/*
 *  VAS_EBOOT  --  GRand Unified Bootloader
 *  Copyright (C) 2013  Free Software Foundation, Inc.
 *
 *  VAS_EBOOT 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.
 *
 *  VAS_EBOOT 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 VAS_EBOOT.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <VasEBoot/types.h>
#include <VasEBoot/misc.h>
#include <VasEBoot/mm.h>
#include <VasEBoot/err.h>
#include <VasEBoot/dl.h>
#include <VasEBoot/file.h>
#include <VasEBoot/command.h>
#include <VasEBoot/crypto.h>
#include <VasEBoot/i18n.h>
#include <VasEBoot/gcrypt/gcrypt.h>
#include <VasEBoot/pubkey.h>
#include <VasEBoot/env.h>
#include <VasEBoot/kernel.h>
#include <VasEBoot/extcmd.h>
#include <VasEBoot/verify.h>

VAS_EBOOT_MOD_LICENSE ("GPLv3+");

enum
  {
    OPTION_SKIP_SIG = 0
  };

static const struct VasEBoot_arg_option options[] =
  {
    {"skip-sig", 's', 0,
     N_("Skip signature-checking of the public key file."), 0, ARG_TYPE_NONE},
    {0, 0, 0, 0, 0, 0}
  };

static VasEBoot_err_t
read_packet_header (VasEBoot_file_t sig, VasEBoot_uint8_t *out_type, VasEBoot_size_t *len)
{
  VasEBoot_uint8_t type;
  VasEBoot_uint8_t l;
  VasEBoot_uint16_t l16;
  VasEBoot_uint32_t l32;

  /* New format.  */
  switch (VasEBoot_file_read (sig, &type, sizeof (type)))
    {
    case 1:
      break;
    case 0:
      {
	*out_type = 0xff;
	return 0;
      }
    default:
      if (VasEBoot_errno)
	return VasEBoot_errno;
      /* TRANSLATORS: it's about GNUPG signatures.  */
      return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
    }

  if (type == 0)
    {
      *out_type = 0xfe;
      return 0;
    }

  if (!(type & 0x80))
    return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
  if (type & 0x40)
    {
      *out_type = (type & 0x3f);
      if (VasEBoot_file_read (sig, &l, sizeof (l)) != 1)
	return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
      if (l < 192)
	{
	  *len = l;
	  return 0;
	}
      if (l < 224)
	{
	  *len = (l - 192) << VAS_EBOOT_CHAR_BIT;
	  if (VasEBoot_file_read (sig, &l, sizeof (l)) != 1)
	    return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
	  *len |= l;
	  return 0;
	}
      if (l == 255)
	{
	  if (VasEBoot_file_read (sig, &l32, sizeof (l32)) != sizeof (l32))
	    return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
	  *len = VasEBoot_be_to_cpu32 (l32);
	  return 0;
	}
      return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
    }
  *out_type = ((type >> 2) & 0xf);
  switch (type & 0x3)
    {
    case 0:
      if (VasEBoot_file_read (sig, &l, sizeof (l)) != sizeof (l))
	return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
      *len = l;
      return 0;
    case 1:
      if (VasEBoot_file_read (sig, &l16, sizeof (l16)) != sizeof (l16))
	return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
      *len = VasEBoot_be_to_cpu16 (l16);
      return 0;
    case 2:
      if (VasEBoot_file_read (sig, &l32, sizeof (l32)) != sizeof (l32))
	return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
      *len = VasEBoot_be_to_cpu32 (l32);
      return 0;
    }
  return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
}

struct signature_v4_header
{
  VasEBoot_uint8_t type;
  VasEBoot_uint8_t pkeyalgo;
  VasEBoot_uint8_t hash;
  VasEBoot_uint16_t hashed_sub;
} VAS_EBOOT_PACKED;

struct
{
  const char *name;
  const char *sigsexp;
  VasEBoot_size_t nmpisig;
  const char *pubsexp;
  VasEBoot_size_t nmpipub;
  struct gcry_pk_spec **algo;
  const char *padding;
  const char *module;
} pkalgos[] =
  {
    [1] = { "rsa", "(sig-val (rsa (s %M)))", 1, "(public-key (dsa (n %M) (e %M)))", 2, &VasEBoot_crypto_pk_rsa, "pkcs1", "gcry_rsa" },
    [3] = { "rsa", "(sig-val (rsa (s %M)))", 1, "(public-key (dsa (n %M) (e %M)))", 2, &VasEBoot_crypto_pk_rsa, "pkcs1", "gcry_rsa" },
    [17] = { "dsa", "(sig-val (dsa (r %M) (s %M)))", 2,
	     "(public-key (dsa (p %M) (q %M) (g %M) (y %M)))",
	     4, &VasEBoot_crypto_pk_dsa, "raw", "gcry_dsa" },
  };

