removed top level directory

1 files changed, 512 insertions, 0 deletions

diff --git a/src/qmail-dksign.c b/src/qmail-dksign.c
new file mode 100755
index 0000000..406afc1
--- /dev/null
+++ b/src/qmail-dksign.c
@@ -0,0 +1,512 @@
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include "sig.h"
+#include "stralloc.h"
+#include "buffer.h"
+#include "error.h"
+#include "auto_qmail.h"
+#include "control.h"
+#include "str.h"
+#include "exit.h"
+#include "case.h"
+#include "constmap.h"
+#include "uint_t.h"
+#include "fd.h"
+#include "logmsg.h"
+#include "open.h"
+#include "fmt.h"
+#include "fmtqfn.h"
+#include "readwrite.h"
+#include "qmail.h"
+#include "wait.h"
+#include "pathexec.h"
+#include "rcpthosts.h"
+
+#define WHO "qmail-dksign"
+
+#define DOMAINKEYS "ssl/domainkeys/"
+
+/** @file qmail-dksign.c -- generate signature and attach in DKIM header to outgoing message
+
+    Steps:
+    ------
+    a) DKIM controls:  get private key for sending domain
+    b) Prepare two staging files at queue/dkim (before and after signing)
+    c) Read input at fd0 and insert CR for every line and store at dkim/x/pre
+    d) DKIM sign the message with provided private key and store at dkim/y/post
+    e) Copy signed file from fd to 0
+    f) Invoke qmail-remote (respecting the \r\n)
+    g) Remove staging files (pre/post)
+
+    Hack for hybrid signatures:
+    ---------------------------
+
+    a) selector is a link to RSA private key
+    b) selector2 is a link to Ed25519 private key
+    c) Both are provided in the 'selector' field of dkimdomains separated by colon
+    d) The coupled selector information is provided to qmail-dkim as: -yselector ,-Yselector2
+    e) The RSA privat key is given unaltered
+    f) The Ed25519 private is supplied as additional argument
+  */
+
+char inbuf[BUFSIZE_LINE]; 
+buffer bi = BUFFER_INIT(read,0,inbuf,sizeof(inbuf));
+char outbuf[BUFSIZE_MESS];
+buffer bo = BUFFER_INIT(write,1,outbuf,sizeof(outbuf));
+
+void die(int e) { _exit(e); }
+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); }
+
+stralloc fndkin = {0};
+stralloc fndkout = {0};
+
+stralloc sender = {0};   // will be re-written
+stralloc senddomain = {0};
+stralloc originator = {0};
+stralloc dkimdomains = {0};
+struct constmap mapdkimdomains;
+
+stralloc ecckey = {0};
+stralloc rsakey = {0};
+char *dkimparams = 0;
+
+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: ");
+  out(error_str(errno));
+  out(fndkin.s); out(". (#4.3.0)\n");
+  zerodie();
+}
+void temp_unlink() 
+{
+  out("ZUnable to unlink DKIM stage file. (#4.3.0)\n");
+  zerodie();
+}
+void temp_control() 
+{
+  out("ZUnable to read DKIM control files. (#4.3.0)\n");
+  zerodie();
+}
+void perm_usage() 
+{
+  out("Zqmail-dksign was invoked improperly. (#5.3.5)\n");
+  zerodie();
+}
+void temp_read()
+{
+  out("DUnable to read message for DKIM signing. (#4.3.0)\n");
+  zerodie();
+}
+void temp_nosignkey()
+{ 
+  out("DCan't read sign key: ");
+  out(rsakey.s);
+  out(" or ");
+  out(ecckey.s);
+	out(". (#4.3.0)\n");
+  zerodie();
+}
+
+int get_controls()
+{
+  int i;
+  stralloc domname = {0};
+
+  if (control_init() == -1) temp_control();
+
+  switch (control_readfile(&dkimdomains,"control/dkimdomains",0)) { 
+    case -1: return 0;
+    case  0: if (!constmap_init(&mapdkimdomains,"",0,1)) temp_nomem(); break; 
+    case  1: if (!constmap_init(&mapdkimdomains,dkimdomains.s,dkimdomains.len,1)) temp_nomem(); break;
+  }
+
+/* Check for disabled DKIM send domains */
+
+  if (!stralloc_copys(&domname,"!")) temp_nomem();
+  if (!stralloc_cats(&domname,senddomain.s)) temp_nomem();
+  if (constmap(&mapdkimdomains,domname.s,domname.len)) return 0;
+
+/* Parenting domains; senddomain 0-terminated; lowercase */
+
+  for (i = 0; i <= senddomain.len; ++i) {
+    if ((i == 0) || (senddomain.s[i] == '.'))
