card_validate/
lib.rs

1//! card-validate detects and validates credit card numbers (type of card, number length and
2//! Luhn checksum).
3
4#[macro_use]
5extern crate lazy_static;
6extern crate regex;
7
8use regex::Regex;
9use std::ops::RangeInclusive;
10
11mod luhn;
12
13// The card formats have been copied from: https://github.com/faaez/creditcardutils/\
14//   blob/master/src/creditcardutils.coffee
15lazy_static! {
16    static ref VISAELECTRON_PATTERN_REGEX: Regex =
17        Regex::new(r"^4(026|17500|405|508|844|91[37])").unwrap();
18    static ref MAESTRO_PATTERN_REGEX: Regex = Regex::new(r"^(5(018|0[23]|[68])|6(39|7))").unwrap();
19    static ref FORBRUGSFORENINGEN_PATTERN_REGEX: Regex = Regex::new(r"^600").unwrap();
20    static ref DANKORT_PATTERN_REGEX: Regex = Regex::new(r"^5019").unwrap();
21    static ref VISA_PATTERN_REGEX: Regex = Regex::new(r"^4").unwrap();
22    static ref MIR_PATTERN_REGEX: Regex = Regex::new(r"^220[0-4]").unwrap();
23    static ref MASTERCARD_PATTERN_REGEX: Regex = Regex::new(r"^(5[1-5]|2[2-7])").unwrap();
24    static ref AMEX_PATTERN_REGEX: Regex = Regex::new(r"^3[47]").unwrap();
25    static ref DINERSCLUB_PATTERN_REGEX: Regex = Regex::new(r"^3[0689]").unwrap();
26    static ref DISCOVER_PATTERN_REGEX: Regex = Regex::new(r"^6([045]|22)").unwrap();
27    static ref UNIONPAY_PATTERN_REGEX: Regex = Regex::new(r"^(62|88)").unwrap();
28    static ref JCB_PATTERN_REGEX: Regex = Regex::new(r"^35").unwrap();
29    static ref OTHER_PATTERN_REGEX: Regex = Regex::new(r"^[0-9]+$").unwrap();
30}
31
32/// Card type. Maps recognized cards, and validates their pattern and length.
33#[derive(Clone, Copy, Debug, PartialEq)]
34#[non_exhaustive]
35pub enum Type {
36    // Debit
37    VisaElectron,
38    Maestro,
39    Forbrugsforeningen,
40    Dankort,
41
42    // Credit
43    Visa,
44    MIR,
45    MasterCard,
46    Amex,
47    DinersClub,
48    Discover,
49    UnionPay,
50    JCB,
51}
52
53/// Validate error. Maps possible validation errors (eg. card number format invalid).
54#[derive(Clone, Copy, Debug, PartialEq)]
55#[non_exhaustive]
56pub enum ValidateError {
57    InvalidFormat,
58    InvalidLength,
59    InvalidLuhn,
60    UnknownType,
61}
62
63impl Type {
64    pub fn name(&self) -> String {
65        match self {
66            Type::VisaElectron => "visaelectron",
67            Type::Maestro => "maestro",
68            Type::Forbrugsforeningen => "forbrugsforeningen",
69            Type::Dankort => "dankort",
70            Type::Visa => "visa",
71            Type::MIR => "mir",
72            Type::MasterCard => "mastercard",
73            Type::Amex => "amex",
74            Type::DinersClub => "dinersclub",
75            Type::Discover => "discover",
76            Type::UnionPay => "unionpay",
77            Type::JCB => "jcb",
78        }
79        .to_string()
80    }
81
82    fn pattern(&self) -> &Regex {
83        match self {
84            Type::VisaElectron => &VISAELECTRON_PATTERN_REGEX,
85            Type::Maestro => &MAESTRO_PATTERN_REGEX,
86            Type::Forbrugsforeningen => &FORBRUGSFORENINGEN_PATTERN_REGEX,
87            Type::Dankort => &DANKORT_PATTERN_REGEX,
88            Type::Visa => &VISA_PATTERN_REGEX,
89            Type::MIR => &MIR_PATTERN_REGEX,
90            Type::MasterCard => &MASTERCARD_PATTERN_REGEX,
91            Type::Amex => &AMEX_PATTERN_REGEX,
92            Type::DinersClub => &DINERSCLUB_PATTERN_REGEX,
93            Type::Discover => &DISCOVER_PATTERN_REGEX,
94            Type::UnionPay => &UNIONPAY_PATTERN_REGEX,
95            Type::JCB => &JCB_PATTERN_REGEX,
