From dbdf5bf63f824e58ede493be16db691e3902e506 Mon Sep 17 00:00:00 2001
From: deuce <>
Date: Thu, 24 Aug 2006 23:59:07 +0000
Subject: [PATCH] Apply some optimize-fu to the brute-force routine. Over twice
as fast now baby... and that's a debug build.
---
src/sbbs3/unbaja.c | 112 +++++++++++++++++++++++----------------------
1 file changed, 58 insertions(+), 54 deletions(-)
diff --git a/src/sbbs3/unbaja.c b/src/sbbs3/unbaja.c
index a57f22bb6a..5ab062114b 100644
--- a/src/sbbs3/unbaja.c
+++ b/src/sbbs3/unbaja.c
@@ -179,52 +179,12 @@ struct var_table_t {
const char *char_table="________________________________________________123456789!_______BCDEFGHIJKLMNOPQRSTUVWXYZ0____A________________________________________________________________________________________________________________________________________________________________";
const char *first_char_table="_________________________________________________________________BCDEFGHIJKLMNOPQRSTUVWXYZ!____A________________________________________________________________________________________________________________________________________________________________";
-char *brute_buf=NULL;
+unsigned char *brute_buf=NULL;
+unsigned long *brute_crc_buf=NULL;
size_t brute_len=0;
char **bruted=NULL;
size_t bruted_len=0;
-/* This can be optimized */
-int increment_name(unsigned char *name, size_t len)
-{
- unsigned char *pos;
- size_t l;
-
- pos=strchr(name,0);
- if(pos==NULL) {
- printf("Brute force increment failure\ncannot find end of string\n");
- return(-1);
- }
- l=pos-name;
- if(pos>name)
- pos--;
- while(pos>name) {
- if(*pos=='9') /* last char from more_chars */
- pos--;
- else {
- *pos=char_table[*pos];
- pos++;
- memset(pos,'_',strlen(pos));
- return(0);
- }
- }
- if(*pos=='Z' || *pos==0) { /* last char from first_chars */
- /* This the max? */
- if(l==len)
- return(-1);
- /* Set string to '_' first char from both */
- memset(name,'_',l+1);
- /* Add new at end */
- pos=name+l+1;
- *pos=0;
- return(0);;
- }
- *pos=first_char_table[*pos];
- pos++;
- memset(pos,'_',strlen(pos));
- return(0);
-}
-
void add_bruted(long name, char *val)
{
char **new_bruted;
@@ -256,11 +216,14 @@ char *find_bruted(long name)
return(NULL);
}
-char* bruteforce(long name)
+char* bruteforce(unsigned long name)
{
long this_crc=0;
char *ret;
int counter=0;
+ unsigned char *pos;
+ size_t l=0;
+ size_t i,j;
if(!brute_len)
return(NULL);
@@ -269,20 +232,56 @@ char* bruteforce(long name)
return(NULL);
return(ret);
}
- brute_buf[0]=0;
- increment_name(brute_buf, brute_len);
+ memset(brute_buf,0,brute_len+1);
+ memset(brute_crc_buf,0,brute_len*sizeof(long));
printf("Brute forcing var_%08x\n",name);
- while(crc32(brute_buf,0)!=name) {
- if(increment_name(brute_buf, brute_len)) {
- printf("\r%s Not found.\n",brute_buf);
- add_bruted(name,"");
- return(NULL);
+ this_crc=crc32(brute_buf,0);
+ while(this_crc!=name) {
+ pos=brute_buf+l;
+ if(pos>brute_buf) {
+ pos--;
+ while(pos>brute_buf) {
+ if(*pos!='9') { /* last char from more_chars */
+ *pos=char_table[*pos];
+ pos++;
+ i=(size_t)(pos-brute_buf);
+ memset(pos,'_',l-i);
+ /* Calculate all the following CRCs */
+ for(i--;brute_buf[i];i++)
+ brute_crc_buf[i]=ucrc32(brute_buf[i],brute_crc_buf[i-1]);
+ goto LOOP_END;
+ }
+ else
+ pos--;
+ }
}
- if(!((++counter)%1000)) {
- printf("\r%s ",brute_buf);
- counter=0;
+ if(*pos=='Z' || *pos==0) { /* last char from first_chars */
+ /* This the max? */
+ if(l==brute_len) {
+ printf("\r%s Not found.\n",brute_buf);
+ add_bruted(name,"");
+ return(NULL);
+ }
+ /* Set string to '_' with one extra at end */
+ memset(brute_buf,'_',++l);
+ brute_crc_buf[0]=ucrc32(brute_buf[0],~0UL);
+ for(i=1;brute_buf[i];i++)
+ brute_crc_buf[i]=ucrc32(brute_buf[i],brute_crc_buf[i-1]);
+ /* String is pre-filled with zeros so no need to terminate */
+ goto LOOP_END;
}
+ *pos=first_char_table[*pos];
+ memset(brute_buf+1,'_',l-1);
+ brute_crc_buf[0]=ucrc32(brute_buf[0],~0UL);
+ for(i=1;brute_buf[i];i++)
+ brute_crc_buf[i]=ucrc32(brute_buf[i],brute_crc_buf[i-1]);
+
+LOOP_END:
+ this_crc=~(brute_crc_buf[l-1]);
+ if(!((++counter)%10000))
+ printf("\r%s ",brute_buf);
}
+
printf("\r%s Found!\n",brute_buf);
add_bruted(name,brute_buf);
return(brute_buf);
@@ -2289,9 +2288,14 @@ int main(int argc, char **argv)
if(!strncmp(argv[f],"-b",2)) {
brute_len=atoi(argv[f]+2);
if(brute_len) {
- brute_buf=(char *)malloc(brute_len-1);
+ brute_buf=(char *)malloc(brute_len+1);
if(!brute_buf)
brute_len=0;
+ brute_crc_buf=(unsigned long *)malloc(brute_len*sizeof(unsigned long));
+ if(!brute_crc_buf) {
+ free(brute_buf);
+ brute_len=0;
+ }
}
printf("Will brute-force up to %d chars\n",brute_len);
continue;
--
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