New client/server components:

- broke out all common functions to "common" file
- put all client commands into "monkeysphere" script
- put all server commands into "monkeysphere-server" script
- moved all code into src directory to clean things up a bit
- this effectively makes obsolete rhesus and howler
- added proposed monkeysphere-ssh-proxycommand script that can be
  called to update known_hosts from ssh ProxyCommand
- updated monkeysphere.conf to work as global client config
- added monkeysphere-server.conf for server config

13 files changed, 2561 insertions, 0 deletions

diff --git a/src/common b/src/common
new file mode 100755
index 0000000..8643080
--- /dev/null
+++ b/src/common
@@ -0,0 +1,353 @@
+# -*-shell-script-*-
+
+# Shared bash functions for the monkeysphere
+#
+# Written by
+# Jameson Rollins <jrollins@fifthhorseman.net>
+#
+# Copyright 2008, released under the GPL, version 3 or later
+
+# all caps variables are meant to be user supplied (ie. from config
+# file) and are considered global
+
+########################################################################
+# managed directories
+ETC="/etc/monkeysphere"
+export ETC
+LIB="/var/lib/monkeysphere"
+export LIB 
+########################################################################
+
+failure() {
+    echo "$1" >&2
+    exit ${2:-'1'}
+}
+
+# write output to stdout
+log() {
+    echo -n "ms: "
+    echo "$@"
+}
+
+# write output to stderr
+loge() {
+    echo -n "ms: " 1>&2
+    echo "$@" 1>&2
+}
+
+# cut out all comments(#) and blank lines from standard input
+meat() {
+    grep -v -e "^[[:space:]]*#" -e '^$'
+}
+
+# cut a specified line from standard input
+cutline() {
+    head --line="$1" | tail -1
+}
+
+# retrieve all keys with given user id from keyserver
+# FIXME: need to figure out how to retrieve all matching keys
+# (not just first 5)
+gpg_fetch_keys() {
+    local id
+    id="$1"
+    echo 1,2,3,4,5 | \
+	gpg --quiet --batch --command-fd 0 --with-colons \
+	--keyserver "$KEYSERVER" \
+	--search ="$id" >/dev/null 2>&1
+}
+
+# check that characters are in a string (in an AND fashion).
+# used for checking key capability
+# check_capability capability a [b...]
+check_capability() {
+    local capability
+    local capcheck
+
+    capability="$1"
+    shift 1
+
+    for capcheck ; do
+	if echo "$capability" | grep -q -v "$capcheck" ; then
+	    return 1
+	fi
+    done
+    return 0
+}
+
+# convert escaped characters from gpg output back into original
+# character
+# FIXME: undo all escape character translation in with-colons gpg output
+unescape() {
+    echo "$1" | sed 's/\\x3a/:/'
+}
+
+# stand in until we get dkg's gpg2ssh program
+gpg2ssh_tmp() {
+    local keyID
+    local userID
+    local host
+
+    keyID="$2"
+    userID="$3"
+
+    if [ "$mode" = 'authorized_keys' ] ; then
+	gpgkey2ssh "$keyID" | sed -e "s/COMMENT/${userID}/"
+
+    # NOTE: it seems that ssh-keygen -R removes all comment fields from
+    # all lines in the known_hosts file.  why?
+    # NOTE: just in case, the COMMENT can be matched with the
+    # following regexp:
+    # '^MonkeySphere[[:digit:]]{4}(-[[:digit:]]{2}){2}T[[:digit:]]{2}(:[[:digit:]]{2}){2}$'
+    elif [ "$MODE" = 'known_hosts' ] ; then
+	host=$(echo "$userID" | sed -e "s|ssh://||")
+	echo -n "$host "; gpgkey2ssh "$keyID" | sed -e "s/COMMENT/MonkeySphere${DATE}/"
+    fi
+}
+
+# userid and key policy checking
+# the following checks policy on the returned keys
+# - checks that full key has appropriate valididy (u|f)
+# - checks key has specified capability (REQUIRED_KEY_CAPABILITY)
+# - checks that particular desired user id has appropriate validity
+# see /usr/share/doc/gnupg/DETAILS.gz
+# expects global variable: "MODE"
+process_user_id() {
+    local userID
+    local cacheDir
+    local requiredPubCapability
+    local gpgOut
+    local line
+    local type
+    local validity
+    local keyid
+    local uidfpr
+    local capability
+    local keyOK
+    local pubKeyID
+    local uidOK
+    local keyIDs
+    local userIDHash
+    local keyID
+
+    userID="$1"
+    cacheDir="$2"
+
+    requiredPubCapability=$(echo "$REQUIRED_KEY_CAPABILITY" | tr "[:lower:]" "[:upper:]")
+
+    # fetch keys from keyserver, return 1 if none found
+    gpg_fetch_keys "$userID" || return 1
+
+    # output gpg info for (exact) userid and store
+    gpgOut=$(gpg --fixed-list-mode --list-key --with-colons \
+	="$userID" 2> /dev/null)
+
+    # return 1 if there only "tru" lines are output from gpg
+    if [ -z "$(echo "$gpgOut" | grep -v '^tru:')" ] ; then
+	loge "  key not found."
+	return 1
+    fi
+
+    # loop over all lines in the gpg output and process.
+    # need to do it this way (as opposed to "while read...") so that
+    # variables set in loop will be visible outside of loop
+    for line in $(seq 1 $(echo "$gpgOut" | wc -l)) ; do
+
+	# read the contents of the line
+	type=$(echo "$gpgOut" | cutline "$line" | cut -d: -f1)
+	validity=$(echo "$gpgOut" | cutline "$line" | cut -d: -f2)
+	keyid=$(echo "$gpgOut" | cutline "$line" | cut -d: -f5)
+	uidfpr=$(echo "$gpgOut" | cutline "$line" | cut -d: -f10)
+	capability=$(echo "$gpgOut" | cutline "$line" | cut -d: -f12)
+
+	# process based on record type
+	case $type in
+	    'pub') # primary keys
+		# new key, wipe the slate
+		keyOK=
+		pubKeyID=
+		uidOK=
+		keyIDs=
+
+		pubKeyID="$keyid"
+
+		# check primary key validity
+		if [ "$validity" != 'u' -a "$validity" != 'f' ] ; then
+		    loge "  unacceptable primary key validity ($validity)."
+		    continue
+		fi
+		# check capability is not Disabled...
+		if check_capability "$capability" 'D' ; then
+		    loge "  key disabled."
+		    continue
+		fi
+		# check overall key capability
+		# must be Encryption and Authentication
+		if ! check_capability "$capability" $requiredPubCapability ; then
+		    loge "  unacceptable primary key capability ($capability)."
+		    continue
+		fi
+
+		# mark if primary key is acceptable
+		keyOK=true
+
+		# add primary key ID to key list if it has required capability
+		if check_capability "$capability" $REQUIRED_KEY_CAPABILITY ; then
+		    keyIDs[${#keyIDs[*]}]="$keyid"
+		fi
+		;;
+	    'uid') # user ids
+		# check key ok and we have key fingerprint
+		if [ -z "$keyOK" ] ; then
+		    continue
+		fi
+		# check key validity
+		if [ "$validity" != 'u' -a "$validity" != 'f' ] ; then
+		    continue
+		fi
+		# check the uid matches
+		if [ "$(unescape "$uidfpr")" != "$userID" ] ; then
+		    continue
+		fi
+
+		# mark if uid acceptable
+		uidOK=true
+		;;
+	    'sub') # sub keys
+		# add sub key ID to key list if it has required capability
+		if check_capability "$capability" $REQUIRED_KEY_CAPABILITY ; then
+		    keyIDs[${#keyIDs[*]}]="$keyid"
+		fi
+		;;
+	esac
+    done
+
+    # hash userid for cache file name
+    userIDHash=$(echo "$userID" | sha1sum | awk '{ print $1 }')
+
+    # touch/clear key cache file
+    # (will be left empty if there are noacceptable keys)
+    > "$cacheDir"/"$userIDHash"."$pubKeyID"
+
+    # for each acceptable key, write an ssh key line to the
+    # key cache file
+    if [ "$keyOK" -a "$uidOK" -a "${keyIDs[*]}" ] ; then
+	for keyID in ${keyIDs[@]} ; do
+	    loge "  acceptable key/uid found."
+
+	    # export the key with gpg2ssh
+            # FIXME: needs to apply extra options for authorized_keys
+	    # lines if specified
+	    gpg2ssh_tmp "$keyID" "$userID" >> "$cacheDir"/"$userIDHash"."$pubKeyID"
+
+	    # hash the cache file if specified
+	    if [ "$MODE" = 'known_hosts' -a "$HASH_KNOWN_HOSTS" ] ; then
+		ssh-keygen -H -f "$cacheDir"/"$userIDHash"."$pubKeyID" > /dev/null 2>&1
+		rm "$cacheDir"/"$userIDHash"."$pubKeyID".old
+	    fi
+	done
+    fi
+
+    # echo the path to the key cache file
+    echo "$cacheDir"/"$userIDHash"."$pubKeyID"
+}
+
+# process a host for addition to a known_host file
+process_host() {
+    local host
+    local cacheDir
+    local hostKeyCachePath
+
+    host="$1"
+    cacheDir="$2"
+
+    log "processing host: '$host'"
+
+    hostKeyCachePath=$(process_user_id "ssh://${host}" "$cacheDir")
+    if [ $? = 0 ] ; then
+	ssh-keygen -R "$host" -f "$USER_KNOWN_HOSTS"
+	cat "$hostKeyCachePath" >> "$USER_KNOWN_HOSTS"
+    fi
+}
+
+# process known_hosts file
+# go through line-by-line, extract each host, and process with the
+# host processing function
+process_known_hosts() {
+    local knownHosts
+    local cacheDir
+    local hosts
+    local host
+
+    knownHosts="$1"
+    cacheDir="$2"
+
+    # take all the hosts from the known_hosts file (first field),
+    # grep out all the hashed hosts (lines starting with '|')
+    cut -d ' ' -f 1 "$knownHosts" | \
+    grep -v '^|.*$' | \
+    while IFS=, read -r -a hosts ; do
+	# process each host
+	for host in ${hosts[*]} ; do
+	    process_host "$host" "$cacheDir"
+	done
+    done
+}
+
+# process authorized_keys file
+# go through line-by-line, extract monkeysphere userids from comment
+# fields, and process each userid
+process_authorized_keys() {
+    local authorizedKeys
+    local cacheDir
+    local userID
+
+    authorizedKeys="$1"
+    cacheDir="$2"
+
+    # take all the monkeysphere userids from the authorized_keys file
+    # comment field (third field) that starts with "MonkeySphere uid:"
+    # FIXME: needs to handle authorized_keys options (field 0)
+    cat "$authorizedKeys" | \
+    while read -r options keytype key comment ; do
+	# if the comment field is empty, assume the third field was
+	# the comment
