Add HMAC and PBKDF2

conf/common.rmk

@@ -624,4 +624,9 @@ crypto_mod_SOURCES = lib/crypto.c
 crypto_mod_CFLAGS = $(COMMON_CFLAGS)
 crypto_mod_LDFLAGS = $(COMMON_LDFLAGS)
 
+pkglib_MODULES += pbkdf2.mod
+pbkdf2_mod_SOURCES = lib/pbkdf2.c
+pbkdf2_mod_CFLAGS = $(COMMON_CFLAGS)
+pbkdf2_mod_LDFLAGS = $(COMMON_LDFLAGS)
+
 include $(srcdir)/conf/gcry.mk

import_gcry.py

@@ -1,3 +1,21 @@
+#*
+#*  GRUB  --  GRand Unified Bootloader
+#*  Copyright (C) 2009  Free Software Foundation, Inc.
+#*
+#*  GRUB 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, either version 3 of the License, or
+#*  (at your option) any later version.
+#*
+#*  GRUB 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 GRUB.  If not, see <http://www.gnu.org/licenses/>.
+#*
+
 import re
 import sys
 import os
@@ -26,9 +44,12 @@ conf = open (os.path.join (outdir, "conf", "gcry.rmk"), "w")
 conf.write ("# -*- makefile -*-\n\n")
 chlog = ""
 
-mdblocksizes = {"_gcry_digest_spec_crc32" : 1,
-                "_gcry_digest_spec_crc32_rfc1510" : 1,
-                "_gcry_digest_spec_crc24_rfc2440" : 1,
+# Strictly speaking CRC32/CRC24 work on bytes so this value should be 1
+# But libgcrypt uses 64. Let's keep the value for compatibility. Since
+# noone uses CRC24/CRC32 for HMAC this is no problem
+mdblocksizes = {"_gcry_digest_spec_crc32" : 64,
+                "_gcry_digest_spec_crc32_rfc1510" : 64,
+                "_gcry_digest_spec_crc24_rfc2440" : 64,
                 "_gcry_digest_spec_md4" : 64,
                 "_gcry_digest_spec_md5" : 64,
                 "_gcry_digest_spec_rmd160" : 64,

include/grub/cipher_wrap.h

@@ -64,7 +64,7 @@ typedef union {
 static inline void
 grub_assert_real (const char *file, int line, int cond)
 {
-  if (cond)
+  if (!cond)
     grub_fatal ("Assertion failed at %s:%d\n", file, line);
 }
 

include/grub/crypto.h

@@ -166,11 +166,15 @@ typedef struct gcry_md_spec
   struct gcry_md_spec *next;
 } gcry_md_spec_t;
 
-typedef struct grub_crypto_cipher_handle
+struct grub_crypto_cipher_handle
 {
   const struct gcry_cipher_spec *cipher;
   char ctx[0];
-} *grub_crypto_cipher_handle_t;
+};
+
+typedef struct grub_crypto_cipher_handle *grub_crypto_cipher_handle_t;
+
+struct grub_crypto_hmac_handle;
 
 const gcry_cipher_spec_t *
 grub_crypto_lookup_cipher_by_name (const char *name);
@@ -213,7 +217,7 @@ grub_md_register (gcry_md_spec_t *digest);
 void 
 grub_md_unregister (gcry_md_spec_t *cipher);
 void
-grub_crypto_hash (const gcry_md_spec_t *hash, void *out, void *in,
+grub_crypto_hash (const gcry_md_spec_t *hash, void *out, const void *in,
 		  grub_size_t inlen);
 const gcry_md_spec_t *
 grub_crypto_lookup_md_by_name (const char *name);
@@ -223,7 +227,35 @@ grub_crypto_gcry_error (gcry_err_code_t in);
 
 void grub_burn_stack (grub_size_t size);
 
+struct grub_crypto_hmac_handle *
+grub_crypto_hmac_init (const struct gcry_md_spec *md,
+		       const void *key, grub_size_t keylen);
+void
+grub_crypto_hmac_write (struct grub_crypto_hmac_handle *hnd, void *data,
+			grub_size_t datalen);
+gcry_err_code_t
+grub_crypto_hmac_fini (struct grub_crypto_hmac_handle *hnd, void *out);
+
+gcry_err_code_t
+grub_crypto_hmac_buffer (const struct gcry_md_spec *md,
+			 const void *key, grub_size_t keylen,
+			 void *data, grub_size_t datalen, void *out);
+
 extern gcry_md_spec_t _gcry_digest_spec_md5;
 #define GRUB_MD_MD5 ((const gcry_md_spec_t *) &_gcry_digest_spec_md5)
+#define GRUB_MD_SHA1 ((const gcry_md_spec_t *) &_gcry_digest_spec_sha1)
+
+/* Implement PKCS#5 PBKDF2 as per RFC 2898.  The PRF to use is HMAC variant
+   of digest supplied by MD.  Inputs are the password P of length PLEN,
+   the salt S of length SLEN, the iteration counter C (> 0), and the
+   desired derived output length DKLEN.  Output buffer is DK which
+   must have room for at least DKLEN octets.  The output buffer will
+   be filled with the derived data.  */
+gcry_err_code_t
+grub_crypto_pbkdf2 (const struct gcry_md_spec *md,
+		    const grub_uint8_t *P, grub_size_t Plen,
+		    const grub_uint8_t *S, grub_size_t Slen,
+		    unsigned int c,
+		    grub_uint8_t *DK, grub_size_t dkLen);
 
