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fix(Security): Don't attempt empty secret fallback on >=v3 ciphertext

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Signed-off-by: Josh <josh.t.richards@gmail.com>
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Josh 2024-06-27 09:59:49 -04:00 committed by GitHub
parent a184161978
commit bf7aee3310
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1 changed files with 18 additions and 5 deletions
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23
lib/private/Security/Crypto.php
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@ -97,9 +97,25 @@ class Crypto implements ICrypto {
}
return $this->decryptWithoutSecret($authenticatedCiphertext, $password);
} catch (Exception $e) {
// If password is empty and the current secret didn't work, attempt with an empty secret as a fallback
// for instances where the secret might not have been set for a time *IF* the ciphertext version
// indicates an empty secret is a possibility. For example, it's pointless (and will fail hard if tried)
// to try the fallback with v3 versioned ciphertext since the keying material can't be empty with that version.
// SO: Only attempt the fallback on older versions (including non-versioned) ciphertexts
if ($password === '') {
// Retry with empty secret as a fallback for instances where the secret might not have been set by accident
return $this->decryptWithoutSecret($authenticatedCiphertext, '');
// Determine the crypto version, if any
$parts = explode('|', $authenticatedCiphertext);
$partCount = \count($parts);
if ($partCount < 3 || $partCount > 4) {
throw new Exception('Authenticated ciphertext could not be decoded (invalid format).');
}
if ($partCount === 4) { // only newer ciphertext has a version field
$version = $parts[3];
}
if ((!empty($version) && $version <= '2') || empty($version)) { // only <3 versioned or old non-versioned ciphertext ever supported empty secrets
return $this->decryptWithoutSecret($authenticatedCiphertext, '');
}
}
throw $e;
}
@ -110,9 +126,6 @@ class Crypto implements ICrypto {
$parts = explode('|', $authenticatedCiphertext);
$partCount = \count($parts);
if ($partCount < 3 || $partCount > 4) {
throw new Exception('Authenticated ciphertext could not be decoded.');
}
$ciphertext = $this->hex2bin($parts[0]);
$iv = $parts[1];