Adding upstream version 2.2.40.upstream/2.2.40upstream

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

1 files changed, 777 insertions, 0 deletions

diff --git a/tools/mime-maker.c b/tools/mime-maker.c
new file mode 100644
index 0000000..91eab82
--- /dev/null
+++ b/tools/mime-maker.c
@@ -0,0 +1,777 @@
+/* mime-maker.c - Create MIME structures
+ * Copyright (C) 2016 g10 Code GmbH
+ * Copyright (C) 2016 Bundesamt für Sicherheit in der Informationstechnik
+ *
+ * This file is part of GnuPG.
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This file 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "../common/util.h"
+#include "../common/zb32.h"
+#include "rfc822parse.h"
+#include "mime-maker.h"
+
+
+/* An object to store an header.  Also used for a list of headers.  */
+struct header_s
+{
+  struct header_s *next;
+  char *value;   /* Malloced value.  */
+  char name[1]; /* Name.  */
+};
+typedef struct header_s *header_t;
+
+
+/* An object to store a MIME part.  A part is the header plus the
+ * content (body). */
+struct part_s
+{
+  struct part_s *next;  /* Next part in the current container.  */
+  struct part_s *child; /* Child container.  */
+  char *boundary;       /* Malloced boundary string.  */
+  header_t headers;     /* List of headers.  */
+  header_t *headers_tail;/* Address of last header in chain.  */
+  size_t bodylen;       /* Length of BODY.   */
+  char *body;           /* Malloced buffer with the body.  This is the
+                         * non-encoded value.  */
+  unsigned int partid;   /* The part ID.  */
+};
+typedef struct part_s *part_t;
+
+
+
+/* Definition of the mime parser object.  */
+struct mime_maker_context_s
+{
+  void *cookie;                /* Cookie passed to all callbacks.  */
+
+  unsigned int verbose:1;      /* Enable verbose mode.  */
+  unsigned int debug:1;        /* Enable debug mode.  */
+
+  part_t mail;                 /* The MIME tree.  */
+  part_t current_part;
+
+  unsigned int partid_counter; /* Counter assign part ids.  */
+
+  int boundary_counter;  /* Used to create easy to read boundaries.  */
+  char *boundary_suffix; /* Random string used in the boundaries.  */
+
+  struct b64state *b64state;     /* NULL or malloced Base64 decoder state.  */
+
+  /* Helper to convey the output stream to recursive functions. */
+  estream_t outfp;
+};
+
+
+/* Create a new mime make object.  COOKIE is a values woich will be
+ * used as first argument for all callbacks registered with this
+ * object.  */
+gpg_error_t
+mime_maker_new (mime_maker_t *r_maker, void *cookie)
+{
+  mime_maker_t ctx;
+
+  *r_maker = NULL;
+
+  ctx = xtrycalloc (1, sizeof *ctx);
+  if (!ctx)
+    return gpg_error_from_syserror ();
+  ctx->cookie = cookie;
+
+  *r_maker = ctx;
+  return 0;
+}
+
+
+static void
+release_parts (part_t part)
+{
+  while (part)
+    {
+      part_t partnext = part->next;
+      while (part->headers)
+        {
+          header_t hdrnext = part->headers->next;
+          xfree (part->headers);
+          part->headers = hdrnext;
+        }
+      release_parts (part->child);
+      xfree (part->boundary);
+      xfree (part->body);
+      xfree (part);
+      part = partnext;
+    }
+}
+
+
+/* Release a mime maker object.  */
+void
+mime_maker_release (mime_maker_t ctx)
+{
+  if (!ctx)
+    return;
+
+  release_parts (ctx->mail);
+  xfree (ctx->boundary_suffix);
+  xfree (ctx);
+}
+
+
+/* Set verbose and debug mode.  */
+void
+mime_maker_set_verbose (mime_maker_t ctx, int level)
+{
+  if (!level)
+    {
+      ctx->verbose = 0;
+      ctx->debug = 0;
+    }
+  else
+    {
+      ctx->verbose = 1;
+      if (level > 10)
+        ctx->debug = 1;
+    }
+}
+
+
+static void
+dump_parts (part_t part, int level)
+{
+  header_t hdr;
+
+  for (; part; part = part->next)
+    {
+      log_debug ("%*s[part %u]\n", level*2, "", part->partid);
+      for (hdr = part->headers; hdr; hdr = hdr->next)
+        {
+          log_debug ("%*s%s: %s\n", level*2, "", hdr->name, hdr->value);
+        }
+      if (part->body)
+        log_debug ("%*s[body %zu bytes]\n", level*2, "", part->bodylen);
+      if (part->child)
+        {
+          log_debug ("%*s[container]\n", level*2, "");
+          dump_parts (part->child, level+1);
