Implement key2root-lskeys

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 142 insertions, 1 deletions

diff --git a/key2root-lskeys.c b/key2root-lskeys.c
index ee1732c..7dee003 100644
--- a/key2root-lskeys.c
+++ b/key2root-lskeys.c
@@ -1,6 +1,11 @@
 /* See LICENSE file for copyright and license details. */
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
 
 #include "arg.h"
 
@@ -16,13 +21,149 @@ usage(void)
 }
 
 
+static int
+outputkey(char *data, size_t whead, size_t *rheadp, size_t *rhead2p, size_t *linenop, const char *user)
+{
+	int failed = 0;
+	size_t len;
+
+	while (*rhead2p < whead || data[*rhead2p] != '\n')
+		++*rhead2p;
+
+	if (data[*rhead2p] != '\n')
+		return 0;
+
+	len = *rhead2p - *rheadp;
+	*linenop += 1;
+
+	if (memchr(&data[*rheadp], '\0', len)) {
+		fprintf(stderr, "%s: NUL byte found in /etc/key2root/%s on line %zu\n", argv0, user, *linenop);
+		failed = 1;
+	}
+	if (!memchr(&data[*rheadp], ' ', len)) {
+		fprintf(stderr, "%s: no SP byte found in /etc/key2root/%s on line %zu\n", argv0, user, *linenop);
+		failed = 1;
+	}
+
+	if (!failed) {
+		data[*rhead2p] = '\0';
+		printf("%s %s\n", user, &data[*rheadp]);
+	}
+
+	*rheadp = ++*rhead2p;
+	return failed;
+}
+
+
+static int
+listkeys(int dir, const char *user)
+{
+	int fd, failed = 0;
+	char *data = NULL, *new;
+	size_t size = 0;
+	size_t whead = 0;
+	size_t rhead = 0;
+	size_t rhead2 = 0;
+	size_t lineno = 0;
+	ssize_t r = 1;
+
+	fd = openat(dir, user, O_RDONLY);
+	if (fd < 0) {
+		if (errno == ENOENT)
+			return 0;
+		fprintf(stderr, "%s: openat /etc/key2root/ %s O_RDONLY: %s\n", argv0, user, strerror(errno));
+		return 1;
+	}
+
+	while (r) {
+		if (whead == size) {
+			memmove(data, &data[rhead], whead -= rhead);
+			rhead2 -= rhead;
+			rhead = 0;
+			if (whead == size) {
+				new = realloc(data, size += 1024);
+				if (!new) {
+					fprintf(stderr, "%s: realloc: %s\n", argv0, strerror(errno));
+					close(fd);
+					return 1;
+				}
+				data = new;
+			}
+		}
+		r = read(fd, &data[whead], size - whead);
+		if (r <= 0) {
+			fprintf(stderr, "%s: read /etc/key2root/%s: %s\n", argv0, user, strerror(errno));
+			close(fd);
+			return 1;
+		}
+		whead += (size_t)r;
+
+		while (rhead2 < whead)
+			failed |= outputkey(data, whead, &rhead, &rhead2, &lineno, user);
+	}
+
+	if (rhead != whead)
+		fprintf(stderr, "%s: file truncated: /etc/key2root/%s\n", argv0, user);
+
+	close(fd);
+	return failed;
+}
+
+
 int
 main(int argc, char *argv[])
 {
+	int failed = 0, fd;
+	DIR *dir;
+	struct dirent *f;
+
 	ARGBEGIN {
 	default:
 		usage();
 	} ARGEND;
 
-	return 0;
+	if (argc) {
+		fd = open("/etc/key2root/", O_PATH);
+		if (fd < 0) {
+			if (errno == ENOENT)
+				return 0;
+			fprintf(stderr, "%s: open /etc/key2root/ O_PATH: %s\n", argv0, strerror(errno));
+			exit(1);
+		}
+		for (; *argv; argv++) {
+			if (!(*argv)[0] || (*argv)[0] == '.' || strchr(*argv, '/') || strchr(*argv, '~')) {
+				fprintf(stderr, "%s: bad user name specified: %s\n", argv0, *argv);
+				failed = 1;
+			} else {
+				failed |= listkeys(fd, *argv);
+			}
+		}
+		close(fd);
+	} else {
+		dir = opendir("/etc/key2root/");
+		if (!dir) {
+			if (errno == ENOENT)
+				return 0;
+			fprintf(stderr, "%s: opendir /etc/key2root/: %s\n", argv0, strerror(errno));
+			exit(1);
+		}
+		fd = dirfd(dir);
+		if (fd < 0)
+			abort();
+		while ((errno = 0, f = readdir(dir))) {
+			if (f->d_name[0] == '.' || strchr(f->d_name, '~'))
+				continue;
+			listkeys(fd, f->d_name);
+		}
+		if (errno || closedir(dir)) {
+			fprintf(stderr, "%s: readdir /etc/key2root/: %s\n", argv0, strerror(errno));
+			exit(1);
+		}
+	}
+
+	if (fflush(stdout) || ferror(stdout) || fclose(stdout)) {
+		fprintf(stderr, "%s: print: %s\n", argv0, strerror(errno));
+		exit(1);
+	}
+	return failed;
 }