+	if [ -z "$comment" ] ; then
+	    comment="$key"
+	fi
+	if ! echo "$comment" | grep '^MonkeySphere userID:.*$' ; then
+	    continue
+	fi
+	userID=$(echo "$comment" | sed -e "/^MonkeySphere userID://")
+	if [ -z "$userID" ] ; then
+	    continue
+	fi
+	# process the userid
+	log "processing userid: '$userID'"
+	process_user_id "$userID" "$cacheDir" > /dev/null
+    done
+}
+
+# process an authorized_*_ids file
+# go through line-by-line, extract each userid, and process
+process_authorized_ids() {
+    local authorizedIDs
+    local cacheDir
+    local userID
+
+    authorizedIDs="$1"
+    cacheDir="$2"
+
+    # clean out keys file and remake keys directory
+    rm -rf "$cacheDir"
+    mkdir -p "$cacheDir"
+
+    # loop through all user ids in file
+    # FIXME: needs to handle authorized_keys options
+    cat "$authorizedIDs" | meat | \
+    while read -r userID ; do
+	# process the userid
+	log "processing userid: '$userID'"
+	process_user_id "$userID" "$cacheDir" > /dev/null
+    done
+}
diff --git a/src/gpg2ssh/Makefile b/src/gpg2ssh/Makefile
new file mode 100644
index 0000000..a0b7241
--- /dev/null
+++ b/src/gpg2ssh/Makefile
@@ -0,0 +1,18 @@
+all: monkeysphere gpg2ssh
+
+monkeysphere: main.c gnutls-helpers.o
+	gcc -g -Wall --pedantic -o monkeysphere main.c `libgnutls-config --libs --cflags` -lgnutls-extra gnutls-helpers.o
+
+gpg2ssh: gpg2ssh.c gnutls-helpers.o
+	gcc -g -Wall --pedantic -o gpg2ssh gpg2ssh.c `libgnutls-config --libs --cflags` -lgnutls-extra gnutls-helpers.o
+
+ssh2gpg: ssh2gpg.c gnutls-helpers.o
+	gcc -g -Wall --pedantic -o ssh2gpg ssh2gpg.c `libgnutls-config --libs --cflags` -lgnutls-extra gnutls-helpers.o
+
+%.o: %.c
+	gcc -g -Wall --pedantic -o $@ -c $<
+
+clean: 
+	rm -f monkeysphere gpg2ssh *.o
+
+.PHONY: clean all
diff --git a/src/gpg2ssh/gnutls-helpers.c b/src/gpg2ssh/gnutls-helpers.c
new file mode 100644
index 0000000..6eae29e
--- /dev/null
+++ b/src/gpg2ssh/gnutls-helpers.c
@@ -0,0 +1,364 @@
+/* Author: Daniel Kahn Gillmor <dkg@fifthhorseman.net> */
+/* Date: Fri, 04 Apr 2008 19:31:16 -0400 */
+/* License: GPL v3 or later */
+
+#include "gnutls-helpers.h"
+/* for htonl() */
+#include <arpa/inet.h>
+
+/* for setlocale() */
+#include <locale.h>
+
+/* for isalnum() */
+#include <ctype.h>
+
+int loglevel = 0;
+
+
+void err(const char* fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+  vfprintf(stderr, fmt, ap);
+  va_end(ap);
+  fflush(stderr);
+}
+
+void logfunc(int level, const char* string) {
+  fprintf(stderr, "GnuTLS Logging (%d): %s\n", level, string);
+}
+
+void init_keyid(gnutls_openpgp_keyid_t keyid) {
+  memset(keyid, 'x', sizeof(gnutls_openpgp_keyid_t));
+}
+
+
+
+void make_keyid_printable(printable_keyid out, gnutls_openpgp_keyid_t keyid)
+{
+  static const char hex[16] = "0123456789ABCDEF";
+  unsigned int kix = 0, outix = 0;
+  
+  while (kix < sizeof(gnutls_openpgp_keyid_t)) {
+    out[outix] = hex[(keyid[kix] >> 4) & 0x0f];
+    out[outix + 1] = hex[keyid[kix] & 0x0f];
+    kix++;
+    outix += 2;
+  }
+}
+
+
+int init_gnutls() {
+  const char* version = NULL;
+  const char* debug_string = NULL;
+  int ret;
+
+  if (ret = gnutls_global_init(), ret) {
+    err("Failed to do gnutls_global_init() (error: %d)\n", ret);
+    return 1;
+  }
+
+  version = gnutls_check_version(NULL);
+
+  if (version) 
+    err("gnutls version: %s\n", version);
+  else {
+    err("no version found!\n");
+    return 1;
+  }
+
+  if (debug_string = getenv("MONKEYSPHERE_DEBUG"), debug_string) {
+    loglevel = atoi(debug_string);
+    gnutls_global_set_log_function(logfunc);
+    
+    gnutls_global_set_log_level(loglevel);
+    err("set log level to %d\n", loglevel);
+  }
+  return 0;
+}
+
+void init_datum(gnutls_datum_t* d) {
+  d->data = NULL;
+  d->size = 0;
+}
+void copy_datum(gnutls_datum_t* dest, const gnutls_datum_t* src) {
+  dest->data = gnutls_realloc(dest->data, src->size);
+  dest->size = src->size;
+  memcpy(dest->data, src->data, src->size);
+}
+int compare_data(const gnutls_datum_t* a, const gnutls_datum_t* b) {
+  if (a->size > b->size) {
+    err("a is larger\n");
+    return 1;
+  }
+  if (a->size < b->size) {
+    err("b is larger\n");
+    return -1;
+  }
+  return memcmp(a->data, b->data, a->size);
+}
+void free_datum(gnutls_datum_t* d) {
+  gnutls_free(d->data);
+  d->data = NULL;
+  d->size = 0;
+}
+
+/* read the passed-in string, store in a single datum */
+int set_datum_string(gnutls_datum_t* d, const char* s) {
+  unsigned int x = strlen(s)+1;
+  unsigned char* c = NULL;
+
+  c = gnutls_realloc(d->data, x);
+  if (NULL == c)
+    return -1;
+  d->data = c;
+  d->size = x;
+  memcpy(d->data, s, x);
+  return 0;
+}
+
+/* read the passed-in file descriptor until EOF, store in a single
+   datum */
+int set_datum_fd(gnutls_datum_t* d, int fd) {
+  unsigned int bufsize = 1024;
+  unsigned int len = 0;
+
+  FILE* f = fdopen(fd, "r");
+  if (bufsize > d->size) {
+    bufsize = 1024;
+    d->data = gnutls_realloc(d->data, bufsize);
+    if (d->data == NULL) {
+      err("out of memory!\n");
+      return -1;
+    }
+    d->size = bufsize;
+  } else {
+    bufsize = d->size;
+  }
+  f = fdopen(fd, "r");
+  if (NULL == f) {
+    err("could not fdopen FD %d\n", fd);
+  }
+  clearerr(f);
+  while (!feof(f) && !ferror(f)) { 
+    if (len == bufsize) {
+      /* allocate more space by doubling: */
+      bufsize *= 2;
+      d->data = gnutls_realloc(d->data, bufsize);
+      if (d->data == NULL) {
+	err("out of memory!\n"); 
+	return -1;
+      };
+      d->size = bufsize;
+    }
+    len += fread(d->data + len, 1, bufsize - len, f);
+    /*     err("read %d bytes\n", len); */
+  }
+  if (ferror(f)) {
+    err("Error reading from fd %d (error: %d) (error: %d '%s')\n", fd, ferror(f), errno, strerror(errno));
+    return -1;
+  }
+    
+  /* touch up buffer size to match reality: */
+  d->data = gnutls_realloc(d->data, len);
+  d->size = len;
+  return 0;
+}
+
+/* read the file indicated (by name) in the fname parameter.  store
+   its entire contents in a single datum. */
+int set_datum_file(gnutls_datum_t* d, const char* fname) {
+  struct stat sbuf;
+  unsigned char* c = NULL;
+  FILE* file = NULL;
+  size_t x = 0;
+
+  if (0 != stat(fname, &sbuf)) {
+    err("failed to stat '%s'\n", fname);
+    return -1;
+  }
+  
+  c = gnutls_realloc(d->data, sbuf.st_size);
+  if (NULL == c) {
+    err("failed to allocate %d bytes for '%s'\n", sbuf.st_size, fname);
+    return -1;
+  }
+
+  d->data = c;
+  d->size = sbuf.st_size;
+  file = fopen(fname, "r");
+  if (NULL == file) {
+    err("failed to open '%s' for reading\n",  fname);
+    return -1;
+  }
+
+  x = fread(d->data, d->size, 1, file);
+  if (x != 1) {
+    err("tried to read %d bytes, read %d instead from '%s'\n", d->size, x, fname);
+    fclose(file);
+    return -1;
+  }
+  fclose(file);
+  return 0;
+}
+
+int write_datum_fd(int fd, const gnutls_datum_t* d) {
+  if (d->size != write(fd, d->data, d->size)) {
+    err("failed to write body of datum.\n");
+    return -1;
+  }
+  return 0;
+}
+
+
+int write_datum_fd_with_length(int fd, const gnutls_datum_t* d) {
+  uint32_t len;
+  int looks_negative = (d->data[0] & 0x80);
+  unsigned char zero = 0;
+
+  /* if the first bit is 1, then the datum will appear negative in the
+     MPI encoding style used by OpenSSH.  In that case, we'll increase
+     the length by one, and dump out one more byte */
+
+  if (looks_negative) {
+    len = htonl(d->size + 1);
+  } else {
+    len = htonl(d->size);
+  }
+  if (write(fd, &len, sizeof(len)) != sizeof(len)) {
+    err("failed to write size of datum.\n");
+    return -2;
+  }
+  if (looks_negative) {
+    if (write(fd, &zero, 1) != 1) {
+      err("failed to write padding byte for MPI.\n");
+      return -2;
+    }
+  }
+  return write_datum_fd(fd, d);
+}
+
+int write_data_fd_with_length(int fd, const gnutls_datum_t** d, unsigned int num) {
+  unsigned int i;
+  int ret;
+
+  for (i = 0; i < num; i++)
+    if (ret = write_datum_fd_with_length(fd, d[i]), ret != 0)
+      return ret;
+
+  return 0;
+}
+
+
+int datum_from_string(gnutls_datum_t* d, const char* str) {
+  d->size = strlen(str);
+  d->data = gnutls_realloc(d->data, d->size);
+  if (d->data == 0)
+    return ENOMEM;
+  memcpy(d->data, str, d->size);
+  return 0;
+}
+
+
+int create_writing_pipe(pid_t* pid, const char* path, char* const argv[]) {
+  int p[2];
+  int ret;
+
+  if (pid == NULL) {
+    err("bad pointer passed to create_writing_pipe()\n");
+    return -1;
+  }
+
+  if (ret = pipe(p), ret == -1) {
+    err("failed to create a pipe (error: %d \"%s\")\n", errno, strerror(errno));
+    return -1;
+  }
+
+  *pid = fork();
+  if (*pid == -1) {
+    err("Failed to fork (error: %d \"%s\")\n", errno, strerror(errno));
+    return -1;
+  }
+  if (*pid == 0) { /* this is the child */
+    close(p[1]); /* close unused write end */
+    
+    if (0 != dup2(p[0], 0)) { /* map the reading end into stdin */
+      err("Failed to transfer reading file descriptor to stdin (error: %d \"%s\")\n", errno, strerror(errno));
+      exit(1);
+    }
+    execv(path, argv);
+    err("exec %s failed (error: %d \"%s\")\n", path, errno, strerror(errno));
+    /* close the open file descriptors */
+    close(p[0]);
+    close(0);
+
+    exit(1);
+  } else { /* this is the parent */
+    close(p[0]); /* close unused read end */
+    return p[1];
+  }
+}
+
+int validate_ssh_host_userid(const char* userid) {
+  char* oldlocale = setlocale(LC_ALL, "C");
