added extpass option

include/pcp/readpass.h

@@ -35,9 +35,14 @@
 #include <termios.h>
 #include <unistd.h>
 
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <fcntl.h>
+#include <sys/wait.h>
+
 #include "defines.h"
 #include "context.h"
-#include "pcp.h"
+#include "util.h"
 
 #define MAXPASSLEN 2048
 
@@ -52,6 +57,13 @@
  * ${passwd}.  The obscure name is to avoid namespace collisions due to the
  * getpass / readpass / readpassphrase / etc. functions in various libraries.
  */
-int pcp_readpass(char **, const char *, const char *, int, char *);
+int pcp_readpass(PCPCTX *ptx, char **passwd, const char *prompt,
+		 const char *confirmprompt, int devtty, char *readfromfile);
+
+/**
+   from encfs getUserKey().
+   
+*/
+int pcp_readpass_fromprog(PCPCTX *ptx, char **passwd, const char *askpass);
 
 #endif /* !_READPASS_H_ */

libpcp/readpass.c

@@ -39,7 +39,7 @@
  * getpass / readpass / readpassphrase / etc. functions in various libraries.
  */
 int
-pcp_readpass(char ** passwd, const char * prompt,
+pcp_readpass(PCPCTX *ptx, char ** passwd, const char * prompt,
 	     const char * confirmprompt, int devtty, char *readfromfile)
 {
 	FILE * readfrom;
@@ -58,6 +58,9 @@ pcp_readpass(char ** passwd, const char * prompt,
 	 */
 	if ((devtty == 0) || ((readfrom = fopen("/dev/tty", "r")) == NULL)) {
 	  if(readfromfile != NULL) {
+	    // FIXME: check if readfromfile is executable,
+	    // if yes, call askextpass(tobewritten) and
+	    // read from the returned fd somehow
 	    if(readfromfile[0] == '-') {
 	      readfrom = stdin;
 	    }
@@ -154,3 +157,114 @@ err1:
 	/* Failure! */
 	return (-1);
 }
+
+
+/*****************************************************************************
+ * Author:   Valient Gough <vgough@pobox.com>
+ *
+ *****************************************************************************
+ * Copyright (c) 2004, Valient Gough
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * modified by tlinden@cpan.org (c++ => c, pcp api)
+ */
+
+int pcp_readpass_fromprog(PCPCTX *ptx, char **passwd, const char *askpass) {
+  // have a child process run the command and get the result back to us.
+  int fds[2], pid;
+  int res;
+  char passbuf[MAXPASSLEN];
+  
+  res = socketpair(PF_UNIX, SOCK_STREAM, 0, fds);
+  if (res == -1) {
+    fatal(ptx, "Internal error: socketpair() failed");
+    goto aerr1;
+  }
+
+  pid = fork();
+  if (pid == -1) {
+    fatal( ptx, "Internal error: fork() failed");
+    close(fds[0]);
+    close(fds[1]);
+    goto aerr1;
+  }
+
+  if (pid == 0) {
+    const char *argv[4];
+    argv[0] = "/bin/sh";
+    argv[1] = "-c";
+    argv[2] = askpass;
+    argv[3] = 0;
+
+    // child process.. run the command and send output to fds[0]
+    close(fds[1]);  // we don't use the other half..
+
+    // make a copy of stdout and stderr descriptors, and set an environment
+    // variable telling where to find them, in case a child wants it..
+    int stdOutCopy = dup(STDOUT_FILENO);
+    int stdErrCopy = dup(STDERR_FILENO);
+    
+    // replace STDOUT with our socket, which we'll used to receive the
+    // password..
+    dup2(fds[0], STDOUT_FILENO);
+
+    // ensure that STDOUT_FILENO and stdout/stderr are not closed on exec..
+    fcntl(STDOUT_FILENO, F_SETFD, 0);  // don't close on exec..
+    fcntl(stdOutCopy, F_SETFD, 0);
+    fcntl(stdErrCopy, F_SETFD, 0);
+
+    char tmpBuf[8];
+
+    snprintf(tmpBuf, sizeof(tmpBuf) - 1, "%i", stdOutCopy);
+    setenv("PCP_ENV_STDOUT", tmpBuf, 1);
+
+    snprintf(tmpBuf, sizeof(tmpBuf) - 1, "%i", stdErrCopy);
+    setenv("PCP_ENV_STDERR", tmpBuf, 1);
+
+    execvp(argv[0], (char *const *)argv);  // returns only on error..
+
+    fatal(ptx, "Internal error: failed to exec program");
+    goto aerr1;
+  }
+
+  close(fds[0]);
+
+  memset(passbuf, 0, MAXPASSLEN);
+  if ( recv(fds[1], passbuf, MAXPASSLEN, 0) <= 0) {
+    fatal(ptx, "Cannot read password\n");
+    goto aerr1;
+  }
+
+
+  close(fds[1]);
+
+  waitpid(pid, NULL, 0);
+
+  /* Terminate the string at the first "\r" or "\n" (if any). */
+  passbuf[strcspn(passbuf, "\r\n")] = '\0';
+
+  /* Copy the password out. */
+  char *p = smalloc(strlen(passbuf) + 1);
+  memcpy(p, passbuf, strlen(passbuf) + 1 );
+  *passwd = p;
+
+  /* Zero any stored passwords. */
+  memset(passbuf, 0, MAXPASSLEN);
+  
+  return 0;
+
+ aerr1:
+  return -1;
+}

