diff options
Diffstat (limited to 'csolver.go')
| -rw-r--r-- | csolver.go | 183 |
1 files changed, 1 insertions, 182 deletions
@@ -3,185 +3,4 @@ package main -const solverProgram = `// This is a reference implementation of the proof of work solver in C. -// For security reasons, it is recommended that you read and understand the -// entire program first if you actually want to run it. -// -// You need to have OpenSSL, and link with -lcrypto - -#include <openssl/evp.h> -#include <openssl/bio.h> -#include <openssl/buffer.h> -#include <stdbool.h> -#include <stdint.h> -#include <stdio.h> -#include <string.h> -#include <unistd.h> -#include <stdlib.h> -#include <errno.h> - -bool validate_bit_zeros(const unsigned char *bs, unsigned long n) -{ - unsigned long q = n / CHAR_BIT; - unsigned char r = n % CHAR_BIT; - - for (unsigned long i = 0; i < q; i++) { - if (bs[i] != 0) - return false; - } - - if (r > 0) { - unsigned char mask = - (unsigned char)(UCHAR_MAX << (CHAR_BIT - r)); - if (bs[q] & mask) - return false; - } - - return true; -} - -int main(int argc, char **argv) -{ - if (argc < 3) { - fprintf(stderr, "usage: %s <base64_data> <difficulty>\n", - argv[0]); - return 1; - } - - size_t base64_data_len = strlen(argv[1]); - unsigned char *base64_data = malloc(base64_data_len); - if (!base64_data) { - perror("malloc"); - return 1; - } - memcpy(base64_data, argv[1], base64_data_len); - - char *endptr = NULL; - errno = 0; - unsigned long difficulty = strtoul(argv[2], &endptr, 10); - if ((difficulty == ULONG_MAX && errno == ERANGE) || *endptr != '\0' - || difficulty > 256) { - fprintf(stderr, "invalid difficulty value\n"); - free(base64_data); - return 1; - } - - BIO *b64 = BIO_new(BIO_f_base64()); - BIO *bmem = BIO_new_mem_buf(base64_data, (int)base64_data_len); - if (!b64 || !bmem) { - fprintf(stderr, "BIO_new/BIO_new_mem_buf\n"); - free(base64_data); - return 1; - } - - BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL); - b64 = BIO_push(b64, bmem); - - size_t decoded_cap = base64_data_len; - unsigned char *decoded = malloc(decoded_cap); - if (!decoded) { - perror("malloc"); - BIO_free_all(b64); - free(base64_data); - return 1; - } - - int decoded_len = BIO_read(b64, decoded, (int)decoded_cap); - if (decoded_len < 0) { - fprintf(stderr, "BIO_read\n"); - BIO_free_all(b64); - free(base64_data); - free(decoded); - return 1; - } - BIO_free_all(b64); - free(base64_data); - - EVP_MD_CTX *mdctx = EVP_MD_CTX_new(); - if (!mdctx) { - fprintf(stderr, "EVP_MD_CTX_new\n"); - free(decoded); - return 1; - } - - size_t len = EVP_MD_size(EVP_sha256()); - unsigned char digest[len]; - size_t next = 0; - - while (1) { - if (EVP_DigestInit_ex(mdctx, EVP_sha256(), NULL) != 1) { - fprintf(stderr, "EVP_DigestInit_ex\n"); - EVP_MD_CTX_free(mdctx); - free(decoded); - return 1; - } - if (EVP_DigestUpdate(mdctx, decoded, decoded_len) != 1) { - fprintf(stderr, "EVP_DigestUpdate(data)\n"); - EVP_MD_CTX_free(mdctx); - free(decoded); - return 1; - } - if (EVP_DigestUpdate(mdctx, &next, sizeof(next)) != 1) { - fprintf(stderr, "EVP_DigestUpdate(next)\n"); - EVP_MD_CTX_free(mdctx); - free(decoded); - return 1; - } - if (EVP_DigestFinal_ex(mdctx, digest, NULL) != 1) { - fprintf(stderr, "EVP_DigestFinal_ex\n"); - EVP_MD_CTX_free(mdctx); - free(decoded); - return 1; - } - if (validate_bit_zeros(digest, difficulty)) { - break; - } - next++; - if (!next) { - fprintf(stderr, "unsigned integer overflow\n"); - EVP_MD_CTX_free(mdctx); - free(decoded); - return 1; - } - } - EVP_MD_CTX_free(mdctx); - free(decoded); - - BIO *b64_out = BIO_new(BIO_f_base64()); - BIO *bmem_out = BIO_new(BIO_s_mem()); - if (!b64_out || !bmem_out) { - fprintf(stderr, "BIO_new\n"); - if (b64_out) - BIO_free_all(b64_out); - if (bmem_out) - BIO_free(bmem_out); - return 1; - } - BIO_set_flags(b64_out, BIO_FLAGS_BASE64_NO_NL); - b64_out = BIO_push(b64_out, bmem_out); - - if (BIO_write(b64_out, &next, sizeof(next)) < 0) { - fprintf(stderr, "BIO_write\n"); - BIO_free_all(b64_out); - return 1; - } - if (BIO_flush(b64_out) < 1) { - fprintf(stderr, "BIO_flush\n"); - BIO_free_all(b64_out); - return 1; - } - - BUF_MEM *bptr = NULL; - BIO_get_mem_ptr(b64_out, &bptr); - if (!bptr || !bptr->data) { - fprintf(stderr, "BIO_get_mem_ptr\n"); - BIO_free_all(b64_out); - return 1; - } - - write(STDOUT_FILENO, bptr->data, bptr->length); - write(STDOUT_FILENO, "\n", 1); - - BIO_free_all(b64_out); - return 0; -}` +const solverProgram = `` |