Re: str 2 int

I just have one comment about the speed of printing strings. PHP is faster when using single quotes '' for printing strings as apposed to double quotes "". For example print 'This is a test'; is faster than print "This is a test"; This is true because when you use single quotes, the PHP parser doesn't waste time looking for variables. I know that this is a minor issue, but if you are trying to shed weight, this is a start -- even though it is extreamly minor. -jeremy brand _______________________________________________________________________ GnuPG Fingerprint: 9F5E 95E0 1CC2 E054 84EA 6099 8ACD 9DBA D2C0 5EA9 _ http://www.jeremybrand.com/jeremy/brand/jeremy_brand.html for more __ > I was looking into some crypto stuff for a current project, and while I > know that using mcrypt is the way to go for anything serious, I thought > I'd try my hand at a PHP version of Bruce Schneier's Solitaire algorithm. > (Reading _Cryptonomicon_ recently probably contributed to the insanity.) > I suppose this could be useful for sites which absolutely cannot/will not > link in mcrypt.... > > Anyway, I was dismayed to find that it ran some 100 times slower than > the reference perl source. Any ideas why? I tweaked on it and switched > to mostly string functions instead of regexps, but it is still some 12 times > slower. Ideas? > > -Greg > > > For your testing pleasure...... > > > PHP source: > > <?php > > // Solitaire cryptosystem: verbose version > // Ian Goldberg <ian@cypherpunks.ca>, 19980817 > // adapted to PHP 2000 Greg Billock > > // benchmark: encrypting and decrypting a 1k block using a fairly long > // key (over 60 characters) takes 24.875 seconds on a P/120 doing > nothing else > // meaning about 12.5 seconds/K on a P/120 - Redhat - PHP3.0.12 > // not your fastest algorithm... > // the original perl algorithm takes about 1.05 seconds/K on the same > // machine. > > > //takes plaintext and key, produces encrypted output or decrypted output > > function solcrypt($input, $key,$decrypt="") { > if ($decrypt) { > print "decrypting..."; > $f = -1; > } else { > $f = 1; > } > > //translate key and input to all uppercase > $key = strtoupper($key); > $key = ereg_replace("[^A-Z]","",$key); > > $input = strtoupper($input); > $input = ereg_replace("[^A-Z]","",$input); > > //pad $input to multiple of 5? > //while (strlen($input)%5 != 0) { > // $input .= "X"; > //} > //print "with $input<P>\n"; > > //print "new key $key<P>\n"; > > $deck = makedeck(); > //print $deck; > > //for each letter in the key, run the setup routine > for ($i=0; $i<strlen($key); $i++) { > sce($deck,$key[$i]); > } > > //print "<P>Scrambled deck: $deck<P>\n"; > > //now do encryption... > $output = ""; > for ($i=0; $i<strlen($input); $i++) { > $cryptletter = sce($deck); //get the encryption letter to combine > with plaintext > //print "$cryptletter-"; > $t = ord($input[$i])-13; //take the value of current char - 13 > //print "($t)"; > //print ($f * $cryptletter)."*"; > $t += $f * $cryptletter; // add encryption > //print "($t)"; > $t = ($t % 26) + 65; //mod 26 + 65 to turn back into letter > //print "($t)"; > //print "=".chr($t)."="; > $output .= chr($t); > } > > //unpad Xs from output? > //if ($decrypt) { > // $output = ereg_replace("(.*)(X*$)","\\1",$output); > //} > > return $output; > } > > function makedeck() { > $deck = ""; > for ($i=33; $i<=86; $i++) { > $deck .= chr($i); > } > return $deck; > } > > //generate the next value in the keystream. Operates on the passed > //deck > //this could be optimized with strchr calls to work faster... > function sce(&$deck,$k="") { > $decklen = strlen($deck); > //print "<P>Scrambling deck $deck with $k<BR>\n"; > > //original regexp code commented out...... > //if joker A is at bottom, bring to top > //$deck = ereg_replace("(.