DIMA/trial1/layer1.c
2020-05-19 15:59:18 +02:00

132 lines
2.6 KiB
C

#include "layer1.h"
//Layer 1 functions
#define UDSFILE "./out/RANDFILE"
#define UDSsize 8 //bytes
int createUDS()
{
int ret = RAND_write_file(UDSFILE);
if (ret == -1)
perror("rand write to file failed\n");
printf("\n %d bytes written to file\n", ret);
//readUDS();
return 0;
}
int readUDS(uint8_t* UDS_M)
{
//1. Create RANDFILE if it does not exist. skip if it exists
//2. Load RANDFILE
//3. Read 64 bits to UDSbuf and compute hash into input arg.
//4. free UDSbuf
BIO *fp, *out;
int i;
//uint8_t UDSbuf[UDSsize] = {0};
//uint8_t UDS_M[SHA256_dig_t] = {0};
uint8_t* UDSbuf = calloc(1,sizeof(uint8_t)*UDSsize);
//uint8_t* UDS_M = calloc(1,sizeof(uint8_t)*SHA256_dig_t);
out = BIO_new_fp(stdout, BIO_NOCLOSE);
int ret = RAND_load_file(UDSFILE, 8);
while (ret < 0)
{
perror("Could not load seed file\n");
BIO_printf(out,"Creating new seed file\n");
createUDS();
ret = RAND_load_file(UDSFILE, 8);
}
fp = BIO_new_file(UDSFILE, "r");
if(!fp)
perror("Opening seed file to read failed\n");
if (BIO_read(fp,UDSbuf,UDSsize) < 0)
perror("BIO read failed\n");
//Compute hash of UDS
if(SHA256(UDSbuf, UDSsize, UDS_M) == NULL)
perror("UDS measurement failed\n");
//Print block. delete later
for(i = 0; i < UDSsize; i++)
BIO_printf(out,"%x",UDSbuf[i]);
BIO_printf(out, "\n");
BIO_printf(out,"UDS digest : ");
for(i = 0; i < SHA256_dig_t; i++)
BIO_printf(out,"%x",UDS_M[i]);
BIO_printf(out, "\n");
free(UDSbuf);
BIO_free(fp);
BIO_free(out);
return 1;
}
int readFWID(uint8_t * FW_M)
{
//1. Read layer1.c into memory
//2. Calcualte hash into arg
printf("in readFWID\n");
uint8_t * source = NULL;
BIO *fp, *out;
int filesize = 0;
int i;
out = BIO_new_fp(stdout, BIO_NOCLOSE);
fp = BIO_new_file("layer1.c", "r");
printf("in 2readFWID\n");
if(!fp)
perror("Opening FW to read failed\n");
if(BIO_eof(fp))
perror("File empty\n");
printf("in 3readFWID\n"); //SEG FAULT!
while(!BIO_eof(fp))
{
BIO_read(fp, source[filesize], 1);
filesize++; //filesize includes EOF
}
printf("in 4readFWID\n");
if(SHA256(source, filesize -1, FW_M) == NULL)
perror("FW measurement failed\n");
//print block
printf("in 5readFWID\n");
BIO_printf(out,"FW digest : ");
for(i = 0; i < SHA256_dig_t; i++)
BIO_printf(out,"%x",FW_M[i]);
BIO_printf(out, "\n");
//free(source);
BIO_free(fp);
BIO_free(out);
return 1;
}
// int calcCDID(uint8_t * UDS_M, uint8_t * FW_M, uint8_t * CDID)
// {
// //0. internally call readUDS and readFWID? abstraction of UDS against layer2
// //1. create sha256 context
// //2. add UDS hash
// //3. add FW hash
// //4. calc composite hash into CDID arg
// return 1;
// }