diff options
Diffstat (limited to 'lwip/src/netif/ppp/chap-md5.c')
| -rw-r--r-- | lwip/src/netif/ppp/chap-md5.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/lwip/src/netif/ppp/chap-md5.c b/lwip/src/netif/ppp/chap-md5.c new file mode 100644 index 0000000..88f069f --- /dev/null +++ b/lwip/src/netif/ppp/chap-md5.c @@ -0,0 +1,126 @@ +/* + * 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 "netif/ppp/ppp_opts.h" +#if PPP_SUPPORT && CHAP_SUPPORT /* don't build if not configured for use in lwipopts.h */ + +#if 0 /* UNUSED */ +#include <stdlib.h> +#include <string.h> +#endif /* UNUSED */ + +#include "netif/ppp/ppp_impl.h" + +#include "netif/ppp/chap-new.h" +#include "netif/ppp/chap-md5.h" +#include "netif/ppp/magic.h" +#include "netif/ppp/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; + LWIP_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) { + lwip_md5_context ctx; + unsigned char idbyte = id; + unsigned char hash[MD5_HASH_SIZE]; + int challenge_len, response_len; + LWIP_UNUSED_ARG(name); + LWIP_UNUSED_ARG(pcb); + + challenge_len = *challenge++; + response_len = *response++; + if (response_len == MD5_HASH_SIZE) { + /* Generate hash of ID, secret, challenge */ + lwip_md5_init(&ctx); + lwip_md5_starts(&ctx); + lwip_md5_update(&ctx, &idbyte, 1); + lwip_md5_update(&ctx, secret, secret_len); + lwip_md5_update(&ctx, challenge, challenge_len); + lwip_md5_finish(&ctx, hash); + lwip_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_) { + lwip_md5_context ctx; + unsigned char idbyte = id; + int challenge_len = *challenge++; + LWIP_UNUSED_ARG(our_name); + LWIP_UNUSED_ARG(private_); + LWIP_UNUSED_ARG(pcb); + + lwip_md5_init(&ctx); + lwip_md5_starts(&ctx); + lwip_md5_update(&ctx, &idbyte, 1); + lwip_md5_update(&ctx, (const u_char *)secret, secret_len); + lwip_md5_update(&ctx, challenge, challenge_len); + lwip_md5_finish(&ctx, &response[1]); + lwip_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 */ |