diff options
Diffstat (limited to 'apps/files_encryption/lib/crypt.php')
| -rwxr-xr-x | apps/files_encryption/lib/crypt.php | 739 |
1 files changed, 356 insertions, 383 deletions
diff --git a/apps/files_encryption/lib/crypt.php b/apps/files_encryption/lib/crypt.php index d00f71b6141..c7a414c5080 100755 --- a/apps/files_encryption/lib/crypt.php +++ b/apps/files_encryption/lib/crypt.php @@ -4,8 +4,8 @@ * ownCloud
*
* @author Sam Tuke, Frank Karlitschek, Robin Appelman
- * @copyright 2012 Sam Tuke samtuke@owncloud.com,
- * Robin Appelman icewind@owncloud.com, Frank Karlitschek
+ * @copyright 2012 Sam Tuke samtuke@owncloud.com,
+ * Robin Appelman icewind@owncloud.com, Frank Karlitschek
* frank@owncloud.org
*
* This library is free software; you can redistribute it and/or
@@ -47,15 +47,15 @@ class Crypt { public static function mode( $user = null ) {
return 'server';
-
+
}
-
- /**
- * @brief Create a new encryption keypair
- * @return array publicKey, privatekey
- */
+
+ /**
+ * @brief Create a new encryption keypair
+ * @return array publicKey, privatekey
+ */
public static function createKeypair() {
-
+
$res = openssl_pkey_new();
// Get private key
@@ -63,570 +63,543 @@ class Crypt { // Get public key
$publicKey = openssl_pkey_get_details( $res );
-
+
$publicKey = $publicKey['key'];
-
+
return( array( 'publicKey' => $publicKey, 'privateKey' => $privateKey ) );
-
+
}
-
- /**
- * @brief Add arbitrary padding to encrypted data
- * @param string $data data to be padded
- * @return padded data
- * @note In order to end up with data exactly 8192 bytes long we must
- * add two letters. It is impossible to achieve exactly 8192 length
- * blocks with encryption alone, hence padding is added to achieve the
- * required length.
- */
+
+ /**
+ * @brief Add arbitrary padding to encrypted data
+ * @param string $data data to be padded
+ * @return padded data
+ * @note In order to end up with data exactly 8192 bytes long we must
+ * add two letters. It is impossible to achieve exactly 8192 length
+ * blocks with encryption alone, hence padding is added to achieve the
+ * required length.
+ */
public static function addPadding( $data ) {
-
+
$padded = $data . 'xx';
-
+
return $padded;
-
+
}
-
- /**
- * @brief Remove arbitrary padding to encrypted data
- * @param string $padded padded data to remove padding from
- * @return unpadded data on success, false on error
- */
+
+ /**
+ * @brief Remove arbitrary padding to encrypted data
+ * @param string $padded padded data to remove padding from
+ * @return unpadded data on success, false on error
+ */
public static function removePadding( $padded ) {
-
+
if ( substr( $padded, -2 ) == 'xx' ) {
-
+
$data = substr( $padded, 0, -2 );
-
+
return $data;
-
+
} else {
-
+
// TODO: log the fact that unpadded data was submitted for removal of padding
return false;
-
+
}
-
+
}
-
- /**
- * @brief Check if a file's contents contains an IV and is symmetrically encrypted
- * @return true / false
- * @note see also OCA\Encryption\Util->isEncryptedPath()
- */
+
+ /**
+ * @brief Check if a file's contents contains an IV and is symmetrically encrypted
+ * @return true / false
+ * @note see also OCA\Encryption\Util->isEncryptedPath()
+ */
public static function isCatfile( $content ) {
-
+
+ if ( !$content ) {
+
+ return false;
+
+ }
+
$noPadding = self::removePadding( $content );
-
+
// Fetch encryption metadata from end of file
$meta = substr( $noPadding, -22 );
-
+
// Fetch IV from end of file
$iv = substr( $meta, -16 );
-
+
// Fetch identifier from start of metadata
$identifier = substr( $meta, 0, 6 );
-
+
if ( $identifier == '00iv00') {
-
+
return true;
-
+
} else {
-
+
return false;
-
+
}
-
+
}
-
+
/**
* Check if a file is encrypted according to database file cache
* @param string $path
* @return bool
*/
public static function isEncryptedMeta( $path ) {
-
+
// TODO: Use DI to get \OC\Files\Filesystem out of here
-
+
