1 files changed, 315 insertions, 0 deletions

diff --git a/usr.bin/ssh/authfile.c b/usr.bin/ssh/authfile.c
new file mode 100644
index 00000000000..3fea2d14b1f
--- /dev/null
+++ b/usr.bin/ssh/authfile.c
@@ -0,0 +1,315 @@
+/*
+
+authfile.c
+
+Author: Tatu Ylonen <ylo@cs.hut.fi>
+
+Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
+                   All rights reserved
+
+Created: Mon Mar 27 03:52:05 1995 ylo
+
+This file contains functions for reading and writing identity files, and
+for reading the passphrase from the user.
+
+*/
+
+#include "includes.h"
+RCSID("$Id: authfile.c,v 1.1 1999/09/26 20:53:33 deraadt Exp $");
+
+#include <gmp.h>
+#include "xmalloc.h"
+#include "idea.h"
+#include "buffer.h"
+#include "bufaux.h"
+#include "cipher.h"
+#include "ssh.h"
+
+/* Version identification string for identity files. */
+#define AUTHFILE_ID_STRING "SSH PRIVATE KEY FILE FORMAT 1.1\n"
+
+/* Saves the authentication (private) key in a file, encrypting it with
+   passphrase.  The identification of the file (lowest 64 bits of n)
+   will precede the key to provide identification of the key without
+   needing a passphrase. */
+
+int save_private_key(const char *filename, const char *passphrase,
+		     RSAPrivateKey *key, const char *comment, 
+		     RandomState *state)
+{
+  Buffer buffer, encrypted;
+  char buf[100], *cp;
+  int f, i;
+  CipherContext cipher;
+  int cipher_type;
+
+  /* If the passphrase is empty, use SSH_CIPHER_NONE to ease converting to
+     another cipher; otherwise use SSH_AUTHFILE_CIPHER. */
+  if (strcmp(passphrase, "") == 0)
+    cipher_type = SSH_CIPHER_NONE;
+  else
+    cipher_type = SSH_AUTHFILE_CIPHER;
+
+  /* This buffer is used to built the secret part of the private key. */
+  buffer_init(&buffer);
+  
+  /* Put checkbytes for checking passphrase validity. */
+  buf[0] = random_get_byte(state);
+  buf[1] = random_get_byte(state);
+  buf[2] = buf[0];
+  buf[3] = buf[1];
+  buffer_append(&buffer, buf, 4);
+
+  /* Store the private key (n and e will not be stored because they will
+     be stored in plain text, and storing them also in encrypted format
+     would just give known plaintext). */
+  buffer_put_mp_int(&buffer, &key->d);
+  buffer_put_mp_int(&buffer, &key->u);
+  buffer_put_mp_int(&buffer, &key->p);
+  buffer_put_mp_int(&buffer, &key->q);
+
+  /* Pad the part to be encrypted until its size is a multiple of 8. */
+  while (buffer_len(&buffer) % 8 != 0)
+    buffer_put_char(&buffer, 0);
+
+  /* This buffer will be used to contain the data in the file. */
+  buffer_init(&encrypted);
+
+  /* First store keyfile id string. */
+  cp = AUTHFILE_ID_STRING;
+  for (i = 0; cp[i]; i++)
+    buffer_put_char(&encrypted, cp[i]);
+  buffer_put_char(&encrypted, 0);
+
+  /* Store cipher type. */
+  buffer_put_char(&encrypted, cipher_type);
+  buffer_put_int(&encrypted, 0);  /* For future extension */
+
+  /* Store public key.  This will be in plain text. */
+  buffer_put_int(&encrypted, key->bits);
+  buffer_put_mp_int(&encrypted, &key->n);
+  buffer_put_mp_int(&encrypted, &key->e);
