Enrollment for a host in an IPA domain

This will create a host service principal and may create a host entry (for
admins).  A keytab will be generated, by default in /etc/krb5.keytab
If no kerberos credentails are available then enrollment over LDAPS is used
if a password is provided.

This change requires that openldap be used as our C LDAP client. It is much
easier to do SSL using openldap than mozldap (no certdb required). Otherwise
we'd have to write a slew of extra code to create a temporary cert database,
import the CA cert, ...

ipa-client/config.c

@@ -0,0 +1,155 @@
+/* Authors: Rob Crittenden <rcritten@redhat.com>
+ *
+ * Copyright (C) 2009  Red Hat
+ * see file 'COPYING' for use and warranty information
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 only
+ *
+ * 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+/* Simple and INI-style file reader.
+ *
+ * usage is:
+ * char * data = read_config_file("/path/to/something.conf")
+ * char * entry = get_config_entry(data, "section", "mykey")
+ *
+ * caller must free data and entry.
+ */
+
+#define _GNU_SOURCE
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+
+char *
+read_config_file(const char *filename)
+{
+    int fd;
+    struct stat st;
+    char *data, *dest;
+    size_t left;
+
+    fd = open(filename, O_RDONLY);
+    if (fd == -1) {
+        fprintf(stderr, "cannot open configuration file %s\n", filename);
+        return NULL;
+    }
+
+    /* stat() the file so we know the size and can pre-allocate the right
+     * amount of memory. */
+    if (fstat(fd, &st) == -1) {
+        fprintf(stderr, "cannot stat() configuration file %s\n", filename);
+        return NULL;
+    }
+    left = st.st_size;
+    data = malloc(st.st_size + 1);
+    dest = data;
+    while (left != 0) {
+        ssize_t res;
+
+        res = read(fd, dest, left);
+        if (res == 0)
+            break;
+        if (res < 0) {
+            fprintf(stderr, "read error\n");
+            close(fd);
+            free(dest);
+            return NULL;
+        }
+        dest += res;
+        left -= res;
+    }
+    close(fd);
+    *dest = 0;
+    return data;
+}
+
+char *
+get_config_entry(char * in_data, const char *section, const char *key)
+{
+    char *ptr, *p, *tmp;
+    char *line;
+    int in_section = 0;
+    char * data = strdup(in_data);
+
+    for (line = strtok_r(data, "\n", &ptr); line != NULL;
+         line = strtok_r(NULL, "\n", &ptr)) {
+        /* Skip initial whitespace. */
+        while (isspace((unsigned char)*line) && (*line != '\0'))
+            line++;
+
+        /* If it's a comment, bail. */
+        if (*line == '#') {
+            continue;
+        }
+
+        /* If it's the beginning of a section, process it and clear the key
+         * and value values. */
+        if (*line == '[') {
+            line++;
+            p = strchr(line, ']');
+            if (p) {
+                tmp = strndup(line, p - line);
+                if (in_section) {
+                    /* We exited the matching section without a match */
+                    free(data);
+                    return NULL;
+                }
+                if (strcmp(section, tmp) == 0) {
+                    free(tmp);
+                    in_section = 1;
+                    continue;
+                }
+            }
+        } /* [ */
+
+        p = strchr(line, '=');
+        if (p != NULL && in_section) {
+            /* Trim any trailing whitespace off the key name. */
+            while (p != line && isspace((unsigned char)p[-1]))
+                p--;
+
+            /* Save the key. */
+            tmp = strndup(line, p - line);
+            if (strcmp(key, tmp) != 0) {
+                free(tmp);
+            } else {
+                free(tmp);
+
+                /* Skip over any whitespace after the equal sign. */
+                line = strchr(line, '=');
+                line++;
+                while (isspace((unsigned char)*line) && (*line != '\0'))
+                    line++;
+
+                /* Trim off any trailing whitespace. */
+                p = strchr(line, '\0');
+                while (p != line && isspace((unsigned char)p[-1]))
+                    p--;
+
+                /* Save the value. */
+                tmp = strndup(line, p - line);
+
+                free(data);
+                return tmp;
+            }
+        }
+    }
+    return NULL;
+}