cryptutils

rc2: Add rc2 utility

Diffstat

2 files changed, 154 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 759df8a..42e693f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -17,5 +17,6 @@ ADD_EXECUTABLE(alder32 ${PROJECT_SOURCE_DIR}/src/alder32.c)
 ADD_EXECUTABLE(crc32   ${PROJECT_SOURCE_DIR}/src/crc32.c)
 ADD_EXECUTABLE(fnv1a64 ${PROJECT_SOURCE_DIR}/src/fnv1a64.c)
 ADD_EXECUTABLE(otp     ${PROJECT_SOURCE_DIR}/src/otp.c)
+ADD_EXECUTABLE(rc2     ${PROJECT_SOURCE_DIR}/src/rc2.c)
 
 TARGET_LINK_LIBRARIES(otp OpenSSL::Crypto)
diff --git a/src/rc2.c b/src/rc2.c
new file mode 100644
index 0000000..aa8b1d1
--- /dev/null
+++ b/src/rc2.c
@@ -0,0 +1,153 @@
+// rc2.c, version 0.2.0
+// OMKOV cryptutils rc2
+// Copyright (C) 2021, Jakob Wakeling
+// All rights reserved.
+
+/*
+OMKOV Permissive Licence, version 1.0
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal with
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+* Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimers.
+* Redistributions in binary form must reproduce the above copyright notice, this
+  list of conditions and the following disclaimers in the documentation and/or
+  other materials provided with the distribution.
+* Neither the names of the copyright holders, nor the names of its contributors
+  may be used to endorse or promote products derived from this Software without
+  specific prior written permission.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE COPYRIGHT
+HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS WITH THE SOFTWARE.
+*/
+
+#include "util/error.c"
+#include "util/optget.h"
+#include "util/rc2.h"
+#include "util/util.h"
+
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+
+#define VERSION "0.2.0"
+
+static struct lop lops[] = {
+	{ "help",    ARG_NUL, 256 },
+	{ "version", ARG_NUL, 257 },
+	{ NULL, 0, 0 }
+};
+
+static int mode = 0;
+static char *karg;
+static int larg;
+
+static inline void rc2(const char *ifile, const char *ofile);
+
+static void hlp(void);
+static void ver(void);
+
+int main(int ac, char *av[]) { A0 = av[0];
+	struct opt opt = OPTGET_INIT; opt.str = "dek:l:m"; opt.lops = lops;
+	for (int o; (o = optget(&opt, av, 1)) != -1;) switch (o) {
+	case 'e': { mode = 0; } break;
+	case 'd': { mode = 1; } break;
+	case 'k': { karg = opt.arg; } break;
+	case 'l': {
+		register int d; register char *p = opt.arg;
+		for (larg = 0; *p >= '0' && *p < '9'; ++p) {
+			d = (int)*p - '0';
+			if (larg > (INT_MAX - d) / 10) { break; }
+			larg = larg * 10 + d;
+		}
+		
+		if (*p) { error(1, "invalid length"); }
+		if (larg > 1024) { error(1, "length must be at most 1024"); }
+		if (larg == 0) { error(1, "length must be greater than 0"); }
+	} break;
+	case 'm': { /* TODO */ error(1, "-m not implemented"); } break;
+	case 256: { hlp(); } return 0;
+	case 257: { ver(); } return 0;
+	default: {} return 1;
+	}
+	
+	if (!larg) { larg = 1024; }
+	
+	if (opt.ind == ac) { error(1, "missing operand"); }
+	else if (opt.ind == ac - 1) { rc2(av[opt.ind], NULL); }
+	else if (opt.ind == ac - 2) { rc2(av[opt.ind], av[opt.ind + 1]); }
+	else { error(1, "excess operand"); }
+	
+	return 0;
+}
+
+static inline void rc2(const char *ifile, const char *ofile) {
+	struct rc2 ctx; u8 b1[128], b2[16]; FILE *fk, *fi, *fo; size_t kl, fl;
+	
+	if (!karg) { error(1, "-k is required"); }
+	else if (!(fk = fopen(karg, "r"))) { error(1, "%s: %s", karg, serr()); }
+	
+	// TODO Check key size is within bounds
+	kl = fread(b1, 1, sizeof (b1), fk); fclose(fk); fk = NULL;
+	rc2expand(&ctx, b1, kl, larg);
+	
+	if (!ifile) { fi = stdin; }
+	else if (!(fi = fopen(ifile, "r"))) { error(1, "%s: %s", ifile, serr()); }
+	
+	if (!ofile) { fo = stdout; }
+	else if (!(fo = fopen(ofile, "w"))) { error(1, "%s: %s", ofile, serr()); }
+	
+	for (size_t c; (c = fread(b1, 1, 8, fi));) {
+		while (c >= 8) {
+			memset(b2, 0, 8);
+			if (mode == 0) { rc2encrypt(&ctx, b1, b2); }
+			if (mode == 1) { rc2decrypt(&ctx, b1, b2); }
+			fwrite(b2, 1, 8, fo); c -= 8;
+		}
+		
+		if (c != 0) { // Should only be true during encryption
+			memset(b2, 0, 8);
+			if (mode == 0) { rc2encrypt(&ctx, b1, b2); }
+			fwrite(b2, 1, 8, fo);
+		}
+		
+		memset(b1, 0, 8);
+	}
+	
+	if (fi != stdin) { fclose(fi); }
+	if (fo != stdin) { fclose(fo); }
+	
+	return;
+}
+
+/* Print help information. */
+static void hlp(void) {
+	puts("rc2 - encrypt and decrypt files using rc2\n");
+	puts("usage: rc2 [-d|-e] [-k keyfile] [-l length] [-m mode] [infile] "
+			"[outfile]\n");
+	puts("options:");
+	puts("  -d         Decrypt the input data");
+	puts("  -e         Encrypt the input data (default)");
+	puts("  -k file    Specify keyfile");
+	puts("  -l length  Override effective key length");
+	puts("  -m mode    Specify block cipher mode of operation");
+	puts("  --help     Display help information");
+	puts("  --version  Display version information");
+}
+
+/* Print version information. */
+static void ver(void) {
+	puts("OMKOV cryptutils rc2, version " VERSION);
+	puts("Copyright (C) 2021, Jakob Wakeling");
+	puts("All rights reserved.");
+	puts("OMKOV Permissive Licence (https://www.omkov.net/OLPE)");
+}