rlp.c

#include <stdio.h>
#include <string.h>


const char* fields[] = {
	"parentHash",
	"ommersHash",
	"beneficiary",
	"stateRoot",
	"transactionsRoot",
	"receiptsRoot",
	"logsBloom",
	"difficulty",
	"number",
	"gasLimit",
	"gasUsed",
	"timestamp",
	"extraData",
	"mixHash",
        "nonce"
};	


typedef unsigned int uint;

typedef struct _rlp_item {
	unsigned char* content;
	uint  len; /* length in bytes */

} rlp_item;


/*****************************************************************************/

static uint decode_single_byte(unsigned char* input, rlp_item* output) {
	output->content = input;
	output->len = 1;
	
	return 1;
}

/*****************************************************************************/

static uint decode_number(unsigned char* input, uint len) {
	uint i, result;
	result = 0;
	for(i = 0 ; i < len ; i++) {
		result = result << 8;
		result += (unsigned char)input[i];
	}

	return result;
}

/*****************************************************************************/

static uint decode_string(unsigned char* input, rlp_item* output) {
	unsigned char first_byte = input[0];
	uint len_num_bytes;
	uint string_len;

	if(first_byte <= 0xb7) {
		output->len = first_byte - 0x80;
		output->content = input + 1;
		len_num_bytes = 1;
	}
	else {
		len_num_bytes = first_byte - 0xb7;
		string_len = decode_number(input + 1, len_num_bytes); 
		output->len = string_len;
		output->content = input + 1 + len_num_bytes;
		len_num_bytes++;
	}

	return output->len + len_num_bytes;
}

/*****************************************************************************/

static void decode_list(unsigned char* input, rlp_item* outputs) {
	unsigned char first_byte = input[0];
	uint len_num_bytes;
	uint list_len;
	uint elm_ind;
	uint elm_len;
	uint outputs_ind;
	unsigned char* current_input = input;
	
	if(first_byte <= 0xf7) {
		list_len = first_byte - 0xc0;
		current_input = input + 1;
	}
	else {
		len_num_bytes = first_byte - 0xf7;
		list_len = decode_number(input + 1, len_num_bytes);
		current_input = input + 1 + len_num_bytes;
	}

	outputs_ind = 0;
	for(elm_ind = 0 ; /*elm_ind < list_len*/ current_input < input + list_len /* elm_ind < 20*/ ; elm_ind++)
	{
		first_byte = current_input[0];

		if(first_byte <= 0x7f) elm_len = decode_single_byte(current_input,outputs + outputs_ind);
		else if(first_byte <= 0xbf) elm_len = decode_string(current_input,outputs + outputs_ind);
		else printf( "error: recursive list\n");

		current_input += elm_len;
		outputs_ind += 1;
	}
}


/*****************************************************************************/
/* tests  								     */


/*****************************************************************************/

static void print_elm(const char* name, rlp_item* item) {
	uint i;
	printf("%s 0x", name);
	for(i = 0 ; i < item->len ;i++) printf("%02X", item->content[i]);
	printf("\n");
}

#define CHECK_RLP_RESULT(_rlp_items, _index, _value){\
	if((_rlp_items[_index]).len != sizeof(_value)) return (-1 * 2 * (_index) - 1);\
	if(memcmp((_rlp_items[_index]).content, (_value), sizeof(_value))) return (-1 * 2 * (_index) - 2);\
}

