Struct password_hash::Value

pub struct Value<'a>(_);

Algorithm parameter value string.

Parameter values are defined in the PHC string format specification.

Constraints

• ASCII-encoded string consisting of the characters [a-zA-Z0-9/+.-] (lowercase letters, digits, and the minus sign)
• Minimum length: 0 (i.e. empty values are allowed)
• Maximum length: 48 ASCII characters (i.e. 48-bytes)

Additional Notes

The PHC spec allows for algorithm-defined maximum lengths for parameter values, however in the interest of interoperability this library defines a Value::max_len of 48 ASCII characters.

Implementations

impl<'a> Value<'a>

pub const fn max_len() -> usize

Maximum length of an Value - 48 ASCII characters (i.e. 48-bytes).

This value is selected based on the maximum value size used in the Argon2 Encoding as described in the PHC string format specification. Namely the data parameter, when encoded as B64, can be up to 43 characters.

This implementation rounds that up to 48 as a safe maximum limit.

pub fn new(input: &'a str) -> Result<Self, ParseError>

Parse a Value from the provided str, validating it according to the PHC string format's rules.

pub fn b64_decode<'b>(&self, buf: &'b mut [u8]) -> Result<&'b [u8], B64Error>

Attempt to decode a b64-encoded Value, writing the decoded result into the provided buffer, and returning a slice of the buffer containing the decoded result on success.

Examples of "B64"-encoded parameters in practice are the keyid and data parameters used by the Argon2 Encoding as described in the PHC string format specification.

pub fn as_str(&self) -> &'a str

Borrow this value as a str.

pub fn as_bytes(&self) -> &'a [u8]

Borrow this value as bytes.

pub fn len(&self) -> usize

Get the length of this value in ASCII characters.

pub fn is_empty(&self) -> bool

Is this value empty?

pub fn decimal(&self) -> Result<Decimal, ParseError>

Attempt to parse this Value as a PHC-encoded decimal (i.e. integer).

Decimal values are integers which follow the rules given in the "Decimal Encoding" section of the PHC string format specification.

The decimal encoding rules are as follows:

For an integer value x, its decimal encoding consist in the following:

• If x < 0, then its decimal encoding is the minus sign - followed by the decimal encoding of -x.
• If x = 0, then its decimal encoding is the single character 0.
• If x > 0, then its decimal encoding is the smallest sequence of ASCII digits that matches its value (i.e. there is no leading zero).

Thus, a value is a valid decimal for an integer x if and only if all of the following hold true:

• The first character is either a - sign, or an ASCII digit.
• All characters other than the first are ASCII digits.
• If the first character is - sign, then there is at least another character, and the second character is not a 0.
• If the string consists in more than one character, then the first one cannot be a 0.

Note: this implementation does not support negative decimals despite them being allowed per the spec above. If you need to parse a negative number, please parse it from the string representation directly e.g. value.as_str().parse::<i32>()

pub fn is_decimal(&self) -> bool

Does this value parse successfully as a decimal?

Trait Implementations

impl<'a> AsRef<str> for Value<'a>

fn as_ref(&self) -> &str

Performs the conversion.

impl<'a> Clone for Value<'a>

fn clone(&self) -> Value<'a>

Returns a copy of the value.

pub fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Copy for Value<'a>

impl<'a> Debug for Value<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Display for Value<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Eq for Value<'a>

impl<'a> Hash for Value<'a>

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

pub fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<'a> Ord for Value<'a>

fn cmp(&self, other: &Value<'a>) -> Ordering

This method returns an Ordering between self and other.

#[must_use]pub fn max(self, other: Self) -> Self

Compares and returns the maximum of two values.

#[must_use]pub fn min(self, other: Self) -> Self

Compares and returns the minimum of two values.

#[must_use]pub fn clamp(self, min: Self, max: Self) -> Self

Restrict a value to a certain interval.

impl<'a> PartialEq<Value<'a>> for Value<'a>

fn eq(&self, other: &Value<'a>) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Value<'a>) -> bool

This method tests for !=.

impl<'a> PartialOrd<Value<'a>> for Value<'a>

fn partial_cmp(&self, other: &Value<'a>) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Value<'a>) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Value<'a>) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Value<'a>) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Value<'a>) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a> StructuralEq for Value<'a>

impl<'a> StructuralPartialEq for Value<'a>

impl<'a> TryFrom<&'_ Value<'a>> for Decimal

type Error = ParseError

The type returned in the event of a conversion error.

fn try_from(value: &Value<'a>) -> Result<Decimal, ParseError>

Performs the conversion.

impl<'a> TryFrom<&'a str> for Value<'a>

type Error = ParseError

The type returned in the event of a conversion error.

fn try_from(input: &'a str) -> Result<Self, ParseError>

Performs the conversion.

impl<'a> TryFrom<Value<'a>> for Decimal

type Error = ParseError

The type returned in the event of a conversion error.

fn try_from(value: Value<'a>) -> Result<Decimal, ParseError>

Performs the conversion.