Adding upstream version 2.2.40.upstream/2.2.40upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 643 insertions, 0 deletions

diff --git a/kbx/keybox-openpgp.c b/kbx/keybox-openpgp.c
new file mode 100644
index 0000000..8ded683
--- /dev/null
+++ b/kbx/keybox-openpgp.c
@@ -0,0 +1,643 @@
+/* keybox-openpgp.c - OpenPGP key parsing
+ * Copyright (C) 2001, 2003, 2011 Free Software Foundation, Inc.
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG 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.
+ *
+ * GnuPG 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, see <https://www.gnu.org/licenses/>.
+ */
+
+/* This is a simple OpenPGP parser suitable for all OpenPGP key
+   material.  It just provides the functionality required to build and
+   parse an KBX OpenPGP key blob.  Thus it is not a complete parser.
+   However it is self-contained and optimized for fast in-memory
+   parsing.  Note that we don't support old ElGamal v3 keys
+   anymore. */
+
+#include <config.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+
+#include "keybox-defs.h"
+
+#include <gcrypt.h>
+
+#include "../common/openpgpdefs.h"
+#include "../common/host2net.h"
+
+struct keyparm_s
+{
+  const char *mpi;
+  int len;   /* int to avoid a cast in gcry_sexp_build.  */
+};
+
+
+/* Assume a valid OpenPGP packet at the address pointed to by BUFBTR
+   which has a maximum length as stored at BUFLEN.  Return the header
+   information of that packet and advance the pointer stored at BUFPTR
+   to the next packet; also adjust the length stored at BUFLEN to
+   match the remaining bytes. If there are no more packets, store NULL
+   at BUFPTR.  Return an non-zero error code on failure or the
+   following data on success:
+
+   R_DATAPKT = Pointer to the begin of the packet data.
+   R_DATALEN = Length of this data.  This has already been checked to fit
+               into the buffer.
+   R_PKTTYPE = The packet type.
+   R_NTOTAL  = The total number of bytes of this packet
+
+   Note that these values are only updated on success.
+*/
+static gpg_error_t
+next_packet (unsigned char const **bufptr, size_t *buflen,
+             unsigned char const **r_data, size_t *r_datalen, int *r_pkttype,
+             size_t *r_ntotal)
+{
+  const unsigned char *buf = *bufptr;
+  size_t len = *buflen;
+  int c, ctb, pkttype;
+  unsigned long pktlen;
+
+  if (!len)
+    return gpg_error (GPG_ERR_NO_DATA);
+
+  ctb = *buf++; len--;
+  if ( !(ctb & 0x80) )
+    return gpg_error (GPG_ERR_INV_PACKET); /* Invalid CTB. */
+
+  if ((ctb & 0x40))  /* New style (OpenPGP) CTB.  */
+    {
+      pkttype = (ctb & 0x3f);
+      if (!len)
+        return gpg_error (GPG_ERR_INV_PACKET); /* No 1st length byte. */
+      c = *buf++; len--;
+      if (pkttype == PKT_COMPRESSED)
+        return gpg_error (GPG_ERR_UNEXPECTED); /* ... packet in a keyblock. */
+      if ( c < 192 )
+        pktlen = c;
+      else if ( c < 224 )
+        {
+          pktlen = (c - 192) * 256;
+          if (!len)
+            return gpg_error (GPG_ERR_INV_PACKET); /* No 2nd length byte. */
+          c = *buf++; len--;
+          pktlen += c + 192;
+        }
+      else if (c == 255)
+        {
+          if (len <4 )
+            return gpg_error (GPG_ERR_INV_PACKET); /* No length bytes. */
+          pktlen = buf32_to_ulong (buf);
+          buf += 4;
+          len -= 4;
+      }
+      else /* Partial length encoding is not allowed for key packets. */
+        return gpg_error (GPG_ERR_UNEXPECTED);
+    }
+  else /* Old style CTB.  */
+    {
+      int lenbytes;
+
+      pktlen = 0;
+      pkttype = (ctb>>2)&0xf;
+      lenbytes = ((ctb&3)==3)? 0 : (1<<(ctb & 3));
+      if (!lenbytes) /* Not allowed in key packets.  */
+        return gpg_error (GPG_ERR_UNEXPECTED);
+      if (len < lenbytes)
+        return gpg_error (GPG_ERR_INV_PACKET); /* Not enough length bytes.  */
+      for (; lenbytes; lenbytes--)
+        {
+          pktlen <<= 8;
+          pktlen |= *buf++; len--;
+	}
+    }
+
+  /* Do some basic sanity check.  */
+  switch (pkttype)
+    {
+    case PKT_SIGNATURE:
+    case PKT_SECRET_KEY:
+    case PKT_PUBLIC_KEY:
+    case PKT_SECRET_SUBKEY:
+    case PKT_MARKER:
+    case PKT_RING_TRUST:
+    case PKT_USER_ID:
+    case PKT_PUBLIC_SUBKEY:
+    case PKT_OLD_COMMENT:
+    case PKT_ATTRIBUTE:
+    case PKT_COMMENT:
+    case PKT_GPG_CONTROL:
+      break; /* Okay these are allowed packets. */
+    default:
+      return gpg_error (GPG_ERR_UNEXPECTED);
+    }
+
+  if (pkttype == 63 && pktlen == 0xFFFFFFFF)
+    /* Sometimes the decompressing layer enters an error state in
+       which it simply outputs 0xff for every byte read.  If we have a
+       stream of 0xff bytes, then it will be detected as a new format
+       packet with type 63 and a 4-byte encoded length that is 4G-1.
