Added support for ~/.ssh/config.

6 files changed, 348 insertions, 0 deletions

diff --git a/include/libssh/libssh.h b/include/libssh/libssh.h
index 3ab9b49..7e4a99d 100644
--- a/include/libssh/libssh.h
+++ b/include/libssh/libssh.h
@@ -401,6 +401,7 @@ LIBSSH_API int ssh_options_set_dsa_server_key(SSH_OPTIONS *opt, const char *dsak
 LIBSSH_API int ssh_options_set_rsa_server_key(SSH_OPTIONS *opt, const char *rsakey);
 LIBSSH_API int ssh_options_set_auth_callback(SSH_OPTIONS *opt, ssh_auth_callback cb,
     void *userdata);
+LIBSSH_API int ssh_options_parse_config(SSH_OPTIONS *opt, const char *filename);
 
 
 /* buffer.c */
diff --git a/include/libssh/priv.h b/include/libssh/priv.h
index 1318cb0..f24102f 100644
--- a/include/libssh/priv.h
+++ b/include/libssh/priv.h
@@ -634,6 +634,9 @@ void ssh_cleanup(SSH_SESSION *session);
 int ssh_send_banner(SSH_SESSION *session, int is_server);
 char *ssh_get_banner(SSH_SESSION *session);
 
+/* config.c */
+int ssh_config_parse_file(ssh_options opt, const char *filename);
+
 /* errors.c */
 void ssh_set_error(void *error, int code, const char *descr, ...) PRINTF_ATTRIBUTE(3, 4);
 
