diff options
Diffstat (limited to '3rdParty/captcha/captcha.c')
| -rw-r--r-- | 3rdParty/captcha/captcha.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/3rdParty/captcha/captcha.c b/3rdParty/captcha/captcha.c new file mode 100644 index 0000000..7881b90 --- /dev/null +++ b/3rdParty/captcha/captcha.c @@ -0,0 +1,193 @@ + +const int gifsize; +void captcha(unsigned char im[70*200], unsigned char l[6]); +void makegif(unsigned char im[70*200], unsigned char gif[gifsize]); + +#include <unistd.h> +#include <stdint.h> +#include <fcntl.h> +#include <string.h> + +static int8_t *lt[]; +const int gifsize=17646; + +void makegif(unsigned char im[70*200], unsigned char gif[gifsize]) { + // tag ; widthxheight ; GCT:0:0:7 ; bgcolor + aspect // GCT + // Image Separator // left x top // widthxheight // Flags + // LZW code size + memcpy(gif,"GIF89a" "\xc8\0\x46\0" "\x83" "\0\0" + "\x00\x00\x00" + "\x10\x10\x10" + "\x20\x20\x20" + "\x30\x30\x30" + "\x40\x40\x40" + "\x50\x50\x50" + "\x60\x60\x60" + "\x70\x70\x70" + "\x80\x80\x80" + "\x90\x90\x90" + "\xa0\xa0\xa0" + "\xb0\xb0\xb0" + "\xc0\xc0\xc0" + "\xd0\xd0\xd0" + "\xe0\xe0\xe0" + "\xff\xff\xff" + "," "\0\0\0\0" "\xc8\0\x46\0" "\0" "\x04",13+48+10+1); + + int x,y; + unsigned char *i=im; + unsigned char *p=gif+13+48+10+1; + for(y=0;y<70;y++) { + *p++=250; // Data length 5*50=250 + for(x=0;x<50;x++) + { + unsigned char a=i[0]>>4,b=i[1]>>4,c=i[2]>>4,d=i[3]>>4; + + p[0]=16|(a<<5); // bbb10000 + p[1]=(a>>3)|64|(b<<7); // b10000xb + p[2]=b>>1; // 0000xbbb + p[3]=1|(c<<1); // 00xbbbb1 + p[4]=4|(d<<3); // xbbbb100 + i+=4; + p+=5; + } + } + + // Data length // End of LZW (b10001) // Terminator // GIF End + memcpy(gif+gifsize-4,"\x01" "\x11" "\x00" ";",4); +} + +static const int8_t sw[200]={0, 4, 8, 12, 16, 20, 23, 27, 31, 35, 39, 43, 47, 50, 54, 58, 61, 65, 68, 71, 75, 78, 81, 84, 87, 90, 93, 96, 98, 101, 103, 105, 108, 110, 112, 114, 115, 117, 119, 120, 121, 122, 123, 124, 125, 126, 126, 127, 127, 127, 127, 127, 127, 127, 126, 126, 125, 124, 123, 122, 121, 120, 119, 117, 115, 114, 112, 110, 108, 105, 103, 101, 98, 96, 93, 90, 87, 84, 81, 78, 75, 71, 68, 65, 61, 58, 54, 50, 47, 43, 39, 35, 31, 27, 23, 20, 16, 12, 8, 4, 0, -4, -8, -12, -16, -20, -23, -27, -31, -35, -39, -43, -47, -50, -54, -58, -61, -65, -68, -71, -75, -78, -81, -84, -87, -90, -93, -96, -98, -101, -103, -105, -108, -110, -112, -114, -115, -117, -119, -120, -121, -122, -123, -124, -125, -126, -126, -127, -127, -127, -127, -127, -127, -127, -126, -126, -125, -124, -123, -122, -121, -120, -119, -117, -115, -114, -112, -110, -108, -105, -103, -101, -98, -96, -93, -90, -87, -84, -81, -78, -75, -71, -68, -65, -61, -58, -54, -50, -47, -43, -39, -35, -31, -27, -23, -20, -16, -12, -8, -4}; + + +#define MAX(x,y) ((x>y)?