apply the big auth patch

6 files changed, 390 insertions, 16 deletions

diff --git a/Makefile b/Makefile
index 0f0e31a..65e9e9c 100644
--- a/Makefile
+++ b/Makefile
@@ -136,6 +136,10 @@ auto_usera.o: \
 compile auto_usera.c
 	./compile auto_usera.c
 
+base64.o: \
+compile base64.c base64.h stralloc.h substdio.h str.h
+	./compile base64.c
+
 binm1: \
 binm1.sh conf-qmail
 	cat binm1.sh \
@@ -1536,12 +1540,12 @@ load qmail-smtpd.o rcpthosts.o commands.o timeoutread.o \
 timeoutwrite.o ip.o ipme.o ipalloc.o control.o constmap.o received.o \
 date822fmt.o now.o qmail.o cdb.a fd.a wait.a datetime.a getln.a \
 open.a sig.a case.a env.a stralloc.a alloc.a substdio.a error.a str.a \
-fs.a auto_qmail.o socket.lib
+fs.a auto_qmail.o base64.o socket.lib
 	./load qmail-smtpd rcpthosts.o commands.o timeoutread.o \
 	timeoutwrite.o ip.o ipme.o ipalloc.o control.o constmap.o \
 	received.o date822fmt.o now.o qmail.o cdb.a fd.a wait.a \
 	datetime.a getln.a open.a sig.a case.a env.a stralloc.a \
-	alloc.a substdio.a error.a str.a fs.a auto_qmail.o  `cat \
+	alloc.a substdio.a error.a str.a fs.a auto_qmail.o base64.o  `cat \
 	socket.lib`
 
 qmail-smtpd.0: \
@@ -1553,7 +1557,8 @@ compile qmail-smtpd.c sig.h readwrite.h stralloc.h gen_alloc.h \
 substdio.h alloc.h auto_qmail.h control.h received.h constmap.h \
 error.h ipme.h ip.h ipalloc.h ip.h gen_alloc.h ip.h qmail.h \
 substdio.h str.h fmt.h scan.h byte.h case.h env.h now.h datetime.h \
-exit.h rcpthosts.h timeoutread.h timeoutwrite.h commands.h
+exit.h rcpthosts.h timeoutread.h timeoutwrite.h commands.h wait.h \
+fd.h base64.h
 	./compile qmail-smtpd.c
 
