Support customizing prefix of private key (binary)

Makefile

@@ -1,6 +1,7 @@
 ## If compiling on mac, comment out LIBS and CFLAGS below, and use the MacOS ones below
 LIBS=-lpcre -lcrypto -lm -lpthread
 CFLAGS=-ggdb -O3 -Wall
+# CFLAGS=-ggdb -O3 -Wall -I /usr/local/cuda-10.2/include/
 
 ## If compiling on a mac make sure you install and use homebrew and run the following command `brew install pcre pcre++`
 ## Uncomment lines below and run `make all` 

README.md

@@ -2,7 +2,13 @@
 Vanity address generator for BTC, ETH, LTC, etc (more than 100 crypto currencies).
 
 # Build
-Run:
+Intall building dependencies in Redhat/CentOS:
+```
+$ yum install openssl-devel
+$ yum install libcurl-devel
+```
+
+Build executable file:
 ```
 $ make          # build: vanitygen++ keyconv
 $ make all      # build: vanitygen++ keyconv oclvanitygen++ oclvanityminer
@@ -52,6 +58,27 @@ ETH Privkey: 0xdb3813534c0c9595f9b8b35d6f544827065b33930ae42c38a9d7ce41a1d74669
 
 If you have OpenCL-compatible GPU, please use `oclvanitygen++`, it's faster.
 
+# Solve Puzzle
+This tool can be used for solving the [Bitcoin puzzle](https://bitcointalk.org/index.php?topic=1306983.0).
+
+For example, solve puzzle 6:
+```
+$ ./vanitygen++ -F compressed -Z 0000000000000000000000000000000000000000000000000000000000000000 -l $((256-6)) 1PitScNLyp2HCygzad
+Difficulty: 376259307977702824629384382540
+Pattern: 1PitScNLyp2HCygzad
+Address: 1PitScNLyp2HCygzadCh7FveTnfmpPbfp8
+Privkey: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qYjgd9M7rFU7Tmu6qHxS
+```
+
+Solve puzzle 20:
+```
+$ ./vanitygen++ -F compressed -Z 0000000000000000000000000000000000000000000000000000000000000000 -l $((256-20)) 1HsMJxNiV7TLxmoF6u
+Difficulty: 376259307977702824629384382540
+Pattern: 1HsMJxNiV7TLxmoF6u
+Address: 1HsMJxNiV7TLxmoF6uJNkydxPFDog4NQum
+Privkey: KwDiBf89QgGbjEhKnhXJuH7LrciVrZi3qYjgd9M7rHfuE2Tg4nJW
+```
+
 # Credit
 Many thanks to following projects:
 1. https://github.com/samr7/vanitygen

oclengine.c

@@ -2100,24 +2100,28 @@ vg_opencl_loop(vg_exec_context_t *arg)
 	vg_exec_context_upgrade_lock(vxcp);
 
 	pattern_generation = vcp->vc_pattern_generation;
-
+regen_key:
 	/* Generate a new random private key */
 	EC_KEY_generate_key(pkey);
 	npoints = 0;
-	if (vcp->vc_privkey_prefix_length > 0) {
+	if (vcp->vc_privkey_prefix_nbits > 0) {
+		/* Adjust private key to meet the requirement of privkey prefix (specified by option -Z) */
 		BIGNUM *pkbn = BN_dup(EC_KEY_get0_private_key(pkey));
 		unsigned char pkey_arr[32];
 		assert(BN_bn2bin(pkbn, pkey_arr) < 33);
-		memcpy((char *) pkey_arr, vcp->vc_privkey_prefix, vcp->vc_privkey_prefix_length);
-		for (i = 0; i < vcp->vc_privkey_prefix_length / 2; i++) {
-			int k = pkey_arr[i];
-			pkey_arr[i] = pkey_arr[vcp->vc_privkey_prefix_length - 1 - i];
-			pkey_arr[vcp->vc_privkey_prefix_length - 1 - i] = k;
-		}
+		copy_nbits((unsigned char *) pkey_arr, (unsigned char *)vcp->vc_privkey_prefix, vcp->vc_privkey_prefix_nbits);
 		BN_bin2bn(pkey_arr, 32, pkbn);
-		EC_KEY_set_private_key(pkey, pkbn);
+		if (BN_is_zero(pkbn)) {
+			fprintf(stderr, "the generated private key is zero, regenerate it\n");
+			goto regen_key;
+		}
+		// FIXME: private key (pbkn) may be too big if prefix specified by -Z has many FF