 #endif

lib/crypto.c

@@ -21,6 +21,13 @@
 #include <grub/misc.h>
 #include <grub/mm.h>
 
+struct grub_crypto_hmac_handle
+{
+  const struct gcry_md_spec *md;
+  void *ctx;
+  void *opad;
+};
+
 static gcry_cipher_spec_t *grub_ciphers = NULL;
 static gcry_md_spec_t *grub_digests = NULL;
 
@@ -69,7 +76,7 @@ grub_md_unregister (gcry_md_spec_t *cipher)
 }
 
 void
-grub_crypto_hash (const gcry_md_spec_t *hash, void *out, void *in,
+grub_crypto_hash (const gcry_md_spec_t *hash, void *out, const void *in,
 		  grub_size_t inlen)
 {
   grub_uint8_t ctx[hash->contextsize];
@@ -228,6 +235,134 @@ grub_crypto_cbc_decrypt (grub_crypto_cipher_handle_t cipher,
   return GPG_ERR_NO_ERROR;
 }
 
+/* Based on gcry/cipher/md.c.  */
+struct grub_crypto_hmac_handle *
+grub_crypto_hmac_init (const struct gcry_md_spec *md,
+		       const void *key, grub_size_t keylen)
+{
+  grub_uint8_t *helpkey = NULL;
+  grub_uint8_t *ipad = NULL, *opad = NULL;
+  void *ctx = NULL;
+  struct grub_crypto_hmac_handle *ret = NULL;
+  unsigned i;
+
+  if (md->mdlen > md->blocksize)
+    return NULL;
+
+  ctx = grub_malloc (md->contextsize);
+  if (!ctx)
+    goto err;
+
+  if ( keylen > md->blocksize ) 
+    {
+      helpkey = grub_malloc (md->mdlen);
+      if (!helpkey)
+	goto err;
+      grub_crypto_hash (md, helpkey, key, keylen);
+
+      key = helpkey;
+      keylen = md->mdlen;
+    }
+
+  ipad = grub_zalloc (md->blocksize);
+  if (!ipad)
+    goto err;
+
+  opad = grub_zalloc (md->blocksize);
+  if (!opad)
+    goto err;
+
+  grub_memcpy ( ipad, key, keylen );
+  grub_memcpy ( opad, key, keylen );
+  for (i=0; i < md->blocksize; i++ ) 
+    {
+      ipad[i] ^= 0x36;
+      opad[i] ^= 0x5c;
+    }
+  grub_free (helpkey);
+  helpkey = NULL;
+
+  md->init (ctx);
+
+  md->write (ctx, ipad, md->blocksize); /* inner pad */
+  grub_memset (ipad, 0, md->blocksize);
+  grub_free (ipad);
+  ipad = NULL;
+
+  ret = grub_malloc (sizeof (*ret));
+  if (!ret)
+    goto err;
+
+  ret->md = md;
+  ret->ctx = ctx;
+  ret->opad = opad;
+
+  return ret;
+
+ err:
+  grub_free (helpkey);
+  grub_free (ctx);
+  grub_free (ipad);
+  grub_free (opad);
+  return NULL;
+}
+
+void
+grub_crypto_hmac_write (struct grub_crypto_hmac_handle *hnd, void *data,
+			grub_size_t datalen)
+{
+  hnd->md->write (hnd->ctx, data, datalen);
+}
+
+gcry_err_code_t
+grub_crypto_hmac_fini (struct grub_crypto_hmac_handle *hnd, void *out)
+{
+  grub_uint8_t *p;
+  grub_uint8_t *ctx2;
+
+  ctx2 = grub_malloc (hnd->md->contextsize);
+  if (!ctx2)
+    return GPG_ERR_OUT_OF_MEMORY;
+
+  hnd->md->final (hnd->ctx);
+  hnd->md->read (hnd->ctx);
+  p = hnd->md->read (hnd->ctx);
+
+  hnd->md->init (ctx2);
+  hnd->md->write (ctx2, hnd->opad, hnd->md->blocksize);
+  hnd->md->write (ctx2, p, hnd->md->mdlen);
+  hnd->md->final (ctx2);
+  grub_memset (hnd->opad, 0, hnd->md->blocksize);
+  grub_free (hnd->opad);
+  grub_memset (hnd->ctx, 0, hnd->md->contextsize);
+  grub_free (hnd->ctx);
+
+  grub_memcpy (out, hnd->md->read (ctx2), hnd->md->mdlen);
+  grub_memset (ctx2, 0, hnd->md->contextsize);
+  grub_free (ctx2);
+
+  grub_memset (hnd, 0, sizeof (*hnd));
+  grub_free (hnd);
+
+  return GPG_ERR_NO_ERROR;
+}
+
+gcry_err_code_t
+grub_crypto_hmac_buffer (const struct gcry_md_spec *md,
+			 const void *key, grub_size_t keylen,
+			 void *data, grub_size_t datalen, void *out)
+{
+  struct grub_crypto_hmac_handle *hnd;
+
+  hnd = grub_crypto_hmac_init (md, key, keylen);
+  if (!hnd)
+    return GPG_ERR_OUT_OF_MEMORY;
+
+  grub_crypto_hmac_write (hnd, data, datalen);
+  return grub_crypto_hmac_fini (hnd, out);
+}
+
+
 grub_err_t
 grub_crypto_gcry_error (gcry_err_code_t in)
 {

