From f38dab94e6bcf01d7e1ed35608fac813e9f66606 Mon Sep 17 00:00:00 2001
From: Krzysztof Jackiewicz <k.jackiewicz@samsung.com>
Date: Thu, 30 Jun 2016 15:10:17 +0200
Subject: [PATCH] Allow NULL value_len in yaca_context_get_property(). Fix
 documentation.

In cases where a property is a single object of a known type theres no point in
passing value_len to yaca_context_get_property().

The documentation related to property getting/setting has been updated.

Change-Id: Idf908e87b87b5fe5239f651fe8546a7bd5a89850
---
 api/yaca/yaca_crypto.h |  8 ++++++++
 api/yaca/yaca_types.h  | 16 +++++++++-------
 src/encrypt.c          |  6 +++---
 src/sign.c             |  5 +++--
 4 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/api/yaca/yaca_crypto.h b/api/yaca/yaca_crypto.h
index baf0315..20cae17 100644
--- a/api/yaca/yaca_crypto.h
+++ b/api/yaca/yaca_crypto.h
@@ -190,6 +190,9 @@ int yaca_randomize_bytes(char *data, size_t data_len);
  * @brief  Sets the non-standard context properties. Can only be called on an
  *         initialized context.
  *
+ * @remarks  The @a value has to be of type appropriate for given property. See #yaca_property_e
+ *           for details on corresponding types.
+ *
  * @since_tizen 3.0
  *
  * @param[in,out] ctx        Previously initialized crypto context
@@ -219,6 +222,11 @@ int yaca_context_set_property(yaca_context_h ctx,
  *
  * @remarks  The @a value should be freed using yaca_free()
  *
+ * @remarks  The @a value has to be of type appropriate for given property. See #yaca_property_e
+ *           for details on corresponding types.
+ *
+ * @remarks  @a value_len can be NULL if returned @a value is a single object (i.e. not an array/buffer)
+ *
  * @param[in]  ctx        Previously initialized crypto context
  * @param[in]  property   Property to be read
  * @param[out] value      Copy of the property value
diff --git a/api/yaca/yaca_types.h b/api/yaca/yaca_types.h
index 2d5edc9..4508c8d 100644
--- a/api/yaca/yaca_types.h
+++ b/api/yaca/yaca_types.h
@@ -385,23 +385,25 @@ typedef enum {
  * @brief Enumeration of YACA non-standard properties for algorithms.
  *
  * @since_tizen 3.0
+ *
+ * @see #yaca_padding_e
  */
 typedef enum {
-	/** Padding */
+	/** Padding. Property type is #yaca_padding_e. */
 	YACA_PROPERTY_PADDING,
 
-	/** GCM Additional Authentication Data */
+	/** GCM Additional Authentication Data. Property type is a buffer (e.g. char*) */
 	YACA_PROPERTY_GCM_AAD,
-	/** GCM Tag bits */
+	/** GCM Tag. Property type is a buffer (e.g. char*) */
 	YACA_PROPERTY_GCM_TAG,
-	/** GCM Tag length */
+	/** GCM Tag length. Property type is size_t. */
 	YACA_PROPERTY_GCM_TAG_LEN,
 
-	/** CCM Additional Authentication Data */
+	/** CCM Additional Authentication Data. Property type is a buffer (e.g. char*) */
 	YACA_PROPERTY_CCM_AAD,
-	/** CCM Tag bits */
+	/** CCM Tag. Property type is a buffer (e.g. char*) */
 	YACA_PROPERTY_CCM_TAG,
-	/** CCM Tag length */
+	/** CCM Tag length. Property type is size_t. */
 	YACA_PROPERTY_CCM_TAG_LEN
 } yaca_property_e;
 
diff --git a/src/encrypt.c b/src/encrypt.c
index 5942e2e..b248896 100644
--- a/src/encrypt.c
+++ b/src/encrypt.c
@@ -168,13 +168,13 @@ int get_encrypt_property(const yaca_context_h ctx, yaca_property_e property,
 {
 	struct yaca_encrypt_context_s *c = get_encrypt_context(ctx);
 
-	if (c == NULL || value == NULL || value_len == NULL)
+	if (c == NULL || value == NULL)
 		return YACA_ERROR_INVALID_PARAMETER;
 	assert(c->cipher_ctx != NULL);
 
 	switch (property) {
 	case YACA_PROPERTY_GCM_TAG:
-		if (c->tag_len == 0)
+		if (c->tag_len == 0 || value_len == 0)
 			return YACA_ERROR_INVALID_PARAMETER;
 
 		if (EVP_CIPHER_CTX_ctrl(c->cipher_ctx,
@@ -186,7 +186,7 @@ int get_encrypt_property(const yaca_context_h ctx, yaca_property_e property,
 		*value_len = c->tag_len;
 		break;
 	case YACA_PROPERTY_CCM_TAG:
-		if (c->tag_len == 0)
+		if (c->tag_len == 0 || value_len == 0)
 			return YACA_ERROR_INVALID_PARAMETER;
 
 		if (EVP_CIPHER_CTX_ctrl(c->cipher_ctx,
diff --git a/src/sign.c b/src/sign.c
index 5dd261c..acb0392 100644
--- a/src/sign.c
+++ b/src/sign.c
@@ -179,7 +179,7 @@ int get_sign_param(const yaca_context_h ctx,
 	int pad;
 	yaca_padding_e padding;
 
-	if (c == NULL || value == NULL || value_len == NULL)
+	if (c == NULL || value == NULL)
 		return YACA_ERROR_INVALID_PARAMETER;
 
 	assert(c->mdctx != NULL);
@@ -230,7 +230,8 @@ int get_sign_param(const yaca_context_h ctx,
 		return ret;
 
 	memcpy(*value, &padding, sizeof(yaca_padding_e));
-	*value_len = sizeof(yaca_padding_e);
+	if (value_len != NULL)
+		*value_len = sizeof(yaca_padding_e);
 
 	return YACA_ERROR_NONE;
 }
-- 
2.7.4