+        }
+    }
+}
+
+
+/* Dump the mime tree for debugging.  */
+void
+mime_maker_dump_tree (mime_maker_t ctx)
+{
+  dump_parts (ctx->mail, 0);
+}
+
+
+/* Find the parent node for NEEDLE starting at ROOT.  */
+static part_t
+find_parent (part_t root, part_t needle)
+{
+  part_t node, n;
+
+  for (node = root->child; node; node = node->next)
+    {
+      if (node == needle)
+        return root;
+      if ((n = find_parent (node, needle)))
+        return n;
+    }
+  return NULL;
+}
+
+/* Find the part node from the PARTID.  */
+static part_t
+find_part (part_t root, unsigned int partid)
+{
+  part_t node, n;
+
+  for (node = root->child; node; node = node->next)
+    {
+      if (node->partid == partid)
+        return root;
+      if ((n = find_part (node, partid)))
+        return n;
+    }
+  return NULL;
+}
+
+
+/* Create a boundary string.  Outr codes is aware of the general
+ * structure of that string (gebins with "=-=") so that
+ * it can protect against accidentally-used boundaries within the
+ * content.   */
+static char *
+generate_boundary (mime_maker_t ctx)
+{
+  if (!ctx->boundary_suffix)
+    {
+      char buffer[12];
+
+      gcry_create_nonce (buffer, sizeof buffer);
+      ctx->boundary_suffix = zb32_encode (buffer, 8 * sizeof buffer);
+      if (!ctx->boundary_suffix)
+        return NULL;
+    }
+
+  ctx->boundary_counter++;
+  return es_bsprintf ("=-=%02d-%s=-=",
+                      ctx->boundary_counter, ctx->boundary_suffix);
+}
+
+
+/* Ensure that the context has a MAIL and CURRENT_PART object and
+ * return the parent object if available  */
+static gpg_error_t
+ensure_part (mime_maker_t ctx, part_t *r_parent)
+{
+  if (!ctx->mail)
+    {
+      ctx->mail = xtrycalloc (1, sizeof *ctx->mail);
+      if (!ctx->mail)
+        {
+          if (r_parent)
+            *r_parent = NULL;
+          return gpg_error_from_syserror ();
+        }
+      log_assert (!ctx->current_part);
+      ctx->current_part = ctx->mail;
+      ctx->current_part->headers_tail = &ctx->current_part->headers;
+    }
+  log_assert (ctx->current_part);
+  if (r_parent)
+    *r_parent = find_parent (ctx->mail, ctx->current_part);
+
+  return 0;
+}
+
+
+/* Check whether a header with NAME has already been set into PART.
+ * NAME must be in canonical capitalized format.  Return true or
+ * false. */
+static int
+have_header (part_t part, const char *name)
+{
+  header_t hdr;
+
+  for (hdr = part->headers; hdr; hdr = hdr->next)
+    if (!strcmp (hdr->name, name))
+      return 1;
+  return 0;
+}
+
+
+/* Helper to add a header to a part.  */
+static gpg_error_t
+add_header (part_t part, const char *name, const char *value)
+{
+  gpg_error_t err;
+  header_t hdr;
+  size_t namelen;
+  const char *s;
+  char *p;
+
+  if (!value)
+    {
+      s = strchr (name, '=');
+      if (!s)
+        return gpg_error (GPG_ERR_INV_ARG);
+      namelen = s - name;
+      value = s+1;
+    }
+  else
+    namelen = strlen (name);
+
+  hdr = xtrymalloc (sizeof *hdr + namelen);
+  if (!hdr)
+    return gpg_error_from_syserror ();
+  hdr->next = NULL;
+  memcpy (hdr->name, name, namelen);
+  hdr->name[namelen] = 0;
+
+  /* Check that the header name is valid.  */
+  if (!rfc822_valid_header_name_p (hdr->name))
+    {
+      xfree (hdr);
+      return gpg_error (GPG_ERR_INV_NAME);
+    }
+
+  rfc822_capitalize_header_name (hdr->name);
+  hdr->value = xtrystrdup (value);
+  if (!hdr->value)
+    {
+      err = gpg_error_from_syserror ();
+      xfree (hdr);
+      return err;
+    }
+
+  for (p = hdr->value + strlen (hdr->value) - 1;
+       (p >= hdr->value
+        && (*p == ' ' || *p == '\t' || *p == '\n' || *p == '\r'));
+       p--)
+    *p = 0;
+  if (!(p >= hdr->value))
+    {
+      xfree (hdr->value);
+      xfree (hdr);
+      return gpg_error (GPG_ERR_INV_VALUE);  /* Only spaces.  */
+    }
+
+  if (part)
+    {
+      *part->headers_tail = hdr;
+      part->headers_tail = &hdr->next;
+    }
+  else
+    xfree (hdr);
+
+  return 0;
+}
+
+
+/* Add a header with NAME and VALUE to the current mail.  A LF in the
+ * VALUE will be handled automagically.  If NULL is used for VALUE it
+ * is expected that the NAME has the format "NAME=VALUE" and VALUE is
+ * taken from there.
