Overhaul ML-KEM regress once more

Implement a file parser that drives a state machine to extract the test data
from the .txt files and manages the parsed data. Comments and empty lines are
ignored. The code currently assumes that instruction lines are at the start
of the file (which isn't generally true) and only supports two line types for
now. This is good enough for all the ML-KEM tests but should be easy enough
to extend.

Once all data for a test case is parsed in the expected order, a test handler
is called which can retrieve the test data via a simple API and throw warnings
and errors with information on the test case line number, etc.

Merge the tests into three programs: one parsing the .txt files and running
the corresponding test cases, a unit test and the iteration tests. Deduplicate
the actual test code and let the caller pass in an object containing the
API functions, private keys and arrays that need to be different between the
768 version and the 1024 version. This way we don't have two sets of half a
dozen .c files differing only in 3 or 4 occurrences of 768 and 1024.

All this will also make it a lot easier to hook these tests into portable.

1 files changed, 83 insertions, 0 deletions

diff --git a/src/regress/lib/libcrypto/mlkem/parse_test_file.h b/src/regress/lib/libcrypto/mlkem/parse_test_file.h
new file mode 100644
index 0000000000..772b7f6232
--- /dev/null
+++ b/src/regress/lib/libcrypto/mlkem/parse_test_file.h
@@ -0,0 +1,83 @@
+/*      $OpenBSD: parse_test_file.h,v 1.1 2024/12/26 00:04:24 tb Exp $ */
+
+/*
+ * Copyright (c) 2024 Theo Buehler <tb@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef PARSE_TEST_FILE_H
+#define PARSE_TEST_FILE_H
+
+#include <stdint.h>
+#include <stdio.h>
+
+#include "bytestring.h"
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
+
+struct parse;
+
+enum line {
+        LINE_STRING_MATCH,      /* Checks if string after label matches. */
+        LINE_HEX,               /* Parses hex into cbb from type2cbb. */
+};
+
+struct line_spec {
+        int              state;
+        enum line        type;
+        const char      *name;
+        const char      *label; /* followed by ": " or " = " */
+        const char      *match; /* only for LINE_STRING_MATCH */
+};
+
+struct test_parse {
+        const struct line_spec *states;
+        size_t num_states;
+
+        const struct line_spec *instructions;
+        size_t num_instructions;
+
+        int (*init)(void *ctx, void *parse_ctx);
+        void (*finish)(void *ctx);
+
+        int (*run_test_case)(void *ctx);
+};
+
+int parse_test_file(const char *fn, const struct test_parse *lctx, void *ctx);
+
+int parse_get_int(struct parse *p, size_t idx, int *out);
+int parse_get_cbs(struct parse *p, size_t idx, CBS *out);
+
+int parse_instruction_get_int(struct parse *p, size_t idx, int *out);
+int parse_instruction_get_cbs(struct parse *p, size_t idx, CBS *out);
+
+int parse_length_equal(struct parse *p, const char *descr, size_t want, size_t got);
+int parse_data_equal(struct parse *p, const char *descr, CBS *want,
+    const uint8_t *got, size_t len);
+
+void parse_info(struct parse *ctx, const char *fmt, ...)
+    __attribute__((__format__ (printf, 2, 3)))
+    __attribute__((__nonnull__ (2)));
+void parse_errx(struct parse *ctx, const char *fmt, ...)
+    __attribute__((__format__ (printf, 2, 3)))
+    __attribute__((__nonnull__ (2)))
+    __attribute__((__noreturn__));
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* PARSE_TEST_FILE_H */