+		EC_KEY_set_private_key(pkey, pkbn); /* set private key in pkey */
 
 		EC_POINT *origin = EC_POINT_new(pgroup);
+		/* EC_POINT_mul: compute public_key = k * private_key
+		   here, origin is public_key, pkbn is private_key
+		   save public_key into 2nd param (origin) */
 		EC_POINT_mul(pgroup, origin, pkbn, NULL, NULL, vxcp->vxc_bnctx);
 		EC_KEY_set_public_key(pkey, origin);
 	}

oclvanitygen.c

@@ -88,6 +88,7 @@ usage(const char *name)
 "-o <file>     Write pattern matches to <file>\n"
 "-s <file>     Seed random number generator from <file>\n"
 "-Z <prefix>   Private key prefix in hex (1Address.io Dapp front-running protection)\n"
+"-l <nbits>    Specify the bits of prefix, only relevant when -Z is specified\n"
 "-z            Format output of matches in CSV(disables verbose mode)\n"
 "              Output as [COIN],[PREFIX],[ADDRESS],[PRIVKEY]\n",
 version, name);
@@ -131,6 +132,7 @@ main(int argc, char **argv)
 	int opened = 0;
 	char privkey_prefix[32];
 	int privkey_prefix_length = 0;
+	int privkey_prefix_nbits = 0;
 
 	FILE *pattfp[MAX_FILE], *fp;
 	int pattfpi[MAX_FILE];
@@ -142,7 +144,7 @@ main(int argc, char **argv)
 	int i;
 
 	while ((opt = getopt(argc, argv,
-			     "vqrik1zC:X:Y:F:eE:p:P:d:w:t:g:b:VSh?f:o:s:D:Z:a:")) != -1) {
+			     "vqrik1zC:X:Y:F:eE:p:P:d:w:t:g:b:VSh?f:o:s:D:Z:a:l:")) != -1) {
 		switch (opt) {
 		case 'r':
 			regex = 1;
@@ -368,9 +370,12 @@ main(int argc, char **argv)
 			for (i = 0; i < privkey_prefix_length; i++) {
 				int value; // Can't sscanf directly to char array because of overlapping on Win32
 				sscanf(&optarg[i*2], "%2x", &value);
-				privkey_prefix[privkey_prefix_length - 1 - i] = value;
+				privkey_prefix[i] = value;
 			}
 			break;
+		case 'l':
+			privkey_prefix_nbits = atoi(optarg);
+			break;
 		default:
 			usage(argv[0]);
 			return 1;
@@ -386,6 +391,24 @@ main(int argc, char **argv)
 	}
 #endif
 
+	/* Option -Z can be used with or without option -l
+	   but, option -l must use together with option -Z */
+	if (privkey_prefix_length == 0) { /* -Z not specified */
+		if (privkey_prefix_nbits > 0) { /* -l specified */
+			fprintf(stderr, "-l must use together with -Z)\n");
+			return 1;
+		}
+	} else if (privkey_prefix_length > 0) { /* -Z specified */
+		if (privkey_prefix_nbits == 0) { /* -l not specified */
+			privkey_prefix_nbits = privkey_prefix_length * 8;
+		} else if (privkey_prefix_nbits > 0) { /* -l specified */
+			if (privkey_prefix_nbits > privkey_prefix_length * 8) {
+				fprintf(stderr, "bits (specified by -l) is too big, must small than bits of prefix (%d bits)\n", privkey_prefix_length * 8);
+				return 1;
+			}
+		}
+	}
+
 	if (caseinsensitive && regex)
 		fprintf(stderr,
 			"WARNING: case insensitive mode incompatible with "
@@ -430,7 +453,7 @@ main(int argc, char **argv)
 	vcp->vc_pubkeytype = addrtype;
 	vcp->vc_pubkey_base = pubkey_base;
 	memcpy(vcp->vc_privkey_prefix, privkey_prefix, privkey_prefix_length);
-	vcp->vc_privkey_prefix_length = privkey_prefix_length;
+	vcp->vc_privkey_prefix_nbits = privkey_prefix_nbits;
 
 	vcp->vc_output_match = vg_output_match_console;
 	vcp->vc_output_timing = vg_output_timing_console;

pattern.h

@@ -114,7 +114,7 @@ struct _vg_context_s {
 	int			vc_pubkeytype;