96        }
97    }
98
99    fn length(&self) -> RangeInclusive<usize> {
100        match self {
101            Type::VisaElectron => 16..=16,
102            Type::Maestro => 12..=19,
103            Type::Forbrugsforeningen => 16..=16,
104            Type::Dankort => 16..=16,
105            Type::Visa => 13..=16,
106            Type::MIR => 16..=19,
107            Type::MasterCard => 16..=16,
108            Type::Amex => 15..=15,
109            Type::DinersClub => 14..=14,
110            Type::Discover => 16..=16,
111            Type::JCB => 16..=16,
112            Type::UnionPay => 16..=19,
113        }
114    }
115
116    const fn all() -> &'static [Type] {
117        // Debit cards must come first, since they have more specific patterns than their
118        // credit-card equivalents.
119        &[
120            Type::VisaElectron,
121            Type::Maestro,
122            Type::Forbrugsforeningen,
123            Type::Dankort,
124            Type::Visa,
125            Type::MIR,
126            Type::MasterCard,
127            Type::Amex,
128            Type::DinersClub,
129            Type::Discover,
130            Type::UnionPay,
131            Type::JCB,
132        ]
133    }
134}
135
136impl ToString for Type {
137    fn to_string(&self) -> String {
138        match self {
139            Type::VisaElectron => "VisaElectron",
140            Type::Maestro => "Maestro",
141            Type::Forbrugsforeningen => "Forbrugsforeningen",
142            Type::Dankort => "Dankort",
143            Type::Visa => "Visa",
144            Type::MIR => "MIR",
145            Type::MasterCard => "MasterCard",
146            Type::Amex => "Amex",
147            Type::DinersClub => "DinersClub",
148            Type::Discover => "Discover",
149            Type::UnionPay => "UnionPay",
150            Type::JCB => "JCB",
151        }
152        .to_string()
153    }
154}
155
156/// Card validation utility. Used to validate a provided card number (length and Luhn checksum).
157#[derive(Clone, Copy, Debug, PartialEq)]
158pub struct Validate {
159    pub card_type: Type,
160}
161
162impl Validate {
163    pub fn from(card_number: &str) -> Result<Validate, ValidateError> {
164        let card_type = Validate::evaluate_type(card_number)?;
165
166        if !Validate::is_length_valid(card_number, &card_type) {
167            return Err(ValidateError::InvalidLength);
168        }
169        if !Validate::is_luhn_valid(card_number) {
170            return Err(ValidateError::InvalidLuhn);
171        }
172
173        Ok(Validate { card_type })
174    }
175
176    pub fn evaluate_type(card_number: &str) -> Result<Type, ValidateError> {
177        // Validate overall card number structure
178        if OTHER_PATTERN_REGEX.is_match(card_number) {
179            for card in Type::all() {
180                // Validate brand-specific card number structure
181                if card.pattern().is_match(card_number) {
182                    return Ok(*card);
183                }
184            }
185
186            Err(ValidateError::UnknownType)
187        } else {
188            Err(ValidateError::InvalidFormat)
189        }
190    }
191
192    pub fn is_length_valid(card_number: &str, card_type: &Type) -> bool {
193        let size = card_number.len();
194        let range = card_type.length();
195
196        range.contains(&size)
197    }
198
199    #[inline(always)]
200    pub fn is_luhn_valid(card_number: &str) -> bool {
201        luhn::valid(card_number)
202    }
203}
card_validate/lib.rs

card_validate/
lib.rs