+       Since packets with type 63 are private and we use them as a
+       control packet, which won't be 4 GB, we reject such packets as
+       invalid.  */
+    return gpg_error (GPG_ERR_INV_PACKET);
+
+  if (pktlen > len)
+    return gpg_error (GPG_ERR_INV_PACKET); /* Packet length header too long. */
+
+  *r_data = buf;
+  *r_datalen = pktlen;
+  *r_pkttype = pkttype;
+  *r_ntotal = (buf - *bufptr) + pktlen;
+
+  *bufptr = buf + pktlen;
+  *buflen = len - pktlen;
+  if (!*buflen)
+    *bufptr = NULL;
+
+  return 0;
+}
+
+
+/* Take a list of key parameters KP for the OpenPGP ALGO and compute
+ * the keygrip which will be stored at GRIP.  GRIP needs to be a
+ * buffer of 20 bytes.  */
+static gpg_error_t
+keygrip_from_keyparm (int algo, struct keyparm_s *kp, unsigned char *grip)
+{
+  gpg_error_t err;
+  gcry_sexp_t s_pkey = NULL;
+
+  switch (algo)
+    {
+    case PUBKEY_ALGO_DSA:
+      err = gcry_sexp_build (&s_pkey, NULL,
+                             "(public-key(dsa(p%b)(q%b)(g%b)(y%b)))",
+                             kp[0].len, kp[0].mpi,
+                             kp[1].len, kp[1].mpi,
+                             kp[2].len, kp[2].mpi,
+                             kp[3].len, kp[3].mpi);
+      break;
+
+    case PUBKEY_ALGO_ELGAMAL:
+    case PUBKEY_ALGO_ELGAMAL_E:
+      err = gcry_sexp_build (&s_pkey, NULL,
+                             "(public-key(elg(p%b)(g%b)(y%b)))",
+                             kp[0].len, kp[0].mpi,
+                             kp[1].len, kp[1].mpi,
+                             kp[2].len, kp[2].mpi);
+      break;
+
+    case PUBKEY_ALGO_RSA:
+    case PUBKEY_ALGO_RSA_S:
+    case PUBKEY_ALGO_RSA_E:
+      err = gcry_sexp_build (&s_pkey, NULL,
+                             "(public-key(rsa(n%b)(e%b)))",
+                             kp[0].len, kp[0].mpi,
+                             kp[1].len, kp[1].mpi);
+      break;
+
+    case PUBKEY_ALGO_EDDSA:
+    case PUBKEY_ALGO_ECDSA:
+    case PUBKEY_ALGO_ECDH:
+      {
+        char *curve = openpgp_oidbuf_to_str (kp[0].mpi, kp[0].len);
+        if (!curve)
+          err = gpg_error_from_syserror ();
+        else
+          {
+            err = gcry_sexp_build
+              (&s_pkey, NULL,
+               (algo == PUBKEY_ALGO_EDDSA)?
+               "(public-key(ecc(curve%s)(flags eddsa)(q%b)))":
+               (algo == PUBKEY_ALGO_ECDH
+                && openpgp_oidbuf_is_cv25519 (kp[0].mpi, kp[0].len))?
+               "(public-key(ecc(curve%s)(flags djb-tweak)(q%b)))":
+               "(public-key(ecc(curve%s)(q%b)))",
+               curve, kp[1].len, kp[1].mpi);
+            xfree (curve);
+          }
+      }
+      break;
+
+    default:
+      err = gpg_error (GPG_ERR_PUBKEY_ALGO);
+      break;
+    }
+
+  if (!err && !gcry_pk_get_keygrip (s_pkey, grip))
+    {
+      /* Some Linux distributions remove certain curves from Libgcrypt
+       * but not from GnuPG and thus the keygrip can't be computed.
