Lowercase

When the lowercase operation is applied to (), the resulting character will be ().

It can pose a risk if the operation is applied during a security control.

How to encode

The encoding required for will be different based on the entrypoint targeted.

'faceboo\u212Aea.com'.ToLower() == 'faceboo\u212Aea.com'

strings.ToLower("adm\u0130n@gosecure.ca") == "admin@gosecure.ca"

'zac\u212A@gosecure.ca'.toLowerCase() == 'zack@gosecure.ca'
'admin@i\u212Aea.com'.toLowerCase() == 'admin@ikea.com'

'zac\u212A@gosecure.ca'.lower() == 'zack@gosecure.ca'
'admin@faceboo\u212A.com'.lower() == 'admin@facebook.com'

'jac\u212A@gosecure.ca'.downcase == 'jack@gosecure.ca'
'admin@v\u212A.com'.downcase == 'admin@vk.com'

Uppercase

When the uppercase operation is applied to (), the resulting character will be ().

It can pose a risk if the operation is applied during a security control.

How to encode

The encoding required for will be different based on the entrypoint targeted.

"north\u017Fec".ToUpper() == "NORTHSEC"

strings.ToUpper("\u017FYSTEM") == "SYSTEM"
strings.ToUpper("ADM\u0131N") == "ADMIN"

"\u017FYSTEM".toUpperCase() == "SYSTEM"
"ADM\u0131N".toUpperCase() == "ADMIN"

"te\uFB06".upper() == 'TEST'

"te\uFB06".upcase == "TEST"

References

Normalization NFC (Canonical equivalence)

When the normalization operation is applied to (), the resulting character will be ().

Normalization is the process of transforming a sequence of characters to equivalent characters. It is usually applied to do a comparison between two strings. It is used in context where extended Unicode characters need to be simplified. Canonical equivalence (NFC/NFD) means that two characters represent the same character. [Source:unicode.org]

How to encode

The encoding required for will be different based on the entrypoint targeted.

input.Normalize(NormalizationForm.FormC);

import (
    "golang.org/x/text/unicode/norm"
)
norm.NFC.String(input)

import java.text.Normalizer
Normalizer.normalize(input, Normalizer.Form.NFC)

import unicodedata
unicodedata.normalize('NFC', input)

input.unicode_normalize(:nfc)

References

Normalization NFKC (Compatibility equivalence)

When the normalization operation is applied to (), the resulting character will be ().

Normalization is the process of transforming a sequence of characters to equivalent characters. It is usually applied to do a comparison between two strings. It is used in context where extended Unicode characters need to be simplified. Compatibility equivalence (NFC/NFD) means that two characters represent the same character. It is less strict than canonical equivalence. Exponents are equivalent to their normal form. (⁵ == 5) Multi-components characters are also equivalent to their decomposed form. (℻ (U+213B) == F A X (U+0046 + U+0041 + U+0058)) [Source:unicode.org]

How to encode

The encoding required for will be different based on the entrypoint targeted.

input.Normalize(NormalizationForm.FormKC);

import (
    "golang.org/x/text/unicode/norm"
)
norm.NFKC.String(input)

import java.text.Normalizer
Normalizer.normalize(input, Normalizer.Form.NFKC)

import unicodedata
unicodedata.normalize('NFKC', input)

input.unicode_normalize(:nfkc)

References