diff options
Diffstat (limited to 'include/crypto.php')
| -rw-r--r-- | include/crypto.php | 112 |
1 files changed, 108 insertions, 4 deletions
diff --git a/include/crypto.php b/include/crypto.php index c67c4a1ef..e9fa320d3 100644 --- a/include/crypto.php +++ b/include/crypto.php @@ -48,27 +48,115 @@ function pkcs5_unpad($text) function AES256CBC_encrypt($data,$key,$iv) { return openssl_encrypt($data,'aes-256-cbc',str_pad($key,32,"\0"),OPENSSL_RAW_DATA,str_pad($iv,16,"\0")); - } function AES256CBC_decrypt($data,$key,$iv) { return openssl_decrypt($data,'aes-256-cbc',str_pad($key,32,"\0"),OPENSSL_RAW_DATA,str_pad($iv,16,"\0")); +} + +function AES128CBC_encrypt($data,$key,$iv) { + $key = substr($key,0,16); + return openssl_encrypt($data,'aes-128-cbc',str_pad($key,16,"\0"),OPENSSL_RAW_DATA,str_pad($iv,16,"\0")); +} + +function AES128CBC_decrypt($data,$key,$iv) { + $key = substr($key,0,16); + return openssl_decrypt($data,'aes-128-cbc',str_pad($key,16,"\0"),OPENSSL_RAW_DATA,str_pad($iv,16,"\0")); +} + +function STD_encrypt($data,$key,$iv) { + $key = substr($key,0,32); + return openssl_encrypt($data,'aes-256-cbc',str_pad($key,32,"\0"),OPENSSL_RAW_DATA,str_pad($iv,16,"\0")); +} + +function STD_decrypt($data,$key,$iv) { + $key = substr($key,0,32); + return openssl_decrypt($data,'aes-256-cbc',str_pad($key,32,"\0"),OPENSSL_RAW_DATA,str_pad($iv,16,"\0")); +} +function CAST5CBC_encrypt($data,$key,$iv) { + $key = substr($key,0,16); + $iv = substr($iv,0,8); + return openssl_encrypt($data,'cast5-cbc',str_pad($key,16,"\0"),OPENSSL_RAW_DATA,str_pad($iv,8,"\0")); +} + +function CAST5CBC_decrypt($data,$key,$iv) { + $key = substr($key,0,16); + $iv = substr($iv,0,8); + return openssl_decrypt($data,'cast5-cbc',str_pad($key,16,"\0"),OPENSSL_RAW_DATA,str_pad($iv,8,"\0")); } function crypto_encapsulate($data,$pubkey,$alg='aes256cbc') { + $fn = strtoupper($alg) . '_encrypt'; + if($alg === 'aes256cbc') return aes_encapsulate($data,$pubkey); + return other_encapsulate($data,$pubkey,$alg); + +} + +function other_encapsulate($data,$pubkey,$alg) { + if(! $pubkey) + logger('no key. data: ' . $data); + + $fn = strtoupper($alg) . '_encrypt'; + if(function_exists($fn)) { + + // A bit hesitant to use openssl_random_pseudo_bytes() as we know + // it has been historically targeted by US agencies for 'weakening'. + // It is still arguably better than trying to come up with an + // alternative cryptographically secure random generator. + // There is little point in using the optional second arg to flag the + // assurance of security since it is meaningless if the source algorithms + // have been compromised. Also none of this matters if RSA has been + // compromised by state actors and evidence is mounting that this has + // already happened. + + $key = openssl_random_pseudo_bytes(256); + $iv = openssl_random_pseudo_bytes(256); + $result['data'] = base64url_encode($fn($data,$key,$iv),true); + // log the offending call so we can track it down + if(! openssl_public_encrypt($key,$k,$pubkey)) { + $x = debug_backtrace(); + logger('RSA failed. ' . print_r($x[0],true)); + } + + $result['alg'] = $alg; + $result['key'] = base64url_encode($k,true); + openssl_public_encrypt($iv,$i,$pubkey); + $result['iv'] = base64url_encode($i,true); + return $result; + } + else { + $x = [ 'data' => $data, 'pubkey' => $pubkey, 'alg' => $alg, 'result' => $data ]; + call_hooks('other_encapsulate', $x); + return $x['result']; + } +} + +function crypto_methods() { + + // 'std' is the new project standard which is aes256cbc but transmits/receives 256-byte key and iv. + // aes256cbc is provided for compatibility with earlier zot implementations which assume 32-byte key and 16-byte iv. + // other_encapsulate() now produces these longer keys/ivs by default so that it is difficult to guess a + // particular implementation or choice of underlying implementations based on the key/iv length. + // The actual methods are responsible for deriving the actual key/iv from the provided parameters; + // possibly by truncation or segmentation - though many other methods could be used. + + $r = [ 'std', 'aes256cbc', 'aes128cbc', 'cast5cbc' ]; + call_hooks('crypto_methods',$r); + return $r; + } function aes_encapsulate($data,$pubkey) { if(! $pubkey) logger('aes_encapsulate: no key. data: ' . $data); - $key = random_string(32,RANDOM_STRING_TEXT); - $iv = random_string(16,RANDOM_STRING_TEXT); + $key = openssl_random_pseudo_bytes(32); + $iv = openssl_random_pseudo_bytes(16); $result['data'] = base64url_encode(AES256CBC_encrypt($data,$key,$iv),true); // log the offending call so we can track it down if(! openssl_public_encrypt($key,$k,$pubkey)) { @@ -89,6 +177,22 @@ function crypto_unencapsulate($data,$prvkey) { if($alg === 'aes256cbc') return aes_unencapsulate($data,$prvkey); + return other_unencapsulate($data,$prvkey,$alg); + +} + +function other_unencapsulate($data,$prvkey,$alg) { + $fn = strtoupper($alg) . '_decrypt'; + if(function_exists($fn)) { + openssl_private_decrypt(base64url_decode($data['key']),$k,$prvkey); + openssl_private_decrypt(base64url_decode($data['iv']),$i,$prvkey); + return $fn(base64url_decode($data['data']),$k,$i); + } + else { + $x = [ 'data' => $data, 'prvkey' => $prvkey, 'alg' => $alg, 'result' => $data ]; + call_hooks('other_unencapsulate',$x); + return $x['result']; + } } @@ -315,7 +419,7 @@ function convert_salmon_key($key) { function z_obscure($s) { - return json_encode(crypto_encapsulate($s,get_config('system','pubkey'),CRYPTO_ALGORITHM)); + return json_encode(crypto_encapsulate($s,get_config('system','pubkey'))); } function z_unobscure($s) { |