crypt.c

mutt-1.5.12 源代码。linux 下邮件接受的工具。

      if (t && m->badsig) t |= BADSIGN;
    }
  }
  else if ((WithCrypto & APPLICATION_PGP) && m->type == TYPETEXT)
  {
    t |= mutt_is_application_pgp (m);
    if (t && m->goodsig)
      t |= GOODSIGN;
  }
  
  if (m->type == TYPEMULTIPART)
  {
    t |= mutt_is_multipart_encrypted(m);
    t |= mutt_is_multipart_signed (m);

    if (t && m->goodsig) 
      t |= GOODSIGN;
  }

  if (m->type == TYPEMULTIPART || m->type == TYPEMESSAGE)
  {
    BODY *p;
    int u, v, w;
    
    u = m->parts ? 0xffffffff : 0;	/* Bits set in all parts */
    w = 0;				/* Bits set in any part  */
 
    for (p = m->parts; p; p = p->next)
    {
      v  = crypt_query (p);
      u &= v; w |= v;
    }
    t |= u | (w & ~GOODSIGN);
    
    if ((w & GOODSIGN) && !(u & GOODSIGN))
      t |= PARTSIGN;
  }

  return t;
}




int crypt_write_signed(BODY *a, STATE *s, const char *tempfile)
{
  FILE *fp;
  int c;
  short hadcr;
  size_t bytes;

  if (!WithCrypto)
    return -1;

  if (!(fp = safe_fopen (tempfile, "w")))
  {
    mutt_perror (tempfile);
    return -1;
  }
      
  fseeko (s->fpin, a->hdr_offset, 0);
  bytes = a->length + a->offset - a->hdr_offset;
  hadcr = 0;
  while (bytes > 0)
  {
    if ((c = fgetc (s->fpin)) == EOF)
      break;
    
    bytes--;
    
    if  (c == '\r')
      hadcr = 1;
    else 
    {
      if (c == '\n' && !hadcr)
	fputc ('\r', fp);
      
      hadcr = 0;
    }
    
    fputc (c, fp);
    
  }
  fclose (fp);

  return 0;
}



void convert_to_7bit (BODY *a)
{
  if (!WithCrypto)
    return;

  while (a)
  {
    if (a->type == TYPEMULTIPART)
    {
      if (a->encoding != ENC7BIT)
      {
        a->encoding = ENC7BIT;
	convert_to_7bit(a->parts);
      }
      else if ((WithCrypto & APPLICATION_PGP) && option (OPTPGPSTRICTENC))
	convert_to_7bit (a->parts);
    } 
    else if (a->type == TYPEMESSAGE &&
	     ascii_strcasecmp(a->subtype, "delivery-status"))
    {
      if(a->encoding != ENC7BIT)
	mutt_message_to_7bit (a, NULL);
    }
    else if (a->encoding == ENC8BIT)
      a->encoding = ENCQUOTEDPRINTABLE;
    else if (a->encoding == ENCBINARY)
      a->encoding = ENCBASE64;
    else if (a->content && a->encoding != ENCBASE64 &&
	     (a->content->from || (a->content->space && 
				   option (OPTPGPSTRICTENC))))
      a->encoding = ENCQUOTEDPRINTABLE;
    a = a->next;
  }
}




void crypt_extract_keys_from_messages (HEADER * h)
{
  int i;
  char tempfname[_POSIX_PATH_MAX], *mbox;
  ADDRESS *tmp = NULL;
  FILE *fpout;

  if (!WithCrypto)
    return;

  mutt_mktemp (tempfname);
  if (!(fpout = safe_fopen (tempfname, "w")))
  {
    mutt_perror (tempfname);
    return;
  }

  if ((WithCrypto & APPLICATION_PGP))
    set_option (OPTDONTHANDLEPGPKEYS);

  if (!h)
  {
    for (i = 0; i < Context->vcount; i++)
    {
      if (Context->hdrs[Context->v2r[i]]->tagged)
      {
	mutt_parse_mime_message (Context, Context->hdrs[Context->v2r[i]]);
	if (Context->hdrs[Context->v2r[i]]->security & ENCRYPT &&
	    !crypt_valid_passphrase (Context->hdrs[Context->v2r[i]]->security))
	{
	  fclose (fpout);
	  break;
	}

	if ((WithCrypto & APPLICATION_PGP)
            && (Context->hdrs[Context->v2r[i]]->security & APPLICATION_PGP))
	{
	  mutt_copy_message (fpout, Context, Context->hdrs[Context->v2r[i]], 
			     M_CM_DECODE|M_CM_CHARCONV, 0);
	  fflush(fpout);
	  