+  
+  /* choke if userid does not match the expected format
+     ("ssh://fully.qualified.domain.name") */
+  if (strncmp("ssh://", userid, strlen("ssh://")) != 0) {
+    err("The user ID should start with ssh:// for a host key\n");
+    goto fail;
+  }
+  /* so that isalnum will work properly */
+  userid += strlen("ssh://");
+  while (0 != (*userid)) {
+    if (!isalnum(*userid)) {
+      err("label did not start with a letter or a digit! (%s)\n", userid);
+      goto fail;
+    }
+    userid++;
+    while (isalnum(*userid) || ('-' == (*userid)))
+      userid++;
+    if (('.' == (*userid)) || (0 == (*userid))) { /* clean end of label:
+						 check last char
+						 isalnum */
+      if (!isalnum(*(userid - 1))) {
+	err("label did not end with a letter or a digit!\n");
+	goto fail;
+      }
+      if ('.' == (*userid)) /* advance to the start of the next label */
+	userid++;
+    } else {
+      err("invalid character in domain name: %c\n", *userid);
+      goto fail;
+    }
+  }
+  /* ensure that the last character is valid: */
+  if (!isalnum(*(userid - 1))) {
+    err("hostname did not end with a letter or a digit!\n");
+    goto fail;
+  }
+  /* FIXME: fqdn's can be unicode now, thanks to RFC 3490 -- how do we
+     make sure that we've got an OK string? */
+
+  return 0;
+
+ fail:
+  setlocale(LC_ALL, oldlocale);
+  return 1;
+}
+
+/* http://tools.ietf.org/html/rfc4880#section-5.5.2 */
+size_t get_openpgp_mpi_size(gnutls_datum_t* d) {
+  return 2 + d->size;
+}
+
+int write_openpgp_mpi_to_fd(int fd, gnutls_datum_t* d) {
+  uint16_t x;
+
+  x = d->size * 8;
+  x = htons(x);
+  
+  write(fd, &x, sizeof(x));
+  write(fd, d->data, d->size);
+  
+  return 0;
+}
diff --git a/src/gpg2ssh/gnutls-helpers.h b/src/gpg2ssh/gnutls-helpers.h
new file mode 100644
index 0000000..9ea22a3
--- /dev/null
+++ b/src/gpg2ssh/gnutls-helpers.h
@@ -0,0 +1,72 @@
+/* Author: Daniel Kahn Gillmor <dkg@fifthhorseman.net> */
+/* Date: Fri, 04 Apr 2008 19:31:16 -0400 */
+/* License: GPL v3 or later */
+
+
+#include <gnutls/gnutls.h>
+#include <gnutls/openpgp.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <stdarg.h>
+
+/* Functions to help dealing with GnuTLS for monkeysphere key
+   translation projects: */
+
+/* set everything up, including logging levels.  Return 0 on
+   success */
+int init_gnutls();
+
+/* logging and output functions: */
+
+void err(const char* fmt, ...);
+void logfunc(int level, const char* string);
+
+/* basic datum manipulations: */
+
+void init_datum(gnutls_datum_t* d);
+void copy_datum(gnutls_datum_t* dest, const gnutls_datum_t* src);
+int compare_data(const gnutls_datum_t* a, const gnutls_datum_t* b);
+void free_datum(gnutls_datum_t* d);
+int write_datum_fd(int fd, const gnutls_datum_t* d);
+int write_datum_fd_with_length(int fd, const gnutls_datum_t* d);
+int write_data_fd_with_length(int fd, const gnutls_datum_t** d, unsigned int num);
+
+/* set up a datum from a null-terminated string */
+int datum_from_string(gnutls_datum_t* d, const char* str);
+
+/* keyid manipulations: */
+typedef unsigned char printable_keyid[16];
+
+void init_keyid(gnutls_openpgp_keyid_t keyid);
+void make_keyid_printable(printable_keyid out, gnutls_openpgp_keyid_t keyid);
+
+/* functions to get data into datum objects: */
+
+/* read the passed-in string, store in a single datum */
+int set_datum_string(gnutls_datum_t* d, const char* s);
+
+/* read the passed-in file descriptor until EOF, store in a single
+   datum */
+int set_datum_fd(gnutls_datum_t* d, int fd);
+
+/* read the file indicated (by name) in the fname parameter.  store
+   its entire contents in a single datum. */
+int set_datum_file(gnutls_datum_t* d, const char* fname);
+
+/* set up file descriptor pipe for writing (child process pid gets
+   stored in pid, fd is returned)*/
+int create_writing_pipe(pid_t* pid, const char* path, char* const argv[]);
+
+/* return 0 if userid matches the monkeysphere spec for ssh host user IDs */
+int validate_ssh_host_userid(const char* userid);
+
+/* how many bytes will it take to write out this datum in OpenPGP MPI form? */
+size_t get_openpgp_mpi_size(gnutls_datum_t* d);
+
+/* write the MPI stored in gnutls_datum_t to file descriptor fd: */
+int write_openpgp_mpi_to_fd(int fd, gnutls_datum_t* d);
diff --git a/src/gpg2ssh/gpg2ssh.c b/src/gpg2ssh/gpg2ssh.c
new file mode 100644
index 0000000..c99f03f
--- /dev/null
+++ b/src/gpg2ssh/gpg2ssh.c
@@ -0,0 +1,293 @@
+#include "gnutls-helpers.h"
+
+#include <gnutls/openpgp.h>
+#include <gnutls/x509.h>
+
+/* for waitpid() */
+#include <sys/types.h>
+#include <sys/wait.h>
+
+/* 
+   Author: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
+   Date: Tue, 08 Apr 2008
+   License: GPL v3 or later
+
+   monkeysphere public key translator: execute this with an GPG
+   certificate (public key(s) + userid(s)) on stdin.  It currently
+   only works with RSA keys.
+
+   It will spit out a version of the first key capable of being used
+   for authentication on stdout.  The output format should be suitable
+   for appending a known_hosts file.
+
+   Requirements: I've only built this so far with GnuTLS v2.3.4 --
+   version 2.2.0 does not contain the appropriate pieces.
+
+ */
+
+int main(int argc, char* argv[]) {
+  gnutls_datum_t data;
+  int ret;
+  gnutls_openpgp_crt_t openpgp_crt;
+  gnutls_openpgp_keyid_t keyid;
+  printable_keyid p_keyid;
+  unsigned int keyidx;
+  unsigned int usage, bits;
+  gnutls_pk_algorithm_t algo;
+
+  gnutls_datum_t m, e, p, q, g, y;
+  gnutls_datum_t algolabel;
+
+  char output_data[10240];
+  char userid[10240];
+  size_t uidsz = sizeof(userid);
+
+  const gnutls_datum_t* all[5];
+  int pipefd;
+  pid_t child_pid;
+  char* const args[] = {"/usr/bin/base64", "--wrap=0", NULL};
+  const char* algoname;
+  int mpicount;
+  int pipestatus;
+
+  init_gnutls();
+  
+  init_datum(&data);
+
+  init_datum(&m);
+  init_datum(&e);
+  init_datum(&p);
+  init_datum(&q);
+  init_datum(&g);
+  init_datum(&y);
+
+  init_datum(&algolabel);
+
+  init_keyid(keyid);
+
+  /* slurp in the private key from stdin */
+  if (ret = set_datum_fd(&data, 0), ret) {
+    err("didn't read file descriptor 0\n");
+    return 1;
+  }
+
+
+  if (ret = gnutls_openpgp_crt_init(&openpgp_crt), ret) {
+    err("Failed to initialize OpenPGP certificate (error: %d)\n", ret);
+    return 1;
+  }
+
+  /* format could be either: GNUTLS_OPENPGP_FMT_RAW,
+     GNUTLS_OPENPGP_FMT_BASE64; if MONKEYSPHERE_RAW is set, use RAW,
+     otherwise, use BASE64: */
+
+  /* FIXME: we should be auto-detecting the input format, and
+     translating it as needed. */
+
+  if (getenv("MONKEYSPHERE_RAW")) {
+    err("assuming RAW formatted certificate\n");
+    if (ret = gnutls_openpgp_crt_import(openpgp_crt, &data, GNUTLS_OPENPGP_FMT_RAW), ret) {
+      err("failed to import the OpenPGP certificate in RAW format (error: %d)\n", ret);
+      return ret;
+    }
+  } else {
+    err("assuming BASE64 formatted certificate\n");
+    if (ret = gnutls_openpgp_crt_import (openpgp_crt, &data, GNUTLS_OPENPGP_FMT_BASE64), ret) {
+      err("failed to import the OpenPGP certificate in BASE64 format (error: %d)\n", ret);
+      return ret;
+    }
+  }
+
+  if (gnutls_openpgp_crt_get_revoked_status(openpgp_crt)) {
+    err("the primary key was revoked!\n");
+    return 1;
+  }
+
+  /* FIXME: We're currently looking at the primary key or maybe the
+     first authentication-capable subkey.  
+
+     Instead, we should be iterating through the primary key and all
+     subkeys: for each one with the authentication usage flag set of a
+     algorithm we can handle, we should output matching UserIDs and
+     the SSH version of the key. */
+     
+
+  if (ret = gnutls_openpgp_crt_get_key_usage(openpgp_crt, &usage), ret) {
+    err("failed to get the usage flags for the primary key (error: %d)\n", ret);
+    return ret;
+  }
+  if (usage & GNUTLS_KEY_KEY_AGREEMENT &&
+      usage & GNUTLS_KEY_KEY_ENCIPHERMENT) {
+    err("the primary key can be used for authentication and communication encryption!\n");
+
+    algo = gnutls_openpgp_crt_get_pk_algorithm(openpgp_crt, &bits);
+    if (algo < 0) {
+      err("failed to get the algorithm of the OpenPGP public key (error: %d)\n", algo);
+      return algo;
+    } else if (algo == GNUTLS_PK_RSA) {
+      
+      err("OpenPGP RSA certificate, with %d bits\n", bits);
+      ret = gnutls_openpgp_crt_get_pk_rsa_raw(openpgp_crt, &m, &e);
+      if (GNUTLS_E_SUCCESS != ret) {
+	err ("failed to export RSA key parameters (error: %d)\n", ret);
+	return 1;
+      }
+    } else if (algo == GNUTLS_PK_DSA) {
+      err("OpenPGP DSA Key, with %d bits\n", bits);
+      ret = gnutls_openpgp_crt_get_pk_dsa_raw(openpgp_crt, &p, &q, &g, &y);
+      if (GNUTLS_E_SUCCESS != ret) {
+	err ("failed to export DSA key parameters (error: %d)\n", ret);
+	return 1;
+      }
+    } else {
+      err("OpenPGP Key was not RSA or DSA -- can't deal! (actual algorithm was: %d)\n", algo);
+      return 1;
+    }
+    
+  } else {
+    err("primary key is not good for authentication and communication encryption.  Trying subkeys...\n");
+    
+    if (ret = gnutls_openpgp_crt_get_auth_subkey(openpgp_crt, keyid, 0), ret) {
+      err("failed to find a subkey capable of authentication and communication encryption (error: %d)\n", ret);
+      return ret;
+    }
+    make_keyid_printable(p_keyid, keyid);
+    err("found authentication subkey %.16s\n", p_keyid);
+