// Fetch all file metadata from DB
$metadata = \OC\Files\Filesystem::getFileInfo( $path, '' );
-
+
// Return encryption status
return isset( $metadata['encrypted'] ) and ( bool )$metadata['encrypted'];
-
+
}
-
- /**
- * @brief Check if a file is encrypted via legacy system
- * @param string $relPath The path of the file, relative to user/data;
- * e.g. filename or /Docs/filename, NOT admin/files/filename
- * @return true / false
- */
+
+ /**
+ * @brief Check if a file is encrypted via legacy system
+ * @param string $relPath The path of the file, relative to user/data;
+ * e.g. filename or /Docs/filename, NOT admin/files/filename
+ * @return true / false
+ */
public static function isLegacyEncryptedContent( $data, $relPath ) {
-
+
// Fetch all file metadata from DB
$metadata = \OC\Files\Filesystem::getFileInfo( $relPath, '' );
-
+
// If a file is flagged with encryption in DB, but isn't a
// valid content + IV combination, it's probably using the
// legacy encryption system
- if (
- isset( $metadata['encrypted'] )
- and $metadata['encrypted'] === true
- and ! self::isCatfile( $data )
+ if (
+ isset( $metadata['encrypted'] )
+ and $metadata['encrypted'] === true
+ and ! self::isCatfile( $data )
) {
-
+
return true;
-
+
} else {
-
+
return false;
-
+
}
-
+
}
-
- /**
- * @brief Symmetrically encrypt a string
- * @returns encrypted file
- */
+
+ /**
+ * @brief Symmetrically encrypt a string
+ * @returns encrypted file
+ */
public static function encrypt( $plainContent, $iv, $passphrase = '' ) {
-
+
if ( $encryptedContent = openssl_encrypt( $plainContent, 'AES-128-CFB', $passphrase, false, $iv ) ) {
return $encryptedContent;
-
+
} else {
-
+
\OC_Log::write( 'Encryption library', 'Encryption (symmetric) of content failed', \OC_Log::ERROR );
-
+
return false;
-
+
}
-
+
}
-
- /**
- * @brief Symmetrically decrypt a string
- * @returns decrypted file
- */
+
+ /**
+ * @brief Symmetrically decrypt a string
+ * @returns decrypted file
+ */
public static function decrypt( $encryptedContent, $iv, $passphrase ) {
-
+
if ( $plainContent = openssl_decrypt( $encryptedContent, 'AES-128-CFB', $passphrase, false, $iv ) ) {
return $plainContent;
-
-
+
+
} else {
-
+
throw new \Exception( 'Encryption library: Decryption (symmetric) of content failed' );
-
- return false;
-
+
}
-
+
}
-
- /**
- * @brief Concatenate encrypted data with its IV and padding
- * @param string $content content to be concatenated
- * @param string $iv IV to be concatenated
- * @returns string concatenated content
- */
+
+ /**
+ * @brief Concatenate encrypted data with its IV and padding
+ * @param string $content content to be concatenated
+ * @param string $iv IV to be concatenated
+ * @returns string concatenated content
+ */
public static function concatIv ( $content, $iv ) {
-
+
$combined = $content . '00iv00' . $iv;
-
+
return $combined;
-
+
}
-
- /**
- * @brief Split concatenated data and IV into respective parts
- * @param string $catFile concatenated data to be split
- * @returns array keys: encrypted, iv
- */
+
+ /**
+ * @brief Split concatenated data and IV into respective parts
+ * @param string $catFile concatenated data to be split
+ * @returns array keys: encrypted, iv
+ */
public static function splitIv ( $catFile ) {
-
+
// Fetch encryption metadata from end of file
$meta = substr( $catFile, -22 );
-
+
// Fetch IV from end of file
$iv = substr( $meta, -16 );
-
+
// Remove IV and IV identifier text to expose encrypted content
$encrypted = substr( $catFile, 0, -22 );
-
+
$split = array(
'encrypted' => $encrypted
- , 'iv' => $iv
+ , 'iv' => $iv
);
-
+
return $split;
-
+
}
-
- /**
- * @brief Symmetrically encrypts a string and returns keyfile content
- * @param $plainContent content to be encrypted in keyfile
- * @returns encrypted content combined with IV
- * @note IV need not be specified, as it will be stored in the returned keyfile
- * and remain accessible therein.