+      if ((dkimparams = constmap(&mapdkimdomains,senddomain.s + i,senddomain.len - i - 1))) {
+        if (!stralloc_copys(&sender,senddomain.s + i)) temp_nomem();
+        if (!stralloc_0(&sender)) temp_nomem();
+        return 3;
+      }
+  }
+
+/* We sign only senddomains we take responsibility for: rcpthosts */
+
+  if ((dkimparams = constmap(&mapdkimdomains,"=",1))) {
+    if (rcpthosts_init() == -1) temp_control();
+    if (rcpthosts(originator.s,originator.len)) {
+      if ((control_readline(&sender,"control/defaultdomain") != 1))
+        if (control_readline(&sender,"control/me") == -1) temp_control();
+      if (!stralloc_0(&sender)) temp_nomem();
+      return 2;
+    }
+  }
+
+/* Default settings for MTA: 'defaultdomain' or even 'me' */
+
+  if ((dkimparams = constmap(&mapdkimdomains,"*",1))) {
+    if ((control_readline(&sender,"control/defaultdomain") != 1))
+      if (control_readline(&sender,"control/me") == -1) temp_control();
+    if (!stralloc_0(&sender)) temp_nomem();
+    return 1;
+  }
+
+  return 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_unlink()
+{
+  if (unlink(fndkin.s) == -1) 
+    if (errno != ENOENT) temp_unlink();
+  if (unlink(fndkout.s) == -1) 
+    if (errno != ENOENT) temp_unlink();
+}
+
+void dkim_stage()
+{
+  int r;
+  int fd;
+  int in, out;
+  struct stat st;
+  unsigned char tmpbuf[BUFSIZE_MESS + 2];        // intermediate write buffer
+
+  if (!stralloc_ready(&fndkin,FMTQFN)) temp_nomem();
+  if (!stralloc_ready(&fndkout,FMTQFN)) temp_nomem();
+
+  fnmake_dkim(getpid());  // pre-staging
+  dkim_unlink();  // duplicate, left over file
+  fd = open_excl(fndkin.s);
+  if (fd == -1) die_write(fndkin.s);
+
+  buffer_init(&bi,read,0,inbuf,sizeof(inbuf));
+  buffer_init(&bo,write,fd,outbuf,sizeof(outbuf));
+
+  while((r = buffer_get(&bi,inbuf,sizeof(inbuf)))) {  // read into buffer
+    if (r == -1) temp_read();
+
+    for (in = out = 0; in < r; in++) {
+      if (inbuf[in] == '\r') continue;           // ignore CR
+      if (inbuf[in] != '\n') {
+        tmpbuf[out++] = inbuf[in];
+      } else {                                   // add CR for every LF
+        tmpbuf[out++] = '\r';
+        tmpbuf[out++] = '\n';
+      } 
+    }
+    if (out) buffer_put(&bo,tmpbuf,out);         // ok
+  }
+
+  if (buffer_flush(&bo) == -1) die(51);
+  if (fstat(fd,&st) == -1) die_read();
+  if (fsync(fd) == -1) die_write(fndkin.s);
+  if (close(fd) == -1) die_write(fndkin.s);
+}
+
+/* to construct DKIM information */
+
+stralloc selector = {0};
+stralloc selectore = {0};
+stralloc sdid = {0};
+stralloc auid = {0};
+stralloc expire = {0};
+stralloc canon = {0};   // -c r = relax, s = simple, t = relaxed/simple, u = simple/realxed
+stralloc hash = {0};    // -z 1/2/3/4/5 sha1/sha2/both/ed25519/ed25519+rsa-sha256
+stralloc length = {0};  // -l
+
+/**
+
+  qmail-dkim [-h|-v|-s] [tags] <msgfile> [<RSAkeyfile> <outfile> <Ed25519keyfile>]
+  --------------------------------------------------------------------------------