+    ret = gnutls_openpgp_crt_get_subkey_idx(openpgp_crt, keyid);
+    if (ret < 0) {
+      err("could not get the index of subkey %.16s (error: %d)\n", ret);
+      return ret;
+    }
+    keyidx = ret;
+
+    if (gnutls_openpgp_crt_get_subkey_revoked_status(openpgp_crt, keyidx)) {
+      err("The authentication subkey was revoked!\n");
+      return 1;
+    }
+
+    if (ret = gnutls_openpgp_crt_get_subkey_usage(openpgp_crt, keyidx, &usage), ret) {
+      err("could not figure out usage of subkey %.16s (error: %d)\n", p_keyid, ret);
+      return ret;
+    }
+    if ((usage & GNUTLS_KEY_KEY_AGREEMENT) == 0 &&
+	usage & GNUTLS_KEY_KEY_ENCIPHERMENT) {
+      err("could not find a subkey with authentication and communication encryption.\n");
+      return 1;
+    }
+
+    /* switch, based on the algorithm in question, to extract the MPI
+       components: */
+
+    algo = gnutls_openpgp_crt_get_subkey_pk_algorithm(openpgp_crt, keyidx, &bits);
+    if (algo < 0) {
+      err("failed to get the algorithm of the authentication subkey (error: %d)\n", algo);
+      return algo;
+    } else if (algo == GNUTLS_PK_RSA) {
+      
+      err("OpenPGP RSA subkey, with %d bits\n", bits);
+      ret = gnutls_openpgp_crt_get_subkey_pk_rsa_raw(openpgp_crt, keyidx, &m, &e);
+      if (GNUTLS_E_SUCCESS != ret) {
+	err ("failed to export RSA subkey parameters (error: %d)\n", ret);
+	return 1;
+      }
+    } else if (algo == GNUTLS_PK_DSA) {
+      err("OpenPGP DSA subkey, with %d bits\n", bits);
+      ret = gnutls_openpgp_crt_get_subkey_pk_dsa_raw(openpgp_crt, keyidx, &p, &q, &g, &y);
+      if (GNUTLS_E_SUCCESS != ret) {
+	err ("failed to export DSA subkey parameters (error: %d)\n", ret);
+	return 1;
+      }
+    } else {
+      err("OpenPGP subkey was not RSA or DSA -- can't deal! (actual algorithm was: %d)\n", algo);
+      return 1;
+    }
+  } 
+
+  /* make sure userid is NULL-terminated */
+  userid[sizeof(userid) - 1] = 0;
+  uidsz--;
+
+  /* FIXME: we're just choosing the first UserID from the certificate:
+     instead, we should be selecting every User ID that is adequately
+     signed and matches the spec, and aggregating them with commas for
+     known_hosts output */
+
+  if (ret = gnutls_openpgp_crt_get_name(openpgp_crt, 0, userid, &uidsz), ret) {
+    err("Failed to fetch the first UserID (error: %d)\n", ret);
+    return ret;
+  }
+
+  if (ret = validate_ssh_host_userid(userid), ret) {
+    err("bad userid: not a valid ssh host.\n");
+    return ret;
+  }
+
+  /* remove ssh:// from the beginning of userid */
+  memmove(userid, userid + strlen("ssh://"), 1 + strlen(userid) - strlen("ssh://"));
+  
+
+  /* now we have algo, and the various MPI data are set.  Can we
+     export them cleanly? */
+
+  /* for the moment, we'll just dump the info raw, and pipe it
+     externally through coreutils' /usr/bin/base64 */
+
+  if (algo == GNUTLS_PK_RSA) {
+    algoname = "ssh-rsa";
+    mpicount = 3;
+
+    all[0] = &algolabel;
+    all[1] = &e;
+    all[2] = &m;
+  } else if (algo == GNUTLS_PK_DSA) {
+    algoname = "ssh-dss";
+    mpicount = 5;
+
+    all[0] = &algolabel;
+    all[1] = &p;
+    all[2] = &q;
+    all[3] = &g;
+    all[4] = &y;
+  } else {
+    err("no idea what this algorithm is: %d\n", algo);
+    return 1;
+  }
+
+  if (ret = datum_from_string(&algolabel, algoname), ret) {
+    err("couldn't label string (error: %d)\n", ret);
+    return ret;
+  }
+
+  snprintf(output_data, sizeof(output_data), "%s %s ", userid, algoname);
+
+  pipefd = create_writing_pipe(&child_pid, args[0], args);
+  if (pipefd < 0) {
+    err("failed to create a writing pipe (returned %d)\n", pipefd);
+    return pipefd;
+  }
+    
+  write(1, output_data, strlen(output_data));
+
+  if (0 != write_data_fd_with_length(pipefd, all, mpicount)) {
+    err("was not able to write out RSA key data\n");
+    return 1;
+  }
+  close(pipefd);
+  if (child_pid != waitpid(child_pid, &pipestatus, 0)) {
+    err("could not wait for child process to return for some reason.\n");
+    return 1;
+  }
+  if (pipestatus != 0) {
+    err("base64 pipe died with return code %d\n", pipestatus);
+    return pipestatus;
+  }
+
+  write(1, "\n", 1);
+
+
+
+  gnutls_openpgp_crt_deinit(openpgp_crt);
+  gnutls_global_deinit();
+  return 0;
+}
diff --git a/src/gpg2ssh/main.c b/src/gpg2ssh/main.c
new file mode 100644
index 0000000..d6bac68
--- /dev/null
+++ b/src/gpg2ssh/main.c
@@ -0,0 +1,271 @@
+#include "gnutls-helpers.h"
+
+#include <gnutls/openpgp.h>
+#include <gnutls/x509.h>
+
+/* 
+   Author: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
+   Date: Tue, 01 Apr 2008
+   License: GPL v3 or later
+
+   monkeysphere private key translator: execute this with an GPG
+   secret key on stdin (at the moment, only passphraseless RSA keys
+   work).
+
+   It will spit out a PEM-encoded version of the key on stdout, which
+   can be fed into ssh-add like this:
+
+    gpg --export-secret-keys $KEYID | monkeysphere | ssh-add -c /dev/stdin
+
+   Requirements: I've only built this so far with GnuTLS v2.3.4 --
+   version 2.2.0 does not contain the appropriate pieces.
+
+   Notes: gpgkey2ssh doesn't seem to provide the same public
+   keys. Mighty weird!
+
+0 wt215@squeak:~/monkeysphere$ gpg --export-secret-keys 1DCDF89F | ~dkg/src/monkeysphere/monkeysphere  | ssh-add -c /dev/stdin
+gnutls version: 2.3.4
+OpenPGP RSA Key, with 1024 bits
+Identity added: /dev/stdin (/dev/stdin)
+The user has to confirm each use of the key
+0 wt215@squeak:~/monkeysphere$ ssh-add -L
+ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAAAgQC9gWQqfrnhQKDQnND/3eOexpddE64J+1zp9fcyCje7H5LKclb6DBV2HS6WgW32PJhIzvP+fYZM3dzXea3fpv14y1SicXiRBDgF9SnsNA1qWn2RyzkLcKy7PmM0PDYtU1oiLTcQj/xkWcqW2sLKHT/WW+vZP5XP7RMGN/yWNMfE2Q== /dev/stdin
+0 wt215@squeak:~/monkeysphere$ gpgkey2ssh 1DCDF89F
+ssh-rsa AAAAB3NzaC1yc2EAAACBAL2BZCp+ueFAoNCc0P/d457Gl10Trgn7XOn19zIKN7sfkspyVvoMFXYdLpaBbfY8mEjO8/59hkzd3Nd5rd+m/XjLVKJxeJEEOAX1Kew0DWpafZHLOQtwrLs+YzQ8Ni1TWiItNxCP/GRZypbawsodP9Zb69k/lc/tEwY3/JY0x8TZAAAAAwEAAQ== COMMENT
+0 wt215@squeak:~/monkeysphere$ 
+
+ */
+
+
+int convert_pgp_to_x509(gnutls_x509_privkey_t* output, gnutls_datum_t* input) {
+  gnutls_openpgp_privkey_t pgp_privkey;
+  gnutls_datum_t m, e, d, p, q, u, g, y, x;
+  gnutls_pk_algorithm_t pgp_algo;
+  unsigned int pgp_bits;
+  int ret;
+
+  init_datum(&m);
+  init_datum(&e);
+  init_datum(&d);
+  init_datum(&p);
+  init_datum(&q);
+  init_datum(&u);
+  init_datum(&g);
+  init_datum(&y);
+  init_datum(&x);
+
+  if (ret = gnutls_openpgp_privkey_init(&pgp_privkey), ret) {
+    err("Failed to initialized OpenPGP private key (error: %d)\n", ret);
+    return 1;
+  }
+
+
+  /* format could be either: GNUTLS_OPENPGP_FMT_RAW,
+     GNUTLS_OPENPGP_FMT_BASE64; if MONKEYSPHERE_RAW is set, use RAW,
+     otherwise, use BASE64: */
+
+  if (getenv("MONKEYSPHERE_RAW")) {
+    err("assuming RAW formatted private keys\n");
+    if (ret = gnutls_openpgp_privkey_import(pgp_privkey, input, GNUTLS_OPENPGP_FMT_RAW, NULL, 0), ret)
+      err("failed to import the OpenPGP private key in RAW format (error: %d)\n", ret);
+  } else {
+    err("assuming BASE64 formatted private keys\n");
+    if (ret = gnutls_openpgp_privkey_import (pgp_privkey, input, GNUTLS_OPENPGP_FMT_BASE64, NULL, 0), ret)
+      err("failed to import the OpenPGP private key in BASE64 format (error: %d)\n", ret);
+  }
+
+  pgp_algo = gnutls_openpgp_privkey_get_pk_algorithm(pgp_privkey, &pgp_bits);
+  if (pgp_algo < 0) {
+    err("failed to get OpenPGP key algorithm (error: %d)\n", pgp_algo);
+    return 1;
+  }
+  if (pgp_algo == GNUTLS_PK_RSA) {
+    err("OpenPGP RSA Key, with %d bits\n", pgp_bits);
+    ret = gnutls_openpgp_privkey_export_rsa_raw(pgp_privkey, &m, &e, &d, &p, &q, &u);
+    if (GNUTLS_E_SUCCESS != ret) {
+      err ("failed to export RSA key parameters (error: %d)\n", ret);
+      return 1;
+    }
+
+    ret = gnutls_x509_privkey_import_rsa_raw (*output, &m, &e, &d, &p, &q, &u); 
+    if (GNUTLS_E_SUCCESS != ret) {
+      err ("failed to import RSA key parameters (error: %d)\n", ret);
+      return 1;
+    }
+  } else if (pgp_algo == GNUTLS_PK_DSA) {
+    err("OpenPGP DSA Key, with %d bits\n", pgp_bits);
+    ret = gnutls_openpgp_privkey_export_dsa_raw(pgp_privkey, &p, &q, &g, &y, &x);
+    if (GNUTLS_E_SUCCESS != ret) {
+      err ("failed to export DSA key parameters (error: %d)\n", ret);
+      return 1;
+    }
+
+    ret = gnutls_x509_privkey_import_dsa_raw (*output, &p, &q, &g, &y, &x); 
+    if (GNUTLS_E_SUCCESS != ret) {
+      err ("failed to import DSA key parameters (error: %d)\n", ret);
+      return 1;
+    }
+  } else {
+    err("OpenPGP Key was not RSA or DSA -- can't deal! (actual algorithm was: %d)\n", pgp_algo);
+    return 1;
+  }
+  
+  ret = gnutls_x509_privkey_fix(*output);
+  if (ret != 0) {
+    err("failed to fix up the private key in X.509 format (error: %d)\n", ret);
+    return 1; 
+  }
+
+  gnutls_openpgp_privkey_deinit(pgp_privkey);
+  return 0;
+}
+
+int convert_x509_to_pgp(gnutls_openpgp_privkey_t* output, gnutls_datum_t* input) {
+  gnutls_x509_privkey_t x509_privkey;
+  gnutls_datum_t m, e, d, p, q, u, g, y, x;
+  gnutls_pk_algorithm_t x509_algo;
+  int ret;
+
+  init_datum(&m);
+  init_datum(&e);
+  init_datum(&d);
+  init_datum(&p);
+  init_datum(&q);
+  init_datum(&u);
+  init_datum(&g);
+  init_datum(&y);
+  init_datum(&x);
+
+  if (ret = gnutls_x509_privkey_init(&x509_privkey), ret) {
+    err("Failed to initialized X.509 private key (error: %d)\n", ret);
