Sorry for the delay.
On Tue, Oct 16, 2018 at 9:49 PM Brandon Enochs <[email protected]> wrote: > > Here's the git format-patch: > > From e7637d4c2cee4fb9e1ebdb96d0330cf69b0bdf49 Mon Sep 17 00:00:00 2001 > From: "Brandon P. Enochs" <[email protected]> > Date: Tue, 16 Oct 2018 15:48:19 -0400 > Subject: [PATCH] Added support for MD5/SHA1 NTP authentication > > Added support for MD5 NTP authentication as described in RFC 5905 [1]. This > patch also supports SHA1 authentication, which is supported by ntpd [2]. The > key file format is the same file format as used by ntpd. The configuration > file format follows standard Unix conventions (# comments) with lines consist > of the following fields separated by whitespace: > <key identifier, [1,65535]> <SHA1|MD5> <an ASCII string of up to 20 > characters|an octet string [a-zA-F0-9] of up to 64 characters>. > > [1] https://www.ietf.org/rfc/rfc5905.txt > [2] http://www.ntp.org/ > > function old new delta > .rodata 166664 166882 +218 > ------------------------------------------------------------------------------ > > Signed-off-by: Brandon P. Enochs <[email protected]> Google mail fails to extract it without whitespace damage. Please resend as attachment. Meanwhile I'm reviewing the patch. > diff --git a/networking/ntpd.c b/networking/ntpd.c > index 1ebdc34..42cb0e7 100644 > --- a/networking/ntpd.c > +++ b/networking/ntpd.c > @@ -62,6 +62,24 @@ > //config: help > //config: Make ntpd look in /etc/ntp.conf for peers. Only "server address" > //config: is supported. > +//config:config FEATURE_NTP_AUTH > +//config: bool "Make ntpd support authentication" > +//config: default n > +//config: depends on NTPD > +//config: help > +//config: Make ntpd support authentication" > +//config:config FEATURE_NTP_AUTH_MD5 > +//config: bool "Make ntpd support MD5 authentication" > +//config: default n > +//config: depends on FEATURE_NTP_AUTH > +//config: help > +//config: Make ntpd support MD5 authentication" > +//config:config FEATURE_NTP_AUTH_SHA1 > +//config: bool "Make ntpd support SHA1 authentication" > +//config: default n > +//config: depends on FEATURE_NTP_AUTH > +//config: help > +//config: Make ntpd support SHA1 authentication" > > //applet:IF_NTPD(APPLET(ntpd, BB_DIR_USR_SBIN, BB_SUID_DROP)) > > @@ -78,6 +96,8 @@ > //usage: "\n -w Do not set time (only query peers), implies -n" > //usage: "\n -S PROG Run PROG after stepping time, stratum change, > and every 11 mins" > //usage: "\n -p PEER Obtain time from PEER (may be repeated)" > +//usage: "\n -K key number for preceding PEER (may be repeated)" > +//usage: "\n -k key file (see man 5 ntp.keys)" > //usage: IF_FEATURE_NTPD_CONF( > //usage: "\n If -p is not given, 'server HOST' lines" > //usage: "\n from /etc/ntp.conf are used" > @@ -227,15 +247,24 @@ > #define FLL (MAXPOLL + 1) > /* Parameter averaging constant */ > #define AVG 4 > - > +#define MAX_KEY_NUMBER 65535 > +#define KEYID_SIZE sizeof(uint32_t) > > enum { > NTP_VERSION = 4, > NTP_MAXSTRATUM = 15, > > +#if ENABLE_FEATURE_NTP_AUTH > + NTP_MD5_DIGESTSIZE = 16, > + NTP_SHA1_DIGESTSIZE = 20, > + NTP_MSGSIZE_NOAUTH = 48, > + NTP_MSGSIZE_MD5_AUTH = NTP_MSGSIZE_NOAUTH + NTP_MD5_DIGESTSIZE + > KEYID_SIZE, > + NTP_MSGSIZE_SHA1_AUTH = NTP_MSGSIZE_NOAUTH + NTP_SHA1_DIGESTSIZE + > KEYID_SIZE, > +#else > NTP_DIGESTSIZE = 16, > NTP_MSGSIZE_NOAUTH = 48, > - NTP_MSGSIZE = (NTP_MSGSIZE_NOAUTH + 4 + NTP_DIGESTSIZE), > + NTP_MSGSIZE = (NTP_MSGSIZE_NOAUTH + KEYID_SIZE + NTP_DIGESTSIZE), > +#endif > > /* Status Masks */ > MODE_MASK = (7 << 0), > @@ -288,7 +317,11 @@ typedef struct { > l_fixedpt_t m_rectime; > l_fixedpt_t m_xmttime; > uint32_t m_keyid; > +#if ENABLE_FEATURE_NTP_AUTH > + uint8_t m_digest[NTP_SHA1_DIGESTSIZE]; > +#else > uint8_t m_digest[NTP_DIGESTSIZE]; > +#endif > } msg_t; > > typedef struct { > @@ -297,6 +330,26 @@ typedef struct { > double d_dispersion; > } datapoint_t; > > +#if ENABLE_FEATURE_NTP_AUTH > +enum hash_type { > + HASH_NONE, > +#if ENABLE_FEATURE_NTP_AUTH_MD5 > + HASH_MD5, > +#endif > +#if ENABLE_FEATURE_NTP_AUTH_SHA1 > + HASH_SHA1 > +#endif > +}; > + > +typedef struct { > + unsigned id; > + enum hash_type type; > + char *key; > + size_t key_length; > + size_t msg_size; > +} key_entry_t; > +#endif > + > typedef struct { > len_and_sockaddr *p_lsa; > char *p_dotted; > @@ -326,6 +379,9 @@ typedef struct { > /* last sent packet: */ > msg_t p_xmt_msg; > char p_hostname[1]; > +#if ENABLE_FEATURE_NTP_AUTH > + key_entry_t *key_entry; > +#endif > } peer_t; > > > @@ -337,13 +393,25 @@ enum { > OPT_q = (1 << 1), > OPT_N = (1 << 2), > OPT_x = (1 << 3), > +#if ENABLE_FEATURE_NTP_AUTH > + OPT_k = (1 << 4), > + OPT_K = (1 << 5), > +#endif > /* Insert new options above this line. */ > /* Non-compat options: */ > +#if ENABLE_FEATURE_NTP_AUTH > + OPT_w = (1 << 6), > + OPT_p = (1 << 7), > + OPT_S = (1 << 8), > + OPT_l = (1 << 9) * ENABLE_FEATURE_NTPD_SERVER, > + OPT_I = (1 << 10) * ENABLE_FEATURE_NTPD_SERVER, > +#else > OPT_w = (1 << 4), > OPT_p = (1 << 5), > OPT_S = (1 << 6), > OPT_l = (1 << 7) * ENABLE_FEATURE_NTPD_SERVER, > OPT_I = (1 << 8) * ENABLE_FEATURE_NTPD_SERVER, > +#endif > /* We hijack some bits for other purposes */ > OPT_qq = (1 << 31), > }; > @@ -816,8 +884,21 @@ resolve_peer_hostname(peer_t *p) > return lsa; > } > > +#if ENABLE_FEATURE_NTP_AUTH > +static void > +free_key_entry(void *data) { > + key_entry_t *key_entry = (key_entry_t *) data; > + > + free(key_entry->key); > + free(key_entry); > +} > + > +static void > +add_peers(const char *s, key_entry_t *key_entry) > +#else > static void > add_peers(const char *s) > +#endif > { > llist_t *item; > peer_t *p; > @@ -840,12 +921,18 @@ add_peers(const char *s) > bb_error_msg("duplicate