*)U$","U\\1",$deck); > if ($deck[$decklen-1]=="U") { > $deck = "U".substr($deck,0,$decklen-1); > } > //swap joker A with card below it > //$deck = ereg_replace("U(.)","\\1U",$deck); > $lu = strpos($deck,"U"); > $deck = substr($deck,0,$lu) . $deck[$lu+1] . "U" . > substr($deck,$lu+2); > > //same with joker B, twice > //$deck = ereg_replace("(.*)V$","V\\1",$deck); > //$deck = ereg_replace("V(.)","\\1V",$deck); > //$deck = ereg_replace("(.*)V$","V\\1",$deck); > //$deck = ereg_replace("V(.)","\\1V",$deck); > if ($deck[$decklen-1]=="V") { > $deck = "V".substr($deck,0,$decklen-1); > } > $lv = strpos($deck,"V"); > $deck = substr($deck,0,$lv) . $deck[$lv+1] . "V" . > substr($deck,$lv+2); > if ($deck[$decklen-1]=="V") { > $deck = "V".substr($deck,0,$decklen-1); > } > $lv = strpos($deck,"V"); > $deck = substr($deck,0,$lv) . $deck[$lv+1] . "V" . > substr($deck,$lv+2); > > //print "Joker swap: $deck<BR>\n"; > > //swap deck slices before and after jokers > //$deck = ereg_replace("(.*)([UV].*[UV])(.*)","\\3\\2\\1",$deck); > $lv = strpos($deck,"V"); > $lu = strpos($deck,"U"); > $f = min($lv,$lu); > $l = max($lv,$lu); > $deck = substr($deck,$l+1) . substr($deck,$f,$l-$f+1) . > substr($deck,0,$f); > //print "triple cut: $deck<BR>\n"; > > //count cut: > $v = deckvalue($deck,53); > //print "cutting with $v<BR>\n"; > $deck = ereg_replace("(.{$v})(.*)(.)","\\2\\1\\3",$deck); > //$deck = substr($deck,$v,$decklen-1-$v+1) . substr($deck,0,$v) . > $deck[$decklen-1]; > //print "Count cut: $deck<BR>\n"; > > //if doing key setup, do another count cut and return > if ($k) { > $v = ord($k)-64; > $deck = ereg_replace("(.{$v})(.*)(.)","\\2\\1\\3",$deck); > //print "Key cut: $deck<BR>\n"; > return; > } > > //if no key setup, go on > $c = deckvalue($deck, deckvalue($deck, 0)); > > if ($c<=52) { > return $c; > } else { > return sce($deck); > } > } > > //returns the value of the $index'th card in the deck > //( the v() function) > function deckvalue($deck,$index) { > $value = ord($deck[$index])-32; > if ($value==54) { > $value = 53; > } > return $value; > } > > ?> > > ============================ > Perl source: (note that this is a bit different than the original; my perl > didn't > like the -d CMD args -> $d assumption) > > #!/usr/bin/perl -s > > ## Solitaire cryptosystem: verbose version > ## Ian Goldberg <ian@cypherpunks.ca>, 19980817 > > ## Make sure we have at least the key phrase argument > die "Usage: $0 [-d] 'key phrase' [infile ...]\n" unless $#ARGV >= > 0; > > ## Set the multiplication factor to -1 if "-d" was specified as an > option > ## (decrypt), or to 1 if not. This factor will be multiplied by the > output > ## of the keystream generator and added to the input (this has the > effect > ## of doing addition for encryption, and subtraction for decryption). > $d = shift; > if ($d eq '-d') { > $f = -1; > $p = shift; > } else { > $f = 1; > $p = $d; > } > > #original: doesn't work > #$f = $d ? -1 : 1; > > ## Load the key phrase, and turn it all into uppercase > #$p = shift; > > $p =~ y/a-z/A-Z/; > > ## Set up the deck in sorted order. chr(33) == '!' represents A of > clubs, > ## chr(34) == '"' represents 2 of clubs, and so on in order until > ## chr(84) == 'T' represents K of spades. chr(85) == 'U' is joker A > and > > ## chr(86) == 'V' is joker B. > $D = pack('C*',33..86); > > > ## For each letter in the key phrase, run the key setup routine (which > ## is the same as the keystream routine, except that $k is set to the > ## value of each successive letter in the key phrase). > $p =~ s/[A-Z]/$k=ord($&)-64,&e/eg; > > #print "Scrambled deck $D\n"; > > ## Stop setting up the key and switch to encrypting/decrypting mode. > $k = 0; > > ## Collect all of the alphabetic characters (in uppercase) from the > input > ## files (or stdin if none specified) into the variable $o > while(<>) { > ## Change all lowercase to uppercase > y/a-z/A-Z/; > ## Remove any non-letters > y/A-Z//dc; > ## Append the input to $o > $o .