struct VasEBoot_public_key
{
  struct VasEBoot_public_key *next;
  struct VasEBoot_public_subkey *subkeys;
};

struct VasEBoot_public_subkey
{
  struct VasEBoot_public_subkey *next;
  VasEBoot_uint8_t type;
  VasEBoot_uint32_t fingerprint[5];
  gcry_mpi_t mpis[10];
};

static void
free_pk (struct VasEBoot_public_key *pk)
{
  struct VasEBoot_public_subkey *nsk, *sk;
  for (sk = pk->subkeys; sk; sk = nsk)
    {
      VasEBoot_size_t i;
      for (i = 0; i < ARRAY_SIZE (sk->mpis); i++)
	if (sk->mpis[i])
	  _gcry_mpi_release (sk->mpis[i]);
      nsk = sk->next;
      VasEBoot_free (sk);
    }
  VasEBoot_free (pk);
}

#define READBUF_SIZE 4096

struct VasEBoot_public_key *
VasEBoot_load_public_key (VasEBoot_file_t f)
{
  VasEBoot_err_t err;
  struct VasEBoot_public_key *ret;
  struct VasEBoot_public_subkey **last = 0;
  void *fingerprint_context = NULL;
  VasEBoot_uint8_t *buffer = NULL;

  ret = VasEBoot_zalloc (sizeof (*ret));
  if (!ret)
    {
      VasEBoot_free (fingerprint_context);
      return NULL;
    }

  buffer = VasEBoot_zalloc (READBUF_SIZE);
  fingerprint_context = VasEBoot_zalloc (VAS_EBOOT_MD_SHA1->contextsize);

  if (!buffer || !fingerprint_context)
    goto fail;

  last = &ret->subkeys;

  while (1)
    {
      VasEBoot_uint8_t type;
      VasEBoot_size_t len;
      VasEBoot_uint8_t v, pk;
      VasEBoot_uint32_t creation_time;
      VasEBoot_off_t pend;
      struct VasEBoot_public_subkey *sk;
      VasEBoot_size_t i;
      VasEBoot_uint16_t len_be;

      err = read_packet_header (f, &type, &len);

      if (err)
	goto fail;
      if (type == 0xfe)
	continue;
      if (type == 0xff)
	{
	  VasEBoot_free (fingerprint_context);
	  VasEBoot_free (buffer);
	  return ret;
	}

      VasEBoot_dprintf ("crypt", "len = %x\n", (int) len);

      pend = VasEBoot_file_tell (f) + len;
      if (type != 6 && type != 14
	  && type != 5 && type != 7)
	{
	  VasEBoot_file_seek (f, pend);
	  continue;
	}

      if (VasEBoot_file_read (f, &v, sizeof (v)) != sizeof (v))
	{
	  VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
	  goto fail;
	}

      VasEBoot_dprintf ("crypt", "v = %x\n", v);

      if (v != 4)
	{
	  VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
	  goto fail;
	}
      if (VasEBoot_file_read (f, &creation_time, sizeof (creation_time)) != sizeof (creation_time))
	{
	  VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
	  goto fail;
	}

      VasEBoot_dprintf ("crypt", "time = %x\n", creation_time);

      if (VasEBoot_file_read (f, &pk, sizeof (pk)) != sizeof (pk))
	{
	  VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
	  goto fail;
	}

      VasEBoot_dprintf ("crypt", "pk = %x\n", pk);

      if (pk >= ARRAY_SIZE (pkalgos) || pkalgos[pk].name == NULL)
	{
	  VasEBoot_file_seek (f, pend);
	  continue;
	}

      sk = VasEBoot_zalloc (sizeof (struct VasEBoot_public_subkey));
      if (!sk)
	goto fail;