diff --git a/libssh/CMakeLists.txt b/libssh/CMakeLists.txt
index ad13b8f..1def4d9 100644
--- a/libssh/CMakeLists.txt
+++ b/libssh/CMakeLists.txt
@@ -74,6 +74,7 @@ set(libssh_SRCS
   buffer.c
   channels.c
   client.c
+  config.c
   connect.c
   crc32.c
   crypt.c
diff --git a/libssh/config.c b/libssh/config.c
new file mode 100644
index 0000000..eaf3a91
--- /dev/null
+++ b/libssh/config.c
@@ -0,0 +1,305 @@
+/*
+ * config.c - parse the ssh config file
+ *
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2009      by Andreas Schneider <mail@cynapses.org>
+ *
+ * The SSH Library 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 2.1 of the License, or (at your
+ * option) any later version.
+ *
+ * The SSH Library 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 the SSH Library; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "libssh/priv.h"
+
+enum ssh_config_opcode_e {
+  SOC_UNSUPPORTED = -1,
+  SOC_HOST,
+  SOC_HOSTNAME,
+  SOC_PORT,
+  SOC_USERNAME,
+  SOC_IDENTITY,
+  SOC_CIPHER,
+  SOC_CIPHERS,
+  SOC_COMPRESSION,
+  SOC_TIMEOUT,
+  SOC_PROTOCOL
+};
+
+struct ssh_config_keyword_table_s {
+  const char *name;
+  enum ssh_config_opcode_e opcode;
+};
+
+static struct ssh_config_keyword_table_s ssh_config_keyword_table[] = {
+  { "host", SOC_HOST },
+  { "hostname", SOC_HOSTNAME },
+  { "port", SOC_PORT },
+  { "user", SOC_USERNAME },
+  { "identityfile", SOC_IDENTITY },
+  { "cipher", SOC_CIPHER },
+  { "ciphers", SOC_CIPHERS },
+  { "compression", SOC_COMPRESSION },
+  { "connecttimeout", SOC_TIMEOUT },
+  { "protocol", SOC_PROTOCOL },
+  { NULL, SOC_UNSUPPORTED }
+};
+
+static enum ssh_config_opcode_e ssh_config_get_opcode(char *keyword) {
+  int i;
+
+  for (i = 0; ssh_config_keyword_table[i].name != NULL; i++) {
+    if (strcasecmp(keyword, ssh_config_keyword_table[i].name) == 0) {
+      return ssh_config_keyword_table[i].opcode;
+    }
+  }
+
+  return SOC_UNSUPPORTED;
+}
+
+static char *ssh_config_get_token(char **str) {
+  register char *c;
+  char *r;
+
+  /* Ignore leading spaces */
+  for (c = *str; *c; c++) {
+    if (! isblank(*c)) {
+      break;
+    }
+  }
+
+  if (*c == '\"') {
+    for (r = ++c; *c; c++) {
+      if (*c == '\"') {
+        *c = '\0';
+        goto out;
+      }
+    }
+  }
+
+  for (r = c; *c; c++) {
+    if (isblank(*c)) {
+      *c = '\0';
+      goto out;
+    }
+  }
+
+out:
+  *str = c + 1;
+
+  return r;
+}
+
+static int ssh_config_get_int(char **str, int notfound) {
+  char *p, *endp;
+  int i;
+
+  p = ssh_config_get_token(str);
+  if (p && *p) {
+    i = strtol(p, &endp, 10);
+    if (p == endp) {
+      return notfound;
+    }
+    return i;
+  }
+
+  return notfound;
+}
+
+static const char *ssh_config_get_str(char **str, const char *def) {
+  char *p;
+
+  p = ssh_config_get_token(str);
+  if (p && *p) {
+    return p;
+  }
+
+  return def;
+}
+
+static int ssh_config_get_yesno(char **str, int notfound) {
+  const char *p;
+
+  p = ssh_config_get_str(str, NULL);
+  if (p == NULL) {
+    return notfound;
+  }
+
+  if (strncasecmp(p, "yes", 3) == 0) {
+    return 1;
+  } else if (strncasecmp(p, "no", 2) == 0) {
+    return 0;
+  }
+
+  return notfound;
+}
+
+static int ssh_config_parse_line(ssh_options opt, const char *line,
+    unsigned int count, int *parsing) {
+  enum ssh_config_opcode_e opcode;
+  const char *p;
+  char *s, *x;
+  char *keyword;
+  size_t len;
+  int i;
+
+  x = s = strdup(line);
+  if (s == NULL) {
+    return -1;
+  }
+
+  /* Remove trailing spaces */
+  for (len = strlen(s) - 1; len > 0; len--) {
+    if (! isspace(s[len])) {
+      break;
+    }
+    s[len] = '\0';
+  }
+
+  keyword = ssh_config_get_token(&s);
+  if (keyword == NULL || *keyword == '#' ||
+      *keyword == '\0' || *keyword == '\n') {
+    SAFE_FREE(x);
+    return 0;
+  }
+
+  opcode = ssh_config_get_opcode(keyword);
+
+  switch (opcode) {
+    case SOC_HOST:
+      *parsing = 0;
+      for (p = ssh_config_get_str(&s, NULL); p && *p;
+          p = ssh_config_get_str(&s, NULL)) {
+        if (match_hostname(opt->host, p, strlen(p))) {
+          *parsing = 1;
+        }
+      }
+      break;
+    case SOC_HOSTNAME:
+      p = ssh_config_get_str(&s, NULL);
+      if (p && *parsing) {
+        ssh_options_set_host(opt, p);
+      }
+      break;
+    case SOC_PORT:
+      i = ssh_config_get_int(&s, -1);
+      if (i > 0 && *parsing) {
+        ssh_options_set_port(opt, (unsigned int) i);
+      }
+      break;
+    case SOC_USERNAME:
+      p = ssh_config_get_str(&s, NULL);
+      if (p && *parsing) {
+        ssh_options_set_username(opt, p);
+      }
+      break;
+    case SOC_IDENTITY:
+      p = ssh_config_get_str(&s, NULL);
+      if (p && *parsing) {
+        ssh_options_set_identity(opt, p);
+      }
+      break;
+    case SOC_CIPHERS:
+      /* TODO */
+      break;
+    case SOC_COMPRESSION:
+      i = ssh_config_get_yesno(&s, -1);
+      if (i >= 0 && *parsing) {
+        if (i) {
+          ssh_options_set_wanted_algos(opt, SSH_COMP_C_S, "zlib");
+          ssh_options_set_wanted_algos(opt, SSH_COMP_S_C, "zlib");
+        } else {
+          ssh_options_set_wanted_algos(opt, SSH_COMP_C_S, "none");
+          ssh_options_set_wanted_algos(opt, SSH_COMP_S_C, "none");
+        }
+      }
+      break;
+    case SOC_PROTOCOL:
+      p = ssh_config_get_str(&s, NULL);
+      if (p && *parsing) {
+        char *a, *b;
+        b = strdup(p);
+        if (b == NULL) {
+          SAFE_FREE(x);
+          return -1;
+        }
+        ssh_options_allow_ssh1(opt, 0);
+        ssh_options_allow_ssh2(opt, 0);
+
+        for (a = strtok(b, ","); a; a = strtok(NULL, ",")) {
+          switch (atoi(a)) {
+            case 1:
+              ssh_options_allow_ssh1(opt, 1);
+              break;
+            case 2:
+              ssh_options_allow_ssh2(opt, 1);
+              break;
+            default:
+              break;
+          }
+        }
+        SAFE_FREE(b);
+      }
+      break;
+    case SOC_TIMEOUT:
+      i = ssh_config_get_int(&s, -1);
+      if (i >= 0 && *parsing) {
+        ssh_options_set_timeout(opt, (long) i, 0);
+      }
+      break;
+    case SOC_UNSUPPORTED:
+      fprintf(stderr, "Unsupported option: %s, line: %d\n", keyword, count);
+      break;
+    default:
+      fprintf(stderr, "ERROR - unimplemented opcode: %d\n", opcode);
+      SAFE_FREE(x);
+      return -1;
+      break;
+  }
+
+  SAFE_FREE(x);
+  return 0;
+}
+
+/* ssh_config_parse_file */
+int ssh_config_parse_file(ssh_options opt, const char *filename) {
+  char line[1024] = {0};
+  unsigned int count = 0;
+  FILE *f;
+  int parsing;
+
+  if ((f = fopen(filename, "r")) == NULL) {
+    return -1;
+  }
+
+  if (opt->log_verbosity) {
+    fprintf(stderr, "Reading configuration data from %s\n", filename);
+  }
+
+  parsing = 1;
+  while (fgets(line, sizeof(line), f)) {
+    count++;
+    if (ssh_config_parse_line(opt, line, count, &parsing) < 0) {
+      fclose(f);
+      return -1;
+    }
+  }
+
+  fclose(f);
+  return 0;
+}
diff --git a/libssh/options.c b/libssh/options.c
index 4e22b77..5d21408 100644
--- a/libssh/options.c
+++ b/libssh/options.c
@@ -1018,5 +1018,40 @@ int ssh_options_set_auth_callback(SSH_OPTIONS *opt, ssh_auth_callback cb,
   return 0;
 }
 
