diff options
Diffstat (limited to 'resolv/res_comp.c')
| -rw-r--r-- | resolv/res_comp.c | 85 |
1 files changed, 82 insertions, 3 deletions
diff --git a/resolv/res_comp.c b/resolv/res_comp.c index 1342205..f234772 100644 --- a/resolv/res_comp.c +++ b/resolv/res_comp.c @@ -148,9 +148,6 @@ dn_expand(msg, eomorig, comp_dn, exp_dn, length) } } *dn = '\0'; - for (dn = exp_dn; (c = *dn) != '\0'; dn++) - if (isascii(c) && isspace(c)) - return (-1); if (len < 0) len = cp - comp_dn; return (len); @@ -340,6 +337,88 @@ dn_find(exp_dn, msg, dnptrs, lastdnptr) } /* + * Verify that a domain name uses an acceptable character set. + */ + +/**** +To: "Lawrence R. Rogers" <lrr@cert.org> +cc: cert@cert.org, pvm@home.net +Subject: Re: VU#14542 +In-reply-to: Your message of "Mon, 19 Feb 1996 17:16:27 PST." +Date: Tue, 20 Feb 1996 22:37:21 -0800 +From: Paul A Vixie <vixie@wisdom.home.vix.com> + +in retrospect, + + hostname = firstlabel ( "." otherlabel )+ + firstchar = [a-zA-Z0-9_] + otherchar = [a-zA-Z0-9_-/] + firstlabel = firstchar otherchar* + otherlabel = otherchar+ + +should have been + + hostname = label ( "." label )+ + firstchar = [a-zA-Z0-9_] + otherchar = [a-zA-Z0-9_-] + label = firstchar otherchar* + +i know of no example of a real host name that needs the looser rule i sent +earlier. since i'm only trying to bend the spec to fit actual known uses, +i should not have widened the rules as far as i did earlier. +****/ + +#define firstchar(c) ((isascii(c) && isalnum(c)) || (c) == '_') +#define otherchar(c) (firstchar(c) || (c) == '-') +#define wildlabel(firstlabel, ch, nch) \ + ((firstlabel) && (ch) == '*' && ((nch) == '.' || (nch) == '\0')) + +int +res_hnok(dn) + const char *dn; +{ + int ppch = '\0', pch = '.', ch = *dn++, firstlabel = 1; + + while (ch != '\0') { + int nch = *dn++; + + if (ch == '.' || (ch == '\\' && nch == '.')) { + NULL; + } else if (pch == '.' && ppch != '\\') { + if (!firstchar(ch) && !wildlabel(firstlabel, ch, nch)) + return (0); + } else { + if (!otherchar(ch)) + return (0); + } + ppch = pch, pch = ch, ch = nch; + firstlabel = 0; + } + return (1); +} + +/* + * This function is quite liberal, since RFC 1034's character sets are only + * recommendations. + * + * Note that some char's are signed, so we have to cast to unsigned. + */ +int +dn_isvalid(dn) + const char *dn; +{ + unsigned char *t = (unsigned char *)dn; + int ch; + + while ((ch = *t++) != '\0') + if (ch <= 0x1f || ch >= 0x7f) { + /* Unprintable in ASCII. */ + return (0); + } + return (1); +} + +/* * Routines to insert/extract short/long's. */ |