      VasEBoot_memset (fingerprint_context, 0, VAS_EBOOT_MD_SHA1->contextsize);
      VAS_EBOOT_MD_SHA1->init (fingerprint_context, 0);
      VAS_EBOOT_MD_SHA1->write (fingerprint_context, "\x99", 1);
      len_be = VasEBoot_cpu_to_be16 (len);
      VAS_EBOOT_MD_SHA1->write (fingerprint_context, &len_be, sizeof (len_be));
      VAS_EBOOT_MD_SHA1->write (fingerprint_context, &v, sizeof (v));
      VAS_EBOOT_MD_SHA1->write (fingerprint_context, &creation_time, sizeof (creation_time));
      VAS_EBOOT_MD_SHA1->write (fingerprint_context, &pk, sizeof (pk));

      for (i = 0; i < pkalgos[pk].nmpipub; i++)
	{
	  VasEBoot_uint16_t l;
	  VasEBoot_size_t lb;
	  if (VasEBoot_file_read (f, &l, sizeof (l)) != sizeof (l))
	    {
	      VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
	      break;
	    }

	  lb = (VasEBoot_be_to_cpu16 (l) + VAS_EBOOT_CHAR_BIT - 1) / VAS_EBOOT_CHAR_BIT;
	  if (lb > READBUF_SIZE - sizeof (VasEBoot_uint16_t))
	    {
	      VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
	      break;
	    }
	  if (VasEBoot_file_read (f, buffer + sizeof (VasEBoot_uint16_t), lb) != (VasEBoot_ssize_t) lb)
	    {
	      VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
	      break;
	    }
	  VasEBoot_memcpy (buffer, &l, sizeof (l));

	  VAS_EBOOT_MD_SHA1->write (fingerprint_context, buffer, lb + sizeof (VasEBoot_uint16_t));

	  if (_gcry_mpi_scan (&sk->mpis[i], GCRYMPI_FMT_PGP,
			     buffer, lb + sizeof (VasEBoot_uint16_t), 0))
	    {
	      VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
	      break;
	    }
	}

      if (i < pkalgos[pk].nmpipub)
	{
	  VasEBoot_free (sk);
	  goto fail;
	}

      VAS_EBOOT_MD_SHA1->final (fingerprint_context);

      VasEBoot_memcpy (sk->fingerprint, VAS_EBOOT_MD_SHA1->read (fingerprint_context), 20);

      *last = sk;
      last = &sk->next;

      VasEBoot_dprintf ("crypt", "actual pos: %x, expected: %x\n", (int)VasEBoot_file_tell (f), (int)pend);

      VasEBoot_file_seek (f, pend);
    }
 fail:
  free_pk (ret);
  VasEBoot_free (fingerprint_context);
  VasEBoot_free (buffer);
  return NULL;
}

struct VasEBoot_public_key *VasEBoot_pk_trusted;

struct VasEBoot_public_subkey *
VasEBoot_crypto_pk_locate_subkey (VasEBoot_uint64_t keyid, struct VasEBoot_public_key *pkey)
{
  struct VasEBoot_public_subkey *sk;
  for (sk = pkey->subkeys; sk; sk = sk->next)
    if (VasEBoot_memcmp (sk->fingerprint + 3, &keyid, 8) == 0)
      return sk;
  return 0;
}

struct VasEBoot_public_subkey *
VasEBoot_crypto_pk_locate_subkey_in_trustdb (VasEBoot_uint64_t keyid)
{
  struct VasEBoot_public_key *pkey;
  struct VasEBoot_public_subkey *sk;
  for (pkey = VasEBoot_pk_trusted; pkey; pkey = pkey->next)
    {
      sk = VasEBoot_crypto_pk_locate_subkey (keyid, pkey);
      if (sk)
	return sk;
    }
  return 0;
}

struct VasEBoot_pubkey_context
{
  VasEBoot_file_t sig;
  struct signature_v4_header v4;
  VasEBoot_uint8_t v;
  const gcry_md_spec_t *hash;
  void *hash_context;
};

static VasEBoot_err_t
VasEBoot_verify_signature_init (struct VasEBoot_pubkey_context *ctxt, VasEBoot_file_t sig)
{
  VasEBoot_size_t len;
  VasEBoot_uint8_t h;
  VasEBoot_uint8_t t;
  VasEBoot_uint8_t pk;
  VasEBoot_err_t err;
  VasEBoot_uint8_t type = 0;