+    return 1;
+  }
+
+
+  /* format could be either:     GNUTLS_X509_FMT_DER,
+    GNUTLS_X509_FMT_PEM; if MONKEYSPHERE_DER is set, use DER,
+     otherwise, use PEM: */
+
+  if (getenv("MONKEYSPHERE_DER")) {
+    err("assuming DER formatted private keys\n");
+    if (ret = gnutls_x509_privkey_import(x509_privkey, input, GNUTLS_X509_FMT_DER), ret)
+      err("failed to import the X.509 private key in DER format (error: %d)\n", ret);
+  } else {
+    err("assuming PEM formatted private keys\n");
+    if (ret = gnutls_x509_privkey_import (x509_privkey, input, GNUTLS_X509_FMT_PEM), ret)
+      err("failed to import the X.509 private key in PEM format (error: %d)\n", ret);
+  }
+
+  x509_algo = gnutls_x509_privkey_get_pk_algorithm(x509_privkey);
+  if (x509_algo < 0) {
+    err("failed to get X.509 key algorithm (error: %d)\n", x509_algo);
+    return 1;
+  }
+  if (x509_algo == GNUTLS_PK_RSA) {
+    err("X.509 RSA Key\n");
+    ret = gnutls_x509_privkey_export_rsa_raw(x509_privkey, &m, &e, &d, &p, &q, &u);
+    if (GNUTLS_E_SUCCESS != ret) {
+      err ("failed to export RSA key parameters (error: %d)\n", ret);
+      return 1;
+    }
+
+    /*     ret = gnutls_openpgp_privkey_import_rsa_raw (*output, &m, &e, &d, &p, &q, &u);  */
+    ret = GNUTLS_E_UNIMPLEMENTED_FEATURE;
+    if (GNUTLS_E_SUCCESS != ret) {
+      err ("failed to import RSA key parameters (error: %d)\n", ret);
+      return 1;
+    }
+  } else if (x509_algo == GNUTLS_PK_DSA) {
+    err("X.509 DSA Key\n");
+    ret = gnutls_x509_privkey_export_dsa_raw(x509_privkey, &p, &q, &g, &y, &x);
+    if (GNUTLS_E_SUCCESS != ret) {
+      err ("failed to export DSA key parameters (error: %d)\n", ret);
+      return 1;
+    }
+
+    /*    ret = gnutls_openpgp_privkey_import_dsa_raw (*output, &p, &q, &g, &y, &x);  */
+    ret = GNUTLS_E_UNIMPLEMENTED_FEATURE;
+    if (GNUTLS_E_SUCCESS != ret) {
+      err ("failed to import DSA key parameters (error: %d)\n", ret);
+      return 1;
+    }
+  } else {
+    err("OpenPGP Key was not RSA or DSA -- can't deal! (actual algorithm was: %d)\n", x509_algo);
+    return 1;
+  }
+  
+  gnutls_x509_privkey_deinit(x509_privkey);
+  return 0;
+}
+
+
+int main(int argc, char* argv[]) {
+  gnutls_datum_t data;
+  int ret;
+  gnutls_x509_privkey_t x509_privkey;
+
+  char output_data[10240];
+  size_t ods = sizeof(output_data);
+
+  init_gnutls();
+  
+  init_datum(&data);
+
+  /* slurp in the private key from stdin */
+  if (ret = set_datum_fd(&data, 0), ret) {
+    err("didn't read file descriptor 0\n");
+    return 1;
+  }
+
+
+
+  /* Or, instead, read in key from a file name: 
+  if (ret = set_datum_file(&data, argv[1]), ret) {
+    err("didn't read file '%s'\n", argv[1]);
+    return 1;
+  }
+*/
+
+  /* treat the passed file as an X.509 private key, and extract its
+     component values: */
+
+/*   if (ret = gnutls_x509_privkey_import(x509_privkey, &data, GNUTLS_X509_FMT_PEM), ret) { */
+/*     err("Failed to import the X.509 key (error: %d)\n", ret); */
+/*     return 1; */
+/*   } */
+/*   gnutls_x509_privkey_export_rsa_raw(x509_privkey, &m, &e, &d, &p, &q, &u); */
+
+  /* try to print the PEM-encoded private key: */
+/*   ret = gnutls_x509_privkey_export (x509_privkey, */
+/* 				    GNUTLS_X509_FMT_PEM, */
+/* 				    output_data, */
+/* 				    &ods); */
+/*   printf("ret: %u; ods: %u;\n", ret, ods); */
+/*   if (ret == 0) { */
+/*     write(0, output_data, ods); */
+/*   } */
+
+
+  if (ret = gnutls_x509_privkey_init(&x509_privkey), ret) {
+    err("Failed to initialize X.509 private key (error: %d)\n", ret);
+    return 1;
+  }
+
+  if (ret = convert_pgp_to_x509(&x509_privkey, &data), ret) {
+    return ret;
+  }
+
+  ret = gnutls_x509_privkey_export (x509_privkey,
+				    GNUTLS_X509_FMT_PEM,
+				    output_data,
+				    &ods);
+  printf("ret: %u; ods: %u;\n", ret, ods);
+  if (ret == 0) {
+    write(1, output_data, ods);
+  }
+
+
+  gnutls_x509_privkey_deinit(x509_privkey);
+  gnutls_global_deinit();
+  return 0;
+}
diff --git a/src/gpg2ssh/ssh2gpg.c b/src/gpg2ssh/ssh2gpg.c
new file mode 100644
index 0000000..b14a540
--- /dev/null
+++ b/src/gpg2ssh/ssh2gpg.c
@@ -0,0 +1,171 @@
+#include "gnutls-helpers.h"
+
+#include <gnutls/openpgp.h>
+#include <gnutls/x509.h>
+
+/* for waitpid() */
+#include <sys/types.h>
+#include <sys/wait.h>
+
+/* for time() */
+#include <time.h>
+
+/* for htons() */
+#include <arpa/inet.h>
+
+
+/* 
+   Author: Daniel Kahn Gillmor <dkg@fifthhorseman.net>
+   Date: Sun, 2008-04-20
+   License: GPL v3 or later
+
+   monkeysphere public key translator: execute this with an ssh
+   private key on stdin.  It currently only works with RSA keys.
+
+   it should eventually work with OpenSSH-style public keys instead of
+   the full private key, but it was easier to do this way.
+
+   It shoud spit out a version of the public key suitable for acting
+   as an OpenPGP public sub key packet.
+
+ */
+
+int main(int argc, char* argv[]) {
+  gnutls_datum_t data;
+  int ret;
+  gnutls_x509_privkey_t x509_privkey;
+  gnutls_openpgp_crt_t openpgp_crt;
+  gnutls_openpgp_keyid_t keyid;
+  printable_keyid p_keyid;
+  unsigned int keyidx;
+  unsigned int usage, bits;
+  gnutls_pk_algorithm_t algo;
+
+  unsigned char packettag;
+  unsigned char openpgpversion;
+  time_t timestamp;
+  uint32_t clunkytime;
+  unsigned char openpgpalgo;
+  unsigned int packetlen;
+  uint16_t plen;
+
+  gnutls_datum_t m, e, d, p, q, u, g, y;
+  gnutls_datum_t algolabel;
+
+  char output_data[10240];
+  char userid[10240];
+  size_t uidsz = sizeof(userid);
+
+  const gnutls_datum_t* all[5];
+  int pipefd;
+  pid_t child_pid;
+  char* const args[] = {"/usr/bin/base64", "--wrap=0", NULL};
+  const char* algoname;
+  int mpicount;
+  int pipestatus;
+
+  init_gnutls();
+  
+  init_datum(&data);
+
+  init_datum(&m);
+  init_datum(&e);
+  init_datum(&d);
+  init_datum(&p);
+  init_datum(&q);
+  init_datum(&u);
+  init_datum(&g);
+  init_datum(&y);
+
+  init_datum(&algolabel);
+
+  init_keyid(keyid);
+
+  /* slurp in the private key from stdin */
+  if (ret = set_datum_fd(&data, 0), ret) {
+    err("didn't read file descriptor 0\n");
+    return 1;
+  }
+
+
+  if (ret = gnutls_x509_privkey_init(&x509_privkey), ret) {
+    err("Failed to initialize private key structure (error: %d)\n", ret);
+    return 1;
+  }
+
+  err("assuming PEM formatted private key\n");
+  if (ret = gnutls_x509_privkey_import(x509_privkey, &data, GNUTLS_X509_FMT_PEM), ret) {
+    err("failed to import the PEM-encoded private key (error: %d)\n", ret);
+    return ret;
+  }
+
+  algo = gnutls_x509_privkey_get_pk_algorithm(x509_privkey);
+  if (algo < 0) {
+    err("failed to get the algorithm of the PEM-encoded public key (error: %d)\n", algo);
+    return algo;
+  } else if (algo == GNUTLS_PK_RSA) {
+    err("RSA private key\n");
+    ret = gnutls_x509_privkey_export_rsa_raw(x509_privkey, &m, &e, &d, &p, &q, &u);
+    if (GNUTLS_E_SUCCESS != ret) {
+      err ("failed to export RSA key parameters (error: %d)\n", ret);
+      return 1;
+    }
+    err("Modulus size %d, exponent size %d\n", m.size, e.size);
+  } else if (algo == GNUTLS_PK_DSA) {
+    err("DSA Key, not implemented!!\n", bits);
+    return 1;
+  } else {
+    err("Key was not RSA or DSA -- can't deal! (actual algorithm was: %d)\n", algo);
+    return 1;
+  }
+
+  /* now we have algo, and the various MPI data are set.  Can we
+     export them as a public subkey packet? */
+
+  /* this packet should be tagged 14, and should contain:
+
+     1 octet: version (4)
+     4 octets: time of generation (seconds since 1970)
+     1 octet: algo (http://tools.ietf.org/html/rfc4880#section-5.5.2 implies 1 for RSA)
+ 
+     MPI: modulus
+     MPI: exponent
+  */
+
+  packetlen = 1 + 4 + 1;
+  /* FIXME: this is RSA only.  for DSA, there'll be more: */
+  packetlen += get_openpgp_mpi_size(&m) + get_openpgp_mpi_size(&e);
+
+  /* FIXME: we should generate this bound more cleanly -- i just
+     happen to know that 65535 is 2^16-1: */
+  if (packetlen > 65535) {
+    err("packet length is too long (%d)\n", packetlen);
+    return 1;
+  }
+
+  /* we're going to emit an old-style packet, with tag 14 (public
+     subkey), with a two-octet packet length */
+  packettag = 0x80 | (14 << 2) | 1;
+  
+  write(1, &packettag, sizeof(packettag));
+  plen = htons(packetlen);
+  write(1, &plen, sizeof(plen));
+
+  openpgpversion = 4;
+  write(1, &openpgpversion, 1);
+
+  timestamp = time(NULL);
+  clunkytime = htonl(timestamp);
+  write(1, &clunkytime, 4);
+
+  /* FIXME: handle things other than RSA */
+  openpgpalgo = 1;
+  write(1, &openpgpalgo, 1);
+  
+  write_openpgp_mpi_to_fd(1, &m);
+  write_openpgp_mpi_to_fd(1, &e);
+
+  gnutls_x509_privkey_deinit(x509_privkey);
+  gnutls_global_deinit();
+  return 0;
+}
diff --git a/src/howler/howler b/src/howler/howler
new file mode 100755
index 0000000..0b67c02
--- /dev/null
+++ b/src/howler/howler
@@ -0,0 +1,134 @@
+#!/bin/sh
+
+# howler: monkeysphere server gpg generator/publisher/maintainer
+#
+# Written by
+# Jameson Rollins <jrollins@fifthhorseman.net>
+#
+# Copyright 2008, released under the GPL, version 3 or later
+
+PGRM=$(basename $0)
+
+########################################################################
+# FUNCTIONS
+########################################################################
+
+usage() {
+cat <<EOF
+usage: $PGRM gen-key
+       $PGRM publish-key
+       $PGRM trust-key KEYID [KEYID...]