/*****************************************************************************/

static int test1() {
	unsigned char rlp_data[] =
{0xf9, 0x02, 0x10, 0xa0, 0x4d, 0x1e, 0x1f, 0x82, 0x40, 0x0b, 0x58, 0x55, 0xf1, 0xec, 0xc1, 0xf6, 0x9e, 0xe5, 0x5b, 0x94, 0xe6, 0x3f, 0x66, 0x8f, 0xf4, 0x41, 0xff, 0xf5, 0xab, 0x5c, 0x54, 0x5e, 0x39, 0xa1, 0x8d, 0x0a, 0xa0, 0xfc, 0x45, 0x8f, 0x61, 0x6c, 0x83, 0x92, 0x48, 0xdc, 0x81, 0x59, 0xb9, 0x1c, 0x6a, 0x57, 0xa0, 0xab, 0xb5, 0xdf, 0x8f, 0x5c, 0xdf, 0x87, 0x49, 0x03, 0xe3, 0xbe, 0x8f, 0x47, 0x84, 0x77, 0x89, 0x94, 0x82, 0x9b, 0xd8, 0x24, 0xb0, 0x16, 0x32, 0x6a, 0x40, 0x1d, 0x08, 0x3b, 0x33, 0xd0, 0x92, 0x29, 0x33, 0x33, 0xa8, 0x30, 0xa0, 0x39, 0x69, 0x11, 0x34, 0x5f, 0xd5, 0xb3, 0x4b, 0x31, 0x89, 0x88, 0x2e, 0x15, 0x73, 0xb8, 0x7f, 0xa6, 0x4a, 0x11, 0xa3, 0x4d, 0x81, 0x0b, 0xbd, 0x77, 0xcb, 0xb3, 0xeb, 0xb4, 0xa1, 0x30, 0x11, 0xa0, 0x1e, 0x93, 0x38, 0x5b, 0xe2, 0x50, 0x04, 0x7b, 0xd0, 0xb5, 0xfc, 0xad, 0x90, 0x4c, 0x42, 0xe4, 0xbf, 0x4c, 0xed, 0x18, 0xda, 0xcc, 0x72, 0x9f, 0xc6, 0x8c, 0xd4, 0xe3, 0x87, 0x17, 0x27, 0xf0, 0xa0, 0x48, 0x52, 0xb4, 0x18, 0x9d, 0x25, 0x34, 0xc3, 0x79, 0xb1, 0x36, 0x5d, 0xf9, 0xbe, 0x0a, 0x51, 0xc1, 0x7f, 0x09, 0xf7, 0xd0, 0x34, 0x56, 0x13, 0x04, 0x0b, 0x1f, 0xa0, 0x20, 0x48, 0x18, 0x06, 0xb9, 0x01, 0x00, 0x04, 0x00, 0x20, 0x00, 0x00, 0x42, 0x00, 0x10, 0x02, 0x00, 0x40, 0x00, 0x08, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x20, 0x01, 0x68, 0x02, 0x00, 0x00, 0x00, 0x00, 0x80, 0x80, 0x00, 0x90, 0x00, 0x80, 0x00, 0x00, 0x4c, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x80, 0x03, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x09, 0x00, 0x04, 0x21, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0xa0, 0x4d, 0x00, 0x00, 0x00, 0x01, 0xa4, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x20, 0xa0, 0x00, 0x00, 0x00, 0x00, 0x40, 0x60, 0x00, 0x00, 0x40, 0x00, 0x00, 0x02, 0x20, 0x00, 0x00, 0x01, 0x06, 0x00, 0x00, 0x04, 0x30, 0x21, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, 0x80, 0x20, 0x00, 0x20, 0x00, 0x00, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00, 0x90, 0x40, 0x00, 0x00, 0x01, 0x00, 0x00, 0x80, 0x00, 0x04, 0x80, 0x02, 0x00, 0x02, 0x01, 0x02, 0x00, 0x00, 0x08, 0x04, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x18, 0x00, 0x40, 0x40, 0x00, 0x80, 0x80, 0x20, 0x00, 0x14, 0x12, 0x00, 0x00, 0x80, 0x10, 0x00, 0x01, 0x30, 0x00, 0x00, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x01, 0x05, 0x20, 0x00, 0x00, 0x00, 0x40, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x01, 0x0a, 0x42, 0x04, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x11, 0x00, 0x00, 0x10, 0x00, 0x04, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0xa2, 0x00, 0x10, 0x20, 0x00, 0x04, 0x00, 0x00, 0x00, 0x80, 0x84, 0x02, 0x10, 0x00, 0x01, 0x10, 0x02, 0x80, 0x87, 0x05, 0x8d, 0x4d, 0x00, 0x3a, 0x5e, 0xae, 0x83, 0x47, 0xb7, 0x60, 0x83, 0x66, 0x25, 0xf7, 0x83, 0x66, 0x07, 0xa1, 0x84, 0x5a, 0x2b, 0x46, 0xbb, 0x8f, 0xe4, 0xb8, 0x83, 0xe5, 0xbd, 0xa9, 0xe7, 0xa5, 0x9e, 0xe4, 0xbb, 0x99, 0xe9, 0xb1, 0xbc, 0xa0, 0x52, 0x47, 0x69, 0x1a, 0xb0, 0x95, 0x3f, 0xa5, 0xc5, 0xc2, 0xc8, 0x4b, 0x0b, 0x14, 0x2b, 0x6d, 0x62, 0xe9, 0xdc, 0x5f, 0x35, 0xa8, 0x65, 0xed, 0x19, 0x7b, 0x9c, 0xd3, 0x73, 0x6a, 0xf6, 0xf1, 0x88, 0x85, 0x72, 0x87, 0x40, 0x01, 0x60, 0x21, 0x8d};