  VasEBoot_memset (ctxt, 0, sizeof (*ctxt));

  err = read_packet_header (sig, &type, &len);
  if (err)
    return err;

  if (type != 0x2)
    return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));

  if (VasEBoot_file_read (sig, &ctxt->v, sizeof (ctxt->v)) != sizeof (ctxt->v))
    return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));

  if (ctxt->v != 4)
    return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));

  if (VasEBoot_file_read (sig, &ctxt->v4, sizeof (ctxt->v4)) != sizeof (ctxt->v4))
    return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));

  h = ctxt->v4.hash;
  t = ctxt->v4.type;
  pk = ctxt->v4.pkeyalgo;

  if (t != 0)
    return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));

  if (pk >= ARRAY_SIZE (pkalgos) || pkalgos[pk].name == NULL)
    return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));

  ctxt->hash = VasEBoot_crypto_lookup_md_by_algo (h);
  if (!ctxt->hash)
    return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, "hash `%d' not loaded", h);

  VasEBoot_dprintf ("crypt", "alive\n");

  ctxt->hash_context = VasEBoot_zalloc (ctxt->hash->contextsize);
  if (!ctxt->hash_context)
    return VasEBoot_errno;

  ctxt->hash->init (ctxt->hash_context, 0);
  ctxt->sig = sig;

  return VAS_EBOOT_ERR_NONE;
}

static VasEBoot_err_t
VasEBoot_pubkey_write (void *ctxt_, void *buf, VasEBoot_size_t size)
{
  struct VasEBoot_pubkey_context *ctxt = ctxt_;
  ctxt->hash->write (ctxt->hash_context, buf, size);
  return VAS_EBOOT_ERR_NONE;
}

static VasEBoot_err_t
VasEBoot_verify_signature_real (struct VasEBoot_pubkey_context *ctxt,
			    struct VasEBoot_public_key *pkey)
{
  gcry_mpi_t mpis[10];
  VasEBoot_uint8_t pk = ctxt->v4.pkeyalgo;
  VasEBoot_size_t i;
  VasEBoot_uint8_t *readbuf = NULL;
  unsigned char *hval;
  VasEBoot_ssize_t rem = VasEBoot_be_to_cpu16 (ctxt->v4.hashed_sub);
  VasEBoot_uint32_t headlen = VasEBoot_cpu_to_be32 (rem + 6);
  VasEBoot_uint8_t s;
  VasEBoot_uint16_t unhashed_sub;
  VasEBoot_ssize_t r;
  VasEBoot_uint8_t hash_start[2];
  VasEBoot_uint64_t keyid = 0;
  struct VasEBoot_public_subkey *sk;

  readbuf = VasEBoot_malloc (READBUF_SIZE);
  if (!readbuf)
    goto fail;

  ctxt->hash->write (ctxt->hash_context, &ctxt->v, sizeof (ctxt->v));
  ctxt->hash->write (ctxt->hash_context, &ctxt->v4, sizeof (ctxt->v4));
  while (rem)
    {
      r = VasEBoot_file_read (ctxt->sig, readbuf,
			  rem < READBUF_SIZE ? rem : READBUF_SIZE);
      if (r < 0)
	goto fail;
      if (r == 0)
	break;
      ctxt->hash->write (ctxt->hash_context, readbuf, r);
      rem -= r;
    }
  ctxt->hash->write (ctxt->hash_context, &ctxt->v, sizeof (ctxt->v));
  s = 0xff;
  ctxt->hash->write (ctxt->hash_context, &s, sizeof (s));
  ctxt->hash->write (ctxt->hash_context, &headlen, sizeof (headlen));
  r = VasEBoot_file_read (ctxt->sig, &unhashed_sub, sizeof (unhashed_sub));
  if (r != sizeof (unhashed_sub))
    goto fail;
  {
    VasEBoot_uint8_t *ptr;
    VasEBoot_uint32_t l;
    rem = VasEBoot_be_to_cpu16 (unhashed_sub);
    if (rem > READBUF_SIZE)
      goto fail;
    r = VasEBoot_file_read (ctxt->sig, readbuf, rem);
    if (r != rem)
      goto fail;
    for (ptr = readbuf; ptr < readbuf + rem; ptr += l)
      {
	if (*ptr < 192)
	  l = *ptr++;
	else if (*ptr < 255)
	  {
	    if (ptr + 1 >= readbuf + rem)
	      break;
	    l = (((ptr[0] & ~192) << VAS_EBOOT_CHAR_BIT) | ptr[1]) + 192;
	    ptr += 2;
	  }
	else
	  {
	    if (ptr + 5 >= readbuf + rem)
	      break;
	    l = VasEBoot_be_to_cpu32 (VasEBoot_get_unaligned32 (ptr + 1));
	    ptr += 5;
	  }
	if (*ptr == 0x10 && l >= 8)
	  keyid = VasEBoot_get_unaligned64 (ptr + 1);
      }
  }

  ctxt->hash->final (ctxt->hash_context);

