Uncertify/ssl_context.py at master · felHR85/Uncertify · GitHub

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import os
import re

init_context_line = "Ljavax/net/ssl/SSLContext;->init([Ljavax/net/ssl/KeyManager;[Ljavax/net/ssl/TrustManager;Ljava/security/SecureRandom;)V"

def modify_ssl_contexts(app_folder):
    modified_files = _search_ssl_contexts(app_folder)
    return len(modified_files) > 0


def _search_ssl_contexts(app_folder):
    modified_files = []
    for root, dirs, files in os.walk(app_folder):
        if "okhttp3" not in root:
            modified_files.append(_bypass_ssl_context_init(files, root))
    return modified_files

def _bypass_ssl_context_init(files, root):
    files_modified = []
    smali_files = list(filter(lambda x: ".smali" in x, files))
    for f in smali_files:
        file_lines = open(os.path.join(root, f), 'r').readlines()
        tuple_lines = zip(range(len(file_lines)), file_lines)
        list_ocurrence = list(filter(lambda x: init_context_line in x[1], tuple_lines))
        if len(list_ocurrence) == 0:
            continue

        for i in list_ocurrence:
            ocurrence = i[0]
            index_begin_method = list(filter(lambda x: ".method" in x[1] and x[0] < ocurrence , zip(range(len(file_lines)), file_lines)))[-1][0]
            # Increase local variables
            current_locals = int(file_lines[index_begin_method + 1].split()[1])
            current_locals = current_locals + 1
            file_lines[index_begin_method + 1] = "\t.locals " + str(current_locals) + "\n"

            # Set the last vX register to null
            dummy_register = "v" + str(current_locals - 1)
            dummy_register_value = "\tconst/4 " + dummy_register + ", 0x0\n"
            file_lines.insert(ocurrence -1, dummy_register_value)

            # Get all vX and pX used in the invocation of SSLContext init method
            line = file_lines[ocurrence + 1]
            findings = re.findall("v[0-9]+|p[0-9]+", line)

            # Replace all of them except the first one for our dummy register
            line = line.replace(findings[1], dummy_register)
            line = line.replace(findings[2], dummy_register)
            line = line.replace(findings[3], dummy_register)

            file_lines[ocurrence + 1] = line

        with open(os.path.join(root, f), 'w') as smali_file:
            for item in file_lines:
                smali_file.write(item)

        files_modified.append((ocurrence, f))

    return files_modified