- */
+
+ /**
+ * @brief Symmetrically encrypts a string and returns keyfile content
+ * @param $plainContent content to be encrypted in keyfile
+ * @returns encrypted content combined with IV
+ * @note IV need not be specified, as it will be stored in the returned keyfile
+ * and remain accessible therein.
+ */
public static function symmetricEncryptFileContent( $plainContent, $passphrase = '' ) {
-
+
if ( !$plainContent ) {
-
+
return false;
-
+
}
-
+
$iv = self::generateIv();
-
+
if ( $encryptedContent = self::encrypt( $plainContent, $iv, $passphrase ) ) {
-
- // Combine content to encrypt with IV identifier and actual IV
- $catfile = self::concatIv( $encryptedContent, $iv );
-
- $padded = self::addPadding( $catfile );
-
- return $padded;
-
+
+ // Combine content to encrypt with IV identifier and actual IV
+ $catfile = self::concatIv( $encryptedContent, $iv );
+
+ $padded = self::addPadding( $catfile );
+
+ return $padded;
+
} else {
-
+
\OC_Log::write( 'Encryption library', 'Encryption (symmetric) of keyfile content failed', \OC_Log::ERROR );
-
+
return false;
-
+
}
-
+
}
/**
- * @brief Symmetrically decrypts keyfile content
- * @param string $source
- * @param string $target
- * @param string $key the decryption key
- * @returns decrypted content
- *
- * This function decrypts a file
- */
+ * @brief Symmetrically decrypts keyfile content
+ * @param string $source
+ * @param string $target
+ * @param string $key the decryption key
+ * @returns decrypted content
+ *
+ * This function decrypts a file
+ */
public static function symmetricDecryptFileContent( $keyfileContent, $passphrase = '' ) {
-
+
if ( !$keyfileContent ) {
-
+
throw new \Exception( 'Encryption library: no data provided for decryption' );
-
+
}
-
+
// Remove padding
$noPadding = self::removePadding( $keyfileContent );
-
+
// Split into enc data and catfile
$catfile = self::splitIv( $noPadding );
-
+
if ( $plainContent = self::decrypt( $catfile['encrypted'], $catfile['iv'], $passphrase ) ) {
-
+
return $plainContent;
-
+
}
-
+
}
-
+
/**
- * @brief Creates symmetric keyfile content using a generated key
- * @param string $plainContent content to be encrypted
- * @returns array keys: key, encrypted
- * @note symmetricDecryptFileContent() can be used to decrypt files created using this method
- *
- * This function decrypts a file
- */
+ * @brief Creates symmetric keyfile content using a generated key
+ * @param string $plainContent content to be encrypted
+ * @returns array keys: key, encrypted
+ * @note symmetricDecryptFileContent() can be used to decrypt files created using this method
+ *
+ * This function decrypts a file
+ */
public static function symmetricEncryptFileContentKeyfile( $plainContent ) {
-
+
$key = self::generateKey();
-
+
if( $encryptedContent = self::symmetricEncryptFileContent( $plainContent, $key ) ) {
-
+
return array(
'key' => $key
- , 'encrypted' => $encryptedContent
+ , 'encrypted' => $encryptedContent
);
-
+
} else {
-
+
return false;
-
+
}
-
+
}
-
+
/**
- * @brief Create asymmetrically encrypted keyfile content using a generated key
