diff options
Diffstat (limited to 'src/lib/krb5/krb/chk_trans.c')
| -rw-r--r-- | src/lib/krb5/krb/chk_trans.c | 438 |
1 files changed, 438 insertions, 0 deletions
diff --git a/src/lib/krb5/krb/chk_trans.c b/src/lib/krb5/krb/chk_trans.c new file mode 100644 index 000000000000..36c6845b9a91 --- /dev/null +++ b/src/lib/krb5/krb/chk_trans.c @@ -0,0 +1,438 @@ +/* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */ +/* lib/krb5/krb/chk_trans.c */ +/* + * Copyright 2001, 2007 by the Massachusetts Institute of Technology. + * All Rights Reserved. + * + * Export of this software from the United States of America may + * require a specific license from the United States Government. + * It is the responsibility of any person or organization contemplating + * export to obtain such a license before exporting. + * + * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and + * distribute this software and its documentation for any purpose and + * without fee is hereby granted, provided that the above copyright + * notice appear in all copies and that both that copyright notice and + * this permission notice appear in supporting documentation, and that + * the name of M.I.T. not be used in advertising or publicity pertaining + * to distribution of the software without specific, written prior + * permission. Furthermore if you modify this software you must label + * your software as modified software and not distribute it in such a + * fashion that it might be confused with the original M.I.T. software. + * M.I.T. makes no representations about the suitability of + * this software for any purpose. It is provided "as is" without express + * or implied warranty. + */ + +#include "k5-int.h" +#include <stdarg.h> + +#if defined (TEST) || defined (TEST2) +# undef DEBUG +# define DEBUG +#endif + +#ifdef DEBUG +#define verbose krb5int_chk_trans_verbose +static int verbose = 0; +# define Tprintf(ARGS) if (verbose) printf ARGS +#else +# define Tprintf(ARGS) (void)(0) +#endif + +#define MAXLEN 512 + +static krb5_error_code +process_intermediates (krb5_error_code (*fn)(krb5_data *, void *), void *data, + const krb5_data *n1, const krb5_data *n2) { + unsigned int len1, len2, i; + char *p1, *p2; + + Tprintf (("process_intermediates(%.*s,%.*s)\n", + (int) n1->length, n1->data, (int) n2->length, n2->data)); + + len1 = n1->length; + len2 = n2->length; + + Tprintf (("(walking intermediates now)\n")); + /* Simplify... */ + if (len1 > len2) { + const krb5_data *p; + int tmp = len1; + len1 = len2; + len2 = tmp; + p = n1; + n1 = n2; + n2 = p; + } + /* Okay, now len1 is always shorter or equal. */ + if (len1 == len2) { + if (memcmp (n1->data, n2->data, len1)) { + Tprintf (("equal length but different strings in path: '%.*s' '%.*s'\n", + (int) n1->length, n1->data, (int) n2->length, n2->data)); + return KRB5KRB_AP_ERR_ILL_CR_TKT; + } + Tprintf (("(end intermediates)\n")); + return 0; + } + /* Now len1 is always shorter. */ + if (len1 == 0) + /* Shouldn't be possible. Internal error? */ + return KRB5KRB_AP_ERR_ILL_CR_TKT; + p1 = n1->data; + p2 = n2->data; + if (p1[0] == '/') { + /* X.500 style names, with common prefix. */ + if (p2[0] != '/') { + Tprintf (("mixed name formats in path: x500='%.*s' domain='%.*s'\n", + (int) len1, p1, (int) len2, p2)); + return KRB5KRB_AP_ERR_ILL_CR_TKT; + } + if (memcmp (p1, p2, len1)) { + Tprintf (("x500 names with different prefixes '%.*s' '%.*s'\n", + (int) len1, p1, (int) len2, p2)); + return KRB5KRB_AP_ERR_ILL_CR_TKT; + } + for (i = len1 + 1; i < len2; i++) + if (p2[i] == '/') { + krb5_data d; + krb5_error_code r; + + d.data = p2; + d.length = i; + r = (*fn) (&d, data); + if (r) + return r; + } + } else { + /* Domain style names, with common suffix. */ + if (p2[0] == '/') { + Tprintf (("mixed name formats in path: domain='%.*s' x500='%.*s'\n", + (int) len1, p1, (int) len2, p2)); + return KRB5KRB_AP_ERR_ILL_CR_TKT; + } + if (memcmp (p1, p2 + (len2 - len1), len1)) { + Tprintf (("domain names with different suffixes '%.*s' '%.*s'\n", + (int) len1, p1, (int) len2, p2)); + return KRB5KRB_AP_ERR_ILL_CR_TKT; + } + for (i = len2 - len1 - 1; i > 0; i--) { + Tprintf (("looking at '%.