add sqmail-4.2.29asqmail-4.2

1 files changed, 365 insertions, 0 deletions

diff --git a/src/qmail-dkverify.c b/src/qmail-dkverify.c
new file mode 100644
index 0000000..e607e08
--- /dev/null
+++ b/src/qmail-dkverify.c
@@ -0,0 +1,365 @@
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include "sig.h"
+#include "stralloc.h"
+#include "buffer.h"
+#include "error.h"
+#include "auto_qmail.h"
+#include "str.h"
+#include "exit.h"
+#include "uint_t.h"
+#include "fd.h"
+#include "open.h"
+#include "fmt.h"
+#include "fmtqfn.h"
+#include "readwrite.h"
+#include "getln.h"
+#include "qmail.h"
+#include "wait.h"
+#include "byte.h"
+#include "case.h"
+#include "control.h"
+#include "pathexec.h"
+#include "env.h"
+#include "logmsg.h"
+
+#define WHO "qmail-dkverify"
+
+/** @file  qmail-dkverify.c 
+    @brief stub routine for DKIM signature verification and indication in received message
+
+    Steps:
+    ------
+    a) Store message with CRLF
+    b) Get DKIM signature from message - if given:
+    c)   Call qmail-dkim for verification
+    d)   Include results as appended header
+    e) Queue the message for processing
+
+  */
+
+char bufin[1024];  // RFC 5322: 998 chars - why?
+buffer bi = BUFFER_INIT(read,0,bufin,sizeof(bufin));    // read buffer 
+char bufout[1024];
+buffer bo = BUFFER_INIT(write,1,bufout,sizeof(bufout)); // output message 
+
+void die(int e) { _exit(e); }
+void die_pipe(char *fn) { unlink(fn); die(53); };
+void die_write(char *fn) { unlink(fn); die(53); };
+void die_read() { die(54); };
+void out(char *s) { if (buffer_puts(&bo,s) == -1) _exit(111); }
+void zero() { if (buffer_put(&bo,"\0",1) == -1) _exit(111); }
+void zerodie() { zero(); buffer_flush(&bo); _exit(111); }
+
+void temp_nomem() 
+{
+  out("ZOut of memory. (#4.3.0)\n");
+  zerodie();
+}
+void temp_chdir() 
+{
+  out("ZUnable to switch to target directory. (#4.3.0)\n");
+  zerodie();
+}
+void temp_create() 
+{
+  out("ZUnable to create DKIM stage file. (#4.3.0)\n");
+  zerodie();
+}
+void temp_unlink() 
+{
+  out("ZUnable to unlink DKIM stage file. (#4.3.0)\n");
+  zerodie();
+}
+void temp_read()
+{
+  out("ZUnable to read message. (#4.3.0)\n");
+  zerodie();
+}
+void temp_socket()
+{
+  out("ZUnable to crate socket pair. (#4.3.0)\n");
+  zerodie();
+}
+void temp_control()
+{
+  out("ZUnable to read control files. (#4.3.0)\n");
+  zerodie();
+}
+
+static stralloc me = {0};
+static stralloc senddomain = {0};
+static stralloc dkheader = {0};
+static stralloc fndkin = {0};
+static stralloc fndkout = {0};
+static stralloc result = {0};
+ 
+void fnmake_dkim(unsigned long id) 
+{ 
+  fndkin.len = fmtqfn(fndkin.s,"queue/dkim/",id,1); 
+  id += id;
+  fndkout.len = fmtqfn(fndkout.s,"queue/dkim/",id,1); 
+} 
+
+void dkim_stage()
+{
+  int r;
+  int fd;
+  char ch;
+  struct stat st;
+
+  if (!stralloc_ready(&fndkin,FMTQFN)) temp_nomem();
+  if (!stralloc_ready(&fndkout,FMTQFN)) temp_nomem();
+
+  fnmake_dkim(getpid());  // pre-staging
+  fd = open_excl(fndkin.s);
+  if (fd == -1) die_write(fndkin.s);