+  tags: 
+  ----
+  -c<canonicalization>    - r=relaxed [DEFAULT], s=simple, t=relaxed/simple, u=simple/relaxed
+  -d<sdid>                - Signing Domain Identifier,if not provided it will be determined from the envelope originator/from header
+  -i<auid>                - Agent User Identifier, usually the sender's email address (optional)
+  -l                      - include body length tag (optional)
+  -q                      - include query method tag
+  -t                      - include a timestamp tag (optional)
+  -x<expire_time>         - the expire time in seconds since epoch (optional, DEFAULT = current time + 604800)
+  -y<selector>            - set RSA selector (DEFAULT: default)
+  -Y<selector>            - set Ed25519 selector (DEFAULT: default)
+  -z<hash>                - set signature type (1=sha1, 2=sha256, 3=both, 4=ed25519, 5=hybrid)
+*/
+
+int dkim_sign(const char *rsakeyfile,const char *ecckeyfile,const char *fnin,const char *fnout)
+{
+  int child;
+  int wstat;
+  char *(args[17]);
+  int i = 0;
+
+  args[i] = "qmail-dkim"; ++i;
+  args[i] = "-s"; ++i; 
+  args[i] = "-q"; ++i;
+  if (sdid.len > 3) { args[i] = sdid.s; ++i; }
+  if (selector.len > 3) { args[i] = selector.s; ++i; }
+  if (selectore.len > 3) { args[i] = selectore.s; ++i; }
+  if (auid.len > 3) { args[i] = auid.s; ++i; }
+  if (expire.len > 3) { args[i] = expire.s; ++i; }
+  if (canon.len > 2) { args[i] = canon.s; ++i; }
+  if (hash.len > 2) { args[i] = hash.s; ++i; }
+  if (length.len > 2) { args[i] = length.s; ++i; }
+  args[i] = fnin; ++i;
+  args[i] = rsakeyfile; ++i;
+  args[i] = fnout; ++i; 
+  if (str_len(ecckeyfile) > 3) { args[i] = ecckeyfile; ++i; }
+  args[i] = 0;
+
+  if (!(child = vfork())) {
+    pathexec(args);
+    if (errno) _exit(111);
+    _exit(100);
+  }
+
+  wait_pid(&wstat,child);
+  if (wait_crashed(wstat)) return 1;
+
+  switch (wait_exitcode(wstat)) {
+    case 1: return 1;
+    default: return 0;
+  }
+}
+
+int qmail_remote(char **qargs,int fd)
+{
+  int child;
+  int wstat;
+  char *(args[5]);
+
+  args[0] = "qmail-remote";
+  args[1] = qargs[1];
+  args[2] = qargs[2];
+  args[3] = qargs[3];
+  args[4] = 0;
+
+  if (!(child = vfork())) {
+    if (fd) {
+      if (fd_move(0,fd) == -1) _exit(111); 
+      if (fd_copy(2,1) == -1) _exit(111);
+    }
+    pathexec(args);
+    if (errno) _exit(111);
+    _exit(100);
+  }
+  
+  wait_pid(&wstat,child);
+  if (wait_crashed(wstat)) return 1;
+
+  switch (wait_exitcode(wstat)) {
+    case 111: return 1;
+    default: return 0;
+  }
+}
+
+void dkim_setup()
+{
+  int c, i, j, k, l;
+  char *opt, *pos;
+
+  /* defaults: selector=default, IETF format, q=dns/txt, z=2, c=r */
+
+  if (!stralloc_copys(&sdid,"-d")) temp_nomem();
+  if (!stralloc_cat(&sdid,&sender)) temp_nomem();
+  if (!stralloc_0(&sdid)) temp_nomem();
+  if (!stralloc_copys(&selector,"-ydefault")) temp_nomem();
+  if (!stralloc_0(&selector)) temp_nomem();
+  if (!stralloc_copys(&selectore,"-Yeddy")) temp_nomem();
