laumann / isincodes

Validation of ISIN codes

isincodes

An ISIN code validator for your Rust projects, as fast as I've been able to make it.

The author found many ISIN code validators online, none of which actually provided an actual implementation (just an interface to use it). This implementation is pieced together from various sources, primarily [1] and [2].

An ISIN code is defined in ISO 6166 [5], as a 12-character alpha-numeric code. At some point in time you may want to validate that a given 12-character string (or byte sequence) is a valid ISIN code.

This implementation handles just validating that the structure of the ISIN is correct. Whether the given code is an actual ISIN code issued by the ISIN organization is not checked at all.

Usage

It is simple to use, there are two exposed functions:

fn compute_isin_checksum(input: &str) -> Option<(u8, u8)>
fn validate_isin(input: &str) -> bool

The latter just builds on the former. compute_isin_checksum() returns the computed ISIN code (a number between 0 and 9) and the check digit (the last digit of the code). For the ISIN to be considered valid the computed code must equal the check digit. validate_isin() just perfoms this check.

A None is returned if the format can be determined to be incorrect before computing the check digit. The checks are:

• Is it exactly 12 alphanumeric characters?
• Are the first two characters letters (in A to Z)?
• Is the last character a digit?

If these conditions hold up, a checksum can be computed and a Some((checksum, digit)) will be returned.

License

The code is licensed under the GNU GPLv3. See the COPYING file.

References

1. https://en.wikipedia.org/wiki/International_Securities_Identification_Number#Examples
2. https://rosettacode.org/wiki/Validate_International_Securities_Identification_Number
3. https://www.isin.org/
4. https://www.isincodes.net/validate-isin/
5. https://www.iso.org/standard/44811.html