	  mutt_endwin (_("Trying to extract PGP keys...\n"));
	  crypt_pgp_invoke_import (tempfname);
	}

	if ((WithCrypto & APPLICATION_SMIME)
            && (Context->hdrs[Context->v2r[i]]->security & APPLICATION_SMIME))
	{
	  if (Context->hdrs[Context->v2r[i]]->security & ENCRYPT)
	    mutt_copy_message (fpout, Context, Context->hdrs[Context->v2r[i]],
			       M_CM_NOHEADER|M_CM_DECODE_CRYPT
                               |M_CM_DECODE_SMIME, 0);
	  else
	    mutt_copy_message (fpout, Context,
			       Context->hdrs[Context->v2r[i]], 0, 0);
	  fflush(fpout);

          if (Context->hdrs[Context->v2r[i]]->env->from)
	    tmp = mutt_expand_aliases (Context->hdrs[Context->v2r[i]]->env->from);
	  else if (Context->hdrs[Context->v2r[i]]->env->sender)
	    tmp = mutt_expand_aliases (Context->hdrs[Context->v2r[i]]
                                                    ->env->sender);
          mbox = tmp ? tmp->mailbox : NULL;
	  if (mbox)
	  {
	    mutt_endwin (_("Trying to extract S/MIME certificates...\n"));
	    crypt_smime_invoke_import (tempfname, mbox);
	    tmp = NULL;
	  }
	}

	rewind (fpout);
      }
    }
  }
  else
  {
    mutt_parse_mime_message (Context, h);
    if (!(h->security & ENCRYPT && !crypt_valid_passphrase (h->security)))
    {
      if ((WithCrypto & APPLICATION_PGP)
          && (h->security & APPLICATION_PGP))
      {
	mutt_copy_message (fpout, Context, h, M_CM_DECODE|M_CM_CHARCONV, 0);
	fflush(fpout);
	mutt_endwin (_("Trying to extract PGP keys...\n"));
	crypt_pgp_invoke_import (tempfname);
      }

      if ((WithCrypto & APPLICATION_SMIME)
          && (h->security & APPLICATION_SMIME))
      {
	if (h->security & ENCRYPT)
	  mutt_copy_message (fpout, Context, h, M_CM_NOHEADER
                                                |M_CM_DECODE_CRYPT
                                                |M_CM_DECODE_SMIME, 0);
	else
	  mutt_copy_message (fpout, Context, h, 0, 0);

	fflush(fpout);
	if (h->env->from) tmp = mutt_expand_aliases (h->env->from);
	else if (h->env->sender)  tmp = mutt_expand_aliases (h->env->sender); 
	mbox = tmp ? tmp->mailbox : NULL;
	if (mbox) /* else ? */
	{
	  mutt_message (_("Trying to extract S/MIME certificates...\n"));
	  crypt_smime_invoke_import (tempfname, mbox);
	}
      }
    }
  }
      
  fclose (fpout);
  if (isendwin())
    mutt_any_key_to_continue (NULL);

  mutt_unlink (tempfname);

  if ((WithCrypto & APPLICATION_PGP))
    unset_option (OPTDONTHANDLEPGPKEYS);
}



int crypt_get_keys (HEADER *msg, char **keylist)
{
  /* Do a quick check to make sure that we can find all of the encryption
   * keys if the user has requested this service.
   */

  if (!WithCrypto)
    return 0;

  if ((WithCrypto & APPLICATION_PGP))
    set_option (OPTPGPCHECKTRUST);

  *keylist = NULL;

  if (msg->security & ENCRYPT)
  {
     if ((WithCrypto & APPLICATION_PGP)
         && (msg->security & APPLICATION_PGP))
     {
       if ((*keylist = crypt_pgp_findkeys (msg->env->to, msg->env->cc,
      			       msg->env->bcc)) == NULL)
           return (-1);
       unset_option (OPTPGPCHECKTRUST);
     }
     if ((WithCrypto & APPLICATION_SMIME)
         && (msg->security & APPLICATION_SMIME))
     {
       if ((*keylist = crypt_smime_findkeys (msg->env->to, msg->env->cc,
      				             msg->env->bcc)) == NULL)
           return (-1);
     }
  }
    
  return (0);
}



static void crypt_fetch_signatures (BODY ***signatures, BODY *a, int *n)
{
  if (!WithCrypto)
    return;

  for (; a; a = a->next)
  {
    if (a->type == TYPEMULTIPART)
      crypt_fetch_signatures (signatures, a->parts, n);
    else
    {
      if((*n % 5) == 0)
	safe_realloc (signatures, (*n + 6) * sizeof (BODY **));