+  buffer_put_string(&encrypted, comment, strlen(comment));
+
+  /* Allocate space for the private part of the key in the buffer. */
+  buffer_append_space(&encrypted, &cp, buffer_len(&buffer));
+
+  cipher_set_key_string(&cipher, cipher_type, passphrase, 1);
+  cipher_encrypt(&cipher, (unsigned char *)cp, 
+		 (unsigned char *)buffer_ptr(&buffer),
+		 buffer_len(&buffer));
+  memset(&cipher, 0, sizeof(cipher));
+
+  /* Destroy temporary data. */
+  memset(buf, 0, sizeof(buf));
+  buffer_free(&buffer);
+
+  /* Write to a file. */
+  f = open(filename, O_WRONLY|O_CREAT|O_TRUNC, 0600);
+  if (f < 0)
+    return 0;
+
+  if (write(f, buffer_ptr(&encrypted), buffer_len(&encrypted)) != 
+      buffer_len(&encrypted))
+    {
+      debug("Write to key file %.200s failed: %.100s", filename,
+	    strerror(errno));
+      buffer_free(&encrypted);
+      close(f);
+      remove(filename);
+      return 0;
+    }
+  close(f);
+  buffer_free(&encrypted);
+  return 1;
+}
+
+/* Loads the public part of the key file.  Returns 0 if an error
+   was encountered (the file does not exist or is not readable), and
+   non-zero otherwise. */
+
+int load_public_key(const char *filename, RSAPublicKey *pub, 
+		    char **comment_return)
+{
+  int f, i;
+  unsigned long len;
+  Buffer buffer;
+  char *cp;
+
+  /* Read data from the file into the buffer. */
+  f = open(filename, O_RDONLY);
+  if (f < 0)
+    return 0;
+
+  len = lseek(f, (off_t)0L, 2);
+  lseek(f, (off_t)0L, 0);
+  
+  buffer_init(&buffer);
+  buffer_append_space(&buffer, &cp, len);
+
+  if (read(f, cp, len) != len)
+    {
+      debug("Read from key file %.200s failed: %.100s", filename, 
+	    strerror(errno));
+      buffer_free(&buffer);
+      close(f);
+      return 0;
+    }
+  close(f);
+
+  /* Check that it is at least big enought to contain the ID string. */
+  if (len < strlen(AUTHFILE_ID_STRING) + 1)
+    {
+      debug("Bad key file %.200s.", filename);
+      buffer_free(&buffer);
+      return 0;
+    }
+
+  /* Make sure it begins with the id string.  Consume the id string from
+     the buffer. */
+  for (i = 0; i < (unsigned int)strlen(AUTHFILE_ID_STRING) + 1; i++)
+    if (buffer_get_char(&buffer) != (unsigned char)AUTHFILE_ID_STRING[i])
+      {
+	debug("Bad key file %.200s.", filename);
+	buffer_free(&buffer);
+	return 0;
+      }
+
+  /* Skip cipher type and reserved data. */
+  (void)buffer_get_char(&buffer); /* cipher type */
+  (void)buffer_get_int(&buffer); /* reserved */
+
+  /* Read the public key from the buffer. */
+  pub->bits = buffer_get_int(&buffer);
+  mpz_init(&pub->n);
+  buffer_get_mp_int(&buffer, &pub->n);
+  mpz_init(&pub->e);
+  buffer_get_mp_int(&buffer, &pub->e);
+  if (comment_return)
+    *comment_return = buffer_get_string(&buffer, NULL);
+  /* The encrypted private part is not parsed by this function. */
+
+  buffer_free(&buffer);
+  
+  return 1;
+}
+
+/* Loads the private key from the file.  Returns 0 if an error is encountered
+   (file does not exist or is not readable, or passphrase is bad).
