ADD: 'amiitool' - Added @socram8888 's great tool for manipulating amiibo tags. The idea is to build it in the pm3 client. It compiles as is, but the hookup in client is not done. *WORK IN PROGRESS*

client/amiitool/drbg.c

@@ -0,0 +1,78 @@
+/*
+ * (c) 2015-2017 Marcos Del Sol Vives
+ * (c) 2016      javiMaD
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#include "drbg.h"
+#include <assert.h>
+#include <string.h>
+#include <mbedtls/md.h>
+
+void nfc3d_drbg_init(nfc3d_drbg_ctx * ctx, const uint8_t * hmacKey, size_t hmacKeySize, const uint8_t * seed, size_t seedSize) {
+	assert(ctx != NULL);
+	assert(hmacKey != NULL);
+	assert(seed != NULL);
+	assert(seedSize <= NFC3D_DRBG_MAX_SEED_SIZE);
+
+	// Initialize primitives
+	ctx->used = false;
+	ctx->iteration = 0;
+	ctx->bufferSize = sizeof(ctx->iteration) + seedSize;
+
+	// The 16-bit counter is prepended to the seed when hashing, so we'll leave 2 bytes at the start
+	memcpy(ctx->buffer + sizeof(uint16_t), seed, seedSize);
+
+	// Initialize underlying HMAC context
+	mbedtls_md_init(&ctx->hmacCtx);
+	mbedtls_md_setup(&ctx->hmacCtx, mbedtls_md_info_from_type(MBEDTLS_MD_SHA256), 1);
+	mbedtls_md_hmac_starts(&ctx->hmacCtx, hmacKey, hmacKeySize);
+}
+
+void nfc3d_drbg_step(nfc3d_drbg_ctx * ctx, uint8_t * output) {
+	assert(ctx != NULL);
+	assert(output != NULL);
+
+	if (ctx->used) {
+		// If used at least once, reinitialize the HMAC
+		mbedtls_md_hmac_reset(&ctx->hmacCtx);
+	} else {
+		ctx->used = true;
+	}
+
+	// Store counter in big endian, and increment it
+	ctx->buffer[0] = ctx->iteration >> 8;
+	ctx->buffer[1] = ctx->iteration >> 0;
+	ctx->iteration++;
+
+	// Do HMAC magic
+	mbedtls_md_hmac_update(&ctx->hmacCtx, ctx->buffer, ctx->bufferSize);
+	mbedtls_md_hmac_finish(&ctx->hmacCtx, output);
+}
+
+void nfc3d_drbg_cleanup(nfc3d_drbg_ctx * ctx) {
+	assert(ctx != NULL);
+	mbedtls_md_free(&ctx->hmacCtx);
+}
+
+void nfc3d_drbg_generate_bytes(const uint8_t * hmacKey, size_t hmacKeySize, const uint8_t * seed, size_t seedSize, uint8_t * output, size_t outputSize) {
+	uint8_t temp[NFC3D_DRBG_OUTPUT_SIZE];
+
+	nfc3d_drbg_ctx rngCtx;
+	nfc3d_drbg_init(&rngCtx, hmacKey, hmacKeySize, seed, seedSize);
+
+	while (outputSize > 0) {
+		if (outputSize < NFC3D_DRBG_OUTPUT_SIZE) {
+			nfc3d_drbg_step(&rngCtx, temp);
+			memcpy(output, temp, outputSize);
+			break;
+		}
+
+		nfc3d_drbg_step(&rngCtx, output);
+		output += NFC3D_DRBG_OUTPUT_SIZE;
+		outputSize -= NFC3D_DRBG_OUTPUT_SIZE;
+	}
+
+	nfc3d_drbg_cleanup(&rngCtx);
+}