+       $PGRM help
+EOF
+}
+
+failure() {
+    echo "$1" >&2
+    exit ${2:-'1'}
+}
+
+# generate server gpg key
+gen_key() {
+    KEY_TYPE=${KEY_TYPE:-RSA}
+    KEY_LENGTH=${KEY_LENGTH:-2048}
+    KEY_USAGE=${KEY_USAGE:-encrypt,auth}
+    SERVICE=${SERVICE:-ssh}
+    HOSTNAME_FQDN=${HOSTNAME_FQDN:-$(hostname -f)}
+
+    USERID=${USERID:-"$SERVICE"://"$HOSTNAME_FQDN"}
+
+    echo "key parameters:"
+    cat <<EOF
+Key-Type: $KEY_TYPE
+Key-Length: $KEY_LENGTH
+Key-Usage: $KEY_USAGE
+Name-Real: $USERID
+EOF
+
+    read -p "generate key? [Y|n]: " OK; OK=${OK:=Y}
+    if [ ${OK/y/Y} != 'Y' ] ; then
+	failure "aborting."
+    fi
+
+    if gpg --list-key ="$USERID" > /dev/null 2>&1 ; then
+	failure "key for '$USERID' already exists"
+    fi
+
+    echo "generating server key..."
+    gpg --batch --gen-key <<EOF
+Key-Type: $KEY_TYPE
+Key-Length: $KEY_LENGTH
+Key-Usage: $KEY_USAGE
+Name-Real: $USERID
+%commit
+EOF
+}
+
+publish_key() {
+    read -p "publish key to $KEYSERVER? [Y|n]: " OK; OK=${OK:=Y}
+    if [ ${OK/y/Y} != 'Y' ] ; then
+	failure "aborting."
+    fi
+
+    keyID=$(gpg --list-key --with-colons ="$USERID" 2> /dev/null | grep '^pub:' | cut -d: -f5)
+
+    # dummy command so as not to publish fakes keys during testing
+    # eventually:
+    #gpg --send-keys --keyserver "$KEYSERVER" "$keyID"
+    echo "gpg --send-keys --keyserver $KEYSERVER $keyID"
+}
+
+trust_key() {
+    for keyID ; do
+	# get the key from the key server
+	gpg --keyserver "$KEYSERVER" --recv-key "$keyID" || failure "could not retrieve key '$keyID'"
+
+	# edit the key to change trust
+	# FIXME: need to figure out how to automate this,
+	# in a batch mode or something.
+	gpg --edit-key "$keyID"
+    done
+}
+
+########################################################################
+# MAIN
+########################################################################
+
+# set ms home directory
+MS_HOME=${MS_HOME:-/etc/monkeysphere}
+
+# load configuration file
+MS_CONF=${MS_CONF:-"$MS_HOME"/monkeysphere.conf}
+[ -e "$MS_CONF" ] && . "$MS_CONF"
+
+GNUPGHOME=${GNUPGHOME:-"$MS_HOME"/gnupg}
+export GNUPGHOME
+KEYSERVER=${KEYSERVER:-subkeys.pgp.net}
+export KEYSERVER
+
+COMMAND="$1"
+[ "$COMMAND" ] || failure "Type '$PGRM help' for usage."
+shift 1
+
+case $COMMAND in
+    'gen-key')
+	gen_key
+	;;
+    'publish-key')
+	publish_key
+	;;
+    'trust-key')
+	if [ -z "$1" ] ; then
+	    failure "you must specify at least one key to trust."
+	fi
+	trust_key "$@"
+	;;
+    'help')
+        usage
+	exit
+        ;;
+    *)
+        failure "Unknown command: '$COMMAND'
+Type '$PGRM help' for usage."
+        ;;
+esac
diff --git a/src/monkeysphere b/src/monkeysphere
new file mode 100755
index 0000000..f279d86
--- /dev/null
+++ b/src/monkeysphere
@@ -0,0 +1,154 @@
+#!/bin/sh
+
+########################################################################
+PGRM=$(basename $0)
+
+SHAREDIR=${SHAREDIR:-"/usr/share/monkeysphere"}
+export SHAREDIR
+. "${SHAREDIR}/common"
+
+GLOBAL_CONFIG=${GLOBAL_CONFIG:-"${ETC}"/monkeysphere.conf}
+[ -r "$GLOBAL_CONFIG" ] && . "$GLOBAL_CONFIG"
+
+# date in UTF format if needed
+DATE=$(date -u '+%FT%T')
+
+# unset some environment variables that could screw things up
+GREP_OPTIONS=
+
+########################################################################
+# FUNCTIONS
+########################################################################
+
+usage() {
+cat <<EOF
+usage: $PGRM <subcommand> [args]
+Monkeysphere client tool.
+
+subcommands:
+  update-known-hosts (k) [HOST]...           update known_hosts file
+  update-authorized-keys (a)                 update authorized_keys file
+  update-userid (u) [USERID]...              add/update userid to
+                                               authorized_user_ids
+  help (h,?)                                 this help
+
+EOF
+}
+
+########################################################################
+# MAIN
+########################################################################
+
+COMMAND="$1"
+[ "$COMMAND" ] || failure "Type '$PGRM help' for usage."
+shift
+
+# set ms home directory
+MS_HOME=${MS_HOME:-"$HOME"/.config/monkeysphere}
+
+# load configuration file
+MS_CONF=${MS_CONF:-"$MS_HOME"/monkeysphere.conf}
+[ -e "$MS_CONF" ] && . "$MS_CONF"
+
+# set empty config variable with defaults
+AUTHORIZED_USER_IDS=${AUTHORIZED_USER_IDS:-"$MS_HOME"/authorized_user_ids}
+GNUPGHOME=${GNUPGHOME:-"$HOME"/.gnupg}
+KEYSERVER=${KEYSERVER:-subkeys.pgp.net}
+REQUIRED_KEY_CAPABILITY=${REQUIRED_KEY_CAPABILITY:-"e a"}
+USER_CONTROLLED_AUTHORIZED_KEYS=${USER_CONTROLLED_AUTHORIZED_KEYS:-%h/.ssh/authorized_keys}
+USER_KNOWN_HOSTS=${USER_KNOWN_HOSTS:-"$HOME"/.ssh/known_hosts}
+HASH_KNOWN_HOSTS=${HASH_KNOWN_HOSTS:-}
+
+export GNUPGHOME
+
+# stagging locations
+hostKeysCacheDir="$MS_HOME"/host_keys
+userKeysCacheDir="$MS_HOME"/user_keys
+msAuthorizedKeys="$MS_HOME"/authorized_keys
+
+# make sure gpg home exists with proper permissions
+mkdir -p -m 0700 "$GNUPGHOME"
+
+case $COMMAND in
+    'update-known-hosts'|'k')
+	MODE='known_hosts'
+
+        # touch the known_hosts file to make sure it exists
+	touch "$USER_KNOWN_HOSTS"
+
+        # if hosts are specified on the command line, process just
+        # those hosts
+	if [ "$1" ] ; then
+            for host ; do
+		process_host "$host" "$hostKeysCacheDir"
+	    done
+
+        # otherwise, if no hosts are specified, process the user
+        # known_hosts file
+	else
+	    if [ ! -s "$USER_KNOWN_HOSTS" ] ; then
+		failure "known_hosts file '$USER_KNOWN_HOSTS' is empty."
+	    fi
+	    log "processing known_hosts file..."
+	    process_known_hosts "$USER_KNOWN_HOSTS" "$hostKeysCacheDir"
+	fi
+	;;
+
+    'update-authorized-keys'|'a')
+	MODE='authorized_keys'
+
+	log "processing authorized_user_ids file..."
+
+        # make sure authorized_user_ids file exists
+	if [ ! -s "$AUTHORIZED_USER_IDS" ] ; then
+	    log "authorized_user_ids file is empty or does not exist."
+	    exit
+	fi
+
+	process_authorized_ids "$AUTHORIZED_USER_IDS" "$userKeysCacheDir"
+
+        # write output key file
+	log "writing monkeysphere authorized_keys file... "
+	touch "$msAuthorizedKeys"
+	if [ "$(ls "$userKeysCacheDir")" ] ; then
+	    log -n "adding gpg keys... "
+	    cat "$userKeysCacheDir"/* > "$msAuthorizedKeys"
+	    echo "done."
+	else
+	log "no gpg keys to add."
+	fi
+	if [ "$USER_CONTROLLED_AUTHORIZED_KEYS" ] ; then
+	    userAuthorizedKeys=${USER_CONTROLLED_AUTHORIZED_KEYS/\%h/"$HOME"}
+	    if [ -s "$userAuthorizedKeys" ] ; then
+		log -n "adding user authorized_keys file... "
+		cat "$userAuthorizedKeys" >> "$msAuthorizedKeys"
+		echo "done."
+	    fi
+	fi
+	log "monkeysphere authorized_keys file generated:"
+	log "$msAuthorizedKeys"
+	;;
+
+    'update-userid'|'u')
+	if [ -z "$1" ] ; then
+	    failure "you must specify at least one userid."
+	fi
+	for userID ; do
+	    if ! grep -q "^${userID}\$" "$AUTHORIZED_USER_IDS" ; then
+		log "userid '$userID' not in authorized_user_ids file."
+		continue
+	    fi
+	    log "processing user id: '$userID'"
+	    process_user_id "$userID" "$userKeysCacheDir" > /dev/null
+	done
+	;;
+
+    'help'|'h'|'?')
+        usage
+        ;;
+
+    *)
+        failure "Unknown command: '$COMMAND'
+Type 'cereal-admin help' for usage."
+        ;;
+esac
diff --git a/src/monkeysphere-server b/src/monkeysphere-server
new file mode 100755
index 0000000..f1b4892
--- /dev/null
+++ b/src/monkeysphere-server
@@ -0,0 +1,219 @@
+#!/bin/sh
+
+########################################################################
+PGRM=$(basename $0)
+
+SHAREDIR=${SHAREDIR:-"/usr/share/monkeysphere"}
+export SHAREDIR
+. "${SHAREDIR}/common"
+
+# date in UTF format if needed
+DATE=$(date -u '+%FT%T')
+
+# unset some environment variables that could screw things up
+GREP_OPTIONS=
+
+########################################################################
+# FUNCTIONS
+########################################################################
+
+usage() {
+cat <<EOF
+usage: $PGRM <subcommand> [args]
+Monkeysphere server admin tool.
+
+subcommands:
+  update-users (s) [USER]...                update authorized_keys file
+  gen-key (g)                               generate gpg key for the host
+  publish-key (p)                           publish host gpg to keyserver
+  trust-key (t) KEYID [KEYID]...            mark keyid as trusted
+  update-user-userid (u) USER UID [UID]...  add/update userid for user
+  help (h,?)                                this help
+
+EOF
+}
+
+# generate server gpg key
+gen_key() {
+    KEY_TYPE=${KEY_TYPE:-RSA}
+    KEY_LENGTH=${KEY_LENGTH:-2048}
+    KEY_USAGE=${KEY_USAGE:-encrypt,auth}
+    SERVICE=${SERVICE:-ssh}
+    HOSTNAME_FQDN=${HOSTNAME_FQDN:-$(hostname -f)}
+
+    USERID=${USERID:-"$SERVICE"://"$HOSTNAME_FQDN"}
+
+    echo "key parameters:"
+    cat <<EOF
+Key-Type: $KEY_TYPE
+Key-Length: $KEY_LENGTH
+Key-Usage: $KEY_USAGE
+Name-Real: $USERID
+EOF
+
+    read -p "generate key? [Y|n]: " OK; OK=${OK:=Y}
+    if [ ${OK/y/Y} != 'Y' ] ; then
+	failure "aborting."
+    fi
+
+    if gpg --list-key ="$USERID" > /dev/null 2>&1 ; then
+	failure "key for '$USERID' already exists"
+    fi
+
+    echo "generating server key..."
+    gpg --batch --gen-key <<EOF
+Key-Type: $KEY_TYPE
+Key-Length: $KEY_LENGTH
+Key-Usage: $KEY_USAGE
+Name-Real: $USERID
+%commit
+EOF
+}
+
+# publish server key to keyserver
+publish_key() {
+    read -p "publish key to $KEYSERVER? [Y|n]: " OK; OK=${OK:=Y}
+    if [ ${OK/y/Y} != 'Y' ] ; then
+	failure "aborting."