- * @param string $plainContent content to be encrypted
- * @returns array keys: key, encrypted
- * @note symmetricDecryptFileContent() can be used to decrypt files created using this method
- *
- * This function decrypts a file
- */
+ * @brief Create asymmetrically encrypted keyfile content using a generated key
+ * @param string $plainContent content to be encrypted
+ * @returns array keys: key, encrypted
+ * @note symmetricDecryptFileContent() can be used to decrypt files created using this method
+ *
+ * This function decrypts a file
+ */
public static function multiKeyEncrypt( $plainContent, array $publicKeys ) {
-
+
// Set empty vars to be set by openssl by reference
$sealed = '';
$envKeys = array();
-
+
if( openssl_seal( $plainContent, $sealed, $envKeys, $publicKeys ) ) {
-
+
return array(
'keys' => $envKeys
- , 'encrypted' => $sealed
+ , 'encrypted' => $sealed
);
-
+
} else {
-
+
return false;
-
+
}
-
+
}
-
+
/**
- * @brief Asymmetrically encrypt a file using multiple public keys
- * @param string $plainContent content to be encrypted
- * @returns string $plainContent decrypted string
- * @note symmetricDecryptFileContent() can be used to decrypt files created using this method
- *
- * This function decrypts a file
- */
+ * @brief Asymmetrically encrypt a file using multiple public keys
+ * @param string $plainContent content to be encrypted
+ * @returns string $plainContent decrypted string
+ * @note symmetricDecryptFileContent() can be used to decrypt files created using this method
+ *
+ * This function decrypts a file
+ */
public static function multiKeyDecrypt( $encryptedContent, $envKey, $privateKey ) {
-
+
if ( !$encryptedContent ) {
-
+
return false;
-
+
}
-
+
if ( openssl_open( $encryptedContent, $plainContent, $envKey, $privateKey ) ) {
-
+
return $plainContent;
-
+
} else {
-
+
\OC_Log::write( 'Encryption library', 'Decryption (asymmetric) of sealed content failed', \OC_Log::ERROR );
-
+
return false;
-
+
}
-
+
}
-
- /**
- * @brief Asymetrically encrypt a string using a public key
- * @returns encrypted file
- */
+
+ /**
+ * @brief Asymmetrically encrypt a string using a public key
+ * @returns encrypted file
+ */
public static function keyEncrypt( $plainContent, $publicKey ) {
-
+
openssl_public_encrypt( $plainContent, $encryptedContent, $publicKey );
-
+
return $encryptedContent;
-
+
}
-
- /**
- * @brief Asymetrically decrypt a file using a private key
- * @returns decrypted file
- */
+
+ /**
+ * @brief Asymetrically decrypt a file using a private key
+ * @returns decrypted file
+ */
public static function keyDecrypt( $encryptedContent, $privatekey ) {
-
+
openssl_private_decrypt( $encryptedContent, $plainContent, $privatekey );
-
+
return $plainContent;
-
+
}
- /**
- * @brief Encrypts content symmetrically and generates keyfile asymmetrically
- * @returns array containing catfile and new keyfile.
- * keys: data, key
- * @note this method is a wrapper for combining other crypt class methods
- */
+ /**
+ * @brief Encrypts content symmetrically and generates keyfile asymmetrically
+ * @returns array containing catfile and new keyfile.
