56 lines
1.4 KiB
C++
56 lines
1.4 KiB
C++
// Based on <https://github.com/grant-olson/bitmessage-powfaster>
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// fastcpu implementation.
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// TODO(Kagami): Port it to WIN32 (see bitmessage-powfaster for an
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// example).
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#include <stdint.h>
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#include <string.h>
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#include <arpa/inet.h>
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#include <openssl/sha.h>
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#define HASH_SIZE 64
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#define NTOHLL(x) ( ( (uint64_t)(ntohl( (unsigned int)((x << 32) >> 32) )) << 32) | ntohl( ((unsigned int)(x >> 32)) ) )
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int pow(size_t pool_size,
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uint64_t target,
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const uint8_t* initial_hash,
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uint64_t max_nonce,
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uint64_t* nonce) {
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uint8_t message[HASH_SIZE+sizeof(uint64_t)];
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uint8_t digest[HASH_SIZE];
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uint64_t* be_nonce;
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uint64_t* be_trial;
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uint64_t i;
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SHA512_CTX sha;
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if (!max_nonce) {
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max_nonce = UINT64_MAX;
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}
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memcpy(message+sizeof(uint64_t), initial_hash, HASH_SIZE);
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be_nonce = (uint64_t *)message;
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be_trial = (uint64_t *)digest;
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i = 0;
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while (1) {
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// This is very unlikely to be ever happen but it's better to be
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// sure anyway.
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if (i > max_nonce) {
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return -1;
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}
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*be_nonce = NTOHLL(i);
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SHA512_Init(&sha);
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SHA512_Update(&sha, message, HASH_SIZE+sizeof(uint64_t));
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SHA512_Final(digest, &sha);
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SHA512_Init(&sha);
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SHA512_Update(&sha, digest, HASH_SIZE);
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SHA512_Final(digest, &sha);
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if (NTOHLL(*be_trial) <= target) {
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break;
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}
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i++;
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}
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*nonce = i;
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return 0;
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}
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