+ *
+ * If no container has been added, the header will be used for the
+ * regular mail headers and not for a MIME part.  If the current part
+ * is in a container and a body has been added, we append a new part
+ * to the current container.  Thus for a non-MIME mail the caller
+ * needs to call this function followed by a call to add a body.  When
+ * adding a Content-Type the boundary parameter must not be included.
+ */
+gpg_error_t
+mime_maker_add_header (mime_maker_t ctx, const char *name, const char *value)
+{
+  gpg_error_t err;
+  part_t part, parent;
+
+  /* Hack to use this function for a syntax check of NAME and VALUE.  */
+  if (!ctx)
+    return add_header (NULL, name, value);
+
+  err = ensure_part (ctx, &parent);
+  if (err)
+    return err;
+  part = ctx->current_part;
+
+  if ((part->body || part->child) && !parent)
+    {
+      /* We already have a body but no parent.  Adding another part is
+       * thus not possible.  */
+      return gpg_error (GPG_ERR_CONFLICT);
+    }
+  if (part->body || part->child)
+    {
+      /* We already have a body and there is a parent.  We now append
+       * a new part to the current container.  */
+      part = xtrycalloc (1, sizeof *part);
+      if (!part)
+        return gpg_error_from_syserror ();
+      part->partid = ++ctx->partid_counter;
+      part->headers_tail = &part->headers;
+      log_assert (!ctx->current_part->next);
+      ctx->current_part->next = part;
+      ctx->current_part = part;
+    }
+
+  /* If no NAME and no VALUE has been given we do not add a header.
+   * This can be used to create a new part without any header.  */
+  if (!name && !value)
+    return 0;
+
+  /* If we add Content-Type, make sure that we have a MIME-version
+   * header first; this simply looks better.  */
+  if (!ascii_strcasecmp (name, "Content-Type")
+      && !have_header (ctx->mail, "MIME-Version"))
+    {
+      err = add_header (ctx->mail, "MIME-Version", "1.0");
+      if (err)
+        return err;
+    }
+  return add_header (part, name, value);
+}
+
+
+/* Helper for mime_maker_add_{body,stream}.  */
+static gpg_error_t
+add_body (mime_maker_t ctx, const void *data, size_t datalen)
+{
+  gpg_error_t err;
+  part_t part, parent;
+
+  err = ensure_part (ctx, &parent);
+  if (err)
+    return err;
+  part = ctx->current_part;
+  if (part->body)
+    return gpg_error (GPG_ERR_CONFLICT);
+
+  part->body = xtrymalloc (datalen? datalen : 1);
+  if (!part->body)
+    return gpg_error_from_syserror ();
+  part->bodylen = datalen;
+  if (data)
+    memcpy (part->body, data, datalen);
+
+  return 0;
+}
+
+
+/* Add STRING as body to the mail or the current MIME container.  A
+ * second call to this function or mime_make_add_body_data is not
+ * allowed.
+ *
+ * FIXME: We may want to have an append_body to add more data to a body.
