New CHAP implementation, rewritten from scratch to avoid the code

[ppp.git] / pppd / chap-new.h

diff --git a/pppd/chap-new.h b/pppd/chap-new.h
new file mode 100644 (file)
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+++ b/pppd/chap-new.h
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+/*
+ * chap-new.c - New CHAP 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. 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(s) of the authors of this software must not be used to
+ *    endorse or promote products derived from this software without
+ *    prior written permission.
+ *
+ * 4. 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.
+ */
+
+/*
+ * CHAP packets begin with a standard header with code, id, len (2 bytes).
+ */
+#define CHAP_HDRLEN    4
+
+/*
+ * Values for the code field.
+ */
+#define CHAP_CHALLENGE 1
+#define CHAP_RESPONSE  2
+#define CHAP_SUCCESS   3
+#define CHAP_FAILURE   4
+
+/*
+ * CHAP digest codes.
+ */
+#define CHAP_MD5               5
+#define CHAP_MICROSOFT         0x80
+#define CHAP_MICROSOFT_V2      0x81
+
+/*
+ * Semi-arbitrary limits on challenge and response fields.
+ */
+#define MAX_CHALLENGE_LEN      64
+#define MAX_RESPONSE_LEN       64
+
+/* bitmask of supported algorithms */
+#define MDTYPE_MICROSOFT_V2    0x1
+#define MDTYPE_MICROSOFT       0x2
+#define MDTYPE_MD5             0x4
+
+#ifdef CHAPMS
+#define MDTYPE_ALL (MDTYPE_MICROSOFT_V2 | MDTYPE_MICROSOFT | MDTYPE_MD5)
+#else
+#define MDTYPE_ALL (MDTYPE_MD5)
+#endif
+#define MDTYPE_NONE 0
+
+/* Return the digest alg. ID for the most preferred digest type. */
+#define CHAP_DIGEST(mdtype) \
+    ((mdtype) & MDTYPE_MICROSOFT_V2)? CHAP_MICROSOFT_V2: \
+    ((mdtype) & MDTYPE_MICROSOFT)? CHAP_MICROSOFT: \
+    ((mdtype) & MDTYPE_MD5)? CHAP_MD5: \
+    0
+
+/* Return the bit flag (lsb set) for our most preferred digest type. */
+#define CHAP_MDTYPE(mdtype) ((mdtype) ^ ((mdtype) - 1)) & (mdtype)
+
+/* Return the bit flag for a given digest algorithm ID. */
+#define CHAP_MDTYPE_D(digest) \
+    ((digest) == CHAP_MICROSOFT_V2)? MDTYPE_MICROSOFT_V2: \
+    ((digest) == CHAP_MICROSOFT)? MDTYPE_MICROSOFT: \
+    ((digest) == CHAP_MD5)? MDTYPE_MD5: \
+    0
+
+/* Can we do the requested digest? */
+#define CHAP_CANDIGEST(mdtype, digest) \
+    ((digest) == CHAP_MICROSOFT_V2)? (mdtype) & MDTYPE_MICROSOFT_V2: \
+    ((digest) == CHAP_MICROSOFT)? (mdtype) & MDTYPE_MICROSOFT: \
+    ((digest) == CHAP_MD5)? (mdtype) & MDTYPE_MD5: \
+    0
+
+/*
+ * The code for each digest type has to supply one of these.
+ */
+struct chap_digest_type {
+       int code;
+
+       /*
+        * Note: challenge and response arguments below are formatted as
+        * a length byte followed by the actual challenge/response data.
+        */
+       void (*generate_challenge)(unsigned char *challenge);
+       int (*verify_response)(int id, char *name,
+               unsigned char *secret, int secret_len,
+               unsigned char *challenge, unsigned char *response,
+               char *message, int message_space);
+       void (*make_response)(unsigned char *response, int id, char *our_name,
+               unsigned char *challenge, char *secret, int secret_len,
+               unsigned char *priv);
+       int (*check_success)(unsigned char *pkt, int len, unsigned char *priv);
+       void (*handle_failure)(unsigned char *pkt, int len);
+
+       struct chap_digest_type *next;
+};
+
+/* Hook for a plugin to validate CHAP challenge */
+extern int (*chap_verify_hook)(char *name, char *ourname, int id,
+                       struct chap_digest_type *digest,
+                       unsigned char *challenge, unsigned char *response,
+                       unsigned char *message, int message_space);
+
+/* Called by digest code to register a digest type */
+extern void chap_register_digest(struct chap_digest_type *);
+
+/* Called by authentication code to start authenticating the peer. */
+extern void chap_auth_peer(int unit, char *our_name, int digest_code);
+
+/* Called by auth. code to start authenticating us to the peer. */
+extern void chap_auth_with_peer(int unit, char *our_name, int digest_code);
+
+/* Represents the CHAP protocol to the main pppd code */
+extern struct protent chap_protent;