	const unsigned char parnetHash[32] = {
		0x4d,0x1e,0x1f,0x82,0x40,0x0b,0x58,0x55,0xf1,0xec,0xc1,0xf6,0x9e,
		0xe5,0x5b,0x94,0xe6,0x3f,0x66,0x8f,0xf4,0x41,0xff,0xf5,0xab,0x5c,
		0x54,0x5e,0x39,0xa1,0x8d,0x0a
	};

	const unsigned char ommersHash[32] = {
		0xfc, 0x45, 0x8f, 0x61, 0x6c, 0x83, 0x92, 0x48, 0xdc, 0x81, 0x59, 0xb9, 0x1c,
		0x6a, 0x57, 0xa0, 0xab, 0xb5, 0xdf, 0x8f, 0x5c, 0xdf, 0x87, 0x49, 0x03, 0xe3,
		0xbe, 0x8f, 0x47, 0x84, 0x77, 0x89
	};

	const unsigned char beneficiary[20] = {
		0x82, 0x9B, 0xD8, 0x24, 0xB0, 0x16, 0x32, 0x6A, 0x40, 0x1D, 0x08, 0x3B, 0x33,
		0xD0, 0x92, 0x29, 0x33, 0x33, 0xA8, 0x30
	};

	const unsigned char stateRoot[32] = {
		0x39, 0x69, 0x11, 0x34, 0x5F, 0xD5, 0xB3, 0x4B, 0x31, 0x89, 0x88, 0x2E, 0x15,
		0x73, 0xB8, 0x7F, 0xA6, 0x4A, 0x11, 0xA3, 0x4D, 0x81, 0x0B, 0xBD, 0x77, 0xCB,
		0xB3, 0xEB, 0xB4, 0xA1, 0x30, 0x11
	};
	
	const unsigned char transactionRoot[32] = {
		0x1E, 0x93, 0x38, 0x5B, 0xE2, 0x50, 0x04, 0x7B, 0xD0, 0xB5, 0xFC, 0xAD, 0x90,
		0x4C, 0x42, 0xE4, 0xBF, 0x4C, 0xED, 0x18, 0xDA, 0xCC, 0x72, 0x9F, 0xC6, 0x8C,
		0xD4, 0xE3, 0x87, 0x17, 0x27, 0xF0
	};

	const unsigned char receiptsRoot[32] = {
		0x48, 0x52, 0xB4, 0x18, 0x9D, 0x25, 0x34, 0xC3, 0x79, 0xB1, 0x36, 0x5D, 0xF9,
		0xBE, 0x0A, 0x51, 0xC1, 0x7F, 0x09, 0xF7, 0xD0, 0x34, 0x56, 0x13, 0x04, 0x0B,
		0x1F, 0xA0, 0x20, 0x48, 0x18, 0x06
	};

	const unsigned char logsBloom[256] = {
0x04, 0x00, 0x20, 0x00, 0x00, 0x42, 0x00, 0x10, 0x02, 0x00, 0x40, 0x00, 0x08, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x20, 0x01, 0x68, 0x02, 0x00, 0x00, 0x00, 0x00, 0x80, 0x80, 0x00, 0x90, 0x00, 0x80, 0x00, 0x00, 0x4C, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x80, 0x03, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0x09, 0x00, 0x04, 0x21, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0xA0, 0x4D, 0x00, 0x00, 0x00, 0x01, 0xA4, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x20, 0xA0, 0x00, 0x00, 0x00, 0x00, 0x40, 0x60, 0x00, 0x00, 0x40, 0x00, 0x00, 0x02, 0x20, 0x00, 0x00, 0x01, 0x06, 0x00, 0x00, 0x04, 0x30, 0x21, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20, 0x80, 0x20, 0x00, 0x20, 0x00, 0x00, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00, 0x90, 0x40, 0x00, 0x00, 0x01, 0x00, 0x00, 0x80, 0x00, 0x04, 0x80, 0x02, 0x00, 0x02, 0x01, 0x02, 0x00, 0x00, 0x08, 0x04, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x00, 0x18, 0x00, 0x40, 0x40, 0x00, 0x80, 0x80, 0x20, 0x00, 0x14, 0x12, 0x00, 0x00, 0x80, 0x10, 0x00, 0x01, 0x30, 0x00, 0x00, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x01, 0x05, 0x20, 0x00, 0x00, 0x00, 0x40, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04, 0x01, 0x0A, 0x42, 0x04, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x11, 0x00, 0x00, 0x10, 0x00, 0x04, 0x00, 0x00, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0xA2, 0x00, 0x10, 0x20, 0x00, 0x04, 0x00, 0x00, 0x00, 0x80, 0x84, 0x02, 0x10, 0x00, 0x01, 0x10, 0x02, 0x80
	};