= $_; > } > > ## If we're encrypting, append X to the input until it's a multiple of 5 > chars > if (!$d) { > $o.='X' while length($o)%5; > } > > ## This next line does the crypto: > ## For each character in the input ($&), which is between 'A' and > 'Z', > > ## find its ASCII value (ord($&)), which is in the range 65..90, > ## subtract 13 (ord($&)-13), to get the range 52..77, > ## add (or subtract if decrypting) the next keystream byte (the output > of > ## the function &e) and take the result mod 26 > ((ord($&)-13+$f*&e)%26), > ## to get the range 0..25, > ## add 65 to get back the range 65..90, and determine the character > with > ## that ASCII value (chr((ord($&)-13+$f*&e)%26+65)), which is > between > ## 'A' and 'Z'. Replace the original character with this new > one. > $o =~ s/./chr((ord($&)-13+$f*&e)%26+65)/eg; > > ## If we're decrypting, remove trailing X's from the newly found > plaintext > $o =~ s/X*$// if $d; > > ## Put a space after each group of 5 characters and print the result > $o =~ s/.{5}/$& /g; > print "$o\n"; > > ## The main program ends here. The following are subroutines. > > ## The following subroutine gives the value of the nth card in the deck. > > ## n is passed in as an argument to this routine ($_[0]). The A of > clubs > ## has value 1, ..., the K of spades has value 52, both jokers have > value 53. > ## The top card is the 0th card, the bottom card is the 53rd card. > sub v { > ## The value of most cards is just the ASCII value minus 32. > ## substr($D,$_[0]) is a string beginning with the nth card in the > deck > $v=ord(substr($D,$_[0]))-32; > ## Special case: both jokers (53 and 54, normally) have value 53, > ## so return 53 if the value is greater than 53, and the value > otherwise. > $v>53?53:$v; > } > > ## The following subroutine generates the next value in the keystream. > sub e { > # print "\nScrambling deck $D with $k\n"; > ## If the U (joker A) is at the bottom of the deck, move it to the > top > $D =~ s/(.*)U$/U$1/; > ## Swap the U (joker A) with the card below it > $D =~ s/U(.)/$1U/; > > ## Do the same as above, but with the V (joker B), and do it twice. > $D =~ s/(.*)V$/V$1/; $D =~ s/V(.)/$1V/; > $D =~ s/(.*)V$/V$1/; $D =~ s/V(.)/$1V/; > > #print "joker swap: $D\n"; > > ## Do the triple cut: swap the pieces before the first joker, and > ## after the second joker. > $D =~ s/(.*)([UV].*[UV])(.*)/$3$2$1/; > > #print "triple cut: $D\n"; > > ## Do the count cut: find the value of the bottom card in the deck > $c=&v(53); > #print "cutting with $c\n"; > ## Switch that many cards from the top of the deck with all but > ## the last card. > $D =~ s/(.{$c})(.*)(.)/$2$1$3/; > > #print "count cut: $D\n"; > > ## If we're doing key setup, do another count cut here, with the > ## count value being the letter value of the key character (A=1, > B=2, > ## etc.; this value will already have been stored in $k). After the > > ## second count cut, return, so that we don't happen to do the loop > ## at the bottom. > if ($k) { > $D =~ s/(.{$k})(.*)(.)/$2$1$3/; > #print "key cut: $D\n"; > return; > } > > ## Find the value of the nth card in the deck, where n is the value > ## of the top card (be careful about off-by-one errors here) > $c=&v(&v(0)); > > ## If this wasn't a joker, return its value. If it was a joker, > ## just start again at the top of this subroutine. > $c>52?&e:$c; > > return $c; > } > > > > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, e-mail: php-general-unsubscribe@lists.php.net > For additional commands, e-mail: php-general-help@lists.php.net > To contact the list administrators, e-mail: php-list-admin@lists.php.net > >