init

2025-10-09 17:41:57 +00:00
commit 7a3b2960f8
146 changed files with 34948 additions and 0 deletions
@@ -0,0 +1,135 @@
+<?php
+
+namespace Elliptic;
+
+class HmacDRBG
+{
+    private $hash;
+    private $predResist;
+    private $outLen;
+    private $minEntropy;
+    private $reseed;
+    private $reseedInterval;
+    private $K;
+    private $V;
+
+    function __construct($options)
+    {
+        Utils::optionAssert($options, "predResist");
+        Utils::optionAssert($options, "hash", null, true);
+        Utils::optionAssert($options["hash"], "outSize", null, true);
+        Utils::optionAssert($options["hash"], "hmacStrength", null, true);
+        Utils::optionAssert($options["hash"], "algo", null, true);
+        Utils::optionAssert($options, "minEntropy");
+        Utils::optionAssert($options, "entropy", null, true);
+        Utils::optionAssert($options, "entropyEnc");
+        Utils::optionAssert($options, "nonce", "");
+        Utils::optionAssert($options, "nonceEnc");
+        Utils::optionAssert($options, "pers", "");
+        Utils::optionAssert($options, "persEnc");
+
+        $this->hash = $options["hash"];
+        $this->predResist = $options["predResist"];
+
+        $this->outLen = $this->hash["outSize"];
+        $this->minEntropy = $options["minEntropy"] ?: $this->hash["hmacStrength"];
+
+        $this->reseed = null;
+        $this->reseedInterval = null;
+        $this->K = null;
+        $this->V = null;
+
+        $entropy  = Utils::toBin($options["entropy"], $options["entropyEnc"]);
+        $nonce  = Utils::toBin($options["nonce"], $options["nonceEnc"]);
+        $pers  = Utils::toBin($options["pers"], $options["persEnc"]);
+        
+        if (Utils::$ASSERT_ENABLED) {
+            assert(strlen($entropy) >= ($this->minEntropy / 8));
+        }
+        $this->_init($entropy, $nonce, $pers);
+    }
+
+    private function _init($entropy, $nonce, $pers)
+    {
+        $seed = $entropy . $nonce . $pers;
+
+        $this->K = str_repeat(chr(0x00), $this->outLen / 8);
+        $this->V = str_repeat(chr(0x01), $this->outLen / 8);
+
+        $this->_update($seed);
+        $this->reseed = 1;
+        $this->reseedInterval = 0x1000000000000; // 2^48
+    }
+
+    private function _hmac()
+    {
+        return hash_init($this->hash["algo"], HASH_HMAC, $this->K);
+    }
+
+    private function _update($seed = false)
+    {
+        $kmac = $this->_hmac();
+        hash_update($kmac, $this->V);
+        hash_update($kmac, chr(0x00));
+
+        if( $seed )
+            hash_update($kmac, $seed);
+        $this->K = hash_final($kmac, true);
+
+        $kmac = $this->_hmac();
+        hash_update($kmac, $this->V);
+        $this->V = hash_final($kmac, true);
+
+        if(!$seed)
+            return;
+
+        $kmac = $this->_hmac();
+        hash_update($kmac, $this->V);
+        hash_update($kmac, chr(0x01));
+            hash_update($kmac, $seed);
+        $this->K = hash_final($kmac, true);
+
+        $kmac = $this->_hmac();
+        hash_update($kmac, $this->V);
+        $this->V = hash_final($kmac, true);        
+    }
+
+    // TODO: reseed()
+
+    public function generate($len, $enc = null, $add = null, $addEnc = null)
+    {
+        if ($this->reseed > $this->reseedInterval)
+            throw new \Exception("Reseed is required");
+
+        // Optional encoding
+        if( !is_string($enc) )
+        {
+            $addEnc = $enc;
+            $add = $enc;
+            $enc = null;
+        }
+
+        // Optional additional data
+        if( $add != null ) {
+            $add = Utils::toBin($add, $addEnc);
+            $this->_update($add);
+        }
+
+        $temp = "";
+        while( strlen($temp) < $len )
+        {
+            $hmac = $this->_hmac();
+            hash_update($hmac, $this->V);
+            $this->V = hash_final($hmac, true);
+            $temp .= $this->V;
+        }
+
+        $res = substr($temp, 0, $len);
+        $this->_update($add);
+        $this->reseed++;
+
+        return Utils::encode(Utils::toArray($res), $enc);
+    }
+}
+
+?>