+/**
+ * @brief Parse the ssh config file.
+ *
+ * This must be the last call of all options, it may overwrite options which
+ * are already set. It requires at least the hostname to be set.
+ *
+ * @param  opt          The options structure to use.
+ *
+ * @param  filename     The options file to use, if NULL the default
+ *                      ~/.ssh/config will be used.
+ *
+ * @return 0 on success, < 0 on error.
+ */
+int ssh_options_parse_config(ssh_options opt, const char *filename) {
+  char buffer[1024] = {0};
+
+  if (opt == NULL || opt->host == NULL) {
+    return -1;
+  }
+
+  if (opt->ssh_dir == NULL) {
+    if (ssh_options_default_ssh_dir(opt) < 0) {
+      return -1;
+    }
+  }
+
+  /* set default filename */
+  if (filename == NULL) {
+    snprintf(buffer, 1024, "%s/config", opt->ssh_dir);
+    filename = buffer;
+  }
+
+  return ssh_config_parse_file(opt, filename);
+}
+
 /** @} */
 /* vim: set ts=2 sw=2 et cindent: */
diff --git a/sample.c b/sample.c
index cc3df54..f028ceb 100644
--- a/sample.c
+++ b/sample.c
@@ -531,6 +531,9 @@ int main(int argc, char **argv){
       ssh_options_free(options);
       return 1;
     }
+
+    ssh_options_parse_config(options, NULL);
+
     session=ssh_new();
     ssh_set_options(session,options);
     if(ssh_connect(session)){