Move verify and resync into the library.

bin/otpkey/otpkey.c

@@ -45,6 +45,7 @@
 
 #include <cryb/ctype.h>
 #include <cryb/oath.h>
+#include <cryb/otp.h>
 #include <cryb/strlcmp.h>
 
 #define MAX_KEYURI_SIZE	4096
@@ -267,7 +268,7 @@ otpkey_verify(int argc, char *argv[])
 {
 	oath_key key;
 	unsigned long counter;
-	unsigned int response;
+	unsigned long response;
 	char *end;
 	int match, ret;
 
@@ -278,27 +279,18 @@ otpkey_verify(int argc, char *argv[])
 	response = strtoul(*argv, &end, 10);
 	if (end == *argv || *end != '\0')
 		response = UINT_MAX; /* never valid */
-	switch (key.mode) {
-	case om_hotp:
+	if (key.mode == om_hotp)
 		counter = key.counter;
-		match = oath_hotp_match(&key, response, HOTP_WINDOW);
-		if (verbose && match > 0 && key.counter > counter + 1)
-			warnx("skipped %lu codes", key.counter - counter - 1);
-		break;
-	case om_totp:
-		match = oath_totp_match(&key, response, TOTP_WINDOW);
-		break;
-	default:
-		match = -1;
-	}
-	/* oath_*_match() return -1 on error, 0 on failure, 1 on success */
+	match = otp_verify(&key, response);
 	if (match < 0) {
 		warnx("OATH error");
 		match = 0;
 	}
-	if (verbose)
-		warnx("response: %u %s", response,
-		    match ? "matched" : "did not match");
+	if (verbose) {
+		warnx("response %s", match ? "matched" : "did not match");
+		if (key.mode == om_hotp && key.counter > counter + 1)
+			warnx("skipped %lu codes", key.counter - counter - 1);
+	}
 	ret = match ? readonly ? RET_SUCCESS : otpkey_save(&key) : RET_FAILURE;
 	oath_key_destroy(&key);
 	return (ret);
@@ -365,7 +357,7 @@ otpkey_resync(int argc, char *argv[])
 {
 	oath_key key;
 	unsigned long counter;
-	unsigned int response[3];
+	unsigned long response[3];
 	char *end;
 	int i, match, n, ret, w;
 
@@ -381,31 +373,18 @@ otpkey_resync(int argc, char *argv[])
 	w -= n;
 	if ((ret = otpkey_load(&key)) != RET_SUCCESS)
 		return (ret);
-	switch (key.mode) {
-	case om_hotp:
-		/* this should be a library function */
+	if (key.mode == om_hotp)
 		counter = key.counter;
-		match = 0;
-		while (key.counter < counter + w && match == 0) {
-			match = oath_hotp_match(&key, response[0],
-			    counter + w - key.counter - 1);
-			if (match <= 0)
-				break;
-			for (i = 1; i < n && match > 0; ++i)
-				match = oath_hotp_match(&key, response[i], 0);
-		}
-		if (verbose && match > 0)
-			warnx("skipped %lu codes", key.counter - counter);
-		break;
-	default:
-		match = -1;
-	}
+	match = otp_resync(&key, response, n);
 	if (match < 0) {
 		warnx("OATH error");
 		match = 0;
 	}
-	if (verbose)
+	if (verbose) {
 		warnx("resynchronization %s", match ? "succeeded" : "failed");
+		if (counter > key.counter + 1)
+			warnx("skipped %lu codes", key.counter - counter);
+	}
 	ret = match ? readonly ? RET_SUCCESS : otpkey_save(&key) : RET_FAILURE;
 	oath_key_destroy(&key);
 	return (ret);

include/cryb/otp.h

@@ -38,6 +38,12 @@ CRYB_BEGIN
 
 const char *cryb_otp_version(void);
 
+#define otp_verify		cryb_otp_verify
+#define otp_resync		cryb_otp_resync
+
+int otp_verify(oath_key *, unsigned long);
+int otp_resync(oath_key *, unsigned long *, unsigned int);
+
 CRYB_END
 
 #endif

lib/otp/Makefile.am

@@ -3,6 +3,8 @@ AM_CPPFLAGS = -I$(top_srcdir)/include
 lib_LTLIBRARIES = libcryb-otp.la
 
 libcryb_otp_la_SOURCES = \
+	cryb_otp_resync.c \
+	cryb_otp_verify.c \
 	\
 	cryb_otp.c
 

lib/otp/cryb_otp.c

@@ -29,9 +29,10 @@
 
 #include "cryb/impl.h"
 
