can pass slh_dsa schemes to copy_from_upstream

Signed-off-by: Ganyu (Bruce) Xu <g66xu@uwaterloo.ca>

scripts/copy_from_upstream/copy_from_slh_dsa_c.py

@@ -337,5 +337,18 @@ def main():
     # apply patches
     apply_patches(slh_patch_dir)
 
+    # NOTE: from [issue 2203](https://github.com/open-quantum-safe/liboqs/issues/2203)
+    # SLH-DSA is not described in copy_from_upstream.yml. It is instead described
+    # here in this separate module. This makes replacing SPHINCS+ with SLH-DSA
+    # in list_standardized_algs.fragment non-trivial because this Jinja template
+    # is rendered from copy_from_upstream.yml.
+    # As a necessary hack, the list of variants (e.g. "pure_sha2_128s") is returned
+    # so that copy_from_upstream.py can use this list to construct a dictionary
+    # that resembles the structure of copy_from_upstream.yml.
+    # In the near future I want to consider refactoring build configuration
+    # management and upstream integration scripts. The status quo is a mess and
+    # will make future integrations all the more difficult.
+    return variants
+
 if __name__ == "__main__":
     main()

scripts/copy_from_upstream/copy_from_upstream.py

@@ -16,6 +16,7 @@ import json
 import platform
 import update_upstream_alg_docs
 import copy_from_slh_dsa_c
+from copy import deepcopy
 
 # kats of all algs
 kats = {}
@@ -701,12 +702,20 @@ def process_families(instructions, basedir, with_kat, with_generator, with_libja
             )
 
 
-def copy_from_upstream():
+def copy_from_upstream(slh_dsa_inst: dict):
+    """Integrate upstreams implementations and algorithms described in 
+    copy_from_upstream.yml.
+
+    :param slh_dsa_inst: instruction for integrating SLH-DSA, only used for 
+    rendering alg_support.cmake
+    """
     for t in ["kem", "sig"]:
         with open(os.path.join(os.environ['LIBOQS_DIR'], 'tests', 'KATs', t, 'kats.json'), 'r') as fp:
             kats[t] = json.load(fp)
 
     instructions = load_instructions('copy_from_upstream.yml')
+    patched_inst: dict = deepcopy(instructions)
+    patched_inst["sigs"].append(slh_dsa_instruction["sigs"][0])
     process_families(instructions, os.environ['LIBOQS_DIR'], True, True)
     replacer('.CMake/alg_support.cmake', instructions, '#####')
     replacer('CMakeLists.txt', instructions, '#####')
@@ -839,9 +848,19 @@ non_upstream_kems = count_non_upstream_kems(['bike', 'frodokem', 'ntruprime', 'n
 
 if args.operation == "copy":
     # copy_from_slh_dsa_c will modify slh_dsa.yml before copy_from_upstream modifies md files
-    copy_from_slh_dsa_c.main()
+    slh_dsa_schemes: list[str] = copy_from_slh_dsa_c.main()
+    slh_dsa_instruction = {
+        "sigs": [
+            {
+                "name": "slh_dsa",
+                "schemes": {
+                    "scheme": scheme for scheme in slh_dsa_schemes
+                }
+            }
+        ]
+    }
     os.chdir(os.path.join(os.environ['LIBOQS_DIR'],"scripts","copy_from_upstream"))
-    copy_from_upstream()
+    copy_from_upstream(slh_dsa_instruction)
 elif args.operation == "libjade":
     copy_from_libjade()
 elif args.operation == "verify":