+ */
+gpg_error_t
+mime_maker_add_body (mime_maker_t ctx, const char *string)
+{
+  return add_body (ctx, string, strlen (string));
+}
+
+
+/* Add (DATA,DATALEN) as body to the mail or the current MIME
+ * container.  Note that a second call to this function or to
+ * mime_make_add_body is not allowed.  */
+gpg_error_t
+mime_maker_add_body_data (mime_maker_t ctx, const void *data, size_t datalen)
+{
+  return add_body (ctx, data, datalen);
+}
+
+
+/* This is the same as mime_maker_add_body but takes a stream as
+ * argument.  As of now the stream is copied to the MIME object but
+ * eventually we may delay that and read the stream only at the time
+ * it is needed.  Note that the address of the stream object must be
+ * passed and that the ownership of the stream is transferred to this
+ * MIME object.  To indicate the latter the function will store NULL
+ * at the ADDR_STREAM so that a caller can't use that object anymore
+ * except for es_fclose which accepts a NULL pointer.  */
+gpg_error_t
+mime_maker_add_stream (mime_maker_t ctx, estream_t *stream_addr)
+{
+  void *data;
+  size_t datalen;
+
+  es_rewind (*stream_addr);
+  if (es_fclose_snatch (*stream_addr, &data, &datalen))
+    return gpg_error_from_syserror ();
+  *stream_addr = NULL;
+  return add_body (ctx, data, datalen);
+}
+
+
+/* Add a new MIME container.  A container can be used instead of a
+ * body.  */
+gpg_error_t
+mime_maker_add_container (mime_maker_t ctx)
+{
+  gpg_error_t err;
+  part_t part;
+
+  err = ensure_part (ctx, NULL);
+  if (err)
+    return err;
+  part = ctx->current_part;
+
+  if (part->body)
+    return gpg_error (GPG_ERR_CONFLICT); /* There is already a body. */
+  if (part->child || part->boundary)
+    return gpg_error (GPG_ERR_CONFLICT); /* There is already a container. */
+
+  /* Create a child node.  */
+  part->child = xtrycalloc (1, sizeof *part->child);
+  if (!part->child)
+    return gpg_error_from_syserror ();
+  part->child->headers_tail = &part->child->headers;
+
+  part->boundary = generate_boundary (ctx);
+  if (!part->boundary)
+    {
+      err = gpg_error_from_syserror ();
+      xfree (part->child);
+      part->child = NULL;
+      return err;
+    }
+
+  part = part->child;
+  part->partid = ++ctx->partid_counter;
+  ctx->current_part = part;
+
+  return 0;
+}
+
+
+/* Finish the current container.  */
+gpg_error_t
+mime_maker_end_container (mime_maker_t ctx)
+{
+  gpg_error_t err;
+  part_t parent;
+
+  err = ensure_part (ctx, &parent);
+  if (err)
+    return err;
+  if (!parent)
+    return gpg_error (GPG_ERR_CONFLICT); /* No container.  */
+  while (parent->next)
+    parent = parent->next;
+  ctx->current_part = parent;
+  return 0;
+}
+
+
+/* Return the part-ID of the current part. */
+unsigned int
+mime_maker_get_partid (mime_maker_t ctx)
+{
+  if (ensure_part (ctx, NULL))
+    return 0; /* Ooops.  */
+  return ctx->current_part->partid;
+}
+
+
+/* Write a header and handle emdedded LFs.  If BOUNDARY is not NULL it
+ * is appended to the value.  */
+/* Fixme: Add automatic line wrapping.  */
+static gpg_error_t
+write_header (mime_maker_t ctx, const char *name, const char *value,
+              const char *boundary)
+{
+  const char *s;
+
+  es_fprintf (ctx->outfp, "%s: ", name);
+
+  /* Note that add_header made sure that VALUE does not end with a LF.
+   * Thus we can assume that a LF is followed by non-whitespace.  */
+  for (s = value; *s; s++)
+    {
+      if (*s == '\n')
+        es_fputs ("\r\n\t", ctx->outfp);
+      else
+        es_fputc (*s, ctx->outfp);
+    }
+  if (boundary)
+    {
+      if (s > value && s[-1] != ';')
+        es_fputc (';', ctx->outfp);
+      es_fprintf (ctx->outfp, "\r\n\tboundary=\"%s\"", boundary);
+    }
+
+  es_fputs ("\r\n", ctx->outfp);
+
+  return es_ferror (ctx->outfp)? gpg_error_from_syserror () : 0;
+}
+
+
+static gpg_error_t
+write_gap (mime_maker_t ctx)
+{
+  es_fputs ("\r\n", ctx->outfp);
+  return es_ferror (ctx->outfp)? gpg_error_from_syserror () : 0;
+}
+
+
+static gpg_error_t
+write_boundary (mime_maker_t ctx, const char *boundary, int last)
+{
+  es_fprintf (ctx->outfp, "\r\n--%s%s\r\n", boundary, last?"--":"");
+  return es_ferror (ctx->outfp)? gpg_error_from_syserror () : 0;
+}
+
+
+/* Fixme: Apply required encoding.  */
+static gpg_error_t
