* Import keyanalyze into signing-party. Thanks to Matthew Wilcox for the

[pgp-tools.git] / keyanalyze / pgpring / pgppacket.c

diff --git a/keyanalyze/pgpring/pgppacket.c b/keyanalyze/pgpring/pgppacket.c
new file mode 100644 (file)
index 0000000..1e6b857
--- /dev/null
+++ b/keyanalyze/pgpring/pgppacket.c
@@ -0,0 +1,225 @@
+/*
+ * Copyright (C) 2001 Thomas Roessler <roessler@does-not-exist.org>
+ * 
+ * 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 of
+ * the License, 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., 59 Temple Place - Suite 330, Boston,
+ * MA 02111, USA.
+ */
+
+#include "config.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <time.h>
+
+#include "sha1.h"
+#include "lib.h"
+#include "pgplib.h"
+#include "pgppacket.h"
+
+#define CHUNKSIZE 1024
+
+static unsigned char *pbuf = NULL;
+static size_t plen = 0;
+
+static int read_material (size_t material, size_t * used, FILE * fp)
+{
+  if (*used + material >= plen)
+  {
+    unsigned char *p;
+    size_t nplen;
+
+    nplen = *used + material + CHUNKSIZE;
+
+    if (!(p = realloc (pbuf, nplen)))  /* __MEM_CHECKED__ */
+    {
+      perror ("realloc");
+      return -1;
+    }
+    plen = nplen;
+    pbuf = p;
+  }
+
+  if (fread (pbuf + *used, 1, material, fp) < material)
+  {
+    perror ("fread");
+    return -1;
+  }
+
+  *used += material;
+  return 0;
+}
+
+unsigned char *pgp_read_packet (FILE * fp, size_t * len)
+{
+  size_t used = 0;
+  long startpos;
+  unsigned char ctb;
+  unsigned char b;
+  size_t material;
+
+  startpos = ftell (fp);
+
+  if (!plen)
+  {
+    plen = CHUNKSIZE;
+    pbuf = safe_malloc (plen);
+  }
+
+  if (fread (&ctb, 1, 1, fp) < 1)
+  {
+    if (!feof (fp))
+      perror ("fread");
+    goto bail;
+  }
+
+  if (!(ctb & 0x80))
+  {
+    goto bail;
+  }
+
+  if (ctb & 0x40)              /* handle PGP 5.0 packets. */
+  {
+    int partial = 0;
+    pbuf[0] = ctb;
+    used++;
+
+    do
+    {
+      if (fread (&b, 1, 1, fp) < 1)
+      {
+       perror ("fread");
+       goto bail;
+      }
+
+      if (b < 192)
+      {
+       material = b;
+       partial = 0;
+       /* material -= 1; */
+      }
+      else if (192 <= b && b <= 223)
+      {
+       material = (b - 192) * 256;
+       if (fread (&b, 1, 1, fp) < 1)
+       {
+         perror ("fread");
+         goto bail;
+       }
+       material += b + 192;
+       partial = 0;
+       /* material -= 2; */
+      }
+      else if (b < 255)
+      {
+       material = 1 << (b & 0x1f);
+       partial = 1;
+       /* material -= 1; */
+      }
+      else
+       /* b == 255 */
+      {
+       unsigned char buf[4];
+       if (fread (buf, 4, 1, fp) < 1)
+       {
+         perror ("fread");
+         goto bail;
+       }
+       /*assert( sizeof(material) >= 4 ); */
+       material = buf[0] << 24;
+       material |= buf[1] << 16;
+       material |= buf[2] << 8;
+       material |= buf[3];
+       partial = 0;
+       /* material -= 5; */
+      }
+
+      if (read_material (material, &used, fp) == -1)
+       goto bail;
+
+    }
+    while (partial);
+  }
+  else
+    /* Old-Style PGP */
+  {
+    int bytes = 0;
+    pbuf[0] = 0x80 | ((ctb >> 2) & 0x0f);
+    used++;
+
+    switch (ctb & 0x03)
+    {
+      case 0:
+      {
+       if (fread (&b, 1, 1, fp) < 1)
+       {
+         perror ("fread");
+         goto bail;
+       }
+
+       material = b;
+       break;
+      }
+
+      case 1:
+      bytes = 2;
+
+      case 2:
+      {
+       int i;
+
+       if (!bytes)
+         bytes = 4;
+
+       material = 0;
+
+       for (i = 0; i < bytes; i++)
+       {
+         if (fread (&b, 1, 1, fp) < 1)
+         {
+           perror ("fread");
+           goto bail;
+         }
+
+         material = (material << 8) + b;
+       }
+       break;
+      }
+
+      default:
+      goto bail;
+    }
+
+    if (read_material (material, &used, fp) == -1)
+      goto bail;
+  }
+
+  if (len)
+    *len = used;
+
+  return pbuf;
+
+bail:
+
+  fseek (fp, startpos, SEEK_SET);
+  return NULL;
+}
+
+void pgp_release_packet (void)
+{
+  plen = 0;
+  safe_free (&pbuf);
+}
+