+   This initializes the private key. */
+
+int load_private_key(const char *filename, const char *passphrase,
+		     RSAPrivateKey *prv, char **comment_return)
+{
+  int f, i, check1, check2, cipher_type;
+  unsigned long len;
+  Buffer buffer, decrypted;
+  char *cp;
+  CipherContext cipher;
+
+  /* Read the file into the buffer. */
+  f = open(filename, O_RDONLY);
+  if (f < 0)
+    return 0;
+
+  len = lseek(f, (off_t)0L, 2);
+  lseek(f, (off_t)0L, 0);
+  
+  buffer_init(&buffer);
+  buffer_append_space(&buffer, &cp, len);
+
+  if (read(f, cp, len) != len)
+    {
+      debug("Read from key file %.200s failed: %.100s", filename,
+	    strerror(errno));
+      buffer_free(&buffer);
+      close(f);
+      return 0;
+    }
+  close(f);
+
+  /* Check that it is at least big enought to contain the ID string. */
+  if (len < strlen(AUTHFILE_ID_STRING) + 1)
+    {
+      debug("Bad key file %.200s.", filename);
+      buffer_free(&buffer);
+      return 0;
+    }
+
+  /* Make sure it begins with the id string.  Consume the id string from
+     the buffer. */
+  for (i = 0; i < (unsigned int)strlen(AUTHFILE_ID_STRING) + 1; i++)
+    if (buffer_get_char(&buffer) != (unsigned char)AUTHFILE_ID_STRING[i])
+      {
+	debug("Bad key file %.200s.", filename);
+	buffer_free(&buffer);
+	return 0;
+      }
+
+  /* Read cipher type. */
+  cipher_type = buffer_get_char(&buffer);
+  (void)buffer_get_int(&buffer);  /* Reserved data. */
+
+  /* Read the public key from the buffer. */
+  prv->bits = buffer_get_int(&buffer);
+  mpz_init(&prv->n);
+  buffer_get_mp_int(&buffer, &prv->n);
+  mpz_init(&prv->e);
+  buffer_get_mp_int(&buffer, &prv->e);
+  if (comment_return)
+    *comment_return = buffer_get_string(&buffer, NULL);
+  else
+    xfree(buffer_get_string(&buffer, NULL));
+
+  /* Check that it is a supported cipher. */
+  if ((cipher_mask() & (1 << cipher_type)) == 0)
+    {
+      debug("Unsupported cipher %.100s used in key file %.200s.",
+	    cipher_name(cipher_type), filename);
+      buffer_free(&buffer);
+      goto fail;
+    }
+
+  /* Initialize space for decrypted data. */
+  buffer_init(&decrypted);
+  buffer_append_space(&decrypted, &cp, buffer_len(&buffer));
+      
+  /* Rest of the buffer is encrypted.  Decrypt it using the passphrase. */
+  cipher_set_key_string(&cipher, cipher_type, passphrase, 0);
+  cipher_decrypt(&cipher, (unsigned char *)cp,
+		 (unsigned char *)buffer_ptr(&buffer),
+		 buffer_len(&buffer));
+
+  buffer_free(&buffer);
+
+  check1 = buffer_get_char(&decrypted);
+  check2 = buffer_get_char(&decrypted);
+  if (check1 != buffer_get_char(&decrypted) ||
+      check2 != buffer_get_char(&decrypted))
+    {
+      if (strcmp(passphrase, "") != 0)
+	debug("Bad passphrase supplied for key file %.200s.", filename);
+      /* Bad passphrase. */
+      buffer_free(&decrypted);
+    fail:
+      mpz_clear(&prv->n);
+      mpz_clear(&prv->e);
+      if (comment_return)
+	xfree(*comment_return);
+      return 0;
+    }
+
+  /* Read the rest of the private key. */
+  mpz_init(&prv->d);
+  buffer_get_mp_int(&decrypted, &prv->d);
+  mpz_init(&prv->u);
+  buffer_get_mp_int(&decrypted, &prv->u);
+  mpz_init(&prv->p);
+  buffer_get_mp_int(&decrypted, &prv->p);
+  mpz_init(&prv->q);
+  buffer_get_mp_int(&decrypted, &prv->q);
+  
+  buffer_free(&decrypted);
+
+  return 1;
+}