+write_body (mime_maker_t ctx, const void *body, size_t bodylen)
+{
+  const char *s;
+
+  for (s = body; bodylen; s++, bodylen--)
+    {
+      if (*s == '\n' && !(s > (const char *)body && s[-1] == '\r'))
+        es_fputc ('\r', ctx->outfp);
+      es_fputc (*s, ctx->outfp);
+    }
+
+  return es_ferror (ctx->outfp)? gpg_error_from_syserror () : 0;
+}
+
+
+/* Recursive worker for mime_maker_make.  */
+static gpg_error_t
+write_tree (mime_maker_t ctx, part_t parent, part_t part)
+{
+  gpg_error_t err;
+  header_t hdr;
+
+  for (; part; part = part->next)
+    {
+      for (hdr = part->headers; hdr; hdr = hdr->next)
+        {
+          if (part->child && !strcmp (hdr->name, "Content-Type"))
+            err = write_header (ctx, hdr->name, hdr->value, part->boundary);
+          else
+            err = write_header (ctx, hdr->name, hdr->value, NULL);
+          if (err)
+            return err;
+        }
+      err = write_gap (ctx);
+      if (err)
+        return err;
+      if (part->body)
+        {
+          err = write_body (ctx, part->body, part->bodylen);
+          if (err)
+            return err;
+        }
+      if (part->child)
+        {
+          log_assert (part->boundary);
+          err = write_boundary (ctx, part->boundary, 0);
+          if (!err)
+            err = write_tree (ctx, part, part->child);
+          if (!err)
+            err = write_boundary (ctx, part->boundary, 1);
+          if (err)
+            return err;
+        }
+
+      if (part->next)
+        {
+          log_assert (parent && parent->boundary);
+          err = write_boundary (ctx, parent->boundary, 0);
+          if (err)
+            return err;
+        }
+    }
+  return 0;
+}
+
+
+/* Add headers we always require.  */
+static gpg_error_t
+add_missing_headers (mime_maker_t ctx)
+{
+  gpg_error_t err;
+
+  if (!ctx->mail)
+    return gpg_error (GPG_ERR_NO_DATA);
+  if (!have_header (ctx->mail, "MIME-Version"))
+    {
+      /* Even if a Content-Type has never been set, we want to
+       * announce that we do MIME.  */
+      err = add_header (ctx->mail, "MIME-Version", "1.0");
+      if (err)
+        goto leave;
+    }
+
+  if (!have_header (ctx->mail, "Date"))
+    {
+      char *p = rfctimestamp (make_timestamp ());
+      if (!p)
+        err = gpg_error_from_syserror ();
+      else
+        err = add_header (ctx->mail, "Date", p);
+      xfree (p);
+      if (err)
+        goto leave;
+    }
+
+  err = 0;
+
+ leave:
+  return err;
+}
+
+
+/* Create message from the tree MIME and write it to FP.  Note that
+ * the output uses only a LF and a later called sendmail(1) is
+ * expected to convert them to network line endings.  */
+gpg_error_t
+mime_maker_make (mime_maker_t ctx, estream_t fp)
+{
+  gpg_error_t err;
+
+  err = add_missing_headers (ctx);
+  if (err)
+    return err;
+
+  ctx->outfp = fp;
+  err = write_tree (ctx, NULL, ctx->mail);
+
+  ctx->outfp = NULL;
+  return err;
+}
+
+
+/* Create a stream object from the MIME part identified by PARTID and
+ * store it at R_STREAM.  If PARTID identifies a container the entire
+ * tree is returned. Using that function may read stream objects
+ * which have been added as MIME bodies.  The caller must close the
+ * stream object. */
+gpg_error_t
+mime_maker_get_part (mime_maker_t ctx, unsigned int partid, estream_t *r_stream)
+{
+  gpg_error_t err;
+  part_t part;
+  estream_t fp;
+
+  *r_stream = NULL;
+
+  /* When the entire tree is requested, we make sure that all missing
+   * headers are applied.  We don't do that if only a part is
+   * requested because the additional headers (like Date:) will only
+   * be added to part 0 headers anyway. */
+  if (!partid)
+    {
+       err = add_missing_headers (ctx);
+       if (err)
+         return err;
+       part = ctx->mail;
+    }
+  else
+    part = find_part (ctx->mail, partid);
+
+  /* For now we use a memory stream object; however it would also be
+   * possible to create an object created on the fly while the caller
+   * is reading the returned stream.  */
+  fp = es_fopenmem (0, "w+b");
+  if (!fp)
+    return gpg_error_from_syserror ();
+
+  ctx->outfp = fp;
+  err = write_tree (ctx, NULL, part);
+  ctx->outfp = NULL;
+
+  if (!err)
+    {
+      es_rewind (fp);
+      *r_stream = fp;
+    }
+  else
+    es_fclose (fp);
+
+  return err;
+}