import re

with open('./mdumpng.bin', 'rb') as f:
    data = f.read().decode('utf-8')

# Find all complete RSA keys
keys = re.findall(
    r'-----BEGIN (?:RSA|OPENSSH) PRIVATE KEY-----[\s\S]{100,3000}?-----END (?:RSA|OPENSSH) PRIVATE KEY-----',
    data
)
for i, k in enumerate(keys):
    print(f"=== KEY {i} ===")
    print(k)
    print()