buf: _gnutls_buffer_pop_data made easier to use

Signed-off-by: Nikos Mavrogiannopoulos <nmav@redhat.com>

3 files changed, 16 insertions, 14 deletions

diff --git a/lib/str.c b/lib/str.c
index 378cedfa0c..c8d742e91e 100644
--- a/lib/str.c
+++ b/lib/str.c
@@ -280,24 +280,23 @@ int _gnutls_buffer_to_datum(gnutls_buffer_st * str, gnutls_datum_t * data, unsig
 	return ret;
 }
 
-/* returns data from a string in a constant buffer.
+/* returns data from a string in a constant buffer. Will
+ * fail with GNUTLS_E_PARSING_ERROR, if the string has not enough data.
  */
-void
+int
 _gnutls_buffer_pop_data(gnutls_buffer_st * str, void *data,
-			size_t * req_size)
+			size_t req_size)
 {
 	gnutls_datum_t tdata;
 
-	_gnutls_buffer_pop_datum(str, &tdata, *req_size);
-	if (tdata.data == NULL) {
-		*req_size = 0;
-		return;
+	_gnutls_buffer_pop_datum(str, &tdata, req_size);
+	if (tdata.data == NULL || tdata.size != req_size) {
+		return GNUTLS_E_PARSING_ERROR;
 	}
 
-	*req_size = tdata.size;
 	memcpy(data, tdata.data, tdata.size);
 
-	return;
+	return 0;
 }
 
 int
diff --git a/lib/str.h b/lib/str.h
index ba4efefb66..da472eb4f7 100644
--- a/lib/str.h
+++ b/lib/str.h
@@ -112,7 +112,7 @@ int _gnutls_buffer_append_fixed_mpi(gnutls_buffer_st * buf,
 
 int _gnutls_buffer_append_data_prefix(gnutls_buffer_st * buf, int pfx_size,
 				      const void *data, size_t data_size);
-void _gnutls_buffer_pop_data(gnutls_buffer_st *, void *, size_t * size);
+int _gnutls_buffer_pop_data(gnutls_buffer_st *, void *, size_t size);
 void _gnutls_buffer_pop_datum(gnutls_buffer_st *, gnutls_datum_t *,
 			      size_t max_size);
 
@@ -234,9 +234,8 @@ int _gnutls_hostname_compare(const char *certname, size_t certnamesize,
     }
 
 #define BUFFER_POP(b, x, s) { \
-	size_t is = s; \
-	_gnutls_buffer_pop_data(b, x, &is); \
-	if (is != s) { \
+	ret = _gnutls_buffer_pop_data(b, x, s); \
+	if (ret < 0) { \
 	    ret = GNUTLS_E_PARSING_ERROR; \
 	    gnutls_assert(); \
 	    goto error; \
diff --git a/lib/tpm.c b/lib/tpm.c
index 1d63f83cb1..30f078f5ef 100644
--- a/lib/tpm.c
+++ b/lib/tpm.c
@@ -798,7 +798,11 @@ unescape_string(char *output, const char *input, size_t * size,
 		return ret;
 	}
 
-	_gnutls_buffer_pop_data(&str, output, size);
+	ret = _gnutls_buffer_pop_data(&str, output, str.length);
+	if (ret < 0) {
+		gnutls_assert();
+		return ret;
+	}
 
 	_gnutls_buffer_clear(&str);