  VasEBoot_dprintf ("crypt", "alive\n");

  hval = ctxt->hash->read (ctxt->hash_context);

  if (VasEBoot_file_read (ctxt->sig, hash_start, sizeof (hash_start)) != sizeof (hash_start))
    goto fail;
  if (VasEBoot_memcmp (hval, hash_start, sizeof (hash_start)) != 0)
    goto fail;

  VasEBoot_dprintf ("crypt", "@ %x\n", (int)VasEBoot_file_tell (ctxt->sig));

  for (i = 0; i < pkalgos[pk].nmpisig; i++)
    {
      VasEBoot_uint16_t l;
      VasEBoot_size_t lb;
      VasEBoot_dprintf ("crypt", "alive\n");
      if (VasEBoot_file_read (ctxt->sig, &l, sizeof (l)) != sizeof (l))
	goto fail;
      VasEBoot_dprintf ("crypt", "alive\n");
      lb = (VasEBoot_be_to_cpu16 (l) + 7) / 8;
      VasEBoot_dprintf ("crypt", "l = 0x%04x\n", VasEBoot_be_to_cpu16 (l));
      if (lb > READBUF_SIZE - sizeof (VasEBoot_uint16_t))
	goto fail;
      VasEBoot_dprintf ("crypt", "alive\n");
      if (VasEBoot_file_read (ctxt->sig, readbuf + sizeof (VasEBoot_uint16_t), lb) != (VasEBoot_ssize_t) lb)
	goto fail;
      VasEBoot_dprintf ("crypt", "alive\n");
      VasEBoot_memcpy (readbuf, &l, sizeof (l));
      VasEBoot_dprintf ("crypt", "alive\n");

      if (_gcry_mpi_scan (&mpis[i], GCRYMPI_FMT_PGP,
			 readbuf, lb + sizeof (VasEBoot_uint16_t), 0))
	goto fail;
      VasEBoot_dprintf ("crypt", "alive\n");
    }

  if (pkey)
    sk = VasEBoot_crypto_pk_locate_subkey (keyid, pkey);
  else
    sk = VasEBoot_crypto_pk_locate_subkey_in_trustdb (keyid);
  if (!sk)
    {
      /* TRANSLATORS: %08x is 32-bit key id.  */
      VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE,
		  N_("public key %08" PRIxVAS_EBOOT_UINT64_T " not found"), keyid);
      goto fail;
    }

  if (!*pkalgos[pk].algo)
    {
      VasEBoot_dl_load (pkalgos[pk].module);
      VasEBoot_errno = VAS_EBOOT_ERR_NONE;
    }

  if (!*pkalgos[pk].algo)
    {
      VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("module `%s' isn't loaded"),
		  pkalgos[pk].module);
      goto fail;
    }

  gcry_sexp_t hsexp, pubkey, sig;
  VasEBoot_size_t errof;

  if(_gcry_sexp_build(&hsexp, &errof, "(data (flags %s) (hash %s %b))", pkalgos[pk].padding, ctxt->hash->name, ctxt->hash->mdlen, hval))
    goto fail;

  if(_gcry_sexp_build(&pubkey, &errof, pkalgos[pk].pubsexp, sk->mpis[0], sk->mpis[1], sk->mpis[2], sk->mpis[3]))
    goto fail;

  if(_gcry_sexp_build(&sig, &errof, pkalgos[pk].sigsexp, mpis[0], mpis[1]))
    goto fail;

  _gcry_sexp_dump(sig);
  _gcry_sexp_dump(hsexp);
  _gcry_sexp_dump(pubkey);

  if ((*pkalgos[pk].algo)->verify (sig, hsexp, pubkey))
    goto fail;

