

func (IBAN) MaskedAndSpaced

❖ 
func (iban IBAN) MaskedAndSpaced() string

MaskedAndSpaced returns the spaced IBAN with only the first and last 3 characters of the BBAN visible (other chars are replaced with "*").

IBANs are not secret, but it shouldn't hurt to hide parts of them. Since BBANs are longer than 11 characters, at least 5 chars will be hidden (still partially recoverable using the leading check digits). Example: 

DE75 512* **** **** ***1 99

func (IBAN) Spaced

❖ 
func (iban IBAN) Spaced() string

Spaced returns the IBAN with spaces between every 4 characters.

func (IBAN) String

❖ 
func (iban IBAN) String() string

String returns the IBAN, without spaces

type IBANValidator

❖ 
type IBANValidator func(IBAN) error

IBANValidator makes additional checks on a given IBAN.

func CountryBelongsToIBANRegistry

❖ 
func CountryBelongsToIBANRegistry() IBANValidator

CountryBelongsToIBANRegistry ensures that the country is listed in the iban registry https://www.swift.com/resource/iban-registry-pdf

func CountryBelongsToSEPA

❖ 
func CountryBelongsToSEPA() IBANValidator

CountryBelongsToSEPA ensures that the country belongs to the Single Euro Payments Area according to https://www.swift.com/resource/iban-registry-pdf

func NationalFormatCheck

❖ 
func NationalFormatCheck() IBANValidator

NationalFormatCheck checks the national rules (format and check digits), if there is a registered BBANChecker for this country code.

type TooShortError

❖ 
type TooShortError struct {
	ActualLen   int
	ExpectedLen int
}

TooShortError indicates that the provided string is shorter than expected.

func (TooShortError) Error

❖ 
func (e TooShortError) Error() string

Source Files

bban.go bban_registry.go bic.go columns.go country.go iban.go

Directories

Path Synopsis
bic package bic computes the BIC from an IBAN (for supported countries).
cmd/iban iban analyses an International Bank Account Number (IBAN).
internal/format package format is used internally to describe the format of an IBAN.

Forge

https://codeberg.org/pfad.fr/swift

git clone 
https://codeberg.org/pfad.fr/swift.git
git@codeberg.org:pfad.fr/swift.git
code.pfad.fr/swift
main