 qmail-start: \
diff --git a/TARGETS b/TARGETS
index facdad7..75ec741 100644
--- a/TARGETS
+++ b/TARGETS
@@ -250,6 +250,7 @@ qmail-qmqpd
 qmail-qmtpd.o
 rcpthosts.o
 qmail-qmtpd
+base64.o
 qmail-smtpd.o
 qmail-smtpd
 sendmail.o
diff --git a/base64.c b/base64.c
new file mode 100644
index 0000000..fbce145
--- /dev/null
+++ b/base64.c
@@ -0,0 +1,90 @@
+#include "base64.h"
+#include "stralloc.h"
+#include "substdio.h"
+#include "str.h"
+
+static char *b64alpha =
+  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+#define B64PAD '='
+
+/* returns 0 ok, 1 illegal, -1 problem */
+
+int b64decode(in,l,out)
+const unsigned char *in;
+int l;
+stralloc *out; /* not null terminated */
+{
+  int i, j;
+  unsigned char a[4];
+  unsigned char b[3];
+  char *s;
+
+  if (l == 0)
+  {
+    if (!stralloc_copys(out,"")) return -1;
+    return 0;
+  }
+
+  if (!stralloc_ready(out,l + 2)) return -1; /* XXX generous */
+  s = out->s;
+
+  for (i = 0;i < l;i += 4) {
+    for (j = 0;j < 4;j++)
+      if ((i + j) < l && in[i + j] != B64PAD)
+      {
+        a[j] = str_chr(b64alpha,in[i + j]);
+        if (a[j] > 63) return 1;
+      }
+      else a[j] = 0;
+
+    b[0] = (a[0] << 2) | (a[1] >> 4);
+    b[1] = (a[1] << 4) | (a[2] >> 2);
+    b[2] = (a[2] << 6) | (a[3]);
+
+    *s++ = b[0];
+
+    if (in[i + 1] == B64PAD) break;
+    *s++ = b[1];
+
+    if (in[i + 2] == B64PAD) break;
+    *s++ = b[2];
+  }
+  out->len = s - out->s;
+  while (out->len && !out->s[out->len - 1]) --out->len; /* XXX avoid? */
+  return 0;
+}
+
+int b64encode(in,out)
+stralloc *in;
+stralloc *out; /* not null terminated */
+{
+  unsigned char a, b, c;
+  int i;
+  char *s;
+
+  if (in->len == 0)
+  {
+    if (!stralloc_copys(out,"")) return -1;
+    return 0;
+  }
+
+  if (!stralloc_ready(out,in->len / 3 * 4 + 4)) return -1;
+  s = out->s;
+
+  for (i = 0;i < in->len;i += 3) {
+    a = in->s[i];
+    b = i + 1 < in->len ? in->s[i + 1] : 0;
+    c = i + 2 < in->len ? in->s[i + 2] : 0;
+
+    *s++ = b64alpha[a >> 2];
+    *s++ = b64alpha[((a & 3 ) << 4) | (b >> 4)];
+
+    if (i + 1 >= in->len) *s++ = B64PAD;
+    else *s++ = b64alpha[((b & 15) << 2) | (c >> 6)];
+
+    if (i + 2 >= in->len) *s++ = B64PAD;
+    else *s++ = b64alpha[c & 63];
+  }
+  out->len = s - out->s;
+  return 0;
+}
diff --git a/base64.h b/base64.h
new file mode 100644
index 0000000..a9164c0
--- /dev/null
+++ b/base64.h
@@ -0,0 +1,7 @@
+#ifndef BASE64_H
+#define BASE64_H
+
+extern int b64decode();
+extern int b64encode();
+
+#endif
diff --git a/qmail-smtpd.8 b/qmail-smtpd.8
index c4640b8..3e6cce2 100644
--- a/qmail-smtpd.8
+++ b/qmail-smtpd.8
@@ -3,6 +3,11 @@
 qmail-smtpd \- receive mail via SMTP
 .SH SYNOPSIS
 .B qmail-smtpd
+[
+.I hostname
+.I checkprogram
+.I subprogram
+]
 .SH DESCRIPTION
 .B qmail-smtpd
 receives mail messages via the Simple Mail Transfer Protocol (SMTP)
@@ -23,7 +28,29 @@ or
 header fields.
 
 .B qmail-smtpd
-supports ESMTP, including the 8BITMIME and PIPELINING options.
+supports ESMTP, including the 8BITMIME, PIPELINING, and AUTH options.
+
+.B qmail-smtpd
+can accept LOGIN, PLAIN, and CRAM-MD5 AUTH types.  It invokes
+.IR checkprogram ,
+which reads on file descriptor 3 the username, a 0 byte, the password
+or challenge derived from
+.IR hostname ,
+another 0 byte, a CRAM-MD5 response (if applicable to the AUTH type),
+and a final 0 byte.
+.I checkprogram
+invokes
+.I subprogram
+upon successful authentication, which should in turn return 0 to
+.BR qmail-smtpd ,
+effectively setting the environment variables RELAYCLIENT and TCPREMOTEINFO
+(any supplied value replaced with the authenticated username).
+.B qmail-smtpd
+will reject the authentication attempt if it receives a nonzero return
+value from
+.I checkprogram
+or
+.IR subprogram .
 .SH TRANSPARENCY
 .B qmail-smtpd
 converts the SMTP newline convention into the UNIX newline convention
@@ -177,3 +204,6 @@ qmail-inject(8),
 qmail-newmrh(8),
 qmail-queue(8),
 qmail-remote(8)
+.SH "HISTORY"
+The patch enabling the ESMTP AUTH option is not part of the standard
+qmail-1.03 distribution.
diff --git a/qmail-smtpd.c b/qmail-smtpd.c
index 54df00c..7390eb4 100644
--- a/qmail-smtpd.c
+++ b/qmail-smtpd.c
@@ -23,7 +23,10 @@
 #include "timeoutread.h"
 #include "timeoutwrite.h"
 #include "commands.h"
+#include "wait.h"
+#include "fd.h"
 
+#define AUTHCRAM
 #define MAXHOPS 100
 unsigned int databytes = 0;
 int timeout = 1200;
@@ -59,6 +62,15 @@ void err_noop(arg) char *arg; { out("250 ok\r\n"); }
 void err_vrfy(arg) char *arg; { out("252 send some mail, i'll try my best\r\n"); }
 void err_qqt() { out("451 qqt failure (#4.3.0)\r\n"); }
 