man/options.pod

@@ -15,6 +15,7 @@
                            is -, read from stdin. This takes
                            precedence over other uses of stdin
                            elsewhere, see below for more details.
+    --extpass <program>    Use external program for password prompt.
  -i --keyid <id>           Specify a key id to import/export.
  -r --recipient <string>   Specify a recpipient, used for public
                            key export and encryption.

man/pcp1.1

@@ -1,4 +1,4 @@
-.\" Automatically generated by Pod::Man 2.27 (Pod::Simple 3.28)
+.\" Automatically generated by Pod::Man 2.28 (Pod::Simple 3.28)
 .\"
 .\" Standard preamble:
 .\" ========================================================================
@@ -133,7 +133,7 @@
 .\" ========================================================================
 .\"
 .IX Title "PCP1 1"
-.TH PCP1 1 "2015-07-22" "PCP 0.3.0" "USER CONTRIBUTED DOCUMENTATION"
+.TH PCP1 1 "2015-07-30" "PCP 0.3.1" "USER CONTRIBUTED DOCUMENTATION"
 .\" For nroff, turn off justification.  Always turn off hyphenation; it makes
 .\" way too many mistakes in technical documents.
 .if n .ad l
@@ -161,6 +161,7 @@ Pretty Curved Privacy \- File encryption using eliptic curve cryptography.
 \&  \-x \-\-xpass <passwd>       Provide password. INSECURE! Use for testing
 \&                            or debugging only!
 \&  \-X \-\-password\-file <file> Read passphrase from <file>.
+\&     \-\-extpass <program>    Use external program for password prompt.
 \&  \-i \-\-keyid <id>           Specify a key id for various operations.
 \&  \-r \-\-recipient <string>   Specify a recpipient, multiple allowed.
 \&  \-t \-\-text                 Print textual representation of ojects.
@@ -218,6 +219,7 @@ Pretty Curved Privacy \- File encryption using eliptic curve cryptography.
 \&                           is \-, read from stdin. This takes
 \&                           precedence over other uses of stdin
 \&                           elsewhere, see below for more details.
+\&    \-\-extpass <program>    Use external program for password prompt.
 \& \-i \-\-keyid <id>           Specify a key id to import/export.
 \& \-r \-\-recipient <string>   Specify a recpipient, used for public
 \&                           key export and encryption.

man/pcp1.html

@@ -7,7 +7,7 @@
 <link rev="made" href="mailto:root@localhost" />
 </head>
 
-<body style="background-color: white">
+<body>
 
 
 
@@ -89,6 +89,7 @@
   -x --xpass &lt;passwd&gt;       Provide password. INSECURE! Use for testing
                             or debugging only!
   -X --password-file &lt;file&gt; Read passphrase from &lt;file&gt;.
+     --extpass &lt;program&gt;    Use external program for password prompt.
   -i --keyid &lt;id&gt;           Specify a key id for various operations.
   -r --recipient &lt;string&gt;   Specify a recpipient, multiple allowed.
   -t --text                 Print textual representation of ojects.
@@ -146,6 +147,7 @@
                            is -, read from stdin. This takes
                            precedence over other uses of stdin
                            elsewhere, see below for more details.
+    --extpass &lt;program&gt;    Use external program for password prompt.
  -i --keyid &lt;id&gt;           Specify a key id to import/export.
  -r --recipient &lt;string&gt;   Specify a recpipient, used for public
                            key export and encryption.

