Extended the PKCS#11 object enumerator by attribute retrieval

src/libstrongswan/plugins/pkcs11/pkcs11_creds.c

@@ -51,68 +51,6 @@ struct private_pkcs11_creds_t {
 	linked_list_t *untrusted;
 };
 
-/**
- * Handle a certificate object, optionally trusted
- */
-static void handle_certificate(private_pkcs11_creds_t *this,
-							CK_SESSION_HANDLE session, CK_OBJECT_HANDLE object,
-							CK_BBOOL trusted)
-{
-	CK_ATTRIBUTE attrs[] = {
-		{CKA_VALUE, NULL, 0},
-		{CKA_LABEL, NULL, 0},
-	};
-	CK_RV rv;
-	certificate_t *cert;
-
-	rv = this->lib->f->C_GetAttributeValue(session, object,
-										   attrs, countof(attrs));
-	if (rv != CKR_OK)
-	{
-		DBG1(DBG_CFG, "C_GetAttributeValue(NULL) error: %N", ck_rv_names, rv);
-		return;
-	}
-	if (attrs[0].ulValueLen)
-	{
-		attrs[0].pValue = malloc(attrs[0].ulValueLen);
-	}
-	if (attrs[1].ulValueLen)
-	{
-		attrs[1].pValue = malloc(attrs[1].ulValueLen);
-	}
-	rv = this->lib->f->C_GetAttributeValue(session, object,
-										   attrs, countof(attrs));
-	if (rv == CKR_OK)
-	{
-		cert = lib->creds->create(lib->creds, CRED_CERTIFICATE, CERT_X509,
-				BUILD_BLOB_ASN1_DER,
-				chunk_create(attrs[0].pValue, attrs[0].ulValueLen),
-				BUILD_END);
-		if (cert)
-		{
-			DBG1(DBG_CFG, "    loaded %strusted cert '%.*s'",
-				 trusted ? "" : "un", attrs[1].ulValueLen, attrs[1].pValue);
-			/* trusted certificates are also returned as untrusted */
-			this->untrusted->insert_last(this->untrusted, cert);
-			if (trusted)
-			{
-				this->trusted->insert_last(this->trusted, cert->get_ref(cert));
-			}
-		}
-		else
-		{
-			DBG1(DBG_CFG, "    loading cert '%.*s' failed",
-				 attrs[1].ulValueLen, attrs[1].pValue);
-		}
-	}
-	else
-	{
-		DBG1(DBG_CFG, "C_GetAttributeValue() error: %N", ck_rv_names, rv);
-	}
-	free(attrs[0].pValue);
-	free(attrs[1].pValue);
-}
-
 /**
  * Find certificates, optionally trusted
  */
@@ -121,19 +59,41 @@ static void find_certificates(private_pkcs11_creds_t *this,
 {
 	CK_OBJECT_CLASS class = CKO_CERTIFICATE;
 	CK_CERTIFICATE_TYPE type = CKC_X_509;
-	CK_ATTRIBUTE template[] = {
+	CK_ATTRIBUTE tmpl[] = {
 		{CKA_CLASS, &class, sizeof(class)},
 		{CKA_CERTIFICATE_TYPE, &type, sizeof(type)},
 		{CKA_TRUSTED, &trusted, sizeof(trusted)},
 	};
 	CK_OBJECT_HANDLE object;
+	CK_ATTRIBUTE attr[] = {
+		{CKA_VALUE, NULL, 0},
+		{CKA_LABEL, NULL, 0},
+	};
 	enumerator_t *enumerator;
+	certificate_t *cert;
 
 	enumerator = this->lib->create_object_enumerator(this->lib,
-										session, template, countof(template));
+							session, tmpl, countof(tmpl), attr, countof(attr));
 	while (enumerator->enumerate(enumerator, &object))
 	{
-		handle_certificate(this, session, object, trusted);
+		cert = lib->creds->create(lib->creds, CRED_CERTIFICATE, CERT_X509,
+							BUILD_BLOB_ASN1_DER,
+							chunk_create(attr[0].pValue, attr[0].ulValueLen),
+							BUILD_END);
+		if (!cert)
+		{
+			DBG1(DBG_CFG, "    loading cert '%.*s' failed",
+				 attr[1].ulValueLen, attr[1].pValue);
+			continue;
+		}
+		DBG1(DBG_CFG, "    loaded %strusted cert '%.*s'",
+			 trusted ? "" : "un", attr[1].ulValueLen, attr[1].pValue);
+		/* trusted certificates are also returned as untrusted */
+		this->untrusted->insert_last(this->untrusted, cert);
+		if (trusted)
+		{
+			this->trusted->insert_last(this->trusted, cert->get_ref(cert));
+		}
 	}
 	enumerator->destroy(enumerator);
 }

src/libstrongswan/plugins/pkcs11/pkcs11_library.c

@@ -20,6 +20,7 @@
 #include <library.h>
 #include <debug.h>
 #include <threading/mutex.h>
+#include <utils/linked_list.h>
 
 typedef struct private_pkcs11_library_t private_pkcs11_library_t;
 
