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/*
* pkd_util.c -- pkd utilities
*
* (c) 2014, 2018 Jon Simons <jon@jonsimons.org>
*/
#include <errno.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>
#include "pkd_client.h"
#include "pkd_util.h"
/**
* @brief runs system(3); exits if that is interrupted with SIGINT/QUIT
* @returns 0 upon success, non-zero otherwise
*/
int system_checked(const char *cmd) {
int rc = system(cmd);
if (WIFSIGNALED(rc) &&
((WTERMSIG(rc) == SIGINT) || (WTERMSIG(rc) == SIGQUIT))) {
exit(1);
}
if (rc == -1) {
return -1;
}
return WEXITSTATUS(rc);
}
static int bin_exists(const char *binary) {
char bin[1024] = { 0 };
snprintf(&bin[0], sizeof(bin), "type %s 1>/dev/null 2>/dev/null", binary);
return (system_checked(bin) == 0);
}
static int is_openssh_client_new_enough(void) {
int rc = -1;
FILE *fp = NULL;
char version_buff[1024] = { 0 };
char *version;
static int version_ok = 0;
unsigned long int major = 0;
char *tmp = NULL;
if (version_ok) {
return version_ok;
}
fp = popen("ssh -V 2>&1", "r");
if (fp == NULL) {
fprintf(stderr, "failed to get OpenSSH client version\n");
goto done;
}
do {
if (fgets(&version_buff[0], sizeof(version_buff), fp) == NULL) {
fprintf(stderr, "failed to get OpenSSH client version string\n");
goto errfgets;
}
version = strstr(version_buff, "OpenSSH");
} while(version == NULL);
/* "OpenSSH_<major>.<minor><SP>..." */
if (strlen(version) < 11) {
goto errversion;
}
/* Extract major. */
major = strtoul(version + 8, &tmp, 10);
if ((tmp == (version + 8)) ||
((errno == ERANGE) && (major == ULONG_MAX)) ||
((errno != 0) && (major == 0)) ||
((major < 1) || (major > 100))) {
fprintf(stderr, "failed to parse OpenSSH client version, "
"errno %d\n", errno);
errno = 0;
goto errversion;
}
if (major < 7) {
fprintf(stderr, "error: minimum OpenSSH client version "
"required is 7, found: %ld\n", major);
goto errversion;
}
version_ok = 1;
errversion:
errfgets:
rc = pclose(fp);
if (rc != 0) {
fprintf(stderr, "failed to get OpenSSH client version: %d\n", rc);
}
done:
return version_ok;
}
int is_openssh_client_enabled(void) {
return (bin_exists(OPENSSH_BINARY) &&
bin_exists(OPENSSH_KEYGEN) &&
is_openssh_client_new_enough());
}
int is_dropbear_client_enabled(void) {
return (bin_exists(DROPBEAR_BINARY) && bin_exists(DROPBEAR_KEYGEN));
}
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