refactor common code with download from s3 demo

demos/http/common/include/http_demo_s3_utils.h

@@ -0,0 +1,170 @@
+/*
+ * AWS IoT Device SDK for Embedded C 202211.00
+ * Copyright (C) 2020 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef HTTP_DEMO_S3_UTILS_H_
+#define HTTP_DEMO_S3_UTILS_H_
+
+/* Standard includes. */
+#include <stdlib.h>
+#include <stdbool.h>
+
+/* *INDENT-OFF* */
+#ifdef __cplusplus
+    extern "C" {
+#endif
+/* *INDENT-ON* */
+
+/* Other HTTP utils header. */
+#include "http_demo_utils.h"
+
+/* JSON API header. */
+#include "core_json.h"
+
+/* SIGV4 API header. */
+#include "sigv4.h"
+
+/**
+ * @brief Length in bytes of hex encoded hash digest.
+ */
+#define HEX_ENCODED_SHA256_HASH_DIGEST_LENGTH         ( ( ( uint16_t ) 64 ) )
+
+/**
+ * @brief Length in bytes of SHA256 hash digest.
+ */
+#define SHA256_HASH_DIGEST_LENGTH                     ( HEX_ENCODED_SHA256_HASH_DIGEST_LENGTH / 2 )
+
+/**
+ * @brief Maximum Length for AWS IOT Credential provider server host name.
+ *
+ * @note length of the AWS IOT Credential provider server host name string
+ * cannot exceed this value.
+ */
+#define SERVER_HOST_NAME_MAX_LENGTH                   65U
+
+/**
+ * @brief The host address string extracted from the AWS IOT CREDENTIAL PROVIDER URL.
+ *
+ * @note SERVER_HOST_NAME_MAX_LENGTH is set as the array length here as the
+ * length of the host name string cannot exceed this value.
+ */
+extern char serverHost[ SERVER_HOST_NAME_MAX_LENGTH ];
+
+/**
+ * @brief The length of the host address found in the the AWS IOT CREDENTIAL PROVIDER URL.
+ */
+extern size_t serverHostLength;
+
+/**
+ * @brief The security token retrieved from AWS IoT credential provider
+ * required for making HTTP requests to AWS S3.
+ */
+extern const char * pSecurityToken;
+
+/**
+ * @brief Length of security token retrieved from AWS IoT credential provider
+ * required for making HTTP requests to AWS S3.
+ */
+extern size_t securityTokenLen;
+
+/**
+ * @brief The expiration time for the temporary credentials retrieved
+ * from AWS IoT credential provider service.
+ */
+extern const char * pExpiration;
+
+/**
+ * @brief Length of expiration time for the temporary credentials retrieved
+ * from AWS IoT credential provider service.
+ */
+size_t expirationLen;
+
+/**
+ * @brief Retrieve the temporary credentials from AWS IOT Credential Provider.
+ *
+ * @param[in] pTransportInterface The transport interface for performing network send/recv operations.
+ * @param[out] pDateISO8601 Buffer to store the ISO8601 formatted date.
+ * @param[in] pDateISO8601Len Length of the buffer provided to store ISO8601 formatted date.
+ * @param[in,out] response Response buffer to store the HTTP response received.
+ * @param[out] sigvCreds Buffer to store the parsed credentials.
+ *
+ * @return `true` if credentials are retrieved successfully otherwise 'false`.
+ */
+bool getTemporaryCredentials( TransportInterface_t * transportInterface,
+                              char * pDateISO8601,
+                              size_t pDateISO8601Len,
+                              HTTPResponse_t * response,
+                              SigV4Credentials_t * sigvCreds );
+
+/**
+ * @brief Calculate SHA256 digest.
+ *
+ * @param[in] pInput Input string to hash.
+ * @param[in] ilen Length of input string.
+ * @param[out] pOutput Buffer to store the generated hash.
+ */
+int32_t sha256( const char * pInput,
+                size_t ilen,
+                char * pOutput );
+
+/**
+ * @brief Application-defined Hash Initialization function provided
+ * to the SigV4 library.
+ *
+ * @note Refer to SigV4CryptoInterface_t interface documentation for this function.
+ */
+int32_t sha256Init( void * hashContext );
+
+/**
+ * @brief Application-defined Hash Update function provided to the SigV4 library.
+ *
+ * @note Refer to SigV4CryptoInterface_t interface documentation for this function.
+ */
+int32_t sha256Update( void * hashContext,
+                      const uint8_t * pInput,
+                      size_t inputLen );
+
+/**
+ * @brief Application-defined Hash Final function provided to the SigV4 library.
+ *
+ * @note Refer to SigV4CryptoInterface_t interface documentation for this function.
+ */
+int32_t sha256Final( void * hashContext,
+                     uint8_t * pOutput,
+                     size_t outputLen );
+
+/**
+ * @brief Connect to AWS IOT Credential Provider server with reconnection retries.
+ *
+ * @param[out] pNetworkContext The output parameter to return the created
+ * network context.
+ *
+ * @return EXIT_FAILURE on failure; EXIT_SUCCESS on successful connection.
+ */
+int32_t connectToIotServer( NetworkContext_t * pNetworkContext );
+
+/* *INDENT-OFF* */
+#ifdef __cplusplus
+    }
+#endif
+/* *INDENT-ON* */
+
+#endif /* ifndef HTTP_DEMO_S3_UTILS_H_ */

demos/http/common/include/http_demo_utils.h

@@ -63,6 +63,17 @@ typedef int32_t ( * TransportConnect_t )( NetworkContext_t * pNetworkContext );
 int32_t connectToServerWithBackoffRetries( TransportConnect_t connectFunction,
                                            NetworkContext_t * pNetworkContext );
 
+/**
+ * @brief Get the starting location of HTTP header in an HTTP request.
+ *
+ * @param[in] requestHeaders HTTP request headers that contains the HTTP request information.
+ * @param[out] pStartHeaderLoc Buffer to store the start Location of the HTTP header.
+ * @param[out] pHeadersDataLen Length of @p pStartHeaderLoc.
+ */
+void getHeaderStartLocFromHttpRequest( HTTPRequestHeaders_t requestHeaders,
+                                       char ** pStartHeaderLoc,
+                                       size_t * pHeadersDataLen );
+
 /**
  * @brief Get the current time in milliseconds.
  *