+  if (!stralloc_0(&selectore)) temp_nomem();
+  if (!stralloc_copys(&canon,"-cr")) temp_nomem();
+  if (!stralloc_0(&canon)) temp_nomem();
+  if (!stralloc_copys(&hash,"-z2")) temp_nomem();
+  if (!stralloc_0(&hash)) temp_nomem();
+
+  /* domain:selector,selectore|sdid|[auid|~]|expire|c:z:l; c=[r|s|t|u], z=[1,2,3,4,5], l=l */
+
+  if (dkimparams && *dkimparams) {
+    i = str_chr(dkimparams,'|');
+    pos = dkimparams + i;
+    if (*pos == '|' || *pos == '\0') {           // selector
+      dkimparams[i] = '\0';
+      c = str_chr(dkimparams,',');               // selectore=eddy
+      if (dkimparams[c] == ',') {
+        dkimparams[c] = '\0';
+        if (str_len(dkimparams + c + 1)) {
+          if (!stralloc_copys(&selectore,"-Y")) temp_nomem();
+          if (!stralloc_cats(&selectore,dkimparams + c + 1)) temp_nomem();
+          if (!stralloc_0(&selectore)) temp_nomem();
+        }
+      } else if (str_len(dkimparams)) {          // selector=default
+        if (!stralloc_copys(&selector,"-y")) temp_nomem();
+        if (!stralloc_cats(&selector,dkimparams)) temp_nomem();
+        if (!stralloc_0(&selector)) temp_nomem();
+      }
+
+      j = str_chr(dkimparams + i + 1,'|');
+      pos = dkimparams + i + j + 1;
+      if (*pos == '|' || *pos == '\0') {         // sdid; domain in DKIM header
+        dkimparams[i + j + 1] = '\0';
+        if (!stralloc_copys(&sdid,"-d")) temp_nomem();
+        if (!stralloc_cats(&sdid,dkimparams + i + 1)) temp_nomem();
+        if (!stralloc_0(&sdid)) temp_nomem();
+
+        k = str_chr(dkimparams + i + j + 2,'|');
+        pos = dkimparams + i + j + k + 2;
+        if (*pos == '|' || *pos == '\0') {       // auid = identifier
+          dkimparams[i + j + k + 2] = '\0';
+          if (!stralloc_copys(&auid,"-i")) temp_nomem();
+          if (dkimparams[i + j + 2] == '~') {
+            if (!stralloc_cat(&auid,&originator)) temp_nomem();
+          } else  
+            if (!stralloc_cats(&auid,dkimparams + i + j + 2)) temp_nomem();
+        
+          if (!stralloc_0(&auid)) temp_nomem();
+  
+          l = str_chr(dkimparams + i + j + k + 3,'|');    
+          pos = dkimparams + i + j + k + l + 3;
+          if (*pos == '|' || *pos == '\0') {     // expire after n secs
+            dkimparams[i + j + k + l + 3] = '\0';
+            if (!stralloc_copys(&expire,"-x")) temp_nomem();
+            if (!stralloc_cats(&expire,dkimparams + i + j + k + 3)) temp_nomem();
+            if (!stralloc_0(&expire)) temp_nomem();
+
+          /* Options to follow */
+
+            opt = dkimparams + i + j + k + l + 4;
+            if (*opt == '\0') return;
+            if (*opt != ':') {    
+              if (!stralloc_copys(&canon,"-c")) temp_nomem();   // canonicalization
+              if (!stralloc_catb(&canon,opt,1)) temp_nomem();
+              if (!stralloc_0(&canon)) temp_nomem();
+              ++opt; if (*opt == '\0') return;  // next colon
+            }