+ * keys: data, key
+ * @note this method is a wrapper for combining other crypt class methods
+ */
public static function keyEncryptKeyfile( $plainContent, $publicKey ) {
-
+
// Encrypt plain data, generate keyfile & encrypted file
$cryptedData = self::symmetricEncryptFileContentKeyfile( $plainContent );
-
+
// Encrypt keyfile
$cryptedKey = self::keyEncrypt( $cryptedData['key'], $publicKey );
-
+
return array( 'data' => $cryptedData['encrypted'], 'key' => $cryptedKey );
-
+
}
-
- /**
- * @brief Takes catfile, keyfile, and private key, and
- * performs decryption
- * @returns decrypted content
- * @note this method is a wrapper for combining other crypt class methods
- */
+
+ /**
+ * @brief Takes catfile, keyfile, and private key, and
+ * performs decryption
+ * @returns decrypted content
+ * @note this method is a wrapper for combining other crypt class methods
+ */
public static function keyDecryptKeyfile( $catfile, $keyfile, $privateKey ) {
-
+
// Decrypt the keyfile with the user's private key
$decryptedKeyfile = self::keyDecrypt( $keyfile, $privateKey );
-
+
// Decrypt the catfile symmetrically using the decrypted keyfile
$decryptedData = self::symmetricDecryptFileContent( $catfile, $decryptedKeyfile );
-
+
return $decryptedData;
-
+
}
-
+
/**
- * @brief Symmetrically encrypt a file by combining encrypted component data blocks
- */
+ * @brief Symmetrically encrypt a file by combining encrypted component data blocks
+ */
public static function symmetricBlockEncryptFileContent( $plainContent, $key ) {
-
+
$crypted = '';
-
+
$remaining = $plainContent;
-
+
$testarray = array();
-
+
while( strlen( $remaining ) ) {
-
+
//echo "\n\n\$block = ".substr( $remaining, 0, 6126 );
-
+
// Encrypt a chunk of unencrypted data and add it to the rest
$block = self::symmetricEncryptFileContent( substr( $remaining, 0, 6126 ), $key );
-
+
$padded = self::addPadding( $block );
-
+
$crypted .= $block;
-
+
$testarray[] = $block;
-
+
// Remove the data already encrypted from remaining unencrypted data
$remaining = substr( $remaining, 6126 );
-
+
}
-
- //echo "hags ";
-
- //echo "\n\n\n\$crypted = $crypted\n\n\n";
-
- //print_r($testarray);
-
+
return $crypted;
}
/**
- * @brief Symmetrically decrypt a file by combining encrypted component data blocks
- */
+ * @brief Symmetrically decrypt a file by combining encrypted component data blocks
+ */
public static function symmetricBlockDecryptFileContent( $crypted, $key ) {
-
+
$decrypted = '';
-
+
$remaining = $crypted;
-
+
$testarray = array();
-
+
while( strlen( $remaining ) ) {
-
+
$testarray[] = substr( $remaining, 0, 8192 );
-
+
// Decrypt a chunk of unencrypted data and add it to the rest
$decrypted .= self::symmetricDecryptFileContent( $remaining, $key );
-
+
// Remove the data already encrypted from remaining unencrypted data
$remaining = substr( $remaining, 8192 );
-
+
}
-
- //echo "\n\n\$testarray = "; print_r($testarray);
-
+
return $decrypted;
-
+
}
-
- /**
- * @brief Generates a pseudo random initialisation vector
- * @return String $iv generated IV
- */
+
+ /**
+ * @brief Generates a pseudo random initialisation vector
+ * @return String $iv generated IV
+ */
public static function generateIv() {
-
+
if ( $random = openssl_random_pseudo_bytes( 12, $strong ) ) {
-
+
if ( !$strong ) {
-
+
// If OpenSSL indicates randomness is insecure, log error
\OC_Log::write( 'Encryption library', 'Insecure symmetric key was generated using openssl_random_pseudo_bytes()', \OC_Log::WARN );
-
+
}
-
+
// We encode the iv purely for string manipulation
// purposes - it gets decoded before use
$iv = base64_encode( $random );
-
+
return $iv;
-
+
} else {
-
- throw new Exception( 'Generating IV failed' );
-
+
+ throw new \Exception( 'Generating IV failed' );
+
}
-
+
}
-
- /**