(x):(y)) + +static int letter(int n, int pos, unsigned char im[70*200], unsigned char swr[200], uint8_t s1, uint8_t s2) { + int8_t *p=lt[n]; + unsigned char *r=im+200*16+pos; + unsigned char *i=r; + int sk1=s1+pos; + int sk2=s2+pos; + int mpos=pos; + int row=0; + for(;*p!=-101;p++) { + if(*p<0) { + if(*p==-100) { r+=200; i=r; sk1=s1+pos; row++; continue; } + i+=-*p; + continue; + } + + if(sk1>=200) sk1=sk1%200; + int skew=sw[sk1]/16; + sk1+=(swr[pos+i-r]&0x1)+1; + + if(sk2>=200) sk2=sk2%200; + int skewh=sw[sk2]/70; + sk2+=(swr[row]&0x1); + + unsigned char *x=i+skew*200+skewh; + mpos=MAX(mpos,pos+i-r); + + if((x-im)<70*200) *x=(*p)<<4; + i++; + } + return mpos; +} + +#define NDOTS 100 + +uint32_t dr[NDOTS]; + +static void line(unsigned char im[70*200], unsigned char swr[200], uint8_t s1) { + int x; + int sk1=s1; + for(x=0;x<199;x++) { + if(sk1>=200) sk1=sk1%200; + int skew=sw[sk1]/16; + sk1+=swr[x]&0x3+1; + unsigned char *i= im+(200*(45+skew)+x); + i[0]=0; i[1]=0; i[200]=0; i[201]=0; + } +} + +static void dots(unsigned char im[70*200]) { + int n; + for(n=0;n<NDOTS;n++) { + uint32_t v=dr[n]; + unsigned char *i=im+v%(200*67); + + i[0]=0xff; + i[1]=0xff; + i[2]=0xff; + i[200]=0xff; + i[201]=0xff; + i[202]=0xff; + } +} +static void blur(unsigned char im[70*200]) { + unsigned char *i=im; + int x,y; + for(y=0;y<68;y++) { + for(x=0;x<198;x++) { + unsigned int c11=*i,c12=i[1],c21=i[200],c22=i[201]; + *i++=((c11+c12+c21+c22)/4); + } + } +} + +static void filter(unsigned char im[70*200]) { + unsigned char om[70*200]; + unsigned char *i=im; + unsigned char *o=om; + + memset(om,0xff,sizeof(om)); + + int x,y; + for(y=0;y<70;y++) { + for(x=4;x<200-4;x++) { + if(i[0]>0xf0 && i[1]<0xf0) { o[0]=0; o[1]=0; } + else if(i[0]<0xf0 && i[1]>0xf0) { o[0]=0; o[1]=0; } + + i++; + o++; + } + } + + memmove(im,om,sizeof(om)); +} + +static const char *letters="abcdafahijklmnopqrstuvwxyz"; + +void captcha(unsigned char im[70*200], unsigned char l[6]) { + unsigned char swr[200]; + uint8_t s1,s2; + + int f=open("/dev/urandom",O_RDONLY); + read(f,l,5); read(f,swr,200); read(f,dr,sizeof(dr)); read(f,&s1,1); read(f,&s2,1); + close(f); + + memset(im,0xff,200*70); s1=s1&0x7f; s2=s2&0x3f; l[0]%=25; l[1]%=25; l[2]%=25; l[3]%=25; l[4]%=25; l[5]=0; + int p=30; p=letter(l[0],p,im,swr,s1,s2); p=letter(l[1],p,im,swr,s1,s2); p=letter(l[2],p,im,swr,s1,s2); p=letter(l[3],p,im,swr,s1,s2); letter(l[4],p,im,swr,s1,s2); + dots(im); blur(im); filter(im); line(im,swr,s1); + l[0]=letters[l[0]]; l[1]=letters[l[1]]; l[2]=letters[l[2]]; l[3]=letters[l[3]]; l[4]=letters[l[4]]; +} + +#ifdef CAPTCHA + +int main() { + char l[6]; + unsigned char im[70*200]; + unsigned char gif[gifsize]; + + captcha(im,l); + makegif(im,gif); + + write(1,gif,gifsize); + write(2,l,5); + + return 0; +} + +#endif + +#include "f.h" |