Add material for generating yotta module
diff --git a/yotta/data/example-hashing/main.cpp b/yotta/data/example-hashing/main.cpp
new file mode 100644
index 0000000..8eb3c1b
--- /dev/null
+++ b/yotta/data/example-hashing/main.cpp
@@ -0,0 +1,157 @@
+/*
+ * Hello world example of using the hashing functions of mbed TLS
+ *
+ * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *
+ * This file is part of mbed TLS (https://tls.mbed.org)
+ */
+
+/*
+ * This program illustrates various ways of hashing a buffer.
+ * You normally need only one of these two includes.
+ */
+#include "mbedtls/sha256.h" /* SHA-256 only */
+#include "mbedtls/md.h" /* generic interface */
+
+#if defined(TARGET_LIKE_MBED)
+#include "mbed/mbed.h"
+#endif
+#include <cstdio>
+
+static void print_hex(const char *title, const unsigned char buf[], size_t len)
+{
+ printf("%s: ", title);
+
+ for (size_t i = 0; i < len; i++)
+ printf("%02x", buf[i]);
+
+ printf("\r\n");
+}
+
+static const char hello_str[] = "Hello, world!";
+static const unsigned char *hello_buffer = (const unsigned char *) hello_str;
+static const size_t hello_len = sizeof hello_str - 1;
+
+int example(void)
+{
+ printf( "\r\n\r\n" );
+
+ /*
+ * Method 1: use all-in-one function of a specific SHA-xxx module
+ */
+ unsigned char output1[32]; /* SHA-256 outputs 32 bytes */
+
+ /* 0 here means use the full SHA-256, not the SHA-224 variant */
+ mbedtls_sha256(hello_buffer, hello_len, output1, 0);
+
+ print_hex("Method 1", output1, sizeof output1);
+
+
+ /*
+ * Method 2: use the streaming interface of a specific SHA-xxx module
+ * This is useful if we get our input piecewise.
+ */
+ unsigned char output2[32];
+ mbedtls_sha256_context ctx2;
+
+ mbedtls_sha256_init(&ctx2);
+ mbedtls_sha256_starts(&ctx2, 0); /* SHA-256, not 224 */
+
+ /* Simulating multiple fragments */
+ mbedtls_sha256_update(&ctx2, hello_buffer, 1);
+ mbedtls_sha256_update(&ctx2, hello_buffer + 1, 1);
+ mbedtls_sha256_update(&ctx2, hello_buffer + 2, hello_len - 2);
+
+ mbedtls_sha256_finish(&ctx2, output2);
+ print_hex("Method 2", output2, sizeof output2);
+
+ /* Or you could re-use the context by doing mbedtls_sha256_starts() again */
+ mbedtls_sha256_free(&ctx2);
+
+ /*
+ * Method 3: use all-in-one function of the generice interface
+ */
+ unsigned char output3[MBEDTLS_MD_MAX_SIZE]; /* Enough for any hash */
+
+ /* Can easily pick any hash you want, by identifier */
+ const mbedtls_md_info_t *md_info3 = mbedtls_md_info_from_type(MBEDTLS_MD_SHA256);
+
+ if (md_info3 == NULL)
+ {
+ printf("SHA256 not available\r\n");
+ return 1;
+ }
+
+ int ret3 = mbedtls_md(md_info3, hello_buffer, hello_len, output3);
+
+ if (ret3 != 0)
+ {
+ printf("md() returned -0x%04X\r\n", -ret3);
+ return 1;
+ }
+
+ print_hex("Method 3", output3, mbedtls_md_get_size(md_info3));
+
+
+ /*
+ * Method 4: streaming & generic interface
+ */
+ unsigned char output4[MBEDTLS_MD_MAX_SIZE]; /* Enough for any hash */
+
+ const mbedtls_md_info_t *md_info4 = mbedtls_md_info_from_type(MBEDTLS_MD_SHA256);
+
+ if (md_info4 == NULL)
+ {
+ printf("SHA256 not available\r\n");
+ return 1;
+ }
+
+ mbedtls_md_context_t ctx4;
+
+ mbedtls_md_init(&ctx4);
+
+ int ret4 = mbedtls_md_init_ctx(&ctx4, md_info4);
+ if (ret4 != 0)
+ {
+ printf("md_init_ctx() returned -0x%04X\r\n", -ret4);
+ return 1;
+ }
+
+ mbedtls_md_starts(&ctx4);
+
+ /* Simulating multiple fragments */
+ mbedtls_md_update(&ctx4, hello_buffer, 1);
+ mbedtls_md_update(&ctx4, hello_buffer + 1, 1);
+ mbedtls_md_update(&ctx4, hello_buffer + 2, hello_len - 2);
+
+ mbedtls_md_finish(&ctx4, output4);
+ print_hex("Method 4", output4, mbedtls_md_get_size(md_info4));
+
+ /* Or you could re-use the context by doing mbedtls_md_starts() again */
+ mbedtls_md_free(&ctx4);
+
+
+ printf("\r\nDONE\r\n");
+
+ return 0;
+}
+
+#if defined(TARGET_LIKE_MBED)
+
+#include "mbed/test_env.h"
+
+int main() {
+ MBED_HOSTTEST_TIMEOUT(10);
+ MBED_HOSTTEST_SELECT(default);
+ MBED_HOSTTEST_DESCRIPTION(mbed TLS example on hashing);
+ MBED_HOSTTEST_START("MBEDTLS_EX_HASHING");
+ MBED_HOSTTEST_RESULT(example() == 0);
+}
+
+#else
+
+int main() {
+ return example();
+}
+
+#endif