  VasEBoot_free (readbuf);

  return VAS_EBOOT_ERR_NONE;

 fail:
  VasEBoot_free (readbuf);
  if (!VasEBoot_errno)
    return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("bad signature"));
  return VasEBoot_errno;
}

static void
VasEBoot_pubkey_close_real (struct VasEBoot_pubkey_context *ctxt)
{
  if (ctxt->sig)
    VasEBoot_file_close (ctxt->sig);
  if (ctxt->hash_context)
    VasEBoot_free (ctxt->hash_context);
}

static void
VasEBoot_pubkey_close (void *ctxt)
{
  VasEBoot_pubkey_close_real (ctxt);
  VasEBoot_free (ctxt);
}

VasEBoot_err_t
VasEBoot_verify_signature (VasEBoot_file_t f, const char *fsig,
		       struct VasEBoot_public_key *pkey)
{
  VasEBoot_file_t sig;
  VasEBoot_err_t err;
  struct VasEBoot_pubkey_context ctxt;
  VasEBoot_uint8_t *readbuf = NULL;

  sig = VasEBoot_file_open (fsig,
			VAS_EBOOT_FILE_TYPE_SIGNATURE
			| VAS_EBOOT_FILE_TYPE_NO_DECOMPRESS);
  if (!sig)
    return VasEBoot_errno;

  err = VasEBoot_verify_signature_init (&ctxt, sig);
  if (err)
    {
      VasEBoot_file_close (sig);
      return err;
    }

  readbuf = VasEBoot_zalloc (READBUF_SIZE);
  if (!readbuf)
    goto fail;

  while (1)
    {
      VasEBoot_ssize_t r;
      r = VasEBoot_file_read (f, readbuf, READBUF_SIZE);
      if (r < 0)
	goto fail;
      if (r == 0)
	break;
      err = VasEBoot_pubkey_write (&ctxt, readbuf, r);
      if (err)
	return err;
    }

  VasEBoot_verify_signature_real (&ctxt, pkey);
 fail:
  VasEBoot_pubkey_close_real (&ctxt);
  return VasEBoot_errno;
}

static VasEBoot_err_t
VasEBoot_cmd_trust (VasEBoot_extcmd_context_t ctxt,
		int argc, char **args)
{
  VasEBoot_file_t pkf;
  struct VasEBoot_public_key *pk = NULL;

  if (argc < 1)
    return VasEBoot_error (VAS_EBOOT_ERR_BAD_ARGUMENT, N_("one argument expected"));

  pkf = VasEBoot_file_open (args[0],
			VAS_EBOOT_FILE_TYPE_PUBLIC_KEY_TRUST
			| VAS_EBOOT_FILE_TYPE_NO_DECOMPRESS
			| (ctxt->state[OPTION_SKIP_SIG].set
			   ? VAS_EBOOT_FILE_TYPE_SKIP_SIGNATURE
			   : VAS_EBOOT_FILE_TYPE_NONE));
  if (!pkf)
    return VasEBoot_errno;
  pk = VasEBoot_load_public_key (pkf);
  if (!pk)
    {
      VasEBoot_file_close (pkf);
      return VasEBoot_errno;
    }
  VasEBoot_file_close (pkf);

  pk->next = VasEBoot_pk_trusted;
  VasEBoot_pk_trusted = pk;

  return VAS_EBOOT_ERR_NONE;
}

static VasEBoot_err_t
VasEBoot_cmd_list (VasEBoot_command_t cmd  __attribute__ ((unused)),
	       int argc __attribute__ ((unused)),
	       char **args __attribute__ ((unused)))
{
  struct VasEBoot_public_key *pk = NULL;
  struct VasEBoot_public_subkey *sk = NULL;

  for (pk = VasEBoot_pk_trusted; pk; pk = pk->next)
    for (sk = pk->subkeys; sk; sk = sk->next)
      {
	unsigned i;
	for (i = 0; i < 20; i += 2)
	  VasEBoot_printf ("%02x%02x ", ((VasEBoot_uint8_t *) sk->fingerprint)[i],
		       ((VasEBoot_uint8_t *) sk->fingerprint)[i + 1]);
	VasEBoot_printf ("\n");
      }

  return VAS_EBOOT_ERR_NONE;
}

static VasEBoot_err_t
VasEBoot_cmd_distrust (VasEBoot_command_t cmd  __attribute__ ((unused)),
		   int argc, char **args)
{
  VasEBoot_uint32_t keyid, keyid_be;
  struct VasEBoot_public_key **pkey;
  struct VasEBoot_public_subkey *sk;

