Implement randomx with preset blake hash

src/randomx.cpp

@@ -431,6 +431,36 @@ extern "C" {
 		return (const unsigned char*)machine->getScratchpad();
 	}
 
+	void randomx_calculate_hash_with_scratchpad_with_presets(randomx_vm *machine, unsigned char *inHash, const int randomxProgramCount) {
+
+		assert(machine != nullptr);
+
+#ifdef USE_CSR_INTRINSICS
+		const unsigned int fpstate = _mm_getcsr();
+#else
+		fenv_t fpstate;
+		fegetenv(&fpstate);
+#endif
+
+		int blakeResult;
+		for (int chain = 0; chain < randomxProgramCount; ++chain) {
+			machine->run(inHash);
+			blakeResult = randomx_blake2b(inHash, sizeof(inHash), machine->getRegisterFile(), sizeof(randomx::RegisterFile), nullptr, 0);
+			assert(blakeResult == 0);
+		}
+
+#ifdef USE_CSR_INTRINSICS
+		_mm_setcsr(fpstate);
+#else
+		fesetenv(&fpstate);
+#endif
+	}
+
+	unsigned char *randomx_get_scratchpad(randomx_vm *machine) {
+		assert(machine != nullptr);
+		return (unsigned char*)machine->getScratchpad();
+	}
+
 	void randomx_calculate_hash_first(randomx_vm* machine, const void* input, size_t inputSize) {
 		blake2b(machine->tempHash, sizeof(machine->tempHash), input, inputSize, nullptr, 0);
 		machine->initScratchpad(machine->tempHash);

src/randomx.h

@@ -190,6 +190,14 @@ RANDOMX_EXPORT void randomx_release_dataset(randomx_dataset *dataset);
  * @return the size of the scratchpad in bytes.
 */
 RANDOMX_EXPORT unsigned long randomx_get_scratchpad_size(void);
+/**
+ * Returns a pointer to the scratchpad memory of the virtual machine.
+ *
+ * @param machine is a pointer to a randomx_vm structure. Must not be NULL.
+ *
+ * @return Pointer to the scratchpad memory of the virtual machine.
+*/
+RANDOMX_EXPORT unsigned char *randomx_get_scratchpad(randomx_vm *machine);
 
 /**
  * Creates and initializes a RandomX virtual machine.
@@ -256,6 +264,7 @@ RANDOMX_EXPORT void randomx_destroy_vm(randomx_vm *machine);
 */
 RANDOMX_EXPORT void randomx_calculate_hash(randomx_vm *machine, const void *input, size_t inputSize, void *output);
 
+
 /**
  * Calculates a RandomX long hash value.
  * Long hash is effectively the vm scratchpad taken after finalizing the regular hash.
@@ -267,6 +276,16 @@ RANDOMX_EXPORT void randomx_calculate_hash(randomx_vm *machine, const void *inpu
 */
 RANDOMX_EXPORT const unsigned char *randomx_calculate_hash_scratchpad(randomx_vm *machine, const void *input, size_t inputSize, const int randomxProgramCount);
 
+/**
+ * Calculates a RandomX long hash value.
+ * Long hash is effectively the vm scratchpad taken after finalizing the regular hash.
+ *
+ * @param machine is a pointer to a randomx_vm structure. Must not be NULL.
+ * @param inHash is a pointer to the initial hash value. Must not be NULL.
+ * @param randomxProgramCount is the number of RandomX iterations.
+*/
+RANDOMX_EXPORT void randomx_calculate_hash_with_scratchpad_with_presets(randomx_vm *machine, unsigned char *inHash, const int randomxProgramCount);
+
 /**
  * Set of functions used to calculate multiple RandomX hashes more efficiently.
  * randomx_calculate_hash_first will begin a hash calculation.