Rewrite dns-cert.c to not use the gpg-only iobuf stuff.

* common/dns-cert.c: Remove iobuf.h.
(get_dns_cert): Rename to _get_dns_cert.  Remove MAX_SIZE arg.  Change
iobuf arg to a estream-t.  Rewrite function to make use of estream
instead of iobuf.  Require all parameters.  Return an gpg_error_t
error instead of the type.  Add arg ERRSOURCE.
* common/dns-cert.h (get_dns_cert): New macro to pass the error source
to _gpg_dns_cert.
* common/t-dns-cert.c (main): Adjust for changes in get_dns_cert.
* g10/keyserver.c (keyserver_import_cert): Ditto.
* doc/gpg.texi (GPG Configuration Options): Remove max-cert-size.

4 files changed, 162 insertions, 89 deletions

diff --git a/common/ChangeLog b/common/ChangeLog
index d5682fc4b..96e4e31a2 100644
--- a/common/ChangeLog
+++ b/common/ChangeLog
@@ -1,3 +1,18 @@
+2011-11-30  Werner Koch  <wk@gnupg.org>
+
+        Rewrite dns-cert.c to not use the gpg-only iobuf stuff.
+        * dns-cert.c: Remove iobuf.h.
+        (get_dns_cert): Rename to _get_dns_cert.  Remove MAX_SIZE arg.
+	Change iobuf arg to a estream-t.  Rewrite function to make use of
+	estream instead of iobuf.  Require all parameters.  Return an
+	gpg_error_t error instead of the type.  Add arg ERRSOURCE.
+        * dns-cert.h (get_dns_cert): New macro to pass the error source to
+	_gpg_dns_cert.
+        * t-dns-cert.c (main): Adjust for changes in get_dns_cert.
+
+        * estream.c (es_fopenmem_init): New.
+	* estream.h (es_fopenmem_init): New.
+
 2011-11-29  Werner Koch  <wk@g10code.com>
 
 	* estream.c (func_mem_create): Don't set FUNC_REALLOC if GROW is
diff --git a/common/dns-cert.c b/common/dns-cert.c
index 9b6c6c893..56af13a1d 100644
--- a/common/dns-cert.c
+++ b/common/dns-cert.c
@@ -37,7 +37,6 @@
 #endif
 
 #include "util.h"
-#include "iobuf.h"
 #include "dns-cert.h"
 
 /* Not every installation has gotten around to supporting CERTs
@@ -63,48 +62,58 @@
 #define CERTTYPE_OID     254 /* OID private.  */
 
 
-/* Returns -1 on error, 0 for no answer, 1 for PGP provided and 2 for
-   IPGP provided.  Note that this function returns the first CERT
-   found with a supported type; it is expected that only one CERT
-   record is used. */
-int
-get_dns_cert (const char *name, size_t max_size, IOBUF * iobuf,
-              unsigned char **fpr, size_t * fpr_len, char **url)
+/* Returns 0 on success or an error code.  If a PGP CERT record was
+   found, a new estream with that key will be returned at R_KEY and
+   the other return parameters are set to NULL/0.  If an IPGP CERT
+   record was found the fingerprint is stored as an allocated block at
+   R_FPR and its length at R_FPRLEN; an URL is is allocated as a
+   string and returned at R_URL.  Note that this function returns the
+   first CERT found with a supported type; it is expected that only
+   one CERT record is used. */
+gpg_error_t
+_get_dns_cert (const char *name, estream_t *r_key,
+               unsigned char **r_fpr, size_t *r_fprlen, char **r_url,
+               gpg_err_source_t errsource)
 {
 #ifdef USE_DNS_CERT
 #ifdef USE_ADNS
+  gpg_error_t err;
   adns_state state;
   adns_answer *answer = NULL;
-  int rc;
   unsigned int ctype;
   int count;
 
-  rc = adns_init (&state, adns_if_noerrprint, NULL);
-  if (rc)
+  *r_key = NULL;
+  *r_fpr = NULL;
+  *r_fprlen = 0;
+  *r_url = NULL;
+
+  if (adns_init (&state, adns_if_noerrprint, NULL))
     {
+      err = gpg_err_make (errsource, gpg_err_code_from_syserror ());
       log_error ("error initializing adns: %s\n", strerror (errno));
-      return -1;
+      return err;
     }
 
-  rc = adns_synchronous (state, name, (adns_r_unknown | my_adns_r_cert),
-                         adns_qf_quoteok_query, &answer);
-  if (rc)
+  if (adns_synchronous (state, name, (adns_r_unknown | my_adns_r_cert),
+                        adns_qf_quoteok_query, &answer))
     {
+      err = gpg_err_make (errsource, gpg_err_code_from_syserror ());
       /* log_error ("DNS query failed: %s\n", strerror (errno)); */
       adns_finish (state);
-      return -1;
+      return err;
     }
   if (answer->status != adns_s_ok)
     {
       /* log_error ("DNS query returned an error: %s (%s)\n", */
       /*            adns_strerror (answer->status), */
       /*            adns_errabbrev (answer->status)); */
-      adns_free (answer);
-      adns_finish (state);
-      return 0;
+      err = gpg_err_make (errsource, GPG_ERR_NOT_FOUND);
+      goto leave;
     }
 
-  for (rc = 0, count = 0; !rc && count < answer->nrrs; count++)
+  err = gpg_err_make (errsource, GPG_ERR_NOT_FOUND);
+  for (count = 0; count < answer->nrrs; count++)
     {
       int datalen = answer->rrs.byteblock[count].len;
       const unsigned char *data = answer->rrs.byteblock[count].data;
@@ -121,8 +130,12 @@ get_dns_cert (const char *name, size_t max_size, IOBUF * iobuf,
         {
           /* CERT type is PGP.  Gpg checks for a minimum length of 11,
              thus we do the same.  */
-          *iobuf = iobuf_temp_with_content ((char *)data, datalen);
-          rc = 1;
+          *r_key = es_fopenmem_init (0, "rwb", data, datalen);
+          if (!*r_key)
+            err = gpg_err_make (errsource, gpg_err_code_from_syserror ());
+          else
+            err = 0;
+          goto leave;
         }
       else if (ctype == CERTTYPE_IPGP && datalen && datalen < 1023
                && datalen >= data[0] + 1 && fpr && fpr_len && url)
@@ -130,50 +143,68 @@ get_dns_cert (const char *name, size_t max_size, IOBUF * iobuf,
           /* CERT type is IPGP.  We made sure that the data is
              plausible and that the caller requested this
              information.  */
-          *fpr_len = data[0];
-          if (*fpr_len)
+          *r_fprlen = data[0];
+          if (*r_fprlen)
             {
-              *fpr = xmalloc (*fpr_len);
-              memcpy (*fpr, data + 1, *fpr_len);
+              *r_fpr = xtrymalloc (*r_fprlen);
+              if (!*r_fpr)
+                {
+                  err = gpg_err_make (errsource, gpg_err_code_from_syserror ());
+                  goto leave;
+                }
+              memcpy (*r_fpr, data + 1, *r_fprlen);
             }
           else
-            *fpr = NULL;
+            *r_fpr = NULL;
 
-          if (datalen > *fpr_len + 1)
+          if (datalen > *r_fprlen + 1)
             {
-              *url = xmalloc (datalen - (*fpr_len + 1) + 1);
-              memcpy (*url, data + (*fpr_len + 1), datalen - (*fpr_len + 1));
-              (*url)[datalen - (*fpr_len + 1)] = '\0';
+              *url = xtrymalloc (datalen - (*r_fprlen + 1) + 1);
+              if (!*r_url)
+                {
+                  err = gpg_err_make (errsource, gpg_err_code_from_syserror ());
+                  xfree (*r_fpr);
+                  *r_fpr = NULL;
+                  goto leave;
+                }
+              memcpy (*url, data + (*r_fprlen + 1), datalen - (*r_fprlen + 1));
+              (*url)[datalen - (*r_fprlen + 1)] = '\0';
             }
           else
-            *url = NULL;
+            *r_url = NULL;
 
-          rc = 2;
+          err = 0;
+          goto leave;
         }
     }
 
+ leave:
   adns_free (answer);
   adns_finish (state);
-  return rc;
+  return err;
 
 #else /*!USE_ADNS*/
 
+  gpg_error_t err;
   unsigned char *answer;
-  int ret = -1;
   int r;
   u16 count;
 
