Squash commits for public release

utils/crypto/elfsign.py

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+import sys
+import hashlib
+import argparse
+import subprocess
+import codecs
+from elftools.elf.elffile import ELFFile
+
+# Test Key Set.
+PRIVATE_D = 0x38df48893d28df263487987da506d0c56d5f817573bc091071c5cd798d78ba4c996f946a2d695b9b4428794c59500ba2e5b2ed383aa791b18f56fd90875010eddb98c37113f9717511a2845edbcc85e9c559f74d474c107767666f894357c1439217ce82d0181a58ce9a8ad75e3a37ccb3aeba5ba07dd2f8cb8b92ae2735e275
+PUBLIC_N = 0xa65f3fc1e6e850b5c7174fb7c0b30f36507ad9a67e83abe707b176fb7f44230711ffe8291119d921e0e483024dc6e603a628996ec2c875069aef21f1b9e9cfbcd3f7ee6f4ecf1bc67d9d7239adef94596038b4b5833ee34b4ddad75b17ad8f8fbb2cd5149115602aa57aecdfdacbea8a7fe735c98784a4b1868986dced517e1d
+PUBLIC_E = 0x10001
+
+parser = argparse.ArgumentParser()
+parser.add_argument('target', type=str, help='Target third_part package')
+parser.add_argument('--overwrite', action='store_true',
+                    help='Overwrites exisiting signature')
+args = parser.parse_args()
+
+
+def shell(cmd, cwd=None):
+    return subprocess.check_output(cmd, shell=True, cwd=cwd).decode("ascii")
+
+
+elffile_path = args.target
+signfield_loc = 0
+sha256_hash = hashlib.sha256()
+
+def int_to_bytes(n, nsize=128):
+    xs = bytearray()
+    while (n):
+        by = n % 256
+        xs.append(by)
+        n //= 256
+
+    while len(xs) < nsize:
+        xs.append(0)
+
+    return xs
+
+with open(elffile_path, 'rb') as elffile:
+    signature_section = None
+    for section in ELFFile(elffile).iter_sections():
+        if section.name == "._signature":
+            signature_section = section
+            signfield_loc = section['sh_offset']
+
+    if signature_section is None:
+        print("Elf file is not configured for signing.")
+        exit(1)
+
+    if not args.overwrite:
+        for byte in signature_section.data():
+            if byte != 0:
+                print("Signature:", ''.join('{:02x}'.format(x)
+                                            for x in signature_section.data()[:128]))
+
+                print("Elf file is already signed.")
+                exit(0)
+
+    signfield_loc = signature_section['sh_offset']
+
+    for segment in ELFFile(elffile).iter_segments():
+        seg_head = segment.header
+        if seg_head.p_type == "PT_LOAD":
+            sha256_hash.update(segment.data())
+
+
+hash = int(codecs.encode(sha256_hash.digest(), 'hex'), 16)
+signature = pow(hash, PRIVATE_D, PUBLIC_N)
+
+signature_file = open(elffile_path, "r+b")
+signature_file.seek(signfield_loc)
+signature_file.write(int_to_bytes(signature))
+signature_file.close()