	const unsigned char difficulty[] = {
		0x05, 0x8D, 0x4D, 0x00, 0x3A, 0x5E, 0xAE
	};

	const unsigned char blockNumber[3] = {
		0x47, 0xB7, 0x60
	};

	const unsigned char gasLimit[3] = {
		0x66, 0x25, 0xF7
	};

	const unsigned char gasUsed[3] = {
		0x66, 0x07, 0xA1
	};

	const unsigned char timestamp[4] = {
		0x5A, 0x2B, 0x46, 0xBB
	};

	const unsigned char extraData[] = {
		0xE4, 0xB8, 0x83, 0xE5, 0xBD, 0xA9, 0xE7, 0xA5, 0x9E, 0xE4, 0xBB, 0x99, 0xE9, 0xB1, 0xBC
	};

	const unsigned char mixHash[] = {
		0x52, 0x47, 0x69, 0x1A, 0xB0, 0x95, 0x3F, 0xA5, 0xC5, 0xC2, 0xC8, 0x4B, 0x0B, 0x14, 0x2B,
		0x6D, 0x62, 0xE9, 0xDC, 0x5F, 0x35, 0xA8, 0x65, 0xED, 0x19, 0x7B, 0x9C, 0xD3, 0x73, 0x6A, 0xF6, 0xF1
	};

	const unsigned char nonce[] = {
		0x85, 0x72, 0x87, 0x40, 0x01, 0x60, 0x21, 0x8D
	};

 


	rlp_item items[15];

	decode_list(rlp_data, items);


	print_elm("parentHash", &items[0]);
	print_elm("ommersHash", &items[1]);
	print_elm("beneficiary", &items[2]);	
	print_elm("stateRoot", &items[3]);
	print_elm("transactionsRoot", &items[4]);
	print_elm("receiptsRoot", &items[5]);
	print_elm("logsBloom", &items[6]);
	print_elm("difficulty", &items[7]);
	print_elm("number", &items[8]);
	print_elm("gasLimit", &items[9]);	
	print_elm("gasUsed", &items[10]);	
	print_elm("timestamp", &items[11]);	
	print_elm("extraData", &items[12]);	
	print_elm("mixHash", &items[13]);	
	print_elm("nonce", &items[14]);

	CHECK_RLP_RESULT(items, 0, parnetHash);
	CHECK_RLP_RESULT(items, 1, ommersHash);
	CHECK_RLP_RESULT(items, 2, beneficiary);
	CHECK_RLP_RESULT(items, 3, stateRoot);
	CHECK_RLP_RESULT(items, 4, transactionRoot);
	CHECK_RLP_RESULT(items, 5, receiptsRoot);	
	CHECK_RLP_RESULT(items, 6, logsBloom);	
	CHECK_RLP_RESULT(items, 7, difficulty);	
	CHECK_RLP_RESULT(items, 8, blockNumber);	
	CHECK_RLP_RESULT(items, 9, gasLimit);	
	CHECK_RLP_RESULT(items, 10, gasUsed);	
	CHECK_RLP_RESULT(items, 11, timestamp);	
	CHECK_RLP_RESULT(items, 12, extraData);	
	CHECK_RLP_RESULT(items, 13, mixHash);	
	CHECK_RLP_RESULT(items, 14, nonce);	


	print_elm("parentHash", &items[0]);
	print_elm("ommersHash", &items[1]);
	print_elm("beneficiary", &items[2]);	
	print_elm("stateRoot", &items[3]);
	print_elm("transactionsRoot", &items[4]);
	print_elm("receiptsRoot", &items[5]);
	print_elm("logsBloom", &items[6]);
	print_elm("difficulty", &items[7]);
	print_elm("number", &items[8]);
	print_elm("gasLimit", &items[9]);	
	print_elm("gasUsed", &items[10]);	
	print_elm("timestamp", &items[11]);	
	print_elm("extraData", &items[12]);	
	print_elm("mixHash", &items[13]);	
	print_elm("nonce", &items[14]);

	return 0;

}


/*****************************************************************************/

int main() {

	printf("%s\n", test1() >= 0 ? "test succesful" : "test failed");		

	return 0;
}