man/pcp1.pod

@@ -24,6 +24,7 @@ Pretty Curved Privacy - File encryption using eliptic curve cryptography.
   -x --xpass <passwd>       Provide password. INSECURE! Use for testing
                             or debugging only!
   -X --password-file <file> Read passphrase from <file>.
+     --extpass <program>    Use external program for password prompt.
   -i --keyid <id>           Specify a key id for various operations.
   -r --recipient <string>   Specify a recpipient, multiple allowed.
   -t --text                 Print textual representation of ojects.
@@ -81,6 +82,7 @@ Pretty Curved Privacy - File encryption using eliptic curve cryptography.
                            is -, read from stdin. This takes
                            precedence over other uses of stdin
                            elsewhere, see below for more details.
+    --extpass <program>    Use external program for password prompt.
  -i --keyid <id>           Specify a key id to import/export.
  -r --recipient <string>   Specify a recpipient, used for public
                            key export and encryption.

src/pcp.c

@@ -66,6 +66,7 @@ int main (int argc, char **argv)  {
   char *xpassfile = NULL;
   char *extra = NULL;
   plist_t *recipient = NULL;
+  char *askpass = NULL;
   FILE *in;
 
   errno = 0;
@@ -93,6 +94,7 @@ int main (int argc, char **argv)  {
     { "text",            required_argument, NULL,           't' },
     { "xpass",           required_argument, NULL,           'x' },
     { "password-file",   required_argument, NULL,           'X' },
+    { "extpass",         required_argument, NULL,           LONG_EXTPASS },
     { "recipient",       required_argument, NULL,           'r' },
 
     /*  key management */
@@ -271,6 +273,10 @@ int main (int argc, char **argv)  {
 	if(strncmp(xpass, "n/a", 3) == 0)
 	  xpass[0] = '\0';
 	break;
+      case LONG_EXTPASS:
+	askpass = malloc(strlen(optarg)+1);
+	strncpy(askpass, optarg, strlen(optarg)+1);
+	break;
       case 'r':
 	p_add(&recipient, optarg);
 	userec = 1;
@@ -415,12 +421,18 @@ int main (int argc, char **argv)  {
   }
 
   if(xpassfile != NULL) {
-    pcp_readpass(&xpass, "passphrase", NULL, 0, xpassfile);
+    if(pcp_readpass(ptx, &xpass, "passphrase", NULL, 0, xpassfile) != 0)
+      goto perr1;
     if(xpassfile[0] != '-')
       xpf = 0; 
     free(xpassfile);
   }
 
+  if(askpass != NULL) {
+    if(pcp_readpass_fromprog(ptx, &xpass, askpass) != 0)
+      goto perr1;
+  }
+  
   /* check if there's some enviroment we could use */
   if(usevault == 1) {
     char *_vaultfile = getenv("PCP_VAULT");
@@ -632,6 +644,7 @@ int main (int argc, char **argv)  {
     }
   }
 
+ perr1:
   fatals_ifany(ptx);
   int e = ptx->pcp_exit;
   ptx_clean(ptx);
@@ -646,6 +659,10 @@ int main (int argc, char **argv)  {
     free(sigfile);
   if(xpass != NULL)
     sfree(xpass);
+  if(askpass != NULL)
+    free(askpass);
+  if(xpassfile != NULL)
+    free(xpassfile);
   if(recipient != NULL)
     p_clean(recipient);
   if(id != NULL)

src/pcp.h

@@ -85,6 +85,8 @@
 #define PCP_HELP_INTRO "This is Pretty Curved Privacy. Licensed under the GPLv3. This is\n" \
 "BETA software. Use with care. NOT intended for production use.\n"
 
+#define LONG_EXTPASS 515
+
 /* some globals */
 vault_t *vault;
 PCPCTX *ptx;

src/usage.h

@@ -19,6 +19,7 @@
 "-x --xpass <passwd>       Provide password. INSECURE! Use for testing\n" \
 "                          or debugging only!\n" \
 "-X --password-file <file> Read passphrase from <file>.\n" \
+"   --extpass <program>    Use external program for password prompt.\n" \
 "-i --keyid <id>           Specify a key id for various operations.\n" \
 "-r --recipient <string>   Specify a recpipient, multiple allowed.\n" \
 "-t --text                 Print textual representation of ojects.\n" \

src/usage.txt

@@ -17,6 +17,7 @@ General Options:
 -x --xpass <passwd>       Provide password. INSECURE! Use for testing
                           or debugging only!
 -X --password-file <file> Read passphrase from <file>.
+   --extpass <program>    Use external program for password prompt.
 -i --keyid <id>           Specify a key id for various operations.
 -r --recipient <string>   Specify a recpipient, multiple allowed.
 -t --text                 Print textual representation of ojects.