From: ian <ian>
Date: Sat, 2 Mar 2002 15:52:36 +0000 (+0000)
Subject: Use openssl bf-ofb instead of md5sum repeatedly.  Make random be own namespace.
X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=commitdiff_plain;h=b9810123714164abb8b92455ae6fc2d16ba5ba99;p=vinegar-ip.git

Use openssl bf-ofb instead of md5sum repeatedly.  Make random be own namespace.
---

diff --git a/make-probes.tcl b/make-probes.tcl
index 2fb83be..8782f1a 100755
--- a/make-probes.tcl
+++ b/make-probes.tcl
@@ -18,9 +18,7 @@ proc manyset {list args} {
 
 proc start_gen {use_gen_counter} {
     global gen_counter rand_counter getlog_log rand_buf
-    set gen_counter $use_gen_counter
-    set rand_counter 0
-    set rand_buf {}
+    random-bytes-init $use_gen_counter
     set getlog_log {}
 }
 
@@ -35,24 +33,33 @@ proc packet-csum-ip {packet} {
     return [expr {$cs & 0xffff}]
 }
 
-set rand_buf {}
-proc random-bytes {n} {
-    global gen_counter rand_counter rand_buf
-    set n [expr {$n*2}]
-    set o {}
-    while {[set w [expr {$n - [string length $o]}]] > 0} {
-	if {![string length $rand_buf]} {
-	    set md5 [exec md5sum << "$gen_counter $rand_counter"]
-	    regexp {^[0-9a-f]{32}} $md5 rand_buf
-	    if {![string length $rand_buf]} { error "?$md5?" }
-	    incr rand_counter
+
+namespace eval Random-Bytes {
+    namespace export random-bytes random-bytes-init
+
+    proc random-bytes-init {seed} {
+	variable counter
+	variable fh
+	catch { set h $fh; unset fh; close $h }
+	set counter 0
+	set fh [open |[list openssl bf-ofb < /dev/zero -e -k " $seed"] r]
+	fconfigure $fh -translation binary
+    }
+    proc random-bytes {n} {
+	variable fh
+	set x [read $fh $n]
+	if {[string length $x] != $n} {
+	    set h $fh; unset fh; close $h
+	    error "openssl bf-ofb exited unexpectedly"
 	}
-	append o [string range $rand_buf 0 [expr {$w-1}]]
-	set rand_buf [string range $rand_buf $w end]
+	binary scan $x H* y
+	if {[string length $y] != $n*2} { error "binary format failed $n $y" }
+	return $y
     }
-    return $o
 }
 
+namespace import Random-Bytes::*
+
 proc choice-int {min max} {
     set rv 0x[random-bytes 3]
     return [expr {
@@ -186,7 +193,7 @@ proc get/v4addr {s v} {
     for {set i 0} {$i<4} {incr i} {
 	set b [random-bytes 1]
 	append rv $b
-	append p $d [format %d $b]
+	append p $d [format %d 0x$b]
 	set d .
     }
     getlog "$v=$p"
@@ -312,22 +319,30 @@ proc assembly-overwrite {outvarname location value} {
     if {$bitlen < 32 && $value >= (1<<$bitlen)} {
 	error "$diag $value >= 2**$bitlen"
     }
-    while {$bitlen > 0} {
-	set byteno [expr {$bit1 / 8}]
-	set char0no [expr {$byteno*2}]
-	set char1no [expr {$char0no+1}]
-	set bytebit [expr {128>>($bit1 % 8)}]
-	set byte 0x[string range $out $char0no $char1no]
-	debug 7 "< $bit1+$bitlen $byteno $char0no $bytebit $byte $out"
-	set byte [expr {
-	    ($value & (1<<($bitlen-1)))
-	    ? ($byte | $bytebit)
-	    : ($byte & ~$bytebit)
-	}]
-	set out [string replace $out $char0no $char1no [format %02x $byte]]
+    if {!($bit1 % 8) && !($bitlen % 8)} {
+	set char0no [expr {$bit1/4}]
+	set charlen [expr {$bitlen/4}]
+	set chareno [expr {$char0no + $charlen -1}]
+	set repl [format %0${charlen}x $value]
+	set out [string replace $out $char0no $chareno $repl]
+    } else {
+	while {$bitlen > 0} {
+	    set byteno [expr {$bit1 / 8}]
+	    set char0no [expr {$byteno*2}]
+	    set char1no [expr {$char0no+1}]
+	    set bytebit [expr {128>>($bit1 % 8)}]
+	    set byte 0x[string range $out $char0no $char1no]
+	    debug 7 "< $bit1+$bitlen $byteno $char0no $bytebit $byte $out"
+	    set byte [expr {
+		($value & (1<<($bitlen-1)))
+		? ($byte | $bytebit)
+		: ($byte & ~$bytebit)
+	    }]
+	    set out [string replace $out $char0no $char1no [format %02x $byte]]
  debug 8 "> $bit1+$bitlen $byteno $char0no $bytebit 0x[format %02x $byte] $out"
-	incr bitlen -1
-	incr bit1
+	    incr bitlen -1
+	    incr bit1
+	}
     }
 }
 
@@ -373,7 +388,7 @@ proc gen_1_ip {mtu} {
    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
     }
     assembly-overwrite ip ${?_header_checksum} [packet-csum-ip $ip]
-    append $ip $body
+    append ip $body
     return $ip
 }
 
@@ -528,6 +543,10 @@ define ip-proto 17 udp {mtu} {
     assembly-overwrite udp ${?_checksum} $csum
 }
 
+
+
+
+
 proc emit {count} {
     global getlog_log errorInfo
     if {[catch {