@@ -483,8 +484,69 @@ typedef struct {
 	CK_SESSION_HANDLE session;
 	/* pkcs11 library */
 	pkcs11_library_t *lib;
+	/* attributes to retreive */
+	CK_ATTRIBUTE_PTR attr;
+	/* number of attributes */
+	CK_ULONG count;
+	/* currently allocated attributes, to free */
+	linked_list_t *freelist;
 } object_enumerator_t;
 
+/**
+ * Free contents of attributes in a list
+ */
+static void free_attrs(object_enumerator_t *this)
+{
+	CK_ATTRIBUTE_PTR attr;
+
+	while (this->freelist->remove_last(this->freelist, (void**)&attr) == SUCCESS)
+	{
+		free(attr->pValue);
+		attr->pValue = NULL;
+		attr->ulValueLen = 0;
+	}
+}
+
+/**
+ * Get attributes for a given object during enumeration
+ */
+static bool get_attributes(object_enumerator_t *this, CK_OBJECT_HANDLE object)
+{
+	CK_RV rv;
+	int i;
+
+	free_attrs(this);
+
+	/* get length of objects first */
+	rv = this->lib->f->C_GetAttributeValue(this->session, object,
+										   this->attr, this->count);
+	if (rv != CKR_OK)
+	{
+		DBG1(DBG_CFG, "C_GetAttributeValue(NULL) error: %N", ck_rv_names, rv);
+		return FALSE;
+	}
+	/* allocate required chunks */
+	for (i = 0; i < this->count; i++)
+	{
+		if (this->attr[i].pValue == NULL &&
+			this->attr[i].ulValueLen != 0 && this->attr[i].ulValueLen != -1)
+		{
+			this->attr[i].pValue = malloc(this->attr[i].ulValueLen);
+			this->freelist->insert_last(this->freelist, &this->attr[i]);
+		}
+	}
+	/* get the data */
+	rv = this->lib->f->C_GetAttributeValue(this->session, object,
+										   this->attr, this->count);
+	if (rv != CKR_OK)
+	{
+		free_attrs(this);
+		DBG1(DBG_CFG, "C_GetAttributeValue(NULL) error: %N", ck_rv_names, rv);
+		return FALSE;
+	}
+	return TRUE;
+}
+
 METHOD(enumerator_t, object_enumerate, bool,
 	object_enumerator_t *this, CK_OBJECT_HANDLE *out)
 {
@@ -500,6 +562,13 @@ METHOD(enumerator_t, object_enumerate, bool,
 	}
 	if (found)
 	{
+		if (this->attr)
+		{
+			if (!get_attributes(this, object))
+			{
+				return FALSE;
+			}
+		}
 		*out = object;
 		return TRUE;
 	}
@@ -510,17 +579,20 @@ METHOD(enumerator_t, object_destroy, void,
 	object_enumerator_t *this)
 {
 	this->lib->f->C_FindObjectsFinal(this->session);
+	free_attrs(this);
+	this->freelist->destroy(this->freelist);
 	free(this);
 }
 
 METHOD(pkcs11_library_t, create_object_enumerator, enumerator_t*,
 	private_pkcs11_library_t *this, CK_SESSION_HANDLE session,
-	CK_ATTRIBUTE_PTR tmpl, CK_ULONG count)
+	CK_ATTRIBUTE_PTR tmpl, CK_ULONG tcount,
+	CK_ATTRIBUTE_PTR attr, CK_ULONG acount)
 {
 	object_enumerator_t *enumerator;
 	CK_RV rv;
 
-	rv = this->public.f->C_FindObjectsInit(session, tmpl, count);
+	rv = this->public.f->C_FindObjectsInit(session, tmpl, tcount);
 	if (rv != CKR_OK)
 	{
 		DBG1(DBG_CFG, "C_FindObjectsInit() failed: %N", ck_rv_names, rv);
@@ -534,6 +606,9 @@ METHOD(pkcs11_library_t, create_object_enumerator, enumerator_t*,
 		},
 		.session = session,
 		.lib = &this->public,
+		.attr = attr,
+		.count = acount,
+		.freelist = linked_list_create(),
 	);
 	return &enumerator->public;
 }

src/libstrongswan/plugins/pkcs11/pkcs11_library.h

@@ -48,12 +48,19 @@ struct pkcs11_library_t {
 	/**
 	 * Create an enumerator over CK_OBJECT_HANDLE using a search template.
 	 *
+	 * An optional attribute array is automatically filled in with the
+	 * objects associated attributes. If the value of an output attribute
+	 * is NULL, the value gets allocated/freed during enumeration.
+	 *
 	 * @param session	session to use
 	 * @param tmpl		search template
-	 * @param count 	number of attributes in the search template
+	 * @param tcount 	number of attributes in the search template
+	 * @param attr		attributes to read from object
+	 * @param acount	number of attributes to read
 	 */
 	enumerator_t* (*create_object_enumerator)(pkcs11_library_t *this,
-			CK_SESSION_HANDLE session, CK_ATTRIBUTE_PTR tmpl, CK_ULONG count);
+			CK_SESSION_HANDLE session, CK_ATTRIBUTE_PTR tmpl, CK_ULONG tcount,
+			CK_ATTRIBUTE_PTR attr, CK_ULONG acount);
 
 	/**
 	 * Destroy a pkcs11_library_t.