-  if (fpr)
-    *fpr = NULL;
+  *r_key = NULL;
+  *r_fpr = NULL;
+  *r_fprlen = 0;
+  *r_url = NULL;
 
-  if (url)
-    *url = NULL;
+  /* Allocate a 64k buffer which is the limit for an DNS response.  */
+  answer = xtrymalloc (65536);
+  if (!answer)
+    return gpg_err_make (errsource, gpg_err_code_from_syserror ());
 
-  answer = xmalloc (max_size);
+  err = gpg_err_make (errsource, GPG_ERR_NOT_FOUND);
 
-  r = res_query (name, C_IN, T_CERT, answer, max_size);
+  r = res_query (name, C_IN, T_CERT, answer, 65536);
   /* Not too big, not too small, no errors and at least 1 answer. */
-  if (r >= sizeof (HEADER) && r <= max_size
+  if (r >= sizeof (HEADER) && r <= 65536
       && (((HEADER *) answer)->rcode) == NOERROR
       && (count = ntohs (((HEADER *) answer)->ancount)))
     {
@@ -188,8 +219,10 @@ get_dns_cert (const char *name, size_t max_size, IOBUF * iobuf,
 
       rc = dn_skipname (pt, emsg);
       if (rc == -1)
-        goto fail;
-
+        {
+          err = gpg_err_make (errsource, GPG_ERR_INV_OBJ);
+          goto leave;
+        }
       pt += rc + QFIXEDSZ;
 
       /* There are several possible response types for a CERT request.
@@ -204,7 +237,10 @@ get_dns_cert (const char *name, size_t max_size, IOBUF * iobuf,
 
           rc = dn_skipname (pt, emsg);  /* the name we just queried for */
           if (rc == -1)
-            break;
+            {
+              err = gpg_err_make (errsource, GPG_ERR_INV_OBJ);
+              goto leave;
+            }
 
           pt += rc;
 
@@ -248,39 +284,54 @@ get_dns_cert (const char *name, size_t max_size, IOBUF * iobuf,
 
           /* 15 bytes takes us to here */
 
-          if (ctype == CERTTYPE_PGP && iobuf && dlen)
+          if (ctype == CERTTYPE_PGP && dlen)
             {
               /* PGP type */
-              *iobuf = iobuf_temp_with_content ((char *) pt, dlen);
-              ret = 1;
-              break;
+              *r_key = es_fopenmem_init (0, "rwb", pt, dlen);
+              if (!*r_key)
+                err = gpg_err_make (errsource, gpg_err_code_from_syserror ());
+              else
+                err = 0;
+              goto leave;
             }
           else if (ctype == CERTTYPE_IPGP
-                   && dlen && dlen < 1023 && dlen >= pt[0] + 1
-                   && fpr && fpr_len && url)
+                   && dlen && dlen < 1023 && dlen >= pt[0] + 1)
             {
               /* IPGP type */
-              *fpr_len = pt[0];
-
-              if (*fpr_len)
+              *r_fprlen = pt[0];
+              if (*r_fprlen)
                 {
-                  *fpr = xmalloc (*fpr_len);
-                  memcpy (*fpr, &pt[1], *fpr_len);
+                  *r_fpr = xtrymalloc (*r_fprlen);
+                  if (!*r_fpr)
+                    {
+                      err = gpg_err_make (errsource,
+                                          gpg_err_code_from_syserror ());
+                      goto leave;
+                    }
+                  memcpy (*r_fpr, &pt[1], *r_fprlen);
                 }
               else
-                *fpr = NULL;
+                *r_fpr = NULL;
 
-              if (dlen > *fpr_len + 1)
+              if (dlen > *r_fprlen + 1)
                 {
-                  *url = xmalloc (dlen - (*fpr_len + 1) + 1);
-                  memcpy (*url, &pt[*fpr_len + 1], dlen - (*fpr_len + 1));
-                  (*url)[dlen - (*fpr_len + 1)] = '\0';
+                  *r_url = xtrymalloc (dlen - (*r_fprlen + 1) + 1);
+                  if (!*r_fpr)
+                    {
+                      err = gpg_err_make (errsource,
+                                          gpg_err_code_from_syserror ());
+                      xfree (*r_fpr);
+                      *r_fpr = NULL;
+                      goto leave;
+                    }
+                  memcpy (*r_url, &pt[*r_fprlen + 1], dlen - (*r_fprlen + 1));
+                  (*r_url)[dlen - (*r_fprlen + 1)] = '\0';
                 }
               else
-                *url = NULL;
+                *r_url = NULL;
 
-              ret = 2;
-              break;
+              err = 0;
+              goto leave;
             }
 
           /* Neither type matches, so go around to the next answer. */
@@ -288,18 +339,18 @@ get_dns_cert (const char *name, size_t max_size, IOBUF * iobuf,
         }
     }
 
- fail:
+ leave:
   xfree (answer);
-  return ret;
+  return err;
+
 #endif /*!USE_ADNS */
 #else /* !USE_DNS_CERT */
   (void)name;
-  (void)max_size;
-  (void)iobuf;
-  (void)fpr;
-  (void)fpr_len;
-  (void)url;
+  (void)r_key;
+  (void)r_fpr;
+  (void)r_fprlen;
+  (void)r_url;
 
-  return -1;
+  return gpg_err_make (errsource, GPG_ERR_NOT_SUPPORTED);
 #endif
 }
diff --git a/common/dns-cert.h b/common/dns-cert.h
index ebfeec838..a1d3d86da 100644
--- a/common/dns-cert.h
+++ b/common/dns-cert.h
@@ -19,8 +19,13 @@
 #ifndef GNUPG_COMMON_DNS_CERT_H
 #define GNUPG_COMMON_DNS_CERT_H
 
-int get_dns_cert (const char *name, size_t max_size, iobuf_t *iobuf,
-                  unsigned char **fpr, size_t *fpr_len, char **url);
+gpg_error_t _get_dns_cert (const char *name, estream_t *r_key,
+                           unsigned char **r_fpr, size_t *r_fprlen,
+                           char **r_url,
+                           gpg_err_source_t errsource);
+#define get_dns_cert(a,b,c,d,e)                                 \
+  _get_dns_cert ((a),(b),(c),(d),(e), GPG_ERR_SOURCE_DEFAULT);
+
 
 
 #endif /*GNUPG_COMMON_DNS_CERT_H*/
diff --git a/common/t-dns-cert.c b/common/t-dns-cert.c
index f3e8892a7..1dcae6f29 100644
--- a/common/t-dns-cert.c
+++ b/common/t-dns-cert.c
@@ -23,18 +23,17 @@
 #include <assert.h>
 
 #include "util.h"
-#include "iobuf.h"
 #include "dns-cert.h"
 
 
 int
 main (int argc, char **argv)
 {
+  gpg_error_t err;
   unsigned char *fpr;
   size_t fpr_len;
   char *url;
-  int rc;
-  iobuf_t iobuf;
+  estream_t key;
   char const *name;
 
   if (argc)
@@ -55,18 +54,19 @@ main (int argc, char **argv)
 
   printf ("CERT lookup on `%s'\n", name);
 
-  rc = get_dns_cert (name, 65536, &iobuf, &fpr, &fpr_len, &url);
-  if (rc == -1)
-    fputs ("lookup result: error\n", stdout);
-  else if (!rc)
-    fputs ("lookup result: no answer\n", stdout);
-  else if (rc == 1)
+  err = get_dns_cert (name, &key, &fpr, &fpr_len, &url);
+  if (err)
+    printf ("get_dns_cert failed: %s <%s>\n",
+            gpg_strerror (err), gpg_strsource (err));
+  else if (key)
     {
-      printf ("lookup result: %d bytes\n",
-              (int)iobuf_get_temp_length(iobuf));
-      iobuf_close (iobuf);
+      int count = 0;
+
+      while (es_getc (key) != EOF)
+        count++;
+      printf ("Key found (%d bytes)\n", count);
     }
-  else if (rc == 2)
+  else
     {
       if (fpr)
 	{
@@ -85,9 +85,11 @@ main (int argc, char **argv)
       else
 	printf ("No URL found\n");
 
-      xfree (fpr);
-      xfree (url);
     }
 
+  es_fclose (key);
+  xfree (fpr);
+  xfree (url);
+
   return 0;
 }