 	EC_POINT		*vc_pubkey_base;
 	char			vc_privkey_prefix[32];
-	int			vc_privkey_prefix_length;
+	int			vc_privkey_prefix_nbits;
 	int			vc_halt;
 
 	vg_exec_context_t	*vc_threads;

util.c

@@ -1455,3 +1455,21 @@ eth_encode_checksum_addr(void * input, int inlen, char *output, int outlen)
 		}
 	}
 }
+
+// Like memcpy, but length specified by bits (rather than bytes)
+void copy_nbits(unsigned char *dst, unsigned char *src, int nbits) {
+	// An example:
+	// dst(input):  MMMMMMMM NNNNNNNN
+	// src:         IIIIIIII JJJJJJJJ
+	// nbits: 11
+	// dst(output): IIIIIIII JJJNNNNN
+	int nbytes = (nbits / 8) + 1; // (11 / 8) + 1 = 2
+	int extra_nbits = nbytes * 8 - nbits; // 2 * 8 - 11 = 5
+	char tab[8] = {0, 1, 3 /* 2 bits 1 */, 7 /* 3 bits 1 */, 15 /* 4 bits 1 */, 31 /* 5 bits 1 */,
+				   63 /* 6 bits 1 */, 127 /* 7 bits 1 */};
+	unsigned char backup = dst[nbytes - 1]; // NNNNNNNN
+	memcpy(dst, src, nbytes);
+	unsigned char after = dst[nbytes - 1]; // JJJJJJJJ
+	dst[nbytes - 1] = (backup & tab[extra_nbits])  // 000NNNNN
+					| (after & ~tab[extra_nbits]); // JJJ00000
+}

util.h

@@ -92,4 +92,5 @@ extern void eth_pubkey2addr(const unsigned char* pubkey_buf, int addrformat, uns
 
 extern void eth_encode_checksum_addr(void *input, int inlen, char *output, int outlen);
 
+extern void copy_nbits(unsigned char *dst, unsigned char *src, int nbits);
 #endif /* !defined (__VG_UTIL_H__) */

vanitygen.c

@@ -28,6 +28,7 @@
 #include <openssl/ec.h>
 #include <openssl/bn.h>
 #include <openssl/rand.h>
+#include <openssl/objects.h>
 
 #include "pattern.h"
 #include "util.h"
@@ -127,24 +128,29 @@ vg_thread_loop(void *arg)
 	while (!vcp->vc_halt) {
 		if (++npoints >= rekey_at) {
 			vg_exec_context_upgrade_lock(vxcp);
+		regen_key:
 			/* Generate a new random private key */
 			EC_KEY_generate_key(pkey);
-			if (vcp->vc_privkey_prefix_length > 0) {
+			if (vcp->vc_privkey_prefix_nbits > 0) {
+				/* Adjust private key to meet the requirement of privkey prefix (specified by option -Z) */
 				BIGNUM *pkbn = BN_dup(EC_KEY_get0_private_key(pkey));
 				unsigned char pkey_arr[32];
 				assert(BN_bn2bin(pkbn, pkey_arr) < 33);
-				memcpy((char *) pkey_arr, vcp->vc_privkey_prefix, vcp->vc_privkey_prefix_length);
-				for (i = 0; i < vcp->vc_privkey_prefix_length / 2; i++) {
-					int k = pkey_arr[i];
-					pkey_arr[i] = pkey_arr[vcp->vc_privkey_prefix_length - 1 - i];
-					pkey_arr[vcp->vc_privkey_prefix_length - 1 - i] = k;
-				}
+				copy_nbits((unsigned char *) pkey_arr, (unsigned char *)vcp->vc_privkey_prefix, vcp->vc_privkey_prefix_nbits);
 				BN_bin2bn(pkey_arr, 32, pkbn);
-				EC_KEY_set_private_key(pkey, pkbn);
+				if (BN_is_zero(pkbn)) {
+					fprintf(stderr, "the generated private key is zero, regenerate it\n");
+					goto regen_key;
+				}
+				// FIXME: private key (pbkn) may be too big if prefix specified by -Z has many FF
+				EC_KEY_set_private_key(pkey, pkbn); /* set private key in pkey */
 
 				EC_POINT *origin = EC_POINT_new(pgroup);
+				/* EC_POINT_mul: compute public_key = k * private_key
+				   here, origin is public_key, pkbn is private_key
+				   save public_key into 2nd param (origin) */
 				EC_POINT_mul(pgroup, origin, pkbn, NULL, NULL, vxcp->vxc_bnctx);
-				EC_KEY_set_public_key(pkey, origin);
+				EC_KEY_set_public_key(pkey, origin); /* set public key in pkey */
 			}
 			npoints = 0;
 
@@ -194,6 +200,8 @@ vg_thread_loop(void *arg)
 			for (nbatch = 0;
 			     (nbatch < ptarraysize) && (npoints < rekey_at);
 			     nbatch++, npoints++) {
+				/* compute public keys from continuous private key,
+				   save public keys into array ppnt */
 				EC_POINT_add(pgroup,
 					     ppnt[nbatch],
 					     ppnt[nbatch],
@@ -332,6 +340,7 @@ usage(const char *name)
 "-o <file>     Write pattern matches to <file>\n"
 "-s <file>     Seed random number generator from <file>\n"
 "-Z <prefix>   Private key prefix in hex (1Address.io Dapp front-running protection)\n"
+"-l <nbits>    Specify the bits of prefix, only relevant when -Z is specified\n"
 "-z            Format output of matches in CSV(disables verbose mode)\n"
 "              Output as [COIN],[PREFIX],[ADDRESS],[PRIVKEY]\n",
 version, name);
@@ -368,6 +377,7 @@ main(int argc, char **argv)
 	EC_POINT *pubkey_base = NULL;
 	char privkey_prefix[32];
 	int privkey_prefix_length = 0;
+	int privkey_prefix_nbits = 0;
 
 	FILE *pattfp[MAX_FILE], *fp;
 	int pattfpi[MAX_FILE];
@@ -377,7 +387,7 @@ main(int argc, char **argv)
 
 	int i;
 
-	while ((opt = getopt(argc, argv, "vqnrik1ezE:P:C:X:Y:F:t:h?f:o:s:Z:a:")) != -1) {
+	while ((opt = getopt(argc, argv, "vqnrik1ezE:P:C:X:Y:F:t:h?f:o:s:Z:a:l:")) != -1) {
 		switch (opt) {
 		case 'c':
 		        compressed = 1;
@@ -565,9 +575,12 @@ main(int argc, char **argv)
 			for (i = 0; i < privkey_prefix_length; i++) {
 				int value; // Can't sscanf directly to char array because of overlapping on Win32
 				sscanf(&optarg[i*2], "%2x", &value);
-				privkey_prefix[privkey_prefix_length - 1 - i] = value;
+				privkey_prefix[i] = value;
 			}
 			break;
+		case 'l':
+			privkey_prefix_nbits = atoi(optarg);
+			break;
 		default:
 			usage(argv[0]);
 			return 1;
@@ -658,6 +671,24 @@ main(int argc, char **argv)
 		return 0;
 	}
 
+	/* Option -Z can be used with or without option -l
+	   but, option -l must use together with option -Z */
+	if (privkey_prefix_length == 0) { /* -Z not specified */
+		if (privkey_prefix_nbits > 0) { /* -l specified */
+			fprintf(stderr, "-l must use together with -Z)\n");
+			return 1;
+		}
+	} else if (privkey_prefix_length > 0) { /* -Z specified */
+		if (privkey_prefix_nbits == 0) { /* -l not specified */
+			privkey_prefix_nbits = privkey_prefix_length * 8;
+		} else if (privkey_prefix_nbits > 0) { /* -l specified */
+			if (privkey_prefix_nbits > privkey_prefix_length * 8) {
+				fprintf(stderr, "bits (specified by -l) is too big, must small than bits of prefix (%d bits)\n", privkey_prefix_length * 8);
+				return 1;
+			}
+		}
+	}
+
 	if (caseinsensitive && regex)
 		fprintf(stderr,
 			"WARNING: case insensitive mode incompatible with "
@@ -714,7 +745,7 @@ main(int argc, char **argv)
 	vcp->vc_pubkeytype = pubkeytype;
 	vcp->vc_pubkey_base = pubkey_base;
 	memcpy(vcp->vc_privkey_prefix, privkey_prefix, privkey_prefix_length);
-	vcp->vc_privkey_prefix_length = privkey_prefix_length;
+	vcp->vc_privkey_prefix_nbits = privkey_prefix_nbits;
 
 	vcp->vc_output_match = vg_output_match_console;
 	vcp->vc_output_timing = vg_output_timing_console;