+    fi
+
+    keyID=$(gpg --list-key --with-colons ="$USERID" 2> /dev/null | grep '^pub:' | cut -d: -f5)
+
+    # dummy command so as not to publish fakes keys during testing
+    # eventually:
+    #gpg --send-keys --keyserver "$KEYSERVER" "$keyID"
+    echo "gpg --send-keys --keyserver $KEYSERVER $keyID"
+}
+
+# trust key
+trust_key() {
+    for keyID ; do
+	# get the key from the key server
+	gpg --keyserver "$KEYSERVER" --recv-key "$keyID" || failure "could not retrieve key '$keyID'"
+
+	# edit the key to change trust
+	# FIXME: need to figure out how to automate this,
+	# in a batch mode or something.
+	gpg --edit-key "$keyID"
+    done
+}
+
+########################################################################
+# MAIN
+########################################################################
+
+COMMAND="$1"
+[ "$COMMAND" ] || failure "Type '$PGRM help' for usage."
+shift
+
+# set ms home directory
+MS_HOME=${MS_HOME:-"$ETC"}
+
+# load configuration file
+MS_CONF=${MS_CONF:-"$MS_HOME"/monkeysphere-server.conf}
+[ -e "$MS_CONF" ] && . "$MS_CONF"
+
+# set empty config variable with defaults
+GNUPGHOME=${GNUPGHOME:-"$MS_HOME"/gnupg}
+KEYSERVER=${KEYSERVER:-subkeys.pgp.net}
+REQUIRED_KEY_CAPABILITY=${REQUIRED_KEY_CAPABILITY:-"e a"}
+USER_CONTROLLED_AUTHORIZED_KEYS=${USER_CONTROLLED_AUTHORIZED_KEYS:-%h/.ssh/authorized_keys}
+STAGING_AREA=${STAGING_AREA:-"$LIB"/stage}
+
+export GNUPGHOME
+
+# make sure gpg home exists with proper permissions
+mkdir -p -m 0700 "$GNUPGHOME"
+
+case $COMMAND in
+    'update-users'|'s')
+	if [ "$1" ] ; then
+	    unames="$@"
+	else
+	    unames=$(ls -1 "$MS_HOME"/authorized_user_ids)
+	fi
+
+	for uname in $unames ; do
+	    MODE="authorized_keys"
+	    authorizedUserIDs="$MS_HOME"/authorized_user_ids/"$uname"
+	    cacheDir="$STAGING_AREA"/"$uname"/user_keys
+	    msAuthorizedKeys="$STAGING_AREA"/"$uname"/authorized_keys
+
+            # make sure authorized_user_ids file exists
+	    if [ ! -s "$authorizedUserIDs" ] ; then
+		log "authorized_user_ids file for '$uname' is empty or does not exist."
+		continue
+	    fi
+
+	    log "processing authorized_keys for user '$uname'..."
+
+	    process_authorized_ids "$authorizedUserIDs" "$cacheDir"
+
+            # write output key file
+	    log "writing monkeysphere authorized_keys file... "
+	    touch "$msAuthorizedKeys"
+	    if [ "$(ls "$cacheDir")" ] ; then
+		log -n "adding gpg keys... "
+		cat "$cacheDir"/* > "$msAuthorizedKeys"
+		echo "done."
+	    else
+		log "no gpg keys to add."
+	    fi
+	    if [ "$USER_CONTROLLED_AUTHORIZED_KEYS" ] ; then
+		userHome=$(getent passwd "$uname" | cut -d: -f6)
+		userAuthorizedKeys=${USER_CONTROLLED_AUTHORIZED_KEYS/\%h/"$userHome"}
+		if [ -s "$userAuthorizedKeys" ] ; then
+		    log -n "adding user authorized_keys file... "
+		    cat "$userAuthorizedKeys" >> "$msAuthorizedKeys"
+		    echo "done."
+		fi
+	    fi
+	    log "monkeysphere authorized_keys file generated:"
+	    log "$msAuthorizedKeys"
+	done
+	;;
+
+    'gen-key'|'g')
+	gen_key
+	;;
+
+    'publish-key'|'p')
+	publish_key
+	;;
+
+    'trust-key'|'t')
+	if [ -z "$1" ] ; then
+	    failure "you must specify at least one key to trust."
+	fi
+	trust_key "$@"
+	;;
+
+    'update-user-userid'|'u')
+	uname="$1"
+	shift
+	if [ -z "$uname" ] ; then
+	    failure "you must specify user."
+	fi
+	if [ -z "$1" ] ; then
+	    failure "you must specify at least one userid."
+	fi
+	for userID ; do
+	    AUTHORIZED_USER_IDS="$MS_HOME"/authorized_user_ids/"$uname"
+	    if ! grep -q "^${userID}\$" "$AUTHORIZED_USER_IDS" ; then
+		log "userid '$userID' not in authorized_user_ids file."
+		continue
+	    fi
+	    log "processing user id: '$userID'"
+	    process_user_id "$userID" "$userKeysCacheDir" > /dev/null
+	done
+	;;
+
+    'help'|'h'|'?')
+        usage
+        ;;
+
+    *)
+        failure "Unknown command: '$COMMAND'
+Type 'cereal-admin help' for usage."
+        ;;
+esac
diff --git a/src/monkeysphere-ssh-proxycommand b/src/monkeysphere-ssh-proxycommand
new file mode 100755
index 0000000..1724966
--- /dev/null
+++ b/src/monkeysphere-ssh-proxycommand
@@ -0,0 +1,16 @@
+#!/bin/sh -e
+
+# MonkeySphere ssh ProxyCommand hook
+# Proxy command script to initiate a monkeysphere known_hosts update
+# before an ssh connection to host is established.
+# Can be added to ~/.ssh/config as follows:
+# ProxyCommand monkeysphere-ssh-proxycommand %h %p
+
+HOST="$1"
+PORT="$2"
+
+# update the known_hosts file for the host
+monkeysphere update-known-hosts "$HOST"
+
+# make a netcat connection to host for the ssh connection
+exec nc "$HOST" "$PORT"
diff --git a/src/rhesus/README b/src/rhesus/README
new file mode 100644
index 0000000..4d383d5
--- /dev/null
+++ b/src/rhesus/README
@@ -0,0 +1,30 @@
+rhesus is the monkeysphere authorized_keys/known_hosts generator.
+
+In authorized_keys mode, rhesus takes an auth_user_ids file, which
+contains gpg user ids, uses gpg to fetch the keys of the specified
+users, does a monkeysphere policy check on each id, and uses gpg2ssh
+to generate authorized_keys lines for each verified id.  The lines are
+then combined with a user's traditional authorized_keys file to create
+a new authorized_keys file.
+
+In known_hosts mode, rhesus takes an auth_host_ids file, which
+contains gpg user ids of the form ssh://URL, uses gpg to fetch the
+keys of the specified hosts, does a monkeysphere policy check on each
+id, and uses gpg2ssh to generate a known_hosts lines for each verified
+id.  The lines are then combined with a user's traditional known_hosts
+file to create a new known_hosts file.
+
+When run as a normal user, no special configuration is needed.
+
+When run as an administrator to update system-maintained
+authorized_keys files for each user, the following environment
+variables should be defined first:
+
+ MS_CONF=/etc/monkeysphere/monkeysphere.conf
+ USER=foo
+
+For example, the command might be run like this:
+
+ for USER in $(ls -1 /home) ; do
+   MS_CONF=/etc/monkeysphere/monkeysphere.conf rhesus --authorized_keys
+ done
diff --git a/src/rhesus/rhesus b/src/rhesus/rhesus
new file mode 100755
index 0000000..f607f0b
--- /dev/null
+++ b/src/rhesus/rhesus
@@ -0,0 +1,466 @@
+#!/bin/sh
+
+# rhesus: monkeysphere authorized_keys/known_hosts generating script
+#
+# Written by
+# Jameson Rollins <jrollins@fifthhorseman.net>
+#
+# Copyright 2008, released under the GPL, version 3 or later
+
+# all caps variables are meant to be user supplied (ie. from config
+# file) and are considered global
+
+PGRM=$(basename $0)
+
+# date in UTF format if needed
+DATE=$(date -u '+%FT%T')
+
+# unset some environment variables that could screw things up
+GREP_OPTIONS=
+
+########################################################################
+# FUNCTIONS
+########################################################################
+
+usage() {
+cat <<EOF
+usage: $PGRM k|known_hosts [host...]
+       $PGRM a|authorized_keys [userid...]
+Monkeysphere update of known_hosts or authorized_keys file.
+If hosts/userids are specified, only those specified will be processed
+EOF
+}
+
+failure() {
+    echo "$1" >&2
+    exit ${2:-'1'}
+}
+
+# write output to stdout
+log() {
+    echo -n "ms: "
+    echo "$@"
+}
+
+# write output to stderr
+loge() {
+    echo -n "ms: " 1>&2
+    echo "$@" 1>&2
+}
+
+# cut out all comments(#) and blank lines from standard input
+meat() {
+    grep -v -e "^[[:space:]]*#" -e '^$'
+}
+
+# cut a specified line from standard input
+cutline() {
+    head --line="$1" | tail -1
+}
+
+# retrieve all keys with given user id from keyserver
+# FIXME: need to figure out how to retrieve all matching keys
+# (not just first 5)
+gpg_fetch_keys() {
+    local id
+    id="$1"
+    echo 1,2,3,4,5 | \
+	gpg --quiet --batch --command-fd 0 --with-colons \
+	--keyserver "$KEYSERVER" \
+	--search ="$id" >/dev/null 2>&1
+}
+
+# check that characters are in a string (in an AND fashion).
+# used for checking key capability
+# check_capability capability a [b...]
+check_capability() {
+    local capability
+    local capcheck
+
+    capability="$1"
+    shift 1
+
+    for capcheck ; do
+	if echo "$capability" | grep -q -v "$capcheck" ; then
+	    return 1
+	fi
+    done
+    return 0
+}
+
+# convert escaped characters from gpg output back into original
+# character
+# FIXME: undo all escape character translation in with-colons gpg output
+unescape() {
+    echo "$1" | sed 's/\\x3a/:/'
+}
+
+# stand in until we get dkg's gpg2ssh program
+gpg2ssh_tmp() {
+    local mode
+    local keyID
+    local userID
+    local host
+
+    mode="$1"
+    keyID="$2"
+    userID="$3"
+
+    if [ "$mode" = 'authorized_keys' ] ; then
+	gpgkey2ssh "$keyID" | sed -e "s/COMMENT/${userID}/"
+
+    # NOTE: it seems that ssh-keygen -R removes all comment fields from
+    # all lines in the known_hosts file.  why?
+    # NOTE: just in case, the COMMENT can be matched with the
+    # following regexp:
+    # '^MonkeySphere[[:digit:]]{4}(-[[:digit:]]{2}){2}T[[:digit:]]{2}(:[[:digit:]]{2}){2}$'
+    elif [ "$mode" = 'known_hosts' ] ; then
+	host=$(echo "$userID" | sed -e "s|ssh://||")
+	echo -n "$host "; gpgkey2ssh "$keyID" | sed -e "s/COMMENT/MonkeySphere${DATE}/"
+    fi
+}
+
+# userid and key policy checking
+# the following checks policy on the returned keys
+# - checks that full key has appropriate valididy (u|f)
+# - checks key has specified capability (REQUIRED_KEY_CAPABILITY)
+# - checks that particular desired user id has appropriate validity
+# see /usr/share/doc/gnupg/DETAILS.gz
+# expects global variable: "mode"
+process_user_id() {
+    local userID
+    local cacheDir
+    local requiredPubCapability
+    local gpgOut
+    local line
+    local type
+    local validity
+    local keyid
+    local uidfpr
+    local capability
+    local keyOK
+    local pubKeyID
+    local uidOK
+    local keyIDs
+    local userIDHash
+    local keyID
+
+    userID="$1"
+    cacheDir="$2"
+
+    requiredPubCapability=$(echo "$REQUIRED_KEY_CAPABILITY" | tr "[:lower:]" "[:upper:]")
+
+    # fetch keys from keyserver, return 1 if none found
+    gpg_fetch_keys "$userID" || return 1
+
+    # output gpg info for (exact) userid and store
+    gpgOut=$(gpg --fixed-list-mode --list-key --with-colons \
+	="$userID" 2> /dev/null)
+
+    # return 1 if there only "tru" lines are output from gpg
+    if [ -z "$(echo "$gpgOut" | grep -v '^tru:')" ] ; then
+	return 1
+    fi
+
+    # loop over all lines in the gpg output and process.
