cat transaction.bin | openssl sha256 -binary | openssl sha256

/*
gcc bctrans.c -o bctrans.exe -lcrypto -I /local/ssl/include -L /local/ssl/lib
*/

#include <stdio.h>
#include <stdlib.h>
#include <stdlib.h>
#include <strings.h>
#include <openssl/sha.h>
#include <openssl/bn.h>


static unsigned char addr_version = 0x00;
static FILE *f = NULL;

BIGNUM *bn58, dv, mo;
BN_CTX *ctx;


#define SHA256(p,l,o) { \
	SHA256_CTX shactx; \
	SHA256_Init(&shactx); \
	SHA256_Update(&shactx, (p), (l)); \
	SHA256_Final((o), &shactx); }


void readfile(unsigned char *p, int len) {
	if (!f) {
		int c, i;
		char s[3];
		while (len>0) {
			for (i=0;i<2;) {
				c = getchar();
				if (c==EOF) {
					fprintf(stderr, "File too short\n");
					exit(1);
				}
				c = tolower(c);
				if (c<='9' && c>='0' || c<='f' && c>='a')  s[i++] = (char)c;
			}
			s[2] = 0;
			sscanf(s, "%x", &c);
			*p = (unsigned char)c;
			p++;
			len--;
		}
	} else {
		if (fread(p, 1, len, f)!=len) {
			fprintf(stderr, "File too short\n");
			fclose(f);
			exit(1);
		}
	}
}

unsigned long long getle(unsigned char *p, int bytes) {
	unsigned long long res=0;
	while (bytes--) {
		res|= ((unsigned long long)(p[bytes]))<<(8*bytes);
	}
	return res;
}

unsigned long long getvl() {
	unsigned char b[8];
	readfile(b, 1);
	switch (*b) {
		case 0xfd:
			readfile(b, 2);
			return getle(b, 2);
		case 0xfe:
			readfile(b, 4);
			return getle(b, 4);
		case 0xff:
			readfile(b, 8);
			return getle(b, 8);
	}
	return *b;
}


void prhash(unsigned char *p, unsigned int l) {
	while (l--) printf("%02x", p[l]);
}


void hexdump(unsigned char *p, unsigned int l) {
	while (l--) printf("%02x", *p++);
}


void printbtcaddr(unsigned char *p) {
	static const char *chrs = "123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
	unsigned char mod;
	char out[64];
	int i=0, j=0;
	BIGNUM *bn = BN_bin2bn(p, 25, NULL);
	while (!BN_is_zero(bn)) {
		BN_div(&dv, &mo, bn, bn58, ctx);
		if (BN_bn2bin(&mo, &mod)==0)  mod = 0;
		out[i++] = chrs[mod];
		BN_copy(bn, &dv);
	}
	BN_free(bn);
	while ((*p)==0) {
		putchar('1');
		p++;
	}
	while (i--)  putchar(out[i]);
}


int main(int argc, char * argv[]) {
	static unsigned char buf[0x10000];
	unsigned long long i, sl, txcnt, v;
	unsigned va, vb;
	int x;
	long fpos;
	char *fname = NULL;

	for (x=1; x<argc; x++) {
		if (strcmp(argv[x], "-t")==0) {
			addr_version = 0x6f; // testnet
		} else {
			fname = argv[x];
		}
	}
	
	if (!fname) {
		printf("Enter transactions hexdump data:\n");
	} else {
		f = fopen(fname, "rb");
		if (!f) {
			fprintf(stderr, "File %s not found\n", fname);
			return 1;
		}
	}

	readfile(buf, 4);
	printf("Version: %llu\n", getle(buf, 4));

	txcnt = getvl();
	printf("TX IN cnt: %llu\n", txcnt);
	for (i=0; i<txcnt; i++) {
		readfile(buf, 36);
		sl = getvl();

		printf("%6d) : ", (int)i);
		prhash(buf, 32);
		printf(" Idx=%2lld  sl=%lld", getle(buf+32, 4), sl);
		readfile(buf, sl);
		readfile(buf, 4);

		printf(" seq=%x\n", (unsigned)getle(buf, 4));
	}

	txcnt = getvl();
	printf("TX OUT cnt: %llu\n", txcnt);

	ctx = BN_CTX_new();
	bn58 = BN_bin2bn("\x3a", 1, NULL);
	BN_init(&dv);
	BN_init(&mo);

	for (i=0; i<txcnt; i++) {
		readfile(buf, 8);
		sl = getvl();
		v = getle(buf, 8);
		va = (unsigned)(v/100000000LL);
		vb = (unsigned)(v%100000000LL);
		printf("%6d) : %7u.%08u BTC", (int)i, va, vb, sl);
		readfile(buf, sl);
		if (sl!=25 || memcmp(buf, "\x76\xa9\x14", 3) || buf[23]!=0x88 || buf[24]!=0xac) {
			printf("  WARNING! Unexpected SIG_SCRIPT:\n"); hexdump(buf, sl);
		} else {
			unsigned char dat[25];
			unsigned char sha[SHA256_DIGEST_LENGTH];
			unsigned char sha2[SHA256_DIGEST_LENGTH];
			dat[0] = addr_version; // version
			memcpy(dat+1, buf+3, 20);
			SHA256(dat, 21, sha);
			SHA256(sha, SHA256_DIGEST_LENGTH, sha2);
			//printf("  chsum:%02x%02x%02x%02x", sha2[0], sha2[1], sha2[2], sha2[3]);
			memcpy(dat+21, sha2, 4); 
			printf("  to address "); printbtcaddr(dat);
		}
		putchar('\n');
	}

	BN_free(bn58);
	BN_CTX_free(ctx);

	readfile(buf, 4);
	printf("Lock Time: %llu\n", getle(buf, 4));

	if (f) {
		fpos = ftell(f);
		fseek(f, 0, SEEK_END);
		if (fpos!=ftell(f)) {
			printf("WARNING!!! File too long. Only %ld bytes expected (%ld too many)\n",
				fpos, ftell(f)-fpos);
		} else {
			printf("File size checked OK - %ld bytes\n", fpos);
		}
		fclose(f);
	}

	return 0;
}

<txid>-<vout> # comment (amount, b58 address, etc - not mandatory)