peer %s (%s)", s, p->p_dotted); > free(p->p_lsa); > free(p->p_dotted); > +#if ENABLE_FEATURE_NTP_AUTH > + free_key_entry(p->key_entry); > +#endif > free(p); > return; > } > } > } > > +#if ENABLE_FEATURE_NTP_AUTH > + p->key_entry = key_entry; > +#endif > llist_add_to(&G.ntp_peers, p); > G.peer_cnt++; > } > @@ -870,6 +957,59 @@ do_sendto(int fd, > return 0; > } > > +#if ENABLE_FEATURE_NTP_AUTH > + > +static void > +hash(key_entry_t *key_entry, const msg_t *msg, uint8_t *output) > +{ > + size_t hash_size = sizeof(msg_t) - sizeof(msg->m_keyid) - > sizeof(msg->m_digest); > + > + switch (key_entry->type) { > +#if ENABLE_FEATURE_NTP_AUTH_MD5 > + case HASH_MD5: { > + md5_ctx_t ctx; > + > + md5_begin(&ctx); > + md5_hash(&ctx, key_entry->key, key_entry->key_length); > + md5_hash(&ctx, msg, hash_size); > + md5_end(&ctx, output); > + } > + break; > +#endif > +#if ENABLE_FEATURE_NTP_AUTH_SHA1 > + case HASH_SHA1: { > + sha1_ctx_t ctx; > + > + sha1_begin(&ctx); > + sha1_hash(&ctx, key_entry->key, key_entry->key_length); > + sha1_hash(&ctx, msg, hash_size); > + sha1_end(&ctx, output); > + } > + break; > +#endif > + case HASH_NONE: > + default: > + bb_perror_msg_and_die("ntpd is in an invalid state."); > + break; > + } > +} > + > +static void > +hash_peer(peer_t *p) > +{ > + p->p_xmt_msg.m_keyid = htonl(p->key_entry->id); > + hash(p->key_entry, &p->p_xmt_msg, p->p_xmt_msg.m_digest); > +} > + > +static bool compare_hashes(peer_t *p, const msg_t *msg) > +{ > + uint8_t digest[NTP_SHA1_DIGESTSIZE]; > + > + hash(p->key_entry, msg, digest); > + return !memcmp(digest, msg->m_digest, p->key_entry->msg_size - > NTP_MSGSIZE_NOAUTH - KEYID_SIZE); > +} > +#endif > + > static void > send_query_to_peer(peer_t *p) > { > @@ -946,9 +1086,18 @@ send_query_to_peer(peer_t *p) > */ > p->reachable_bits <<= 1; > > +#if ENABLE_FEATURE_NTP_AUTH > + if (p->key_entry != NULL) { > + hash_peer(p); > + } > + if (do_sendto(p->p_fd, /*from:*/ NULL, /*to:*/ &p->p_lsa->u.sa, > /*addrlen:*/ p->p_lsa->len, > + &p->p_xmt_msg, p->key_entry == NULL ? NTP_MSGSIZE_NOAUTH : > p->key_entry->msg_size) < 0 > + ) { > +#else > if (do_sendto(p->p_fd, /*from:*/ NULL, /*to:*/ &p->p_lsa->u.sa, > /*addrlen:*/ p->p_lsa->len, > &p->p_xmt_msg, NTP_MSGSIZE_NOAUTH) == -1 > ) { > +#endif > close(p->p_fd); > p->p_fd = -1; > /* > @@ -1924,10 +2073,21 @@ recv_and_process_peer_pkt(peer_t *p) > bb_perror_msg_and_die("recv(%s) error", p->p_dotted); > } > > +#if ENABLE_FEATURE_NTP_AUTH > + if (size != NTP_MSGSIZE_NOAUTH && size != NTP_MSGSIZE_MD5_AUTH && size > != NTP_MSGSIZE_SHA1_AUTH) { > + bb_error_msg("malformed packet received from %s", p->p_dotted); > + return; > + } > + if (p->key_entry != NULL && !compare_hashes(p, &msg)) { > + bb_error_msg("invalid cryptographic hash received from %s", > p->p_dotted); > + return; > + } > +#else > if (size != NTP_MSGSIZE_NOAUTH && size != NTP_MSGSIZE) { > bb_error_msg("malformed packet received from %s", p->p_dotted); > return; > } > +#endif > > if (msg.m_orgtime.int_partl != p->p_xmt_msg.m_xmttime.int_partl > || msg.m_orgtime.fractionl != p->p_xmt_msg.m_xmttime.fractionl > @@ -2135,7 +2295,11 @@ recv_and_process_client_pkt(void /*int fd*/) > from = xzalloc(to->len); > > size = recv_from_to(G_listen_fd, &msg, sizeof(msg), MSG_DONTWAIT, from, > &to->u.sa, to->len); > +#if ENABLE_FEATURE_NTP_AUTH > + if (size != NTP_MSGSIZE_NOAUTH && size != NTP_MSGSIZE_SHA1_AUTH && size > != NTP_MSGSIZE_MD5_AUTH) { > +#else > if (size != NTP_MSGSIZE_NOAUTH && size != NTP_MSGSIZE) { > +#endif > char *addr; > if (size < 0) { > if (errno == EAGAIN) > @@ -2278,6 +2442,26 @@ recv_and_process_client_pkt(void /*int fd*/) > * with the -g and -q options. See the tinker command for other options. > * Note: The kernel time discipline is disabled with this option. > */ > +#if ENABLE_FEATURE_NTP_AUTH > +static key_entry_t * > +find_key_entry(llist_t *key_entries, unsigned id) > +{ > + key_entry_t *result = NULL; > + llist_t *iterator = key_entries; > + key_entry_t *temporary; > + > + while(iterator != NULL && result == NULL) { > + temporary = (key_entry_t *) iterator->data; > + if(temporary->id == id) { > + result = xzalloc(sizeof(key_entry_t)); > + memcpy(result, temporary, sizeof(key_entry_t)); > + result->key = xstrdup(temporary->key); > + } > + iterator = iterator->link; > + } > + return result; > +} > +#endif > > /* By doing init in a separate function we decrease stack usage > * in main loop. > @@ -2286,6 +2470,11 @@ static NOINLINE void ntp_init(char **argv) > { > unsigned opts; > llist_t *peers; > +#if ENABLE_FEATURE_NTP_AUTH > + llist_t *key_ids; > + llist_t *key_entries = NULL; > + char *key_file_path = NULL; > +#endif > > srand(getpid()); > > @@ -2304,6 +2493,7 @@ static NOINLINE void ntp_init(char **argv) > peers = NULL; > opts = getopt32(argv, "^" > "nqNx" /* compat */ > + IF_FEATURE_NTP_AUTH("K:*k:") > "wp:*S:"IF_FEATURE_NTPD_SERVER("l") /* NOT compat */ > IF_FEATURE_NTPD_SERVER("I:") /* compat */ > "d" /* compat */ > @@ -2311,6 +2501,10 @@ static NOINLINE void ntp_init(char **argv) > "\0" > "dd:wn" /* -d: counter; -p: list; -w implies -n */ > IF_FEATURE_NTPD_SERVER(":Il") /* -I implies -l */ > + IF_FEATURE_NTP_AUTH(":K?k") /* -k is required if -K appears > */ > +#if ENABLE_FEATURE_NTP_AUTH > + , &key_ids, &key_file_path > +#endif > , &peers, &G.script_name, > #if ENABLE_FEATURE_NTPD_SERVER > &G.if_name, > @@ -2341,9 +2535,76 @@ static NOINLINE void ntp_init(char **argv) > logmode = LOGMODE_NONE; > } > > +#if ENABLE_FEATURE_NTP_AUTH > + if (opts & OPT_k) { > + char *tokens[4]; > + parser_t *key_file_parser; > + int token_count; > + > + key_file_parser = config_open(key_file_path); > + while ((token_count = config_read(key_file_parser, tokens, 4, 3, "# > \t", PARSE_NORMAL | PARSE_MIN_DIE)) == 3) { > + enum hash_type hash_type = HASH_NONE; > + size_t key_length; > + key_entry_t *key_entry = (key_entry_t *) > xzalloc(sizeof(key_entry_t)); > + > +#if ENABLE_FEATURE_NTP_AUTH_MD5 > + if (strcasecmp(tokens[1], "MD5") == 0) { > + hash_type = HASH_MD5; > + key_entry->msg_size = NTP_MSGSIZE_MD5_AUTH; > + } > +#endif > +#if ENABLE_FEATURE_NTP_AUTH_SHA1 > + if (strcasecmp(tokens[1], "SHA1") == 0) { > + hash_type = HASH_SHA1; > + key_entry->msg_size = NTP_MSGSIZE_SHA1_AUTH; > + } > +#endif > + if (hash_type == HASH_NONE) { > + bb_error_msg_and_die("busybox only supports MD5 and SHA1 NTP > keys"); > + } > + key_entry->type = hash_type; > + key_entry->id = xatou_range(tokens[0], 1, MAX_KEY_NUMBER); > + key_length = strlen(tokens[2]); > + if (key_length <= 20) { > + key_entry->key = xstrdup(tokens[2]); > + key_entry->key_length = key_length; > + } else if ((key_length & 1) == 0 && key_length <= 64) { > + char buffer[64]; > + char *key; > + size_t byte_count = key_length / 2; > + > + memset(buffer, 0, sizeof(buffer)); > + key = hex2bin(buffer, tokens[2], byte_count); > + if (key == NULL) { > + bb_error_msg_and_die("malformed key #%d", key_entry->id); > + } > + key_entry->key = xstrdup(buffer); > + key_entry->key_length = byte_count; > + } else { > + bb_error_msg_and_die("malformed key #%d", key_entry->id); > + } > + llist_add_to(&key_entries, key_entry); > + } > + config_close(key_file_parser); > + } > + > +#endif > if (peers) { > +#if ENABLE_FEATURE_NTP_AUTH > + while (peers) { > + key_entry_t *key_entry = NULL; > + > + if (key_ids) { > + int key_id = xatou_range(llist_pop(&key_ids), 1, > MAX_KEY_NUMBER); > + > + key_entry = find_key_entry(key_entries, key_id); > + } > + add_peers(llist_pop(&peers), key_entry); > + } > +#else > while (peers) > add_peers(llist_pop(&peers)); > +#endif > } > #if ENABLE_FEATURE_NTPD_CONF > else { > @@ -2353,7 +2614,11 @@ static NOINLINE void ntp_init(char **argv) > parser = config_open("/etc/ntp.conf"); > while (config_read(parser, token, 3, 1, "# \t", PARSE_NORMAL)) { > if (strcmp(token[0], "server") == 0 && token[1]) { > +#if ENABLE_FEATURE_NTP_AUTH > + add_peers(token[1], NULL); > +#else > add_peers(token[1]); > +#endif > continue; > } > bb_error_msg("skipping %s:%u: unimplemented command '%s'", > @@ -2394,6 +2659,9 @@ static NOINLINE void ntp_init(char **argv) > | (1 << SIGCHLD) > , SIG_IGN > ); > +#if ENABLE_FEATURE_NTP_AUTH > + llist_free(key_entries, free_key_entry); > +#endif > } > > int ntpd_main(int argc UNUSED_PARAM, char **argv) MAIN_EXTERNALLY_VISIBLE; > -- > 2.9.3 > > _______________________________________________ > busybox mailing list > [email protected] > http://lists.busybox.net/mailman/listinfo/busybox _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox
