change license + misc

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

1 files changed, 251 insertions, 0 deletions

diff --git a/file2key.c b/file2key.c
new file mode 100644
index 0000000..77b9fc3
--- /dev/null
+++ b/file2key.c
@@ -0,0 +1,251 @@
+/* See LICENSE file for copyright and license details. */
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <passphrase.h>
+#include <libkeccak.h>
+
+#include "config.h"
+#include "settings.h"
+
+
+/**
+ * Map from hexadecimal to colour-coded hexadecimal
+ */
+const char *const COLOUR_HEX[] = {
+	['0'] = "\033[31m0",
+	['1'] = "\033[31m1",
+	['2'] = "\033[32m2",
+	['3'] = "\033[33m3",
+	['4'] = "\033[32m4",
+	['5'] = "\033[33m5",
+	['6'] = "\033[31m6",
+	['7'] = "\033[34m7",
+	['8'] = "\033[34m8",
+	['9'] = "\033[34m9",
+	['a'] = "\033[32ma",
+	['b'] = "\033[31mb",
+	['c'] = "\033[33mc",
+	['d'] = "\033[34md",
+	['e'] = "\033[33me",
+	['f'] = "\033[32mf",
+};
+
+
+
+/**
+ * `argv[0]` from `main`
+ */
+static char *argv0;
+
+
+
+/**
+ * Ask the user for the passphrase
+ * 
+ * @param   passphrasep  Output parameter for the passphrase
+ * @return               Zero on success, an appropriate exit value on error
+ */
+static int
+get_passphrase(char **passphrasep)
+{
+	int ttyfd;
+	ttyfd = open("/dev/tty", O_RDONLY);
+	if (ttyfd < 0) {
+		perror(argv0);
+		return 2;
+	}
+	passphrase_disable_echo1(ttyfd);
+	fprintf(stderr, "%s", PASSPHRASE_PROMPT_STRING);
+	fflush(stderr);
+	*passphrasep = passphrase_read2(ttyfd, PASSPHRASE_READ_EXISTING);
+	if (!*passphrasep)
+		perror(argv0);
+	passphrase_reenable_echo1(ttyfd);
+	close(ttyfd);
+	return *passphrasep ? 0 : 2;
+}
+
+
+/**
+ * Hash, and display, passphrase so to hint the
+ * user whether it as typed correctly or not
+ * 
+ * @param   passphrase  The passphrase
+ * @return              Zero on success, an appropriate exit value on error
+ */
+static int
+hash_passphrase(const char *passphrase)
+{
+	struct libkeccak_spec spec;
+	struct libkeccak_state state;
+	char hashsum[PASSPHRASE_KECCAK_OUTPUT / 8];
+	char hexsum[PASSPHRASE_KECCAK_OUTPUT / 4 + 1];
+	size_t i, n;
+
+	spec.bitrate  = PASSPHRASE_KECCAK_RATE;
+	spec.capacity = PASSPHRASE_KECCAK_CAPACITY;
+	spec.output   = PASSPHRASE_KECCAK_OUTPUT;
+
+	if (libkeccak_spec_check(&spec) || PASSPHRASE_KECCAK_SQUEEZES <= 0) {
+		fprintf(stderr, "%s: bad passhprase hashing parameters, please recompile file2key with with "
+		                    "proper values on PASSPHRASE_KECCAK_RATE, PASSPHRASE_KECCAK_CAPACITY, "
+		                    "PASSPHRASE_KECCAK_OUTPUT and PASSPHRASE_KECCAK_SQUEEZES", argv0);
+		return 1;
+	}
+
+	if (libkeccak_state_initialise(&state, &spec)) {
+		perror(argv0);
+		return 2;
+	}
+
+	if (libkeccak_digest(&state, passphrase, strlen(passphrase), 0, NULL, PASSPHRASE_KECCAK_SQUEEZES == 1 ? hashsum : NULL)) {
+		perror(argv0);
+		libkeccak_state_destroy(&state);
+		return 2;
+	}
+	if (PASSPHRASE_KECCAK_SQUEEZES > 2)
+		libkeccak_fast_squeeze(&state, PASSPHRASE_KECCAK_SQUEEZES - 2);
+	if (PASSPHRASE_KECCAK_SQUEEZES > 1)