+       * Emit a better error message for this case.  */
+      if (!gcry_pk_get_curve (s_pkey, 0, NULL))
+        err = gpg_error (GPG_ERR_UNKNOWN_CURVE);
+      else
+        {
+          log_info ("kbx: error computing keygrip\n");
+          err = gpg_error (GPG_ERR_GENERAL);
+        }
+    }
+
+  gcry_sexp_release (s_pkey);
+
+  if (err)
+    memset (grip, 0, 20);
+  return err;
+}
+
+
+/* Parse a key packet and store the information in KI. */
+static gpg_error_t
+parse_key (const unsigned char *data, size_t datalen,
+           struct _keybox_openpgp_key_info *ki)
+{
+  gpg_error_t err;
+  const unsigned char *data_start = data;
+  int i, version, algorithm;
+  size_t n;
+  int npkey;
+  unsigned char hashbuffer[768];
+  gcry_md_hd_t md;
+  int is_ecc = 0;
+  struct keyparm_s keyparm[OPENPGP_MAX_NPKEY];
+  unsigned char *helpmpibuf[OPENPGP_MAX_NPKEY] = { NULL };
+
+  if (datalen < 5)
+    return gpg_error (GPG_ERR_INV_PACKET);
+  version = *data++; datalen--;
+  if (version < 2 || version > 4 )
+    return gpg_error (GPG_ERR_INV_PACKET); /* Invalid version. */
+
+  /*timestamp = ((data[0]<<24)|(data[1]<<16)|(data[2]<<8)|(data[3]));*/
+  data +=4; datalen -=4;
+
+  if (version < 4)
+    {
+      if (datalen < 2)
+        return gpg_error (GPG_ERR_INV_PACKET);
+      data +=2; datalen -= 2;
+    }
+
+  if (!datalen)
+    return gpg_error (GPG_ERR_INV_PACKET);
+  algorithm = *data++; datalen--;
+
+  switch (algorithm)
+    {
+    case PUBKEY_ALGO_RSA:
+    case PUBKEY_ALGO_RSA_E:
+    case PUBKEY_ALGO_RSA_S:
+      npkey = 2;
+      break;
+    case PUBKEY_ALGO_ELGAMAL_E:
+    case PUBKEY_ALGO_ELGAMAL:
+      npkey = 3;
+      break;
+    case PUBKEY_ALGO_DSA:
+      npkey = 4;
+      break;
+    case PUBKEY_ALGO_ECDH:
+      npkey = 3;
+      is_ecc = 1;
+      break;
+    case PUBKEY_ALGO_ECDSA:
+    case PUBKEY_ALGO_EDDSA:
+      npkey = 2;
+      is_ecc = 1;
+      break;
+    default: /* Unknown algorithm. */
+      return gpg_error (GPG_ERR_UNKNOWN_ALGORITHM);
+    }
+
+  ki->algo = algorithm;
+
+  for (i=0; i < npkey; i++ )
+    {
+      unsigned int nbits, nbytes;
+
+      if (datalen < 2)
+        return gpg_error (GPG_ERR_INV_PACKET);
+
+      if (is_ecc && (i == 0 || i == 2))
+        {
+          nbytes = data[0];
+          if (nbytes < 2 || nbytes > 254)
+            return gpg_error (GPG_ERR_INV_PACKET);
+          nbytes++; /* The size byte itself.  */
+          if (datalen < nbytes)
+            return gpg_error (GPG_ERR_INV_PACKET);
+
+          keyparm[i].mpi = data;
+          keyparm[i].len = nbytes;
+        }
+      else
+        {
+          nbits = ((data[0]<<8)|(data[1]));
+          data += 2;
+          datalen -= 2;
+          nbytes = (nbits+7) / 8;
+          if (datalen < nbytes)
+            return gpg_error (GPG_ERR_INV_PACKET);
+
+          keyparm[i].mpi = data;
+          keyparm[i].len = nbytes;
+        }
+
+      data += nbytes; datalen -= nbytes;
+    }
+  n = data - data_start;
+
+
+  /* Note: Starting here we need to jump to leave on error. */
+
+  /* Make sure the MPIs are unsigned.  */
+  for (i=0; i < npkey; i++)
+    {
+      if (!keyparm[i].len || (keyparm[i].mpi[0] & 0x80))
+        {
+          helpmpibuf[i] = xtrymalloc (1+keyparm[i].len);
+          if (!helpmpibuf[i])
+            {
+              err = gpg_error_from_syserror ();
+              goto leave;
+            }
+          helpmpibuf[i][0] = 0;
+          memcpy (helpmpibuf[i]+1, keyparm[i].mpi, keyparm[i].len);
+          keyparm[i].mpi = helpmpibuf[i];
+          keyparm[i].len++;
+        }
+    }
+
+  err = keygrip_from_keyparm (algorithm, keyparm, ki->grip);
+  if (err)
+    goto leave;
+
+  if (version < 4)
+    {
+      /* We do not support any other algorithm than RSA in v3
+         packets. */
+      if (algorithm < 1 || algorithm > 3)