+#include <stddef.h>
 #include <stdint.h>
-#include <unistd.h>
 
+#include <cryb/oath.h>
 #include <cryb/otp.h>
 
 static const char *cryb_otp_version_string = PACKAGE_VERSION;

lib/otp/cryb_otp_impl.h

@@ -0,0 +1,40 @@
+/*-
+ * Copyright (c) 2018 The University of Oslo
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef CRYB_OTP_IMPL_H_INCLUDED
+#define CRYB_OTP_IMPL_H_INCLUDED
+
+/* XXX hardcoded windows */
+#define HOTP_WINDOW	9
+#define TOTP_WINDOW	2
+
+struct otp_store {
+};
+
+#endif

lib/otp/cryb_otp_resync.c

@@ -0,0 +1,96 @@
+/*-
+ * Copyright (c) 2013-2018 The University of Oslo
+ * Copyright (c) 2016-2018 Dag-Erling Smørgrav
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "cryb/impl.h"
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <cryb/assert.h>
+#include <cryb/oath.h>
+#include <cryb/otp.h>
+
+#include "cryb_otp_impl.h"
+
+/*
+ * Resynchronize a desynchronized event-mode key.
+ *
+ * XXX review carefully for off-by-one errors, and write unit tests
+ */
+
+static int
+otp_resync_recursive(oath_key *key, unsigned long *response,
+    unsigned int n, unsigned int w)
+{
+	uint64_t first, prev, last;
+	int ret;
+
+	first = key->counter;
+	last = first + w;
+	while (w > 0) {
+		prev = key->counter;
+		ret = oath_hotp_match(key, response[0], last - key->counter);
+		if (ret < 1)
+			return (ret);
+		assertf(key->counter > prev, "counter did not advance");
+		w -= key->counter - prev;
+		if (n == 1)
+			return (key->counter - prev);
+		prev = key->counter;
+		ret = otp_resync_recursive(key, response + 1, n - 1, w);
+		if (ret > 0)
+			return (ret);
+		key->counter = prev;
+	}
+	return (0);
+}
+
+int
+otp_resync(oath_key *key, unsigned long *response, unsigned int n)
+{
+	unsigned int i, w;
+	int ret;
+
+	/* only applicable to RFC 4226 HOTP for now */
+	/* note: n == 1 is identical to otp_verify() */
+	if (key->mode != om_hotp || n < 1)
+		return (-1);
+
+	/* compute window size based on number of responses */
+	for (i = 0, w = 1; i < n; ++i)
+		w = w * (HOTP_WINDOW + 1);
+
+	/* recursive search within window */
+	ret = otp_resync_recursive(key, response, n, w);
+
+	/* ... */
+
+	return (ret);
+}

lib/otp/cryb_otp_verify.c

@@ -0,0 +1,75 @@
+/*-
+ * Copyright (c) 2013-2018 The University of Oslo
+ * Copyright (c) 2016-2018 Dag-Erling Smørgrav
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior written
+ *    permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "cryb/impl.h"
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include <cryb/assert.h>
+#include <cryb/oath.h>
+#include <cryb/otp.h>
+
+#include "cryb_otp_impl.h"
+
+/*
+ * Check whether a given response is correct for the given keyfile.
+ */
+int
+otp_verify(oath_key *key, unsigned long response)
+{
+	uint64_t prev;
+	int ret;
+
+	switch (key->mode) {
+	case om_hotp:
+		prev = key->counter;
+		ret = oath_hotp_match(key, response, HOTP_WINDOW);
+		assertf(key->counter >= prev, "counter went backwads");
+		if (ret > 0) {
+			assertf(key->counter > prev, "counter did not advance");
+			ret = key->counter - prev - 1;
+		}
+		break;
+	case om_totp:
+		prev = key->lastused;
+		ret = oath_totp_match(key, response, TOTP_WINDOW);
+		assertf(key->lastused >= prev, "lastused went backwards");
+		if (ret > 0) {
+			assertf(key->lastused > prev, "lastused did not advance");
+			ret = key->lastused - prev / key->timestep;
+		}
+		break;
+	default:
+		ret = -1;
+	}
+	/* oath_*_ret() return -1 on error, 0 on failure, 1 on success */
+	return (ret);
+}

libexec/login_otp/login_otp.c

@@ -33,6 +33,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+#include <cryb/oath.h>
 #include <cryb/otp.h>
 
 static void

pam/pam_otp/pam_otp.c

@@ -36,6 +36,7 @@
 #include <security/pam_modules.h>
 #include <security/pam_appl.h>
 
+#include <cryb/oath.h>
 #include <cryb/otp.h>
 
 int

sbin/otpradiusd/otpradiusd.c

@@ -33,6 +33,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+#include <cryb/oath.h>
 #include <cryb/otp.h>
 
 static void