  if (argc < 1)
    return VasEBoot_error (VAS_EBOOT_ERR_BAD_ARGUMENT, N_("one argument expected"));
  keyid = VasEBoot_strtoull (args[0], 0, 16);
  if (VasEBoot_errno)
    return VasEBoot_errno;
  keyid_be = VasEBoot_cpu_to_be32 (keyid);

  for (pkey = &VasEBoot_pk_trusted; *pkey; pkey = &((*pkey)->next))
    {
      struct VasEBoot_public_key *next;
      for (sk = (*pkey)->subkeys; sk; sk = sk->next)
	if (VasEBoot_memcmp (sk->fingerprint + 4, &keyid_be, 4) == 0)
	  break;
      if (!sk)
	continue;
      next = (*pkey)->next;
      free_pk (*pkey);
      *pkey = next;
      return VAS_EBOOT_ERR_NONE;
    }
  /* TRANSLATORS: %08x is 32-bit key id.  */
  return VasEBoot_error (VAS_EBOOT_ERR_BAD_SIGNATURE, N_("public key %08x not found"), keyid);
}

static VasEBoot_err_t
VasEBoot_cmd_verify_signature (VasEBoot_extcmd_context_t ctxt,
			   int argc, char **args)
{
  VasEBoot_file_t f = NULL;
  VasEBoot_err_t err = VAS_EBOOT_ERR_NONE;
  struct VasEBoot_public_key *pk = NULL;

  VasEBoot_dprintf ("crypt", "alive\n");

  if (argc < 2)
    return VasEBoot_error (VAS_EBOOT_ERR_BAD_ARGUMENT, N_("two arguments expected"));

  VasEBoot_dprintf ("crypt", "alive\n");

  if (argc > 2)
    {
      VasEBoot_file_t pkf;
      pkf = VasEBoot_file_open (args[2],
			    VAS_EBOOT_FILE_TYPE_PUBLIC_KEY
			    | VAS_EBOOT_FILE_TYPE_NO_DECOMPRESS
			    | (ctxt->state[OPTION_SKIP_SIG].set
			       ? VAS_EBOOT_FILE_TYPE_SKIP_SIGNATURE
			       : VAS_EBOOT_FILE_TYPE_NONE));
      if (!pkf)
	return VasEBoot_errno;
      pk = VasEBoot_load_public_key (pkf);
      if (!pk)
	{
	  VasEBoot_file_close (pkf);
	  return VasEBoot_errno;
	}
      VasEBoot_file_close (pkf);
    }

  f = VasEBoot_file_open (args[0], VAS_EBOOT_FILE_TYPE_VERIFY_SIGNATURE);
  if (!f)
    {
      err = VasEBoot_errno;
      goto fail;
    }

  err = VasEBoot_verify_signature (f, args[1], pk);
 fail:
  if (f)
    VasEBoot_file_close (f);
  if (pk)
    free_pk (pk);
  return err;
}

static int sec = 0;

static VasEBoot_err_t
VasEBoot_pubkey_init (VasEBoot_file_t io, enum VasEBoot_file_type type __attribute__ ((unused)),
		  void **context, enum VasEBoot_verify_flags *flags)
{
  VasEBoot_file_t sig;
  char *fsuf, *ptr;
  VasEBoot_err_t err;
  struct VasEBoot_pubkey_context *ctxt;

  if (!sec)
    {
      *flags = VAS_EBOOT_VERIFY_FLAGS_SKIP_VERIFICATION;
      return VAS_EBOOT_ERR_NONE;
    }

  fsuf = VasEBoot_malloc (VasEBoot_strlen (io->name) + sizeof (".sig"));
  if (!fsuf)
    return VasEBoot_errno;
  ptr = VasEBoot_stpcpy (fsuf, io->name);
  VasEBoot_memcpy (ptr, ".sig", sizeof (".sig"));

  sig = VasEBoot_file_open (fsuf, VAS_EBOOT_FILE_TYPE_SIGNATURE);
  VasEBoot_free (fsuf);
  if (!sig)
    return VasEBoot_errno;

  ctxt = VasEBoot_malloc (sizeof (*ctxt));
  if (!ctxt)
    {
      VasEBoot_file_close (sig);
      return VasEBoot_errno;
    }
  err = VasEBoot_verify_signature_init (ctxt, sig);
  if (err)
    {
      VasEBoot_free (ctxt);
      VasEBoot_file_close (sig);
      return err;
    }
  *context = ctxt;
  return VAS_EBOOT_ERR_NONE;
}

