Import Mbed OS hard-float snapshot

connectivity/libraries/ppp/source/chap-md5.c

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+/*
+ * chap-md5.c - New CHAP/MD5 implementation.
+ *
+ * Copyright (c) 2003 Paul Mackerras. 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. The name(s) of the authors of this software must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission.
+ *
+ * 3. Redistributions of any form whatsoever must retain the following
+ *    acknowledgment:
+ *    "This product includes software developed by Paul Mackerras
+ *     <paulus@samba.org>".
+ *
+ * THE AUTHORS OF THIS SOFTWARE DISCLAIM ALL WARRANTIES WITH REGARD TO
+ * THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS, IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY
+ * SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN
+ * AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "ppp_opts.h"
+#if PPP_SUPPORT && CHAP_SUPPORT  /* don't build if not configured for use in ppp_opts.h */
+
+#if 0 /* UNUSED */
+#include <stdlib.h>
+#include <string.h>
+#endif /* UNUSED */
+
+#include "ppp_impl.h"
+
+#include "chap-new.h"
+#include "chap-md5.h"
+#include "magic.h"
+#include "pppcrypt.h"
+
+#define MD5_HASH_SIZE		16
+#define MD5_MIN_CHALLENGE	17
+#define MD5_MAX_CHALLENGE	24
+#define MD5_MIN_MAX_POWER_OF_TWO_CHALLENGE     3   /* 2^3-1 = 7, 17+7 = 24 */
+
+#if PPP_SERVER
+static void chap_md5_generate_challenge(ppp_pcb *pcb, unsigned char *cp) {
+	int clen;
+	PPP_UNUSED_ARG(pcb);
+
+	clen = MD5_MIN_CHALLENGE + magic_pow(MD5_MIN_MAX_POWER_OF_TWO_CHALLENGE);
+	*cp++ = clen;
+	magic_random_bytes(cp, clen);
+}
+
+static int chap_md5_verify_response(ppp_pcb *pcb, int id, const char *name,
+			 const unsigned char *secret, int secret_len,
+			 const unsigned char *challenge, const unsigned char *response,
+			 char *message, int message_space) {
+	MD5_context ctx;
+	unsigned char idbyte = id;
+	unsigned char hash[MD5_HASH_SIZE];
+	int challenge_len, response_len;
+	PPP_UNUSED_ARG(name);
+	PPP_UNUSED_ARG(pcb);
+
+	challenge_len = *challenge++;
+	response_len = *response++;
+	if (response_len == MD5_HASH_SIZE) {
+		/* Generate hash of ID, secret, challenge */
+		MD5_Init(&ctx);
+		MD5_starts(&ctx);
+		MD5_update(&ctx, &idbyte, 1);
+		MD5_update(&ctx, secret, secret_len);
+		MD5_update(&ctx, challenge, challenge_len);
+		MD5_finish(&ctx, hash);
+		MD5_free(&ctx);
+
+		/* Test if our hash matches the peer's response */
+		if (memcmp(hash, response, MD5_HASH_SIZE) == 0) {
+			ppp_slprintf(message, message_space, "Access granted");
+			return 1;
+		}
+	}
+	ppp_slprintf(message, message_space, "Access denied");
+	return 0;
+}
+#endif /* PPP_SERVER */
+
+static void chap_md5_make_response(ppp_pcb *pcb, unsigned char *response, int id, const char *our_name,
+		       const unsigned char *challenge, const char *secret, int secret_len,
+		       unsigned char *private_) {
+	MD5_context ctx;
+	unsigned char idbyte = id;
+	int challenge_len = *challenge++;
+	PPP_UNUSED_ARG(our_name);
+	PPP_UNUSED_ARG(private_);
+	PPP_UNUSED_ARG(pcb);
+
+	MD5_init(&ctx);
+	MD5_starts(&ctx);
+	MD5_update(&ctx, &idbyte, 1);
+	MD5_update(&ctx, (const u_char *)secret, secret_len);
+	MD5_update(&ctx, challenge, challenge_len);
+	MD5_finish(&ctx, &response[1]);
+	MD5_free(&ctx);
+	response[0] = MD5_HASH_SIZE;
+}
+
+const struct chap_digest_type md5_digest = {
+	CHAP_MD5,		/* code */
+#if PPP_SERVER
+	chap_md5_generate_challenge,
+	chap_md5_verify_response,
+#endif /* PPP_SERVER */
+	chap_md5_make_response,
+	NULL,			/* check_success */
+	NULL,			/* handle_failure */
+};
+
+#endif /* PPP_SUPPORT && CHAP_SUPPORT */