+        return gpg_error (GPG_ERR_UNSUPPORTED_ALGORITHM);
+
+      err = gcry_md_open (&md, GCRY_MD_MD5, 0);
+      if (err)
+        return err; /* Oops */
+      gcry_md_write (md, keyparm[0].mpi, keyparm[0].len);
+      gcry_md_write (md, keyparm[1].mpi, keyparm[1].len);
+      memcpy (ki->fpr, gcry_md_read (md, 0), 16);
+      gcry_md_close (md);
+      ki->fprlen = 16;
+
+      if (keyparm[0].len < 8)
+        {
+          /* Moduli less than 64 bit are out of the specs scope.  Zero
+             them out because this is what gpg does too. */
+          memset (ki->keyid, 0, 8);
+        }
+      else
+        memcpy (ki->keyid, keyparm[0].mpi + keyparm[0].len - 8, 8);
+    }
+  else
+    {
+      /* Its a pity that we need to prefix the buffer with the tag
+         and a length header: We can't simply pass it to the fast
+         hashing function for that reason.  It might be a good idea to
+         have a scatter-gather enabled hash function. What we do here
+         is to use a static buffer if this one is large enough and
+         only use the regular hash functions if this buffer is not
+         large enough. */
+      if ( 3 + n < sizeof hashbuffer )
+        {
+          hashbuffer[0] = 0x99;     /* CTB */
+          hashbuffer[1] = (n >> 8); /* 2 byte length header. */
+          hashbuffer[2] = n;
+          memcpy (hashbuffer + 3, data_start, n);
+          gcry_md_hash_buffer (GCRY_MD_SHA1, ki->fpr, hashbuffer, 3 + n);
+        }
+      else
+        {
+          err = gcry_md_open (&md, GCRY_MD_SHA1, 0);
+          if (err)
+            return err; /* Oops */
+          gcry_md_putc (md, 0x99 );     /* CTB */
+          gcry_md_putc (md, (n >> 8) ); /* 2 byte length header. */
+          gcry_md_putc (md, n );
+          gcry_md_write (md, data_start, n);
+          memcpy (ki->fpr, gcry_md_read (md, 0), 20);
+          gcry_md_close (md);
+        }
+      ki->fprlen = 20;
+      memcpy (ki->keyid, ki->fpr+12, 8);
+    }
+
+ leave:
+  for (i=0; i < npkey; i++)
+    xfree (helpmpibuf[i]);
+
+  return err;
+}
+
+
+
+/* The caller must pass the address of an INFO structure which will
+   get filled on success with information pertaining to the OpenPGP
+   keyblock IMAGE of length IMAGELEN.  Note that a caller does only
+   need to release this INFO structure if the function returns
+   success.  If NPARSED is not NULL the actual number of bytes parsed
+   will be stored at this address.  */
+gpg_error_t
+_keybox_parse_openpgp (const unsigned char *image, size_t imagelen,
+                       size_t *nparsed, keybox_openpgp_info_t info)
+{
+  gpg_error_t err = 0;
+  const unsigned char *image_start, *data;
+  size_t n, datalen;
+  int pkttype;
+  int first = 1;
+  int read_error = 0;
+  struct _keybox_openpgp_key_info *k, **ktail = NULL;
+  struct _keybox_openpgp_uid_info *u, **utail = NULL;
+
+  memset (info, 0, sizeof *info);
+  if (nparsed)
+    *nparsed = 0;
+
+  image_start = image;
+  while (image)
+    {
+      err = next_packet (&image, &imagelen, &data, &datalen, &pkttype, &n);
+      if (err)
+        {
+          read_error = 1;
+          break;
+        }
+
+      if (first)
+        {
+          if (pkttype == PKT_PUBLIC_KEY)
+            ;
+          else if (pkttype == PKT_SECRET_KEY)
+            info->is_secret = 1;
+          else
+            {
+              err = gpg_error (GPG_ERR_UNEXPECTED);
+              if (nparsed)
+                *nparsed += n;
+              break;
+            }
+          first = 0;
+        }
+      else if (pkttype == PKT_PUBLIC_KEY || pkttype == PKT_SECRET_KEY)
+        break; /* Next keyblock encountered - ready. */
+
+      if (nparsed)
+        *nparsed += n;
+
+      if (pkttype == PKT_SIGNATURE)
+        {
+          /* For now we only count the total number of signatures. */
+          info->nsigs++;