      (*signatures)[(*n)++] = a;
    }
  }
}


/*
 * This routine verifies a  "multipart/signed"  body.
 */

int mutt_signed_handler (BODY *a, STATE *s)
{
  char tempfile[_POSIX_PATH_MAX];
  char *protocol;
  int protocol_major = TYPEOTHER;
  char *protocol_minor = NULL;
  
  BODY *b = a;
  BODY **signatures = NULL;
  int sigcnt = 0;
  int i;
  short goodsig = 1;
  int rc = 0;

  if (!WithCrypto)
    return -1;

  protocol = mutt_get_parameter ("protocol", a->parameter);
  a = a->parts;

  /* extract the protocol information */
  
  if (protocol)
  {
    char major[STRING];
    char *t;

    if ((protocol_minor = strchr (protocol, '/'))) protocol_minor++;
    
    strfcpy (major, protocol, sizeof(major));
    if((t = strchr(major, '/')))
      *t = '\0';
    
    protocol_major = mutt_check_mime_type (major);
  }

  /* consistency check */

  if (!(a && a->next && a->next->type == protocol_major && 
      !mutt_strcasecmp (a->next->subtype, protocol_minor)))
  {
    state_attach_puts (_("[-- Error: "
                         "Inconsistent multipart/signed structure! --]\n\n"),
                       s);
    return mutt_body_handler (a, s);
  }

  
  if ((WithCrypto & APPLICATION_PGP)
      && protocol_major == TYPEAPPLICATION
      && !ascii_strcasecmp (protocol_minor, "pgp-signature"))
    ;
  else if ((WithCrypto & APPLICATION_SMIME)
           && protocol_major == TYPEAPPLICATION
	   && !(ascii_strcasecmp (protocol_minor, "x-pkcs7-signature")
	       && ascii_strcasecmp (protocol_minor, "pkcs7-signature")))
    ;
  else if (protocol_major == TYPEMULTIPART
	   && !ascii_strcasecmp (protocol_minor, "mixed"))
    ;
  else
  {
    state_printf (s, _("[-- Error: "
                       "Unknown multipart/signed protocol %s! --]\n\n"),
                  protocol);
    return mutt_body_handler (a, s);
  }
  
  if (s->flags & M_DISPLAY)
  {
    
    crypt_fetch_signatures (&signatures, a->next, &sigcnt);
    
    if (sigcnt)
    {
      mutt_mktemp (tempfile);
      if (crypt_write_signed (a, s, tempfile) == 0)
      {
	for (i = 0; i < sigcnt; i++)
	{
	  if ((WithCrypto & APPLICATION_PGP)
              && signatures[i]->type == TYPEAPPLICATION 
	      && !ascii_strcasecmp (signatures[i]->subtype, "pgp-signature"))
	  {
	    if (crypt_pgp_verify_one (signatures[i], s, tempfile) != 0)
	      goodsig = 0;
	    
	    continue;
	  }

	  if ((WithCrypto & APPLICATION_SMIME)
              && signatures[i]->type == TYPEAPPLICATION 
	      && (!ascii_strcasecmp(signatures[i]->subtype, "x-pkcs7-signature")
		  || !ascii_strcasecmp(signatures[i]->subtype, "pkcs7-signature")))
	  {
	    if (crypt_smime_verify_one (signatures[i], s, tempfile) != 0)
	      goodsig = 0;
	    
	    continue;
	  }

	  state_printf (s, _("[-- Warning: "
                             "We can't verify %s/%s signatures. --]\n\n"),
			  TYPE(signatures[i]), signatures[i]->subtype);
	}
      }
      
      mutt_unlink (tempfile);

      b->goodsig = goodsig;
      b->badsig  = !goodsig;
      
      /* Now display the signed body */
      state_attach_puts (_("[-- The following data is signed --]\n\n"), s);


      FREE (&signatures);
    }
    else
      state_attach_puts (_("[-- Warning: Can't find any signatures. --]\n\n"), s);
  }
  
  rc = mutt_body_handler (a, s);
  
  if (s->flags & M_DISPLAY && sigcnt)
    state_attach_puts (_("\n[-- End of signed data --]\n"), s);
  
  return rc;
}