/* Pass len=0 to hash an entire file */ static int process_file(hash_state *hs, const char *filename, unsigned int len, int prngd) { static int already_blocked = 0; int readfd; unsigned int readcount; int ret = DROPBEAR_FAILURE; #ifdef DROPBEAR_PRNGD_SOCKET if (prngd) { readfd = connect_unix(filename); } else #endif { readfd = open(filename, O_RDONLY); } if (readfd < 0) { goto out; } readcount = 0; while (len == 0 || readcount < len) { int readlen, wantread; unsigned char readbuf[4096]; if (!already_blocked && !prngd) { int res; struct timeval timeout; fd_set read_fds; timeout.tv_sec = 2; timeout.tv_usec = 0; FD_ZERO(&read_fds); FD_SET(readfd, &read_fds); res = select(readfd + 1, &read_fds, NULL, NULL, &timeout); if (res == 0) { dropbear_log(LOG_WARNING, "Warning: Reading the randomness source '%s' seems to have blocked.\nYou may need to find a better entropy source.", filename); already_blocked = 1; } } if (len == 0) { wantread = sizeof(readbuf); } else { wantread = MIN(sizeof(readbuf), len-readcount); } #ifdef DROPBEAR_PRNGD_SOCKET if (prngd) { char egdcmd[2]; egdcmd[0] = 0x02; /* blocking read */ egdcmd[1] = (unsigned char)wantread; if (write(readfd, egdcmd, 2) < 0) { dropbear_exit("Can't send command to egd"); } } #endif readlen = read(readfd, readbuf, wantread); if (readlen <= 0) { if (readlen < 0 && errno == EINTR) { continue; } if (readlen == 0 && len == 0) { /* whole file was read as requested */ break; } goto out; } sha1_process(hs, readbuf, readlen); readcount += readlen; } ret = DROPBEAR_SUCCESS; out: close(readfd); return ret; }
static void readrand(unsigned char* buf, unsigned int buflen) { static int already_blocked = 0; int readfd; unsigned int readpos; int readlen; #ifdef DROPBEAR_PRNGD_SOCKET struct sockaddr_un egdsock; char egdcmd[2]; #endif #ifdef DROPBEAR_RANDOM_DEV readfd = open(DROPBEAR_RANDOM_DEV, O_RDONLY); if (readfd < 0) { dropbear_exit("Couldn't open random device"); } #endif #ifdef DROPBEAR_PRNGD_SOCKET readfd = connect_unix(DROPBEAR_PRNGD_SOCKET); if (readfd < 0) { dropbear_exit("Couldn't open random device"); } if (buflen > 255) dropbear_exit("Can't request more than 255 bytes from egd"); egdcmd[0] = 0x02; /* blocking read */ egdcmd[1] = (unsigned char)buflen; if (write(readfd, egdcmd, 2) < 0) dropbear_exit("Can't send command to egd"); #endif /* read the actual random data */ readpos = 0; do { if (!already_blocked) { int ret; struct timeval timeout; fd_set read_fds; timeout.tv_sec = 2; /* two seconds should be enough */ timeout.tv_usec = 0; FD_ZERO(&read_fds); FD_SET(readfd, &read_fds); ret = select(readfd + 1, &read_fds, NULL, NULL, &timeout); if (ret == 0) { dropbear_log(LOG_INFO, "Warning: Reading the random source seems to have blocked.\nIf you experience problems, you probably need to find a better entropy source."); already_blocked = 1; } } readlen = read(readfd, &buf[readpos], buflen - readpos); if (readlen <= 0) { if (readlen < 0 && errno == EINTR) { continue; } dropbear_exit("Error reading random source"); } readpos += readlen; } while (readpos < buflen); close (readfd); }