*s'\n", (int) (len2 - i), p2+i)); + if (p2[i-1] == '.') { + krb5_data d; + krb5_error_code r; + + d.data = p2+i; + d.length = len2 - i; + r = (*fn) (&d, data); + if (r) + return r; + } + } + } + Tprintf (("(end intermediates)\n")); + return 0; +} + +static krb5_error_code +maybe_join (krb5_data *last, krb5_data *buf, unsigned int bufsiz) +{ + if (buf->length == 0) + return 0; + if (buf->data[0] == '/') { + if (last->length + buf->length > bufsiz) { + Tprintf (("too big: last=%d cur=%d max=%d\n", last->length, buf->length, bufsiz)); + return KRB5KRB_AP_ERR_ILL_CR_TKT; + } + memmove (buf->data+last->length, buf->data, buf->length); + memcpy (buf->data, last->data, last->length); + buf->length += last->length; + } else if (buf->data[buf->length-1] == '.') { + /* We can ignore the case where the previous component was + empty; the strcat will be a no-op. It should probably + be an error case, but let's be flexible. */ + if (last->length+buf->length > bufsiz) { + Tprintf (("too big\n")); + return KRB5KRB_AP_ERR_ILL_CR_TKT; + } + memcpy (buf->data + buf->length, last->data, last->length); + buf->length += last->length; + } + /* Otherwise, do nothing. */ + return 0; +} + +/* The input strings cannot contain any \0 bytes, according to the + spec, but our API is such that they may not be \0 terminated + either. Thus we keep on treating them as krb5_data objects instead + of C strings. */ +static krb5_error_code +foreach_realm (krb5_error_code (*fn)(krb5_data *comp,void *data), void *data, + const krb5_data *crealm, const krb5_data *srealm, + const krb5_data *transit) +{ + char buf[MAXLEN], last[MAXLEN]; + char *p, *bufp; + int next_lit, intermediates, l; + krb5_data this_component; + krb5_error_code r; + krb5_data last_component; + + /* Invariants: + - last_component points to last[] + - this_component points to buf[] + - last_component has length of last + - this_component has length of buf when calling out + Keep these consistent, and we should be okay. */ + + next_lit = 0; + intermediates = 0; + memset (buf, 0, sizeof (buf)); + + this_component.data = buf; + last_component.data = last; + last_component.length = 0; + +#define print_data(fmt,d) Tprintf((fmt,(int)(d)->length,(d)->data)) + print_data ("client realm: %.*s\n", crealm); + print_data ("server realm: %.*s\n", srealm); + print_data ("transit enc.: %.*s\n", transit); + + if (transit->length == 0) { + Tprintf (("no other realms transited\n")); + return 0; + } + + bufp = buf; + for (p = transit->data, l = transit->length; l; p++, l--) { + if (next_lit) { + *bufp++ = *p; + if (bufp == buf+sizeof(buf)) + return KRB5KRB_AP_ERR_ILL_CR_TKT; + next_lit = 0; + } else if (*p == '\\') { + next_lit = 1; + } else if (*p == ',') { + if (bufp != buf) { + this_component.length = bufp - buf; + r = maybe_join (&last_component, &this_component, sizeof(buf)); + if (r) + return r; + r = (*fn) (&this_component, data); + if (r) + return r; + if (intermediates) { + if (p == transit->data) + r = process_intermediates (fn, data, + &this_component, crealm); + else { + r = process_intermediates (fn, data, &this_component, + &last_component); + } + if (r) + return r; + } + intermediates = 0; + memcpy (last, buf, sizeof (buf)); + last_component.length = this_component.length; + memset (buf, 0, sizeof (buf)); + bufp = buf; + } else { + intermediates = 1; + if (p == transit->data) { + if (crealm->length >= MAXLEN) + return KRB5KRB_AP_ERR_ILL_CR_TKT; + if (crealm->length > 0) + memcpy (last, crealm->data, crealm->length); + last[crealm->length] = '\0'; + last_component.length = crealm->length; + } + } + } else if (*p == ' ' && bufp == buf) { + /* This next component stands alone, even if it has a + trailing dot or leading slash. */ + memset (last, 0, sizeof (last)); + last_component.length = 0; + } else { + /* Not a special character; literal. */ + *bufp++ = *p; + if (bufp == buf+sizeof(buf)) + return KRB5KRB_AP_ERR_ILL_CR_TKT; + } + } + /* At end. Must be normal state. */ + if (next_lit) + Tprintf (("ending in next-char-literal state\n")); + /* Process trailing element or comma. */ + if (bufp == buf) { + /* Trailing comma. */ + r = process_intermediates (fn, data, &last_component, srealm); + } else { + /* Trailing component. */ + this_component.length = bufp - buf; + r = maybe_join (&last_component, &this_component, sizeof(buf)); + if (r) + return r; + r = (*fn) (&this_component, data); + if (r) + return r; + if (intermediates) + r = process_intermediates (fn, data, &this_component, + &last_component); + } + if (r != 0) + return r; + return 0; +} + +struct check_data { + krb5_context ctx; + krb5_principal *tgs; +}; + +static krb5_error_code +check_realm_in_list (krb5_data *realm, void *data) +{ + struct check_data *cdata = data; + int i; + + Tprintf ((".. checking '%.*s'\n", (int) realm->length, realm->data)); + for (i = 0; cdata->tgs[i]; i++) { + if (data_eq (cdata->tgs[i]->realm, *realm)) + return 0; + } + Tprintf (("BAD!\n")); + return KRB5KRB_AP_ERR_ILL_CR_TKT; +} + +krb5_error_code +krb5_check_transited_list (krb5_context ctx, const krb5_data *trans_in, + const krb5_data *crealm, const krb5_data *srealm) +{ + krb5_data trans; + struct check_data cdata; + krb5_error_code r; + const krb5_data *anonymous; + + trans.length = trans_in->length; + trans.data = (char *) trans_in->data; + if (trans.length && (trans.data[trans.length-1] == '\0')) + trans.length--; + + Tprintf (("krb5_check_transited_list(trans=\"%.*s\", crealm=\"%.*s\", srealm=\"%.*s\")\n", + (int) trans.length, trans.data, + (int) crealm->length, crealm->data, + (int) srealm->length, srealm->data)); + if (trans.length == 0) + return 0; + anonymous = krb5_anonymous_realm(); + if (crealm->length == anonymous->length && + (memcmp(crealm->data, anonymous->data, anonymous->length) == 0)) + return 0; /* Nothing to check for anonymous */ + + r = krb5_walk_realm_tree (ctx, crealm, srealm, &cdata.tgs, + KRB5_REALM_BRANCH_CHAR); + if (r) { + Tprintf (("error %ld\n", (long) r)); + return r; + } +#ifdef DEBUG /* avoid compiler warning about 'd' unused */ + { + int i; + Tprintf (("tgs list = {\n")); + for (i = 0; cdata.tgs[i]; i++) { + char *name; + r = krb5_unparse_name (ctx, cdata.tgs[i], &name); + Tprintf (("\t'%s'\n", name)); + free (name); + } + Tprintf (("}\n")); + } +#endif + cdata.ctx = ctx; + r = foreach_realm (check_realm_in_list, &cdata, crealm, srealm, &trans); + krb5_free_realm_tree (ctx, cdata.tgs); + return r; +} + +#ifdef TEST + +static krb5_error_code +print_a_realm (krb5_data *realm, void *data) +{ + printf ("%.*s\n", (int) realm->length, realm->data); + return 0; +} + +int main (int argc, char *argv[]) { + const char *me; + krb5_data crealm, srealm, transit; + krb5_error_code r; + int expand_only = 0; + + me = strrchr (argv[0], '/'); + me = me ? me+1 : argv[0]; + + while (argc > 3 && argv[1][0] == '-') { + if (!strcmp ("-v", argv[1])) + verbose++, argc--, argv++; + else if (!strcmp ("-x", argv[1])) + expand_only++, argc--, argv++; + else + goto usage; + } + + if (argc != 4) { + usage: + printf ("usage: %s [-v] [-x] clientRealm serverRealm transitEncoding\n", + me); + return 1; + } + + crealm.data = argv[1]; + crealm.length = strlen(argv[1]); + srealm.data = argv[2]; + srealm.length = strlen(argv[2]); + transit.data = argv[3]; + transit.length = strlen(argv[3]); + + if (expand_only) { + + printf ("client realm: %s\n", argv[1]); + printf ("server realm: %s\n", argv[2]); + printf ("transit enc.: %s\n", argv[3]); + + if (argv[3][0] == 0) { + printf ("no other realms transited\n"); + return 0; + } + + r = foreach_realm (print_a_realm, NULL, &crealm, &srealm, &transit); + if (r) + printf ("--> returned error %ld\n", (long) r); + return r != 0; + + } else { + + /* Actually check the values against the supplied krb5.conf file. */ + krb5_context ctx; + r = krb5_init_context (&ctx); + if (r) { + com_err (me, r, "initializing krb5 context"); + return 1; + } + r = krb5_check_transited_list (ctx, &transit, &crealm, &srealm); + if (r == KRB5KRB_AP_ERR_ILL_CR_TKT) { + printf ("NO\n"); + } else if (r == 0) { + printf ("YES\n"); + } else { + printf ("kablooey!\n"); + com_err (me, r, "checking transited-realm list"); + return 1; + } + return 0; + } +} + +#endif /* TEST */ |
