From c5b0d8c76eacbafc4990f247e1de41304265801a Mon Sep 17 00:00:00 2001
From: Christian Grothoff <christian@grothoff.org>
Date: Sat, 18 Apr 2015 00:30:21 +0200
Subject: [PATCH] implementing /test/hkdf

---
 src/mint/taler-mint-httpd.c      |  7 ++++
 src/mint/taler-mint-httpd_test.c | 65 +++++++++++++++++++++++++++++++-
 src/mint/taler-mint-httpd_test.h | 25 ++++++++++++
 3 files changed, 95 insertions(+), 2 deletions(-)

diff --git a/src/mint/taler-mint-httpd.c b/src/mint/taler-mint-httpd.c
index b04583c2a..2b7d1d5e2 100644
--- a/src/mint/taler-mint-httpd.c
+++ b/src/mint/taler-mint-httpd.c
@@ -211,6 +211,13 @@ handle_mhd_request (void *cls,
         "Only POST is allowed", 0,
         &TMH_MHD_handler_send_json_pack_error, MHD_HTTP_METHOD_NOT_ALLOWED },
 
+      { "/test/hkdf", MHD_HTTP_METHOD_POST, "application/json",
+	NULL, 0,
+	&TMH_TEST_handler_test_hkdf, MHD_HTTP_OK },
+      { "/test/hkdf", NULL, "text/plain",
+        "Only POST is allowed", 0,
+        &TMH_MHD_handler_send_json_pack_error, MHD_HTTP_METHOD_NOT_ALLOWED },
+
       { "/test/ecdhe", MHD_HTTP_METHOD_POST, "application/json",
 	NULL, 0,
 	&TMH_TEST_handler_test_ecdhe, MHD_HTTP_OK },
diff --git a/src/mint/taler-mint-httpd_test.c b/src/mint/taler-mint-httpd_test.c
index 004138e80..5061b22b8 100644
--- a/src/mint/taler-mint-httpd_test.c
+++ b/src/mint/taler-mint-httpd_test.c
@@ -20,7 +20,6 @@
  * @author Christian Grothoff
  *
  * TODO:
- * - HKDF operations
  * - Symmetric encryption/decryption
  * - high-level transfer key logic
  */
@@ -49,7 +48,7 @@
  * @param upload_data upload data
  * @param[in,out] upload_data_size number of bytes (left) in @a upload_data
  * @return MHD result code
-  */
+ */
 int
 TMH_TEST_handler_test_base32 (struct TMH_RequestHandler *rh,
 			      struct MHD_Connection *connection,
@@ -93,6 +92,68 @@ TMH_TEST_handler_test_base32 (struct TMH_RequestHandler *rh,
 }
 
 
+/**
+ * Handle a "/test/hkdf" request.  Parses the JSON in the post, runs
+ * the Crockford Base32 decoder on the "input" field in the JSON,
+ * computes `HKDF(input, "salty")` and sends the result back as a JSON
+ * string with in Base32 Crockford encoding.  Thus, this API allows
+ * testing the use of the (H)KDF.  Note that the test fixes the
+ * input and output sizes and the salt (and the hash functions used
+ * by the HKDF), so this is only useful to test the HKDF in the
+ * same way it will be used within Taler/GNUnet.
+ *
+ * @param rh context of the handler
+ * @param connection the MHD connection to handle
+ * @param[in,out] connection_cls the connection's closure (can be updated)
+ * @param upload_data upload data
+ * @param[in,out] upload_data_size number of bytes (left) in @a upload_data
+ * @return MHD result code
+ */
+int
+TMH_TEST_handler_test_hkdf (struct TMH_RequestHandler *rh,
+			    struct MHD_Connection *connection,
+			    void **connection_cls,
+			    const char *upload_data,
+			    size_t *upload_data_size)
+{
+  json_t *json;
+  int res;
+  struct GNUNET_HashCode hc;
+  struct TMH_PARSE_FieldSpecification spec[] = {
+    TMH_PARSE_MEMBER_VARIABLE ("input"),
+    TMH_PARSE_MEMBER_END
+  };
+
+  res = TMH_PARSE_post_json (connection,
+                             connection_cls,
+                             upload_data,
+                             upload_data_size,
+                             &json);
+  if (GNUNET_SYSERR == res)
+    return MHD_NO;
+  if ( (GNUNET_NO == res) || (NULL == json) )
+    return MHD_YES;
+  res = TMH_PARSE_json_data (connection,
+			     json,
+			     spec);
+  if (GNUNET_YES != res)
+    return (GNUNET_NO == res) ? MHD_YES : MHD_NO;
+  GNUNET_CRYPTO_kdf (&hc, sizeof (hc),
+		     "salty", strlen ("salty"),
+		     spec[0].destination,
+		     spec[0].destination_size_out,
+		     NULL, 0);
+  TMH_PARSE_release_data (spec);
+  json_decref (json);
+  json = TALER_json_from_data (&hc, sizeof (struct GNUNET_HashCode));
+  res = TMH_RESPONSE_reply_json (connection,
+				 json,
+				 MHD_HTTP_OK);
+  json_decref (json);
+  return res;
+}
+
+
 /**
  * Handle a "/test/ecdhe" request.  Parses the JSON in the post, which
  * must contain a "ecdhe_pub" with a public key and an "ecdhe_priv"
diff --git a/src/mint/taler-mint-httpd_test.h b/src/mint/taler-mint-httpd_test.h
index 4ac1d94a0..5de63bb15 100644
--- a/src/mint/taler-mint-httpd_test.h
+++ b/src/mint/taler-mint-httpd_test.h
@@ -49,6 +49,31 @@ TMH_TEST_handler_test_base32 (struct TMH_RequestHandler *rh,
 			      size_t *upload_data_size);
 
 
+/**
+ * Handle a "/test/hkdf" request.  Parses the JSON in the post, runs
+ * the Crockford Base32 decoder on the "input" field in the JSON,
+ * computes `HKDF(input, "salty")` and sends the result back as a JSON
+ * string with in Base32 Crockford encoding.  Thus, this API allows
+ * testing the use of the (H)KDF.  Note that the test fixes the
+ * input and output sizes and the salt (and the hash functions used
+ * by the HKDF), so this is only useful to test the HKDF in the
+ * same way it will be used within Taler/GNUnet.
+ *
+ * @param rh context of the handler
+ * @param connection the MHD connection to handle
+ * @param[in,out] connection_cls the connection's closure (can be updated)
+ * @param upload_data upload data
+ * @param[in,out] upload_data_size number of bytes (left) in @a upload_data
+ * @return MHD result code
+ */
+int
+TMH_TEST_handler_test_hkdf (struct TMH_RequestHandler *rh,
+			    struct MHD_Connection *connection,
+			    void **connection_cls,
+			    const char *upload_data,
+			    size_t *upload_data_size);
+
+
 /**
  * Handle a "/test/ecdhe" request.  Parses the JSON in the post, which
  * must contain a "ecdhe_pub" with a public key and an "ecdhe_priv"