+            if (*opt != ':' || *opt == '\0') return;
+            if (*opt == ':') ++opt;
+            if (*opt != ':') {
+              if (!stralloc_copys(&hash,"-z")) temp_nomem();    // hash
+              if (!stralloc_catb(&hash,opt,1)) temp_nomem();
+              if (!stralloc_0(&hash)) temp_nomem();
+              ++opt; if (*opt == '\0') return;  // next colon
+            }
+            if (*opt != ':' || *opt == '\0') return;
+            if (*opt == ':') ++opt;
+            if (*opt != ':' && *opt == 'l') {
+              if (!stralloc_copys(&length,"-l")) temp_nomem();  // length
+              if (!stralloc_0(&length)) temp_nomem();
+            }
+          }
+        }
+      }   
+    } 
+  }
+
+  return;
+}
+
+int main(int argc,char **args)
+{
+  int i; 
+  int fdin = 0;   // initial read from FD 0
+  int nkey = 0;
+  char *(qargs[4]);
+  struct stat st;
+
+  qargs[0] = args[0];
+  qargs[1] = args[1];  // host
+  qargs[2] = args[2];  // originator
+  qargs[3] = args[3];  // recipient
+
+  umask(033);
+  sig_pipeignore();
+  if (argc < 4) perm_usage();
+  if (chdir(auto_qmail) == -1) temp_chdir();
+
+  if (str_len(args[2]) > 2) {
+    i = str_chr(args[2],'@');
+    if (*(args[2] + i) == '@') 
+      if (!stralloc_copys(&senddomain,args[2] + i + 1)) temp_nomem(); 
+  }
+  if (!stralloc_0(&senddomain)) temp_nomem(); 
+  if (!stralloc_copys(&originator,args[2])) temp_nomem(); 
+
+  if (!get_controls()) { 
+    qmail_remote(qargs,fdin);
+    _exit(0);
+  }
+
+  dkim_setup();  // sender is evaluated from originator (senddomain)
+
+  /* Setup keys: they are composed from selector */
+
+  case_lowerb(sender.s,sender.len); // needs to be lowercase
+  if (!stralloc_copys(&rsakey,DOMAINKEYS)) temp_nomem();
+  if (!stralloc_cats(&rsakey,sender.s)) temp_nomem();
+  if (!stralloc_cats(&rsakey,"/")) temp_nomem();
+
+  if (!stralloc_copys(&ecckey,DOMAINKEYS)) temp_nomem();
+  if (!stralloc_cats(&ecckey,sender.s)) temp_nomem();
+  if (!stralloc_cats(&ecckey,"/")) temp_nomem();
+
+  /* RSA key common for SHA1 and SHA256: rsakeyfile -> selector */
+
+  if (!stralloc_cats(&rsakey,selector.s + 2)) temp_nomem();    // -y prepended
+  if (!stralloc_0(&rsakey)) temp_nomem();
+  if (stat(rsakey.s,&st) != -1) 
+    if (open_read(rsakey.s) > 0) ++nkey;
+
+  /* ECC key follows: ecckeyfile -> (,)selector2 */
+
+  if (!stralloc_cats(&ecckey,selectore.s + 2)) temp_nomem();   // -Y prepended
+  if (!stralloc_0(&ecckey)) temp_nomem();
+  if (stat(ecckey.s,&st) != -1) 
+    if (open_read(ecckey.s) > 0) ++nkey;
+
+  /* We got keys - go for staging */
+  
+  if (nkey) { // otherwise no key exists; why bother
+    dkim_stage();
+    if (!dkim_sign(rsakey.s,ecckey.s,fndkin.s,fndkout.s)) {
+      fdin = open_read(fndkout.s);
+      if (fdin == -1) die_read();
+    } else {
+      fdin = fndkin.s;  // DKIM key failed to sign
+    }
+  } else
+    temp_nosignkey();
+   
+  qmail_remote(qargs,fdin);  // closes fdin
+  if (nkey) dkim_unlink();
+
+  _exit(0);
+}