+		libkeccak_squeeze(&state, hashsum);
+
+	libkeccak_state_destroy(&state);
+
+	libkeccak_behex_lower(hexsum, hashsum, sizeof(hashsum) / sizeof(char));
+	fprintf(stderr, "%s: passphrase hash: ", argv0);
+	for (i = 0, n = strlen(hexsum); i < n; i++)
+		fprintf(stderr, "%s", COLOUR_HEX[(unsigned char)hexsum[i]]);
+	fprintf(stderr, "\033[00m\n");
+
+	return 0;
+}
+
+
+/**
+ * @return  0: success
+ *          1: user error
+ *          2: on system error
+ */
+int
+main(int argc, char *argv[])
+{
+	struct libkeccak_generalised_spec gspec;
+	struct libkeccak_spec spec;
+	struct libkeccak_state state;
+	char *passphrase = NULL;
+	char *hash = NULL;
+	size_t hash_size = 0;
+	size_t hash_ptr = 0;
+	char *data = NULL;
+	size_t data_size = 0;
+	size_t data_ptr = 0;
+	size_t blksize = 4096;
+	int r, fd = -1;
+	struct stat attr;
+	size_t start;
+	ssize_t n;
+
+	argv0 = *argv++, argc--;
+	if (argc > 0 && argv[0][0] == '-') {
+		if (argv[0][1] == '-' && !argv[0][2])
+			argv++, argc--;
+		else if (argv[0][1])
+			goto usage;
+	}
+	if (argc > 1) {
+	usage:
+		fprintf(stderr, "usage: %s [file]\n", argv0);
+		return 1;
+	}
+
+	if (argc > 0 && strcmp(argv[0], "-")) {
+		fd = open(argv[0], O_RDONLY);
+		if (fd < 0)
+			goto pfail;
+	} else {
+		fd = STDIN_FILENO;
+	}
+	if (isatty(fd)) {
+		fprintf(stderr, "%s: input file must not be a terminal\n", argv0);
+		close(fd);
+		return 1;
+	}
+	if (fstat(fd, &attr) == 0)
+		if (attr.st_blksize > 0)
+			blksize = (size_t)attr.st_blksize;
+
+	libkeccak_generalised_spec_initialise(&gspec);
+	libkeccak_degeneralise_spec(&gspec, &spec);
+	if (libkeccak_state_initialise(&state, &spec))
+		goto pfail;
+	if ((r = get_passphrase(&passphrase)))
+		goto fail;
+	if ((r = hash_passphrase(passphrase)))
+		goto fail;
+	if (libkeccak_update(&state, passphrase, strlen(passphrase)))
+		goto pfail;
+	passphrase_wipe(passphrase, strlen(passphrase));
+	free(passphrase);
+	passphrase = NULL;
+
+	hash_size = (size_t)(spec.output / 8);
+	if (!(hash = malloc(hash_size)))
+		goto pfail;
+	if (!(data = malloc(blksize)))
+		goto pfail;
+
+	if (libkeccak_digest(&state, KEY_PEPPER, strlen(KEY_PEPPER), 0, NULL, hash))
+		goto pfail;
+
+	for (;;) {
+		if (hash_ptr == hash_size) {
+			libkeccak_squeeze(&state, hash);
+			hash_ptr = 0;
+		}
+
+		if (data_ptr == data_size) {
+			n = read(fd, data, blksize);
+			if (n <= 0) {
+				if (!n)
+					break;
+				goto pfail;
+			}
+			data_size = (size_t)n;
+			data_ptr = 0;
+		}
+
+		start = data_ptr;
+		while (hash_ptr < hash_size && data_ptr < data_size)
+			data[data_ptr++] ^= hash[hash_ptr++];
+
+		while (start < data_ptr) {
+			n = write(STDOUT_FILENO, &data[start], data_ptr - start);
+			if (n <= 0)
+				goto pfail;
+			start += (size_t)n;
+		}
+	}
+
+	r = 0;
+	goto done;
+
+pfail:
+	r = 2;
+	perror(*argv);
+fail:
+	if (passphrase) {
+		passphrase_wipe(passphrase, strlen(passphrase));
+		free(passphrase);
+	}
+done:
+	libkeccak_state_destroy(&state);
+	free(data);
+	free(hash);
+	if (argc > 0 && fd >= 0)
+		close(fd);
+	return r;
+}