+int err_child() { out("454 oops, problem with child and I can't auth (#4.3.0)\r\n"); return -1; }
+int err_fork() { out("454 oops, child won't start and I can't auth (#4.3.0)\r\n"); return -1; }
+int err_pipe() { out("454 oops, unable to open pipe and I can't auth (#4.3.0)\r\n"); return -1; }
+int err_write() { out("454 oops, unable to write pipe and I can't auth (#4.3.0)\r\n"); return -1; }
+void err_authd() { out("503 you're already authenticated (#5.5.0)\r\n"); }
+void err_authmail() { out("503 no auth during mail transaction (#5.5.0)\r\n"); }
+int err_noauth() { out("504 auth type unimplemented (#5.5.1)\r\n"); return -1; }
+int err_authabrt() { out("501 auth exchange cancelled (#5.0.0)\r\n"); return -1; }
+int err_input() { out("501 malformed auth input (#5.5.4)\r\n"); return -1; }
 
 stralloc greeting = {0};
 
@@ -86,8 +98,8 @@ stralloc helohost = {0};
 char *fakehelo; /* pointer into helohost, or 0 */
 
 void dohelo(arg) char *arg; {
-  if (!stralloc_copys(&helohost,arg)) die_nomem(); 
-  if (!stralloc_0(&helohost)) die_nomem(); 
+  if (!stralloc_copys(&helohost,arg)) die_nomem();
+  if (!stralloc_0(&helohost)) die_nomem();
   fakehelo = case_diffs(remotehost,helohost.s) ? helohost.s : 0;
 }
 
@@ -101,7 +113,7 @@ void setup()
 {
   char *x;
   unsigned long u;
- 
+
   if (control_init() == -1) die_control();
   if (control_rldef(&greeting,"control/smtpgreeting",1,(char *) 0) != 1)
     die_control();
@@ -116,12 +128,12 @@ void setup()
   if (bmfok == -1) die_control();
   if (bmfok)
     if (!constmap_init(&mapbmf,bmf.s,bmf.len,0)) die_nomem();
- 
+
   if (control_readint(&databytes,"control/databytes") == -1) die_control();
   x = env_get("DATABYTES");
   if (x) { scan_ulong(x,&u); databytes = u; }
   if (!(databytes + 1)) --databytes;
- 
+
   remoteip = env_get("TCPREMOTEIP");
   if (!remoteip) remoteip = "unknown";
   local = env_get("TCPLOCALHOST");
@@ -146,7 +158,7 @@ char *arg;
   struct ip_address ip;
   int flagesc;
   int flagquoted;
- 
+
   terminator = '>';
   i = str_chr(arg,'<');
   if (arg[i])
@@ -229,7 +241,15 @@ void smtp_helo(arg) char *arg;
 }
 void smtp_ehlo(arg) char *arg;
 {
-  smtp_greet("250-"); out("\r\n250-PIPELINING\r\n250 8BITMIME\r\n");
+  smtp_greet("250-");
+#ifdef AUTHCRAM
+  out("\r\n250-AUTH LOGIN CRAM-MD5 PLAIN");
+  out("\r\n250-AUTH=LOGIN CRAM-MD5 PLAIN");
+#else
+  out("\r\n250-AUTH LOGIN PLAIN");
+  out("\r\n250-AUTH=LOGIN PLAIN");
+#endif
+  out("\r\n250-PIPELINING\r\n250 8BITMIME\r\n");
   seenmail = 0; dohelo(arg);
 }
 void smtp_rset(arg) char *arg;
@@ -300,7 +320,7 @@ int *hops;
   int flagmaybex; /* 1 if this line might match RECEIVED, if fih */
   int flagmaybey; /* 1 if this line might match \r\n, if fih */
   int flagmaybez; /* 1 if this line might match DELIVERED, if fih */
- 
+
   state = 1;
   *hops = 0;
   flaginheader = 1;
@@ -369,7 +389,7 @@ void smtp_data(arg) char *arg; {
   int hops;
   unsigned long qp;
   char *qqx;
- 
+
   if (!seenmail) { err_wantmail(); return; }
   if (!rcptto.len) { err_wantrcpt(); return; }
   seenmail = 0;
@@ -377,14 +397,14 @@ void smtp_data(arg) char *arg; {
   if (qmail_open(&qqt) == -1) { err_qqt(); return; }
   qp = qmail_qp(&qqt);
   out("354 go ahead\r\n");
- 
+
   received(&qqt,"SMTP",local,remoteip,remotehost,remoteinfo,fakehelo);
   blast(&hops);
   hops = (hops >= MAXHOPS);
   if (hops) qmail_fail(&qqt);
   qmail_from(&qqt,mailfrom.s);
   qmail_put(&qqt,rcptto.s,rcptto.len);
- 
+
   qqx = qmail_close(&qqt);
   if (!*qqx) { acceptmessage(qp); return; }
   if (hops) { out("554 too many hops, this message is looping (#5.4.6)\r\n"); return; }
@@ -394,10 +414,226 @@ void smtp_data(arg) char *arg; {
   out("\r\n");
 }
 
