1 files changed, 145 insertions, 0 deletions
diff --git a/src/ext/equix/include/equix.h b/src/ext/equix/include/equix.h
new file mode 100644
index 0000000000..01ab249437
--- /dev/null
+++ b/src/ext/equix/include/equix.h
@@ -0,0 +1,145 @@
+/* Copyright (c) 2020 tevador <tevador@gmail.com> */
+/* See LICENSE for licensing information */
+
+#ifndef EQUIX_H
+#define EQUIX_H
+
+#include <stdint.h>
+#include <stddef.h>
+
+/*
+ * The solver will return at most this many solutions.
+ */
+#define EQUIX_MAX_SOLS 8
+
+/*
+ * The number of indices.
+ */
+#define EQUIX_NUM_IDX 8
+
+/*
+ * 16-bit index.
+ */
+typedef uint16_t equix_idx;
+
+/*
+ *  The solution.
+ */
+typedef struct equix_solution {
+    equix_idx idx[EQUIX_NUM_IDX];
+} equix_solution;
+
+/*
+ * Solution verification results
+ */
+typedef enum equix_result {
+    EQUIX_OK,               /* Solution is valid */
+    EQUIX_CHALLENGE,        /* The challenge is invalid (the internal hash
+                               function doesn't pass validation). */
+    EQUIX_ORDER,            /* Indices are not in the correct order. */
+    EQUIX_PARTIAL_SUM,      /* The partial sums of the hash values don't
+                               have the required number of trailing zeroes. */
+    EQUIX_FINAL_SUM         /* The hash values don't sum to zero. */
+} equix_result;
+
+/*
+ * Opaque struct that holds the Equi-X context
+ */
+typedef struct equix_ctx equix_ctx;
+
+/*
+ * Flags for context creation
+*/
+typedef enum equix_ctx_flags {
+    EQUIX_CTX_VERIFY = 0,       /* Context for verification */
+    EQUIX_CTX_SOLVE = 1,        /* Context for solving */
+    EQUIX_CTX_COMPILE = 2,      /* Compile internal hash function */
+    EQUIX_CTX_HUGEPAGES = 4,    /* Allocate solver memory using HugePages */
+} equix_ctx_flags;
+
+/* Sentinel value used to indicate unsupported type */
+#define EQUIX_NOTSUPP ((equix_ctx*)-1)
+
+#if defined(_WIN32) || defined(__CYGWIN__)
+#define EQUIX_WIN
+#endif
+
+/* Shared/static library definitions */
+#ifdef EQUIX_WIN
+    #ifdef EQUIX_SHARED
+        #define EQUIX_API __declspec(dllexport)
+    #elif !defined(EQUIX_STATIC)
+        #define EQUIX_API __declspec(dllimport)
+    #else
+        #define EQUIX_API
+    #endif
+    #define EQUIX_PRIVATE
+#else
+    #ifdef EQUIX_SHARED
+        #define EQUIX_API __attribute__ ((visibility ("default")))
+    #else
+        #define EQUIX_API __attribute__ ((visibility ("hidden")))
+    #endif
+    #define EQUIX_PRIVATE __attribute__ ((visibility ("hidden")))
+#endif
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Allocate an Equi-X context.
+ *
+ * @param flags is the type of context to be created
+ *
+ * @return pointer to a newly created context. Returns NULL on memory
+ *         allocation failure and EQUIX_NOTSUPP if the requested type
+ *         is not supported.
+ */
+EQUIX_API equix_ctx* equix_alloc(equix_ctx_flags flags);
+
+/*
+* Free an Equi-X a context.
+*
+* @param ctx is a pointer to the context
+*/
+EQUIX_API void equix_free(equix_ctx* ctx);
+
+/*
+ * Find Equi-X solutions for the given challenge.
+ *
+ * @param ctx             pointer to an Equi-X context
+ * @param challenge       pointer to the challenge data
+ * @param challenge_size  size of the challenge
+ * @param output          pointer to the output array where solutions will be
+ *                        stored
+ *
+ * @return the number of solutions found
+ */
+EQUIX_API int equix_solve(
+    equix_ctx* ctx,
+    const void* challenge,
+    size_t challenge_size,
+    equix_solution output[EQUIX_MAX_SOLS]);
+
+/*
+ * Verify an Equi-X solution.
+ *
+ * @param ctx             pointer to an Equi-X context
+ * @param challenge       pointer to the challenge data
+ * @param challenge_size  size of the challenge
+ * @param solution        pointer to the solution to be verified
+ *
+ * @return verification result
+*/
+EQUIX_API equix_result equix_verify(
+    equix_ctx* ctx,
+    const void* challenge,
+    size_t challenge_size,
+    const equix_solution* solution);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif