Add more error checks to read_dsa_privatekey().

git-svn-id: svn+ssh://svn.berlios.de/svnroot/repos/libssh/trunk@562 7dcaeef0-15fb-0310-b436-a5af3365683c

1 files changed, 48 insertions, 29 deletions

diff --git a/libssh/keyfiles.c b/libssh/keyfiles.c
index 8a7678a6..51b99e8e 100644
--- a/libssh/keyfiles.c
+++ b/libssh/keyfiles.c
@@ -512,43 +512,62 @@ error:
 
 static int read_dsa_privatekey(FILE *fp, gcry_sexp_t *r, ssh_auth_callback cb,
     void *userdata, const char *desc) {
-  STRING *p;
-  STRING *q;
-  STRING *g;
-  STRING *y;
-  STRING *x;
-  STRING *v;
-  BUFFER *buffer;
-
-  if (!(buffer=privatekey_file_to_buffer(fp, TYPE_DSS, cb, userdata, desc)))
+  BUFFER *buffer = NULL;
+  STRING *p = NULL;
+  STRING *q = NULL;
+  STRING *g = NULL;
+  STRING *y = NULL;
+  STRING *x = NULL;
+  STRING *v = NULL;
+  int rc = 1;
+
+  buffer = privatekey_file_to_buffer(fp, TYPE_DSS, cb, userdata, desc);
+  if (buffer == NULL) {
     return 0;
-  if (!asn1_check_sequence(buffer))
-  {
+  }
+
+  if (!asn1_check_sequence(buffer)) {
     buffer_free(buffer);
     return 0;
   }
-  v=asn1_get_int(buffer);
-  if (ntohl(v->size)!=1 || v->string[0]!=0)
-  {
+
+  v = asn1_get_int(buffer);
+  if (ntohl(v->size) != 1 || v->string[0] != 0) {
     buffer_free(buffer);
     return 0;
   }
-  p=asn1_get_int(buffer);
-  q=asn1_get_int(buffer);
-  g=asn1_get_int(buffer);
-  y=asn1_get_int(buffer);
-  x=asn1_get_int(buffer);
+
+  p = asn1_get_int(buffer);
+  q = asn1_get_int(buffer);
+  g = asn1_get_int(buffer);
+  y = asn1_get_int(buffer);
+  x = asn1_get_int(buffer);
   buffer_free(buffer);
-  if (!p || !q || !g || !y || !x)
-    return 0;
-  gcry_sexp_build(r,NULL,"(private-key(dsa(p %b)(q %b)(g %b)(y %b)(x %b)))",ntohl(p->size),p->string,ntohl(q->size),q->string,ntohl(g->size),g->string,ntohl(y->size),y->string,ntohl(x->size),x->string);
-  free(p);
-  free(q);
-  free(g);
-  free(y);
-  free(x);
-  free(v);
-  return 1;
+
+  if (p == NULL || q == NULL || g == NULL || y == NULL || x == NULL) {
+    rc = 0;
+    goto error;
+  }
+
+  if (gcry_sexp_build(r, NULL,
+        "(private-key(dsa(p %b)(q %b)(g %b)(y %b)(x %b)))",
+        ntohl(p->size), p->string,
+        ntohl(q->size), q->string,
+        ntohl(g->size), g->string,
+        ntohl(y->size), y->string,
+        ntohl(x->size), x->string)) {
+    rc = 0;
+  }
+
+error:
+  string_free(p);
+  string_free(q);
+  string_free(g);
+  string_free(y);
+  string_free(x);
+  string_free(v);
+
+  return rc;
 }
 #endif /* HAVE_LIBGCRYPT */