- * @brief Generate a pseudo random 1024kb ASCII key
- * @returns $key Generated key
- */
+
+ /**
+ * @brief Generate a pseudo random 1024kb ASCII key
+ * @returns $key Generated key
+ */
public static function generateKey() {
-
+
// Generate key
if ( $key = base64_encode( openssl_random_pseudo_bytes( 183, $strong ) ) ) {
-
+
if ( !$strong ) {
-
+
// If OpenSSL indicates randomness is insecure, log error
- throw new Exception ( 'Encryption library, Insecure symmetric key was generated using openssl_random_pseudo_bytes()' );
-
+ throw new \Exception ( 'Encryption library, Insecure symmetric key was generated using openssl_random_pseudo_bytes()' );
+
}
-
+
return $key;
-
+
} else {
-
+
return false;
-
- }
-
- }
- public static function changekeypasscode( $oldPassword, $newPassword ) {
-
- if ( \OCP\User::isLoggedIn() ) {
-
- $key = Keymanager::getPrivateKey( $user, $view );
-
- if ( ( $key = Crypt::symmetricDecryptFileContent($key,$oldpasswd) ) ) {
-
- if ( ( $key = Crypt::symmetricEncryptFileContent( $key, $newpasswd ) ) ) {
-
- Keymanager::setPrivateKey( $key );
-
- return true;
- }
-
- }
-
}
-
- return false;
-
+
}
-
+
/**
* @brief Get the blowfish encryption handeler for a key
* @param $key string (optional)
@@ -635,21 +608,21 @@ class Crypt { * if the key is left out, the default handeler will be used
*/
public static function getBlowfish( $key = '' ) {
-
+
if ( $key ) {
-
+
return new \Crypt_Blowfish( $key );
-
+
} else {
-
+
return false;
-
+
}
-
+
}
-
+
public static function legacyCreateKey( $passphrase ) {
-
+
// Generate a random integer
$key = mt_rand( 10000, 99999 ) . mt_rand( 10000, 99999 ) . mt_rand( 10000, 99999 ) . mt_rand( 10000, 99999 );
@@ -657,9 +630,9 @@ class Crypt { $legacyEncKey = self::legacyEncrypt( $key, $passphrase );
return $legacyEncKey;
-
+
}
-
+
/**
* @brief encrypts content using legacy blowfish system
* @param $content the cleartext message you want to encrypt
@@ -669,54 +642,54 @@ class Crypt { * This function encrypts an content
*/
public static function legacyEncrypt( $content, $passphrase = '' ) {
-
+
$bf = self::getBlowfish( $passphrase );
-
+
return $bf->encrypt( $content );
-
+
}
-
+
/**
- * @brief decrypts content using legacy blowfish system
- * @param $content the cleartext message you want to decrypt
- * @param $key the encryption key (optional)
- * @returns cleartext content
- *
- * This function decrypts an content
- */
+ * @brief decrypts content using legacy blowfish system
+ * @param $content the cleartext message you want to decrypt
+ * @param $key the encryption key (optional)
+ * @returns cleartext content
+ *
+ * This function decrypts an content
+ */
public static function legacyDecrypt( $content, $passphrase = '' ) {
-
+
$bf = self::getBlowfish( $passphrase );
-
+
$decrypted = $bf->decrypt( $content );
-
+
$trimmed = rtrim( $decrypted, "\0" );
-
+
return $trimmed;
-
+
}
-
+
public static function legacyKeyRecryptKeyfile( $legacyEncryptedContent, $legacyPassphrase, $publicKey, $newPassphrase ) {
-
+
$decrypted = self::legacyDecrypt( $legacyEncryptedContent, $legacyPassphrase );
-
+
$recrypted = self::keyEncryptKeyfile( $decrypted, $publicKey );
-
+
return $recrypted;
-
+
}
-
+
/**
- * @brief Re-encryptes a legacy blowfish encrypted file using AES with integrated IV
- * @param $legacyContent the legacy encrypted content to re-encrypt
- * @returns cleartext content
- *
- * This function decrypts an content
- */
+ * @brief Re-encryptes a legacy blowfish encrypted file using AES with integrated IV
+ * @param $legacyContent the legacy encrypted content to re-encrypt
+ * @returns cleartext content
+ *
+ * This function decrypts an content
+ */
public static function legacyRecrypt( $legacyContent, $legacyPassphrase, $newPassphrase ) {
-
+
// TODO: write me
-
+
}
-
+
}
\ No newline at end of file |