/* * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") * Copyright (c) 1999-2003 by Internet Software Consortium * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR * ANY SPECIAL, DIRECT, 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. * * Internet Systems Consortium, Inc. * 950 Charter Street * Redwood City, CA 94063 * * http://www.isc.org/ */ #ifndef lint static const char rcsid[] = "$Id: ns_sign.c,v 1.4.2.4 2004/06/10 17:59:42 dhankins Exp $"; #endif #if defined (TRACING) #define time(x) trace_mr_time (x) time_t trace_mr_time (time_t *); #endif /* Import. */ #include #include #include #include #include #include #include #include #include #include #include #include #include "minires/minires.h" #include "arpa/nameser.h" #include #define BOUNDS_CHECK(ptr, count) \ do { \ if ((ptr) + (count) > eob) { \ return ISC_R_NOSPACE; \ } \ } while (0) /* ns_sign * Parameters: * msg message to be sent * msglen input - length of message * output - length of signed message * msgsize length of buffer containing message * error value to put in the error field * key tsig key used for signing * querysig (response), the signature in the query * querysiglen (response), the length of the signature in the query * sig a buffer to hold the generated signature * siglen input - length of signature buffer * output - length of signature * * Errors: * - bad input data (-1) * - bad key / sign failed (-BADKEY) * - not enough space (NS_TSIG_ERROR_NO_SPACE) */ isc_result_t ns_sign(u_char *msg, unsigned *msglen, unsigned msgsize, int error, void *k, const u_char *querysig, unsigned querysiglen, u_char *sig, unsigned *siglen, time_t in_timesigned) { HEADER *hp = (HEADER *)msg; DST_KEY *key = (DST_KEY *)k; u_char *cp = msg + *msglen, *eob = msg + msgsize; u_char *lenp; u_char *name, *alg; unsigned n; time_t timesigned; dst_init(); if (msg == NULL || msglen == NULL || sig == NULL || siglen == NULL) return ISC_R_INVALIDARG; /* Name. */ if (key != NULL && error != ns_r_badsig && error != ns_r_badkey) n = dn_comp(key->dk_key_name, cp, (unsigned)(eob - cp), NULL, NULL); else n = dn_comp("", cp, (unsigned)(eob - cp), NULL, NULL); if (n < 0) return ISC_R_NOSPACE; name = cp; cp += n; /* Type, class, ttl, length (not filled in yet). */ BOUNDS_CHECK(cp, INT16SZ + INT16SZ + INT32SZ + INT16SZ); PUTSHORT(ns_t_tsig, cp); PUTSHORT(ns_c_any, cp); PUTLONG(0, cp); /* TTL */ lenp = cp; cp += 2; /* Alg. */ if (key != NULL && error != ns_r_badsig && error != ns_r_badkey) { if (key->dk_alg != KEY_HMAC_MD5) return ISC_R_BADKEY; n = dn_comp(NS_TSIG_ALG_HMAC_MD5, cp, (unsigned)(eob - cp), NULL, NULL); } else n = dn_comp("", cp, (unsigned)(eob - cp), NULL, NULL); if (n < 0) return ISC_R_NOSPACE; alg = cp; cp += n; /* Time. */ BOUNDS_CHECK(cp, INT16SZ + INT32SZ + INT16SZ); PUTSHORT(0, cp); timesigned = time(NULL); if (error != ns_r_badtime) PUTLONG(timesigned, cp); else PUTLONG(in_timesigned, cp); PUTSHORT(NS_TSIG_FUDGE, cp); /* Compute the signature. */ if (key != NULL && error != ns_r_badsig && error != ns_r_badkey) { void *ctx; u_char buf[MAXDNAME], *cp2; unsigned n; dst_sign_data(SIG_MODE_INIT, key, &ctx, NULL, 0, NULL, 0); /* Digest the query signature, if this is a response. */ if (querysiglen > 0 && querysig != NULL) { u_int16_t len_n = htons(querysiglen); dst_sign_data(SIG_MODE_UPDATE, key, &ctx, (u_char *)&len_n, INT16SZ, NULL, 0); dst_sign_data(SIG_MODE_UPDATE, key, &ctx, querysig, querysiglen, NULL, 0); } /* Digest the message. */ dst_sign_data(SIG_MODE_UPDATE, key, &ctx, msg, *msglen, NULL, 0); /* Digest the key name. */ n = ns_name_ntol(name, buf, sizeof(buf)); dst_sign_data(SIG_MODE_UPDATE, key, &ctx, buf, n, NULL, 0); /* Digest the class and TTL. */ cp2 = buf; PUTSHORT(ns_c_any, cp2); PUTLONG(0, cp2); dst_sign_data(SIG_MODE_UPDATE, key, &ctx, buf, (unsigned)(cp2-buf), NULL, 0); /* Digest the algorithm. */ n = ns_name_ntol(alg, buf, sizeof(buf)); dst_sign_data(SIG_MODE_UPDATE, key, &ctx, buf, n, NULL, 0); /* Digest the time signed, fudge, error, and other data */ cp2 = buf; PUTSHORT(0, cp2); /* Top 16 bits of time */ if (error != ns_r_badtime) PUTLONG(timesigned, cp2); else PUTLONG(in_timesigned, cp2); PUTSHORT(NS_TSIG_FUDGE, cp2); PUTSHORT(error, cp2); /* Error */ if (error != ns_r_badtime) PUTSHORT(0, cp2); /* Other data length */ else { PUTSHORT(INT16SZ+INT32SZ, cp2); /* Other data length */ PUTSHORT(0, cp2); /* Top 16 bits of time */ PUTLONG(timesigned, cp2); } dst_sign_data(SIG_MODE_UPDATE, key, &ctx, buf, (unsigned)(cp2-buf), NULL, 0); n = dst_sign_data(SIG_MODE_FINAL, key, &ctx, NULL, 0, sig, *siglen); if (n < 0) return ISC_R_BADKEY; *siglen = n; } else *siglen = 0; /* Add the signature. */ BOUNDS_CHECK(cp, INT16SZ + (*siglen)); PUTSHORT(*siglen, cp); memcpy(cp, sig, *siglen); cp += (*siglen); /* The original message ID & error. */ BOUNDS_CHECK(cp, INT16SZ + INT16SZ); PUTSHORT(ntohs(hp->id), cp); /* already in network order */ PUTSHORT(error, cp); /* Other data. */ BOUNDS_CHECK(cp, INT16SZ); if (error != ns_r_badtime) PUTSHORT(0, cp); /* Other data length */ else { PUTSHORT(INT16SZ+INT32SZ, cp); /* Other data length */ BOUNDS_CHECK(cp, INT32SZ+INT16SZ); PUTSHORT(0, cp); /* Top 16 bits of time */ PUTLONG(timesigned, cp); } /* Go back and fill in the length. */ PUTSHORT(cp - lenp - INT16SZ, lenp); hp->arcount = htons(ntohs(hp->arcount) + 1); *msglen = (cp - msg); return ISC_R_SUCCESS; } #if 0 isc_result_t ns_sign_tcp_init(void *k, const u_char *querysig, unsigned querysiglen, ns_tcp_tsig_state *state) { dst_init(); if (state == NULL || k == NULL || querysig == NULL || querysiglen < 0) return ISC_R_INVALIDARG; state->counter = -1; state->key = k; if (state->key->dk_alg != KEY_HMAC_MD5) return ISC_R_BADKEY; if (querysiglen > sizeof(state->sig)) return ISC_R_NOSPACE; memcpy(state->sig, querysig, querysiglen); state->siglen = querysiglen; return ISC_R_SUCCESS; } isc_result_t ns_sign_tcp(u_char *msg, unsigned *msglen, unsigned msgsize, int error, ns_tcp_tsig_state *state, int done) { u_char *cp, *eob, *lenp; u_char buf[MAXDNAME], *cp2; HEADER *hp = (HEADER *)msg; time_t timesigned; int n; if (msg == NULL || msglen == NULL || state == NULL) return ISC_R_INVALIDARG; state->counter++; if (state->counter == 0) return ns_sign(msg, msglen, msgsize, error, state->key, state->sig, state->siglen, state->sig, &state->siglen, 0); if (state->siglen > 0) { u_int16_t siglen_n = htons(state->siglen); dst_sign_data(SIG_MODE_INIT, state->key, &state->ctx, NULL, 0, NULL, 0); dst_sign_data(SIG_MODE_UPDATE, state->key, &state->ctx, (u_char *)&siglen_n, INT16SZ, NULL, 0); dst_sign_data(SIG_MODE_UPDATE, state->key, &state->ctx, state->sig, state->siglen, NULL, 0); state->siglen = 0; } dst_sign_data(SIG_MODE_UPDATE, state->key, &state->ctx, msg, *msglen, NULL, 0); if (done == 0 && (state->counter % 100 != 0)) return ISC_R_SUCCESS; cp = msg + *msglen; eob = msg + msgsize; /* Name. */ n = dn_comp(state->key->dk_key_name, cp, (unsigned)(eob - cp), NULL, NULL); if (n < 0) return ISC_R_NOSPACE; cp += n; /* Type, class, ttl, length (not filled in yet). */ BOUNDS_CHECK(cp, INT16SZ + INT16SZ + INT32SZ + INT16SZ); PUTSHORT(ns_t_tsig, cp); PUTSHORT(ns_c_any, cp); PUTLONG(0, cp); /* TTL */ lenp = cp; cp += 2; /* Alg. */ n = dn_comp(NS_TSIG_ALG_HMAC_MD5, cp, (unsigned)(eob - cp), NULL, NULL); if (n < 0) return ISC_R_NOSPACE; cp += n; /* Time. */ BOUNDS_CHECK(cp, INT16SZ + INT32SZ + INT16SZ); PUTSHORT(0, cp); timesigned = time(NULL); PUTLONG(timesigned, cp); PUTSHORT(NS_TSIG_FUDGE, cp); /* * Compute the signature. */ /* Digest the time signed and fudge. */ cp2 = buf; PUTSHORT(0, cp2); /* Top 16 bits of time */ PUTLONG(timesigned, cp2); PUTSHORT(NS_TSIG_FUDGE, cp2); dst_sign_data(SIG_MODE_UPDATE, state->key, &state->ctx, buf, (unsigned)(cp2 - buf), NULL, 0); n = dst_sign_data(SIG_MODE_FINAL, state->key, &state->ctx, NULL, 0, state->sig, sizeof(state->sig)); if (n < 0) return ISC_R_BADKEY; state->siglen = n; /* Add the signature. */ BOUNDS_CHECK(cp, INT16SZ + state->siglen); PUTSHORT(state->siglen, cp); memcpy(cp, state->sig, state->siglen); cp += state->siglen; /* The original message ID & error. */ BOUNDS_CHECK(cp, INT16SZ + INT16SZ); PUTSHORT(ntohs(hp->id), cp); /* already in network order */ PUTSHORT(error, cp); /* Other data. */ BOUNDS_CHECK(cp, INT16SZ); PUTSHORT(0, cp); /* Go back and fill in the length. */ PUTSHORT(cp - lenp - INT16SZ, lenp); hp->arcount = htons(ntohs(hp->arcount) + 1); *msglen = (cp - msg); return ISC_R_SUCCESS; } #endif