/*
  Copyright 2002 Colin Percival

  For the terms under which this work may be distributed, please see
  the adjoining file "LICENSE".
*/
/*
  verify.c

  Reads a 256 byte signature from stdin, reads a public key from
  pub.key, and outputs the verified data to stdout.  (If the
  signature is invalid, zero bytes will be written.)

  Typical usage:
    md5 -q ${FILE} > ${FILE}.md5 &&				\
    cat ${FILE}.sig | ./verify | cmp -s - ${FILE}.md5 &&	\
    echo "Verified!"

  Signatures are generated by sign.c
*/

#include <stdlib.h>
#include <stdio.h>

#include "ptypes.h"
#include "rsa.h"

#define KEYLEN 2048

int main(int argc,char *argv[])
{
    uint8 *dat,*pub,*T1;
    uint32 len;
    FILE * f;

    dat=malloc(KEYLEN/8);
    pub=malloc(KEYLEN/8);
    T1=malloc(KEYLEN*8);

    if((!dat)||(!pub)||(!T1)) {
        fprintf(stderr,"Out of memory\n");
        return 1;
    };

    if((f=fopen("pub.key","r"))==NULL) {
        fprintf(stderr,"Could not open public key file\n");
        return 1;
    };
    if(fread(pub,KEYLEN/8,1,f)<1) {
        fprintf(stderr,"Error reading from public key file\n");
        return 1;
    };
    if(fclose(f)) {
        fprintf(stderr,"Error closing public key file\n");
        return 1;
    };

    if(fread(dat,KEYLEN/8,1,stdin)<1) {
        fprintf(stderr,"Error reading %d bytes from stdin\n",KEYLEN/8);
        return 1;
    };

    len=rsa_verify(dat,dat,pub,KEYLEN,T1);

    if(fwrite(dat,len,1,stdout)<1) {
        fprintf(stderr,"Error writing to stdout\n");
        return 1;
    };

    free(T1);
    free(pub);
    free(dat);

    return 0;
}