diff options
| -rw-r--r-- | Zotlabs/Web/HTTPSig.php | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/Zotlabs/Web/HTTPSig.php b/Zotlabs/Web/HTTPSig.php new file mode 100644 index 000000000..48adf4ad2 --- /dev/null +++ b/Zotlabs/Web/HTTPSig.php @@ -0,0 +1,220 @@ +<?php + +namespace Zotlabs\Web; + +/** + * Implements HTTP Signatures per draft-cavage-http-signatures-07 + */ + + +class HTTPSig { + + // See RFC5843 + + static function generate_digest($body,$set = true) { + $digest = base64_encode(hash('sha256',$body,true)); + + if($set) { + header('Digest: SHA-256=' . $digest); + } + return $digest; + } + + // See draft-cavage-http-signatures-07 + + static function verify($data,$key = '') { + + $body = $data; + $headers = null; + + // decide if $data arrived via controller submission or curl + if(is_array($data) && $data['header']) { + if(! $data['success']) + return false; + $h = new \Zotlabs\Web\HTTPHeaders($data['header']); + $headers = $h->fetcharr(); + $body = $data['body']; + } + + else { + $headers = []; + $headers['(request-target)'] = + $_SERVER['REQUEST_METHOD'] . ' ' . + $_SERVER['REQUEST_URI']; + foreach($_SERVER as $k => $v) { + if(strpos($k,'HTTP_') === 0) { + $field = str_replace('_','-',strtolower(substr($k,5))); + $headers[$field] = $v; + } + } + } + + $sig_block = null; + + if(array_key_exists('signature',$headers)) { + $sig_block = self::parse_sigheader($headers['signature']); + } + elseif(array_key_exists('authorization',$headers)) { + $sig_block = self::parse_sigheader($headers['authorization']); + } + + if(! $sig_block) + return null; + + $signed_headers = $sig_block['headers']; + if(! $signed_headers) + $signed_headers = [ 'date' ]; + + $signed_data = ''; + foreach($signed_headers as $h) { + if(array_key_exists($h,$headers)) { + $signed_data .= $h . ': ' . $headers[$h] . "\n"; + } + } + $signed_data = rtrim($signed_data,"\n"); + + $algorithm = null; + if($sig_block['algorithm'] === 'rsa-sha256') { + $algorithm = 'sha256'; + } + + if(! $key) { + $key = self::get_activitypub_key($sig_block['keyId']); + } + + if(! $key) + return null; + + $x = rsa_verify($signed_data,$sig_block['signature'],$key,$algorithm); + + if($x === false) + return $x; + + if(in_array('digest',$signed_headers)) { + $digest = explode('=', $headers['digest']); + if($digest[0] === 'SHA-256') + $hashalg = 'sha256'; + + // The explode operation will have stripped the '=' padding, so compare against unpadded base64 + if(rtrim(base64_encode(hash($hashalg,$body,true)),'=') === $digest[1]) + return true; + else + return false; + } + + return $x; + + } + + function get_activitypub_key($id) { + + $x = q("select xchan_pubkey from xchan where xchan_hash = '%s' and xchan_network = 'activitypub' ", + dbesc($id) + ); + + if($x && $x[0]['xchan_pubkey']) { + return ($x[0]['xchan_pubkey']); + } + $r = as_fetch($id); + + if($r) { + $j = json_decode($r,true); + + if($j['id'] !== $id) + return false; + if(array_key_exists('publicKey',$j) && array_key_exists('publicKeyPem',$j['publicKey'])) { + return($j['publicKey']['publicKeyPem']); + } + } + return false; + } + + + + + static function create_sig($request,$head,$prvkey,$keyid = 'Key',$send_headers = false,$alg = 'sha256') { + + $return_headers = []; + + if($alg === 'sha256') { + $algorithm = 'rsa-sha256'; + } + + $x = self::sign($request,$head,$prvkey,$alg); + + $sighead = 'Signature: keyId="' . $keyid . '",algorithm="' . $algorithm + . '",headers="' . $x['headers'] . '",signature="' . $x['signature'] . '"'; + + if($head) { + foreach($head as $k => $v) { + if($send_headers) { + header($k . ': ' . $v); + } + else { + $return_headers[] = $k . ': ' . $v; + } + } + } + if($send_headers) { + header($sighead); + } + else { + $return_headers[] = $sighead; + } + return $return_headers; + } + + + + static function sign($request,$head,$prvkey,$alg = 'sha256') { + + $ret = []; + + $headers = ''; + $fields = ''; + if($request) { + $headers = '(request-target)' . ': ' . trim($request) . "\n"; + $fields = '(request-target)'; + } + + if(head) { + foreach($head as $k => $v) { + $headers .= strtolower($k) . ': ' . trim($v) . "\n"; + if($fields) + $fields .= ' '; + $fields .= strtolower($k); + } + // strip the trailing linefeed + $headers = rtrim($headers,"\n"); + } + + $sig = base64_encode(rsa_sign($headers,$prvkey,$alg)); + + $ret['headers'] = $fields; + $ret['signature'] = $sig; + + return $ret; + } + + static function parse_sigheader($header) { + $ret = []; + $matches = []; + if(preg_match('/keyId="(.*?)"/ism',$header,$matches)) + $ret['keyId'] = $matches[1]; + if(preg_match('/algorithm="(.*?)"/ism',$header,$matches)) + $ret['algorithm'] = $matches[1]; + if(preg_match('/headers="(.*?)"/ism',$header,$matches)) + $ret['headers'] = explode(' ', $matches[1]); + if(preg_match('/signature="(.*?)"/ism',$header,$matches)) + $ret['signature'] = base64_decode(preg_replace('/\s+/','',$matches[1])); + + if(($ret['signature']) && ($ret['algorithm']) && (! $ret['headers'])) + $ret['headers'] = [ 'date' ]; + + return $ret; + } + + +} + + |