+
+  buffer_init(&bi,read,0,bufin,sizeof(bufin));
+  buffer_init(&bo,write,fd,bufout,sizeof(bufout));
+
+  for (int i = 0;;) {
+    r = buffer_get(&bi,&ch,1);
+    if (r == 0) break;
+    if (r == -1) temp_read();
+
+    while (ch != '\n') {
+      if (ch != '\r') buffer_put(&bo,&ch,1);
+      r = buffer_get(&bi,&ch,1);
+      if (r == -1) temp_read();
+      i++;
+    }
+    buffer_put(&bo,"\r\n",2);
+  }
+
+  if (buffer_flush(&bo) == -1) die(51);
+  if (fstat(fd,&st) == -1) die_write(fndkin.s);
+  if (fsync(fd) == -1) die_write(fndkin.s);
+  if (close(fd) == -1) die_write(fndkin.s);
+}
+
+int mess_dkim()
+{
+  stralloc line = {0};
+  int match;
+  int fd;
+  int at = 0;
+  int ket = 0;
+  int end = 0;
+  int len = 0;
+  int r = 0;
+  int i;
+
+  fd = open_read(fndkin.s);
+  if (fd == -1) die_read(); 
+  buffer_init(&bi,read,fd,bufin,sizeof(bufin));
+
+  if (!stralloc_copys(&senddomain,"")) temp_nomem();
+ 
+  for (;;) {
+    if (getln(&bi,&line,&match,'\n') == -1) temp_read();
+    if (case_starts(line.s,"DKIM-Signature: ")) r = 1;
+    if (r == 1) { 
+      if (case_starts(line.s,"From: ")) {  // fallback: From
+        at = str_chr(line.s,'@');
+        if (at < line.len) {
+          end = str_chr(line.s,'\n');      // From: user@senddomain\n
+          ket = str_chr(line.s,'>');       // From: User <user@senddomain>
+          len = (ket < end) ? ket : end;
+          len -= at - 1;
+          if (len) {
+            if (!stralloc_copyb(&senddomain,line.s + at + 1,len)) temp_nomem();
+          } else
+            if (!stralloc_copys(&senddomain,"uknown")) temp_nomem();
+          r = 2;
+        }
+      }
+      for (i = 0; i < line.len; ++i) {     // d=domain.tld
+        if (*(line.s + i) == '=' && *(line.s + i - 1) == 'd') {
+          ++i;                             // gotcha
+          while (*(line.s + i) != ';') {
+            if (!stralloc_catb(&senddomain,line.s + i,1)) temp_nomem();
+            i++;
+            r = 3;
+          }
+        }
+      }
+    }
+    if (r >= 2 || !match) break;
+  }
+  if (senddomain.len < 2) 
+    if (!stralloc_copys(&senddomain,"unknown")) temp_nomem();
+  if (!stralloc_0(&senddomain)) temp_nomem();
+
+  return r;
+}
+
+int dkim_verify()
+{
+  int child;
+  int wstat;
+  char *(args[6]);
+  int r = -1;
+
+  args[0] = "qmail-dkim";
+  args[1] = "-V";
+  args[2] = fndkin.s;
+  args[3] = "none";
+  args[4] = fndkout.s;
+  args[5] = 0;
+
+  if (!(child = fork())) { 
+    pathexec(args);
+    if (errno) _exit(111);
+    _exit(100);
+  }
+
+  wait_pid(&wstat,child);
+  if (wait_crashed(wstat)) return 1;
+
+  switch (r = wait_exitcode(wstat)) {
+    case 10: return 1;
+    default: return 0;
+  }
+}
+
+int dkim_result(const char *me)
+{
+  int max = 64;
+  int fd;
+  int j;
+  char ch;
+  int r = 0; 
+
+  if (!stralloc_copys(&result,"")) temp_nomem();
+
+  if ((fd = open_read(fndkout.s)) == -1) return 0; // nothing to read
+  while ((r = read(fd,bufin,sizeof(bufin))) > 0) 
