smtpd: cleanup hello() domain check code
theres no point in doing domain checks on literal ip addresses, so handle that case early.
This commit is contained in:
cinap_lenrek
parent
4908ea43d7
commit
e4af9bc392
1 changed files with 74 additions and 72 deletions
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@ -335,6 +335,7 @@ hello(String *himp, int extended)
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{
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char **mynames;
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char *ldot, *rdot;
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char *p;
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him = s_to_c(himp);
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syslog(0, "smtpd", "%s from %s as %s", extended? "ehlo": "helo",
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@ -342,89 +343,81 @@ hello(String *himp, int extended)
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if(rejectcheck())
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return;
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if (strchr(him, '.') && nci && !trusted && fflag &&
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strcmp(nci->rsys, nci->lsys) != 0){
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if (him[0] == '[') {
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/*
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* We don't care if he lies about who he is, but it is
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* not okay to pretend to be us. Many viruses do this,
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* just parroting back what we say in the greeting.
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* reject literal ip addresses when not trusted.
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*/
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if(strcmp(him, dom) == 0)
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if (!trusted)
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goto Liarliar;
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for(mynames = sysnames_read(); mynames && *mynames; mynames++){
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if(cistrcmp(*mynames, him) == 0){
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Liarliar:
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syslog(0, "smtpd",
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"Hung up on %s; claimed to be %s",
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nci->rsys, him);
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if(Dflag)
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sleep(delaysecs()*1000);
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reply("554 5.7.0 Liar!\r\n");
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exits("client pretended to be us");
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return;
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}
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him = nci->rsys;
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} else {
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if (!trusted && fflag && nci && strcmp(nci->rsys, nci->lsys) != 0){
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/*
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* We don't care if he lies about who he is, but it is
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* not okay to pretend to be us. Many viruses do this,
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* just parroting back what we say in the greeting.
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*/
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if(cistrcmp(him, dom) == 0)
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goto Liarliar;
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for(mynames = sysnames_read(); mynames && *mynames; mynames++)
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if(cistrcmp(*mynames, him) == 0)
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goto Liarliar;
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}
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}
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/*
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* it is unacceptable to claim any string that doesn't look like
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* a domain name (e.g., has at least one dot in it), but
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* Microsoft mail client software gets this wrong, so let trusted
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* (local) clients omit the dot.
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*/
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rdot = strrchr(him, '.');
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if (rdot && rdot[1] == '\0') {
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*rdot = '\0'; /* clobber trailing dot */
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rdot = strrchr(him, '.'); /* try again */
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}
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if (!trusted && rdot == nil)
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goto Liarliar;
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/*
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* Reject obviously bogus domains and those reserved by RFC 2606.
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*/
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if (rdot == nil)
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rdot = him;
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else
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rdot++;
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if (cistrcmp(rdot, "localdomain") == 0 ||
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cistrcmp(rdot, "localhost") == 0 ||
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cistrcmp(rdot, "example") == 0 ||
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cistrcmp(rdot, "invalid") == 0 ||
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cistrcmp(rdot, "test") == 0)
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goto Liarliar; /* bad top-level domain */
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/* check second-level RFC 2606 domains: example\.(com|net|org) */
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if (rdot != him)
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*--rdot = '\0';
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ldot = strrchr(him, '.');
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if (rdot != him)
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*rdot = '.';
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if (ldot == nil)
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ldot = him;
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else
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ldot++;
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if (cistrcmp(ldot, "example.com") == 0 ||
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cistrcmp(ldot, "example.net") == 0 ||
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cistrcmp(ldot, "example.org") == 0)
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goto Liarliar;
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/*
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* similarly, if the claimed domain is not an address-literal,
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* require at least one letter, which there will be in
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* at least the last component (e.g., .com, .net) if it's real.
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* this rejects non-address-literal IP addresses,
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* among other bogosities.
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*/
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if (!trusted && him[0] != '[') {
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char *p;
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/*
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* require at least one letter, which there will be in
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* at least the last component (e.g., .com, .net) if it's real.
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* this rejects non-address-literal IP addresses,
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* among other bogosities.
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*/
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for (p = him; *p != '\0'; p++)
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if (isascii(*p) && isalpha(*p))
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break;
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if (*p == '\0')
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goto Liarliar;
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/*
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* it is unacceptable to claim any string that doesn't look like
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* a domain name (e.g., has at least one dot in it), but
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* Microsoft mail client software gets this wrong, so let trusted
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* (local) clients omit the dot.
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*/
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rdot = strrchr(him, '.');
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if (rdot && rdot[1] == '\0') {
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*rdot = '\0'; /* clobber trailing dot */
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rdot = strrchr(him, '.'); /* try again */
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}
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if (!trusted && rdot == nil)
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goto Liarliar;
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/*
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* Reject obviously bogus domains and those reserved by RFC 2606.
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*/
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if (rdot == nil)
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rdot = him;
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else
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rdot++;
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if (cistrcmp(rdot, "localdomain") == 0 ||
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cistrcmp(rdot, "localhost") == 0 ||
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cistrcmp(rdot, "example") == 0 ||
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cistrcmp(rdot, "invalid") == 0 ||
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cistrcmp(rdot, "test") == 0)
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goto Liarliar; /* bad top-level domain */
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/* check second-level RFC 2606 domains: example\.(com|net|org) */
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if (rdot != him)
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*--rdot = '\0';
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ldot = strrchr(him, '.');
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if (rdot != him)
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*rdot = '.';
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if (ldot == nil)
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ldot = him;
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else
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ldot++;
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if (cistrcmp(ldot, "example.com") == 0 ||
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cistrcmp(ldot, "example.net") == 0 ||
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cistrcmp(ldot, "example.org") == 0)
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goto Liarliar;
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}
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if(strchr(him, '.') == 0 && nci != nil && strchr(nci->rsys, '.') != nil)
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him = nci->rsys;
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if(Dflag)
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sleep(delaysecs()*1000);
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@ -438,6 +431,15 @@ Liarliar:
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else
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reply("250 AUTH CRAM-MD5\r\n");
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}
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return;
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Liarliar:
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syslog(0, "smtpd", "Hung up on %s; claimed to be %s",
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nci->rsys, him);
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if(Dflag)
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sleep(delaysecs()*1000);
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reply("554 5.7.0 Liar!\r\n");
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exits("client pretended to be us");
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}
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void
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