+    # need to do it this way (as opposed to "while read...") so that
+    # variables set in loop will be visible outside of loop
+    for line in $(seq 1 $(echo "$gpgOut" | wc -l)) ; do
+
+	# read the contents of the line
+	type=$(echo "$gpgOut" | cutline "$line" | cut -d: -f1)
+	validity=$(echo "$gpgOut" | cutline "$line" | cut -d: -f2)
+	keyid=$(echo "$gpgOut" | cutline "$line" | cut -d: -f5)
+	uidfpr=$(echo "$gpgOut" | cutline "$line" | cut -d: -f10)
+	capability=$(echo "$gpgOut" | cutline "$line" | cut -d: -f12)
+
+	# process based on record type
+	case $type in
+	    'pub') # primary keys
+		# new key, wipe the slate
+		keyOK=
+		pubKeyID=
+		uidOK=
+		keyIDs=
+
+		pubKeyID="$keyid"
+
+		# check primary key validity
+		if [ "$validity" != 'u' -a "$validity" != 'f' ] ; then
+		    loge "  unacceptable primary key validity ($validity)."
+		    continue
+		fi
+		# check capability is not Disabled...
+		if check_capability "$capability" 'D' ; then
+		    loge "  key disabled."
+		    continue
+		fi
+		# check overall key capability
+		# must be Encryption and Authentication
+		if ! check_capability "$capability" $requiredPubCapability ; then
+		    loge "  unacceptable primary key capability ($capability)."
+		    continue
+		fi
+
+		# mark if primary key is acceptable
+		keyOK=true
+
+		# add primary key ID to key list if it has required capability
+		if check_capability "$capability" $REQUIRED_KEY_CAPABILITY ; then
+		    keyIDs[${#keyIDs[*]}]="$keyid"
+		fi
+		;;
+	    'uid') # user ids
+		# check key ok and we have key fingerprint
+		if [ -z "$keyOK" ] ; then
+		    continue
+		fi
+		# check key validity
+		if [ "$validity" != 'u' -a "$validity" != 'f' ] ; then
+		    continue
+		fi
+		# check the uid matches
+		if [ "$(unescape "$uidfpr")" != "$userID" ] ; then
+		    continue
+		fi
+
+		# mark if uid acceptable
+		uidOK=true
+		;;
+	    'sub') # sub keys
+		# add sub key ID to key list if it has required capability
+		if check_capability "$capability" $REQUIRED_KEY_CAPABILITY ; then
+		    keyIDs[${#keyIDs[*]}]="$keyid"
+		fi
+		;;
+	esac
+    done
+
+    # hash userid for cache file name
+    userIDHash=$(echo "$userID" | sha1sum | awk '{ print $1 }')
+
+    # touch/clear key cache file
+    # (will be left empty if there are noacceptable keys)
+    > "$cacheDir"/"$userIDHash"."$pubKeyID"
+
+    # for each acceptable key, write an ssh key line to the
+    # key cache file
+    if [ "$keyOK" -a "$uidOK" -a "${keyIDs[*]}" ] ; then
+	for keyID in ${keyIDs[@]} ; do
+	    # export the key with gpg2ssh
+            # FIXME: needs to apply extra options for authorized_keys
+	    # lines if specified
+	    gpg2ssh_tmp "$mode" "$keyID" "$userID" >> "$cacheDir"/"$userIDHash"."$pubKeyID"
+
+	    # hash the cache file if specified
+	    if [ "$mode" = 'known_hosts' -a "$HASH_KNOWN_HOSTS" ] ; then
+		ssh-keygen -H -f "$cacheDir"/"$userIDHash"."$pubKeyID" > /dev/null 2>&1
+		rm "$cacheDir"/"$userIDHash"."$pubKeyID".old
+	    fi
+	done
+    fi
+
+    # echo the path to the key cache file
+    echo "$cacheDir"/"$userIDHash"."$pubKeyID"
+}
+
+# process a host for addition to a known_host file
+process_host() {
+    local host
+    local cacheDir
+    local hostKeyCachePath
+
+    host="$1"
+    cacheDir="$2"
+
+    log "processing host: '$host'"
+
+    hostKeyCachePath=$(process_user_id "ssh://${host}" "$cacheDir")
+    if [ $? = 0 ] ; then
+	ssh-keygen -R "$host" -f "$USER_KNOWN_HOSTS"
+	cat "$hostKeyCachePath" >> "$USER_KNOWN_HOSTS"
+    fi
+}
+
+# process known_hosts file
+# go through line-by-line, extract each host, and process with the
+# host processing function
+process_known_hosts() {
+    local cacheDir
+    local userID
+
+    cacheDir="$1"
+
+    # take all the hosts from the known_hosts file (first field),
+    # grep out all the hashed hosts (lines starting with '|')
+    cut -d ' ' -f 1 "$USER_KNOWN_HOSTS" | \
+    grep -v '^|.*$' | \
+    while IFS=, read -r -a hosts ; do
+	# process each host
+	for host in ${hosts[*]} ; do
+	    process_host "$host" "$cacheDir"
+	done
+    done
+}
+
+# process an authorized_*_ids file
+# go through line-by-line, extract each userid, and process
+process_authorized_ids() {
+    local authorizedIDsFile
+    local cacheDir
+    local userID
+    local userKeyCachePath
+
+    authorizedIDsFile="$1"
+    cacheDir="$2"
+
+    # clean out keys file and remake keys directory
+    rm -rf "$cacheDir"
+    mkdir -p "$cacheDir"
+
+    # loop through all user ids in file
+    # FIXME: needs to handle extra options if necessary
+    cat "$authorizedIDsFile" | meat | \
+    while read -r userID ; do
+	# process the userid
+	log "processing userid: '$userID'"
+	userKeyCachePath=$(process_user_id "$userID" "$cacheDir")
+	if [ -s "$userKeyCachePath" ] ; then
+	    loge "  acceptable key/uid found."
+	fi
+    done
+}
+
+########################################################################
+# MAIN
+########################################################################
+
+if [ -z "$1" ] ; then
+    usage
+    exit 1
+fi
+
+# mode given in first variable
+mode="$1"
+shift 1
+
+# check user
+if ! id -u "$USER" > /dev/null 2>&1 ; then
+    failure "invalid user '$USER'."
+fi
+
+# set user home directory
+HOME=$(getent passwd "$USER" | cut -d: -f6)
+
+# set ms home directory
+MS_HOME=${MS_HOME:-"$HOME"/.config/monkeysphere}
+
+# load configuration file
+MS_CONF=${MS_CONF:-"$MS_HOME"/monkeysphere.conf}
+[ -e "$MS_CONF" ] && . "$MS_CONF"
+
+# set config variable defaults
+STAGING_AREA=${STAGING_AREA:-"$MS_HOME"}
+AUTHORIZED_USER_IDS=${AUTHORIZED_USER_IDS:-"$MS_HOME"/authorized_user_ids}
+GNUPGHOME=${GNUPGHOME:-"$HOME"/.gnupg}
+KEYSERVER=${KEYSERVER:-subkeys.pgp.net}
+REQUIRED_KEY_CAPABILITY=${REQUIRED_KEY_CAPABILITY:-"e a"}
+USER_CONTROLLED_AUTHORIZED_KEYS=${USER_CONTROLLED_AUTHORIZED_KEYS:-"$HOME"/.ssh/authorized_keys}
+USER_KNOWN_HOSTS=${USER_KNOWN_HOSTS:-"$HOME"/.ssh/known_hosts}
+HASH_KNOWN_HOSTS=${HASH_KNOWN_HOSTS:-}
+
+# export USER and GNUPGHOME variables, since they are used by gpg
+export USER
+export GNUPGHOME
+
+# stagging locations
+hostKeysCacheDir="$STAGING_AREA"/host_keys
+userKeysCacheDir="$STAGING_AREA"/user_keys
+msKnownHosts="$STAGING_AREA"/known_hosts
+msAuthorizedKeys="$STAGING_AREA"/authorized_keys
+
+# make sure gpg home exists with proper permissions
+mkdir -p -m 0700 "$GNUPGHOME"
+
+## KNOWN_HOST MODE
+if [ "$mode" = 'known_hosts' -o "$mode" = 'k' ] ; then
+    mode='known_hosts'
+
+    cacheDir="$hostKeysCacheDir"
+
+    log "user '$USER': monkeysphere known_hosts processing"
+
+    # touch the known_hosts file to make sure it exists
+    touch "$USER_KNOWN_HOSTS"
+
+    # if hosts are specified on the command line, process just
+    # those hosts
+    if [ "$1" ] ; then
+        for host ; do
+	    process_host "$host" "$cacheDir"
+	done
+
+    # otherwise, if no hosts are specified, process the user
+    # known_hosts file
+    else
+	if [ ! -s "$USER_KNOWN_HOSTS" ] ; then
+	    failure "known_hosts file '$USER_KNOWN_HOSTS' is empty."
+	fi
+	process_known_hosts "$cacheDir"
+    fi
+
+## AUTHORIZED_KEYS MODE
+elif [ "$mode" = 'authorized_keys' -o "$mode" = 'a' ] ; then
+    mode='authorized_keys'
+
+    cacheDir="$userKeysCacheDir"
+
+    # check auth ids file
+    if [ ! -s "$AUTHORIZED_USER_IDS" ] ; then
+	log "authorized_user_ids file is empty or does not exist."
+	exit
+    fi
+
+    log "user '$USER': monkeysphere authorized_keys processing"
+
+    # if userids are specified on the command line, process just
+    # those userids
+    if [ "$1" ] ; then
+	for userID ; do
+	    if ! grep -q "$userID" "$AUTHORIZED_USER_IDS" ; then
+		log "userid '$userID' not in authorized_user_ids file."
+		continue
+	    fi
+	    log "processing user id: '$userID'"
+	    process_user_id "$userID" "$cacheDir" > /dev/null
+	done
+
+    # otherwise, if no userids are specified, process the entire
+    # authorized_user_ids file
+    else
+	process_authorized_ids "$AUTHORIZED_USER_IDS" "$cacheDir"
+    fi
+
+    # write output key file
+    log "writing monkeysphere authorized_keys file... "
+    touch "$msAuthorizedKeys"
+    if [ "$(ls "$cacheDir")" ] ; then
+	log -n "adding gpg keys... "
+	cat "$cacheDir"/* > "$msAuthorizedKeys"
+	echo "done."
+    else
+	log "no gpg keys to add."
+    fi
+    if [ "$USER_CONTROLLED_AUTHORIZED_KEYS" ] ; then
+	if [ -s "$USER_CONTROLLED_AUTHORIZED_KEYS" ] ; then
+	    log -n "adding user authorized_keys file... "
+	    cat "$USER_CONTROLLED_AUTHORIZED_KEYS" >> "$msAuthorizedKeys"
+	    echo "done."
+	fi
+    fi
+    log "monkeysphere authorized_keys file generated:"
+    log "$msAuthorizedKeys"
+
+else
+    failure "unknown command '$mode'."
+fi