+
+char unique[FMT_ULONG + FMT_ULONG + 3];
+static stralloc authin = {0};
+static stralloc user = {0};
+static stralloc pass = {0};
+static stralloc resp = {0};
+static stralloc slop = {0};
+char *hostname;
+char **childargs;
+substdio ssup;
+char upbuf[128];
+int authd = 0;
+
+int authgetl(void) {
+  int i;
+
+  if (!stralloc_copys(&authin, "")) die_nomem();
+
+  for (;;) {
+    if (!stralloc_readyplus(&authin,1)) die_nomem(); /* XXX */
+    i = substdio_get(&ssin,authin.s + authin.len,1);
+    if (i != 1) die_read();
+    if (authin.s[authin.len] == '\n') break;
+    ++authin.len;
+  }
+
+  if (authin.len > 0) if (authin.s[authin.len - 1] == '\r') --authin.len;
+  authin.s[authin.len] = 0;
+
+  if (*authin.s == '*' && *(authin.s + 1) == 0) { return err_authabrt(); }
+  if (authin.len == 0) { return err_input(); }
+  return authin.len;
+}
+
+int authenticate(void)
+{
+  int child;
+  int wstat;
+  int pi[2];
+
+  if (!stralloc_0(&user)) die_nomem();
+  if (!stralloc_0(&pass)) die_nomem();
+  if (!stralloc_0(&resp)) die_nomem();
+
+  if (fd_copy(2,1) == -1) return err_pipe();
+  close(3);
+  if (pipe(pi) == -1) return err_pipe();
+  if (pi[0] != 3) return err_pipe();
+  switch(child = fork()) {
+    case -1:
+      return err_fork();
+    case 0:
+      close(pi[1]);
+      sig_pipedefault();
+      execvp(*childargs, childargs);
+      _exit(1);
+  }
+  close(pi[0]);
+
+  substdio_fdbuf(&ssup,write,pi[1],upbuf,sizeof upbuf);
+  if (substdio_put(&ssup,user.s,user.len) == -1) return err_write();
+  if (substdio_put(&ssup,pass.s,pass.len) == -1) return err_write();
+  if (substdio_put(&ssup,resp.s,resp.len) == -1) return err_write();
+  if (substdio_flush(&ssup) == -1) return err_write();
+
+  close(pi[1]);
+  byte_zero(pass.s,pass.len);
+  byte_zero(upbuf,sizeof upbuf);
+  if (wait_pid(&wstat,child) == -1) return err_child();
+  if (wait_crashed(wstat)) return err_child();
+  if (wait_exitcode(wstat)) { sleep(5); return 1; } /* no */
+  return 0; /* yes */
+}
+
+int auth_login(arg) char *arg;
+{
+  int r;
+
+  if (*arg) {
+    if (r = b64decode(arg,str_len(arg),&user) == 1) return err_input();
+  }
+  else {
+    out("334 VXNlcm5hbWU6\r\n"); flush(); /* Username: */
+    if (authgetl() < 0) return -1;
+    if (r = b64decode(authin.s,authin.len,&user) == 1) return err_input();
+  }
+  if (r == -1) die_nomem();
+
+  out("334 UGFzc3dvcmQ6\r\n"); flush(); /* Password: */
+
+  if (authgetl() < 0) return -1;
+  if (r = b64decode(authin.s,authin.len,&pass) == 1) return err_input();
+  if (r == -1) die_nomem();
+
+  if (!user.len || !pass.len) return err_input();
+  return authenticate();
+}
+
+int auth_plain(arg) char *arg;
+{
+  int r, id = 0;
+
+  if (*arg) {
+    if (r = b64decode(arg,str_len(arg),&slop) == 1) return err_input();
+  }
+  else {
+    out("334 \r\n"); flush();
+    if (authgetl() < 0) return -1;
+    if (r = b64decode(authin.s,authin.len,&slop) == 1) return err_input();
+  }
+  if (r == -1 || !stralloc_0(&slop)) die_nomem();