lib/pbkdf2.c

@@ -0,0 +1,101 @@
+/* gc-pbkdf2-sha1.c --- Password-Based Key Derivation Function a'la PKCS#5
+   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2009 Free Software Foundation, Inc.
+
+   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; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Simon Josefsson.  */
+
+#include <grub/crypto.h>
+#include <grub/mm.h>
+#include <grub/misc.h>
+
+/* Implement PKCS#5 PBKDF2 as per RFC 2898.  The PRF to use is HMAC variant
+   of digest supplied by MD.  Inputs are the password P of length PLEN,
+   the salt S of length SLEN, the iteration counter C (> 0), and the
+   desired derived output length DKLEN.  Output buffer is DK which
+   must have room for at least DKLEN octets.  The output buffer will
+   be filled with the derived data.  */
+gcry_err_code_t
+grub_crypto_pbkdf2 (const struct gcry_md_spec *md,
+		    const grub_uint8_t *P, grub_size_t Plen,
+		    const grub_uint8_t *S, grub_size_t Slen,
+		    unsigned int c,
+		    grub_uint8_t *DK, grub_size_t dkLen)
+{
+  unsigned int hLen = md->mdlen;
+  grub_uint8_t U[md->mdlen];
+  grub_uint8_t T[md->mdlen];
+  unsigned int u;
+  unsigned int l;
+  unsigned int r;
+  unsigned int i;
+  unsigned int k;
+  gcry_err_code_t rc;
+  grub_uint8_t *tmp;
+  grub_size_t tmplen = Slen + 4;
+
+  if (c == 0)
+    return GPG_ERR_INV_ARG;
+
+  if (dkLen == 0)
+    return GPG_ERR_INV_ARG;
+
+  if (dkLen > 4294967295U)
+    return GPG_ERR_INV_ARG;
+
+  l = ((dkLen - 1) / hLen) + 1;
+  r = dkLen - (l - 1) * hLen;
+
+  tmp = grub_malloc (tmplen);
+  if (tmp == NULL)
+    return GPG_ERR_OUT_OF_MEMORY;
+
+  grub_memcpy (tmp, S, Slen);
+
+  for (i = 1; i <= l; i++)
+    {
+      grub_memset (T, 0, hLen);
+
+      for (u = 1; u <= c; u++)
+	{
+	  if (u == 1)
+	    {
+	      tmp[Slen + 0] = (i & 0xff000000) >> 24;
+	      tmp[Slen + 1] = (i & 0x00ff0000) >> 16;
+	      tmp[Slen + 2] = (i & 0x0000ff00) >> 8;
+	      tmp[Slen + 3] = (i & 0x000000ff) >> 0;
+
+	      rc = grub_crypto_hmac_buffer (md, P, Plen, tmp, tmplen, U);
+	    }
+	  else
+	    rc = grub_crypto_hmac_buffer (md, P, Plen, U, hLen, U);
+
+	  if (rc != GPG_ERR_NO_ERROR)
+	    {
+	      grub_free (tmp);
+	      return rc;
+	    }
+
+	  for (k = 0; k < hLen; k++)
+	    T[k] ^= U[k];
+	}
+
+      grub_memcpy (DK + (i - 1) * hLen, T, i == l ? r : hLen);
+    }
+
+  grub_free (tmp);
+
+  return GPG_ERR_NO_ERROR;
+}