+    if (!stralloc_catb(&result,bufin,r)) temp_nomem();
+
+  if (!stralloc_0(&result)) temp_nomem();
+
+  if (result.len > 2) {
+    if (case_starts(result.s,"pass")) r = 0;
+    if (case_starts(result.s,"fail")) r = 35;
+  } else
+    if (!stralloc_copys(&result,"unknown")) temp_nomem();
+
+  if (!stralloc_copys(&dkheader,"X-Authentication-Results: ")) temp_nomem();
+  if (!stralloc_cats(&dkheader,senddomain.s)) temp_nomem();
+  if (!stralloc_cats(&dkheader,"; dkim=")) temp_nomem();
+
+  for (j = 0; j < result.len; j++) {
+    ch = result.s[j];
+    if (ch == '\r' || ch == '\n' || ch == '\0') continue;
+    if (j <= max) if (!stralloc_catb(&dkheader,&ch,1)) temp_nomem();
+    if (ch == ' ' && (j > max)) {
+      if (!stralloc_cats(&dkheader,"\n  ")) temp_nomem();
+      max += max;
+    }
+  }
+
+  if (!stralloc_cats(&dkheader,"; ")) temp_nomem();
+  if (!stralloc_cats(&dkheader,me)) temp_nomem();
+  if (!stralloc_0(&dkheader)) temp_nomem();
+
+  return r;
+}
+
+int qmail_queue() 
+{
+  int fd;
+  int r;
+  int child;
+  int wstat;
+  int pi[2];
+  char *(args[2]);
+  char ch;
+
+  if (pipe(pi) == -1) die_pipe(fndkin.s);
+
+  args[0] = "qmail-queue";
+  args[1] = 0;
+
+  switch (child = vfork()) {
+    case -1: 
+      close(pi[0]); close(pi[1]); 
+      die_write(fndkin.s); 
+    case  0: 
+      close(pi[1]);
+      if (fd_move(0,pi[0]) == -1) die_pipe(fndkin.s);
+      sig_pipedefault();
+      pathexec(args);
+      if (errno) _exit(111);
+      _exit(100);
+  }
+  close(pi[0]);
+
+  buffer_init(&bo,write,pi[1],bufout,sizeof(bufout));
+
+  if (dkheader.len > 2) {    // write DKIM header
+    if (buffer_put(&bo,dkheader.s,dkheader.len - 1) == -1) die_write(fndkout.s);
+    if (buffer_put(&bo,"\n",1) == -1) die_write(fndkout.s);
+    if (buffer_flush(&bo) == -1) die_write(fndkout.s);
+  }
+
+  /* read/write message byte-by-byte; we need to remove the CR (inefficient) */
+
+  if ((fd = open_read(fndkin.s)) == -1) die_read();
+  while ((r = read(fd,&ch,1)) > 0) 
+    if (ch != '\r')
+      if (buffer_put(&bo,&ch,1) == -1) die_write(fndkin.s);
+
+  if (buffer_flush(&bo) == -1) die_write(fndkin.s);
+  close(pi[1]);
+
+  wait_pid(&wstat,child);
+  if (wait_crashed(wstat)) return 1;
+
+  switch (r = wait_exitcode(wstat)) {
+    case 10: return 1;
+    default: return 0;
+  }
+
+  return 0;
+}
+
+void dkim_unlink()
+{
+  if (unlink(fndkin.s) == -1)
+    if (errno != ENOENT) temp_unlink();
+  if (unlink(fndkout.s) == -1)
+    if (errno != ENOENT) temp_unlink();
+}
+
+int main()
+{
+  int r = 0;
+  char *mode = 0;
+
+  umask(033);
+  if (chdir(auto_qmail) == -1) temp_chdir();
+  if (control_init() == -1) temp_control();
+  if (control_readline(&me,"control/me") == -1) temp_control();
+  if (!stralloc_0(&me)) temp_nomem();
+
+  dkim_stage();
+
+  if (mess_dkim()) {
+    dkim_verify(); 
+    r = dkim_result(me.s);
+  }
+
+  /* we are done: call qmail-queue */
+
+  mode = env_get("DKIM");
+  if (!mode || *mode != '+') r = 0;
+
+  qmail_queue();
+  dkim_unlink();
+
+  _exit(r);
+}