1 files changed, 172 insertions, 0 deletions
diff --git a/demo-login.c b/demo-login.c
new file mode 100644
index 0000000..fd3c750
--- /dev/null
+++ b/demo-login.c
@@ -0,0 +1,172 @@
+/* See LICENSE file for copyright and license details. */
+#include "libsecauth.h"
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define PEPPER "pepper"
+
+
+static char *
+server_lookup_hash(void)
+{
+	char *settings;
+	size_t size, len;
+	ssize_t r;
+	int fd;
+
+	fd = open("democonfig", O_RDONLY);
+	if (fd < 0) {
+		perror("open");
+		return NULL;
+	}
+	settings = NULL;
+	size = 0;
+	for (len = 0;; len += (size_t)r) {
+		if (len == size) {
+			settings = realloc(settings, size += 128);
+			if (!settings) {
+				perror("realloc");
+				return NULL;
+			}
+		}
+		r = read(fd, &settings[len], size - len);
+		if (r <= 0) {
+			if (!r)
+				break;
+			perror("read");
+			return NULL;
+		}
+	}
+	close(fd);
+	if (!len || settings[len - 1] != '\n') {
+		fprintf(stderr, "./democonfig is corrupt\n");
+		return NULL;
+	}
+	settings[len - 1] = '\0';
+
+	return settings;
+}
+
+int
+main(int argc, char *argv[])
+{
+	struct libsecauth_spec spec;
+	char *message, *settings, *expected;
+	size_t size, off;
+	int fd;
+	ssize_t w;
+	int r;
+
+	if (argc != 2) {
+		fprintf(stderr, "usage: %s password", argv[0]);
+		return 1;
+	}
+
+	/* -- SERVER -- */
+
+	settings = server_lookup_hash();
+	if (!settings)
+		return 1;
+	if (libsecauth_parse_spec(&spec, settings)) {
+		perror("libsecauth_parse_spec");
+		return 1;
+	}
+	spec.posthash = NULL;
+	spec.expected = NULL;
+	spec.client_rounds -= spec.client_rounds > 0;
+	spec.server_rounds = 0;
+
+	size = libsecauth_format_spec(&spec, NULL, 0);
+	message = malloc(size);
+	if (!message) {
+		perror("malloc");
+		return 1;
+	}
+	libsecauth_format_spec(&spec, message, size);
+	free(settings);
+
+	/* -- CLIENT -- */
+
+	settings = message;
+	if (libsecauth_parse_spec(&spec, settings)) {
+		perror("libsecauth_parse_spec");
+		return 1;
+	}
+	message = libsecauth_client_hash(&spec, argv[1]);
+	if (!message) {
+		perror("libsecauth_client_hash");
+		return 1;
+	}
+	free(settings);
+
+	/* -- SERVER -- */
+
+	settings = server_lookup_hash();
+	if (!settings)
+		return 1;
+	if (libsecauth_parse_spec(&spec, settings)) {
+		perror("libsecauth_parse_spec");
+		return 1;
+	}
+	spec.server_rounds += spec.client_rounds > 0;
+	spec.client_rounds -= spec.client_rounds > 0;
+	r = libsecauth_server_hash(&spec, message, PEPPER, NULL);
+	if (r < 0) {
+		perror("libsecauth_server_hash");
+		return 1;
+	} else if (!r) {
+		free(settings);
+		free(message);
+		printf("Incorrect password\n");
+		return 0;
+	}
+	printf("Login OK\n");
+
+	expected = NULL;
+	if (!spec.client_rounds) {
+		spec.xferhash = "$1$newsalt1$";
+		spec.posthash = "$6$rounds=1000$newsalt2$";
+		spec.expected = NULL;
+		spec.server_rounds = 100;
+		if (libsecauth_server_hash(&spec, message, PEPPER, &expected) < 0) {
+			perror("libsecauth_server_hash");
+			return 1;
+		}
+		spec.client_rounds = spec.server_rounds;
+		spec.server_rounds = 0;
+		spec.expected = expected;
+		printf("password rehashed\n");
+	}
+	free(message);
+	size = libsecauth_format_spec(&spec, NULL, 0);
+	message = malloc(size);
+	if (!message) {
+		perror("malloc");
+		return 1;
+	}
+	libsecauth_format_spec(&spec, message, size);
+	free(settings);
+	free(expected);
+
+	message[size - 1] = '\n';
+	fd = open("democonfig", O_WRONLY | O_TRUNC, 0600);
+	if (fd < 0) {
+		perror("open");
+		return 1;
+	}
+	for (off = 0; off < size; off += (size_t)w) {
+		w = write(fd, &message[off], size - off);
+		if (w <= 0) {
+			perror("write");
+			return 1;
+		}
+	}
+	close(fd);
+
+	free(message);
+
+	return 0;
+}