qmail-popup.8 (1350B)
1 .TH qmail-popup 8 2 .SH NAME 3 qmail-popup \- read a POP username and password 4 .SH SYNOPSIS 5 .B qmail-popup 6 .I hostname 7 .I subprogram 8 .SH DESCRIPTION 9 .B qmail-popup 10 reads a POP username and password from the network. 11 It then runs 12 .IR subprogram . 13 14 .B qmail-popup 15 is most commonly invoked from 16 .B inetd 17 as 18 19 .EX 20 qmail-popup CHANGEME checkpassword qmail-pop3d Maildir 21 .EE 22 23 with 24 CHANGEME 25 replaced by the fully qualified domain name of the local host. 26 27 .B qmail-popup 28 expects descriptor 0 to read from the network 29 and descriptor 1 to write to the network. 30 It reads a username and password from descriptor 0 31 in POP's USER-PASS style or APOP style. 32 It invokes 33 .IR subprogram , 34 with the same descriptors 0 and 1, 35 and with descriptor 3 reading the username, a 0 byte, the password, 36 another 0 byte, 37 an APOP timestamp derived from 38 .IR hostname , 39 and a final 0 byte. 40 .B qmail-popup 41 then waits for 42 .I subprogram 43 to finish. 44 It prints an error message if 45 .I subprogram 46 crashes or exits nonzero. 47 48 .B qmail-popup 49 should be used only within 50 a secure network. 51 Otherwise an eavesdropper can steal passwords. 52 Even if you use APOP, 53 an active attacker can still take over the connection 54 and wreak havoc. 55 56 .B qmail-popup 57 has a 20-minute idle timeout. 58 59 .B qmail-popup 60 is based on a program contributed by Russ Nelson. 61 .SH "SEE ALSO" 62 maildir(5), 63 qmail-local(8), 64 qmail-pop3d(8)