+        }
+      else if (pkttype == PKT_USER_ID)
+        {
+          info->nuids++;
+          if (info->nuids == 1)
+            {
+              info->uids.off = data - image_start;
+              info->uids.len = datalen;
+              utail = &info->uids.next;
+            }
+          else
+            {
+              u = xtrycalloc (1, sizeof *u);
+              if (!u)
+                {
+                  err = gpg_error_from_syserror ();
+                  break;
+                }
+              u->off = data - image_start;
+              u->len = datalen;
+              *utail = u;
+              utail = &u->next;
+            }
+        }
+      else if (pkttype == PKT_PUBLIC_KEY || pkttype == PKT_SECRET_KEY)
+        {
+          err = parse_key (data, datalen, &info->primary);
+          if (err)
+            break;
+        }
+      else if( pkttype == PKT_PUBLIC_SUBKEY && datalen && *data == '#' )
+        {
+          /* Early versions of GnuPG used old PGP comment packets;
+           * luckily all those comments are prefixed by a hash
+           * sign - ignore these packets. */
+        }
+      else if (pkttype == PKT_PUBLIC_SUBKEY || pkttype == PKT_SECRET_SUBKEY)
+        {
+          info->nsubkeys++;
+          if (info->nsubkeys == 1)
+            {
+              err = parse_key (data, datalen, &info->subkeys);
+              if (err)
+                {
+                  info->nsubkeys--;
+                  /* We ignore subkeys with unknown algorithms. */
+                  if (gpg_err_code (err) == GPG_ERR_UNKNOWN_ALGORITHM
+                      || gpg_err_code (err) == GPG_ERR_UNSUPPORTED_ALGORITHM)
+                    err = 0;
+                  if (err)
+                    break;
+                }
+              else
+                ktail = &info->subkeys.next;
+            }
+          else
+            {
+              k = xtrycalloc (1, sizeof *k);
+              if (!k)
+                {
+                  err = gpg_error_from_syserror ();
+                  break;
+                }
+              err = parse_key (data, datalen, k);
+              if (err)
+                {
+                  xfree (k);
+                  info->nsubkeys--;
+                  /* We ignore subkeys with unknown algorithms. */
+                  if (gpg_err_code (err) == GPG_ERR_UNKNOWN_ALGORITHM
+                      || gpg_err_code (err) == GPG_ERR_UNSUPPORTED_ALGORITHM)
+                    err = 0;
+                  if (err)
+                    break;
+                }
+              else
+                {
+                  *ktail = k;
+                  ktail = &k->next;
+                }
+            }
+        }
+    }
+
+  if (err)
+    {
+      _keybox_destroy_openpgp_info (info);
+      if (!read_error)
+        {
+          /* Packet parsing worked, thus we should be able to skip the
+             rest of the keyblock.  */
+          while (image)
+            {
+              if (next_packet (&image, &imagelen,
+                               &data, &datalen, &pkttype, &n) )
+                break; /* Another error - stop here. */
+
+              if (pkttype == PKT_PUBLIC_KEY || pkttype == PKT_SECRET_KEY)
+                break; /* Next keyblock encountered - ready. */
+
+              if (nparsed)
+                *nparsed += n;
+            }
+        }
+    }
+
+  return err;
+}
+
+
+/* Release any malloced data in INFO but not INFO itself! */
+void
+_keybox_destroy_openpgp_info (keybox_openpgp_info_t info)
+{
+  struct _keybox_openpgp_key_info *k, *k2;
+  struct _keybox_openpgp_uid_info *u, *u2;
+
+  assert (!info->primary.next);
+  for (k=info->subkeys.next; k; k = k2)
+    {
+      k2 = k->next;
+      xfree (k);
+    }
+
+  for (u=info->uids.next; u; u = u2)
+    {
+      u2 = u->next;
+      xfree (u);
+    }
+}