+  while (slop.s[id]) id++; /* ignore authorize-id */
+
+  if (slop.len > id + 1)
+    if (!stralloc_copys(&user,slop.s + id + 1)) die_nomem();
+  if (slop.len > id + user.len + 2)
+    if (!stralloc_copys(&pass,slop.s + id + user.len + 2)) die_nomem();
+
+  if (!user.len || !pass.len) return err_input();
+  return authenticate();
+}
+
+#ifdef AUTHCRAM
+int auth_cram()
+{
+  int i, r;
+  char *s;
+
+  s = unique;
+  s += fmt_uint(s,getpid());
+  *s++ = '.';
+  s += fmt_ulong(s,(unsigned long) now());
+  *s++ = '@';
+  *s++ = 0;
+
+  if (!stralloc_copys(&pass,"<")) die_nomem();
+  if (!stralloc_cats(&pass,unique)) die_nomem();
+  if (!stralloc_cats(&pass,hostname)) die_nomem();
+  if (!stralloc_cats(&pass,">")) die_nomem();
+  if (b64encode(&pass,&slop) < 0) die_nomem();
+  if (!stralloc_0(&slop)) die_nomem();
+
+  out("334 ");
+  out(slop.s);
+  out("\r\n");
+  flush();
+
+  if (authgetl() < 0) return -1;
+  if (r = b64decode(authin.s,authin.len,&slop) == 1) return err_input();
+  if (r == -1 || !stralloc_0(&slop)) die_nomem();
+
+  i = str_chr(slop.s,' ');
+  s = slop.s + i;
+  while (*s == ' ') ++s;
+  slop.s[i] = 0;
+  if (!stralloc_copys(&user,slop.s)) die_nomem();
+  if (!stralloc_copys(&resp,s)) die_nomem();
+
+  if (!user.len || !resp.len) return err_input();
+  return authenticate();
+}
+#endif
+
+struct authcmd {
+  char *text;
+  int (*fun)();
+} authcmds[] = {
+  { "login", auth_login }
+, { "plain", auth_plain }
+#ifdef AUTHCRAM
+, { "cram-md5", auth_cram }
+#endif
+, { 0, err_noauth }
+};
+
+void smtp_auth(arg)
+char *arg;
+{
+  int i;
+  char *cmd = arg;
+
+  if (!hostname || !*childargs)
+  {
+    out("503 auth not available (#5.3.3)\r\n");
+    return;
+  }
+  if (authd) { err_authd(); return; }
+  if (seenmail) { err_authmail(); return; }
+
+  if (!stralloc_copys(&user,"")) die_nomem();
+  if (!stralloc_copys(&pass,"")) die_nomem();
+  if (!stralloc_copys(&resp,"")) die_nomem();
+
+  i = str_chr(cmd,' ');
+  arg = cmd + i;
+  while (*arg == ' ') ++arg;
+  cmd[i] = 0;
+
+  for (i = 0;authcmds[i].text;++i)
+    if (case_equals(authcmds[i].text,cmd)) break;
+
+  switch (authcmds[i].fun(arg)) {
+    case 0:
+      authd = 1;
+      relayclient = "";
+      remoteinfo = user.s;
+      if (!env_unset("TCPREMOTEINFO")) die_read();
+      if (!env_put2("TCPREMOTEINFO",remoteinfo)) die_nomem();
+      out("235 ok, go ahead (#2.0.0)\r\n");
+      break;
+    case 1:
+      out("535 authorization failed (#5.7.0)\r\n");
+  }
+}
+
 struct commands smtpcommands[] = {
   { "rcpt", smtp_rcpt, 0 }
 , { "mail", smtp_mail, 0 }
 , { "data", smtp_data, flush }
+, { "auth", smtp_auth, flush }
 , { "quit", smtp_quit, flush }
 , { "helo", smtp_helo, flush }
 , { "ehlo", smtp_ehlo, flush }
@@ -408,8 +644,13 @@ struct commands smtpcommands[] = {
 , { 0, err_unimpl, flush }
 } ;
 
-void main()
+void main(argc,argv)
+int argc;
+char **argv;
 {
+  hostname = argv[1];
+  childargs = argv + 2;
+
   sig_pipeignore();
   if (chdir(auto_qmail) == -1) die_control();
   setup();