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[Validator] Improve entropy estimation in PasswordStrengthValidator #49879

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Merged
merged 1 commit into from
Apr 1, 2023
Merged

[Validator] Improve entropy estimation in PasswordStrengthValidator #49879

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14 changes: 9 additions & 5 deletions src/Symfony/Component/Validator/Constraints/PasswordStrength.php
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Original file line number Diff line number Diff line change
Expand Up @@ -40,12 +40,16 @@ final class PasswordStrength extends Constraint

public int $minScore;

public function __construct(int $minScore = self::STRENGTH_REASONABLE, mixed $options = null, array $groups = null, mixed $payload = null)
public function __construct(array $options = null, int $minScore = null, array $groups = null, mixed $payload = null)
{
if (isset($minScore) && (!\is_int($minScore) || $minScore < 1 || $minScore > 4)) {
throw new ConstraintDefinitionException(sprintf('The parameter "minScore" of the "%s" constraint must be an integer between 1 and 4.', static::class));
}
$options['minScore'] = $minScore;
$options['minScore'] ??= self::STRENGTH_REASONABLE;

parent::__construct($options, $groups, $payload);

$this->minScore = $minScore ?? $this->minScore;

if ($this->minScore < 1 || 4 < $this->minScore) {
throw new ConstraintDefinitionException(sprintf('The parameter "minScore" of the "%s" constraint must be an integer between 1 and 4.', self::class));
}
}
}
21 changes: 20 additions & 1 deletion src/Symfony/Component/Validator/Constraints/PasswordStrengthValidator.php
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Expand Up @@ -58,7 +58,26 @@ public function validate(#[\SensitiveParameter] mixed $value, Constraint $constr
*/
private static function estimateStrength(#[\SensitiveParameter] string $password): int
{
$entropy = log(\strlen(count_chars($password, 3)) ** \strlen($password), 2);
if (!$length = \strlen($password)) {
return PasswordStrength::STRENGTH_VERY_WEAK;
}
$password = count_chars($password, 1);
$chars = \count($password);

$control = $digit = $upper = $lower = $symbol = $other = 0;
foreach ($password as $chr => $count) {
match (true) {
$chr < 32 || 127 === $chr => $control = 33,
48 <= $chr && $chr <= 57 => $digit = 10,
65 <= $chr && $chr <= 90 => $upper = 26,
97 <= $chr && $chr <= 122 => $lower = 26,
128 <= $chr => $other = 128,
default => $symbol = 33,
};
}

$pool = $lower + $upper + $digit + $symbol + $control + $other;
$entropy = $chars * log($pool, 2) + ($length - $chars) * log($chars, 2);

return match (true) {
$entropy >= 120 => PasswordStrength::STRENGTH_VERY_STRONG,
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14 changes: 12 additions & 2 deletions src/Symfony/Component/Validator/Tests/Constraints/PasswordStrengthValidatorTest.php
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Expand Up @@ -30,12 +30,22 @@ public function testValidValues(string $value, int $expectedStrength)
$this->validator->validate($value, new PasswordStrength(minScore: $expectedStrength));

$this->assertNoViolation();

if (PasswordStrength::STRENGTH_VERY_STRONG === $expectedStrength) {
return;
}

$this->validator->validate($value, new PasswordStrength(minScore: $expectedStrength + 1));

$this->buildViolation('The password strength is too low. Please use a stronger password.')
->setCode(PasswordStrength::PASSWORD_STRENGTH_ERROR)
->assertRaised();
}

public static function getValidValues(): iterable
{
yield ['How-is this 🤔?!', PasswordStrength::STRENGTH_WEAK];
yield ['Reasonable-pwd-❤️', PasswordStrength::STRENGTH_REASONABLE];
yield ['How-is-this', PasswordStrength::STRENGTH_WEAK];
yield ['Reasonable-pwd', PasswordStrength::STRENGTH_REASONABLE];
yield ['This 1s a very g00d Pa55word! ;-)', PasswordStrength::STRENGTH_VERY_STRONG];
yield ['pudding-smack-👌🏼-fox-😎', PasswordStrength::STRENGTH_VERY_STRONG];
}
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