static VasEBoot_err_t
VasEBoot_pubkey_fini (void *ctxt)
{
  return VasEBoot_verify_signature_real (ctxt, NULL);
}

static char *
VasEBoot_env_write_sec (struct VasEBoot_env_var *var __attribute__ ((unused)),
		    const char *val)
{
  sec = (*val == '1') || (*val == 'e');
  return VasEBoot_strdup (sec ? "enforce" : "no");
}

static VasEBoot_ssize_t
pseudo_read (struct VasEBoot_file *file, char *buf, VasEBoot_size_t len)
{
  VasEBoot_memcpy (buf, (VasEBoot_uint8_t *) file->data + file->offset, len);
  return len;
}


/* Filesystem descriptor.  */
struct VasEBoot_fs pseudo_fs =
  {
    .name = "pseudo",
    .fs_read = pseudo_read
  };

struct VasEBoot_file_verifier VasEBoot_pubkey_verifier =
  {
    .name = "pgp",
    .init = VasEBoot_pubkey_init,
    .fini = VasEBoot_pubkey_fini,
    .write = VasEBoot_pubkey_write,
    .close = VasEBoot_pubkey_close,
  };

static VasEBoot_extcmd_t cmd, cmd_trust;
static VasEBoot_command_t cmd_distrust, cmd_list;

VAS_EBOOT_MOD_INIT(pgp)
{
  const char *val;
  struct VasEBoot_module_header *header;

  val = VasEBoot_env_get ("check_signatures");
  if (val && (val[0] == '1' || val[0] == 'e'))
    sec = 1;
  else
    sec = 0;

  VasEBoot_register_variable_hook ("check_signatures", 0, VasEBoot_env_write_sec);
  VasEBoot_env_export ("check_signatures");

  VasEBoot_pk_trusted = 0;
  FOR_MODULES (header)
  {
    struct VasEBoot_file pseudo_file;
    struct VasEBoot_public_key *pk = NULL;

    VasEBoot_memset (&pseudo_file, 0, sizeof (pseudo_file));

    /* Not an ELF module, skip.  */
    if (header->type != OBJ_TYPE_GPG_PUBKEY)
      continue;

    pseudo_file.fs = &pseudo_fs;
    pseudo_file.size = (header->size - sizeof (struct VasEBoot_module_header));
    pseudo_file.data = (char *) header + sizeof (struct VasEBoot_module_header);

    pk = VasEBoot_load_public_key (&pseudo_file);
    if (!pk)
      VasEBoot_fatal ("error loading initial key: %s\n", VasEBoot_errmsg);

    pk->next = VasEBoot_pk_trusted;
    VasEBoot_pk_trusted = pk;
  }

  if (!val)
    VasEBoot_env_set ("check_signatures", VasEBoot_pk_trusted ? "enforce" : "no");

  cmd = VasEBoot_register_extcmd ("verify_detached", VasEBoot_cmd_verify_signature, 0,
			      N_("[-s|--skip-sig] FILE SIGNATURE_FILE [PUBKEY_FILE]"),
			      N_("Verify detached signature."),
			      options);
  cmd_trust = VasEBoot_register_extcmd ("trust", VasEBoot_cmd_trust, 0,
				     N_("[-s|--skip-sig] PUBKEY_FILE"),
				     N_("Add PUBKEY_FILE to trusted keys."),
				     options);
  cmd_list = VasEBoot_register_command ("list_trusted", VasEBoot_cmd_list,
				    0,
				    N_("Show the list of trusted keys."));
  cmd_distrust = VasEBoot_register_command ("distrust", VasEBoot_cmd_distrust,
					N_("PUBKEY_ID"),
					N_("Remove PUBKEY_ID from trusted keys."));

  VasEBoot_verifier_register (&VasEBoot_pubkey_verifier);
}

VAS_EBOOT_MOD_FINI(pgp)
{
  VasEBoot_register_variable_hook ("check_signatures", NULL, NULL);
  VasEBoot_env_unset ("check_signatures");
  VasEBoot_verifier_unregister (&VasEBoot_pubkey_verifier);
  VasEBoot_unregister_extcmd (cmd);
  VasEBoot_unregister_extcmd (cmd_trust);
  VasEBoot_unregister_command (cmd_list);
  VasEBoot_unregister_command (cmd_distrust);
}