OpenSSL 3.0 performance issue: SSLContext.set_default_verify_paths / load_verify_locations about 5x slower

從提供的 Python 重現程式開始，在 Ubuntu 20.04/OpenSSL 1.1 和 Ubuntu 22.04/OpenSSL 3.0.2 上對 SSLContext.load_verify_locations 和 set_default_verify_paths 進行基準測試。追蹤回歸問題究竟出在 CPython 的 ssl 整合中還是 OpenSSL 中，然後確認原因，並根據報告中的耗時驗證效能改善。

Bug report
Example code in ubuntu20.04(openssl1.1) is much faster than ubuntu22.04(openssl3.x)
Not just speed, CPU occupancy ubuntu22.04(openssl3.x) is many times of ubuntu20.04(openssl1.1)
I'm not sure whether it's OpenSSL or Python adaptation problem

import socket
import ssl
import time

import certifi
hostname = 'www.python.org'  # any support https hostname
times = 100
pem_where = certifi.where()
context = ssl.create_default_context()
verify_total_time = 0

for i in range(times):
    with socket.create_connection((hostname, 443)) as sock:
        with context.wrap_socket(sock, server_hostname=hostname) as ssock:
            verify_start_time = time.time()
            context.load_verify_locations(pem_where)
            verify_total_time += time.time() - verify_start_time
            ssock.version()
            
print(f"total {verify_total_time:.4f}, avg {verify_total_time/times:.4f}")

in my environment with docker:

  PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
 3321 root      20   0  304140  81148  12792 S  42.0   0.8   0:29.69 ipython    (ubuntu22.04)
 3850 root      20   0  203348  52632  11576 S  16.7   0.5   0:06.34 ipython    (ubuntu20.04)

total 5.8634, avg 0.0586  (ubuntu22.04)
total 0.6753, avg 0.0068  (ubuntu20.04)

Your environment

• CPython versions tested on: 3.10.5
• Operating system and architecture: ubuntu20.04(openssl1.1) and ubuntu22.04(openssl3.0.2), build from source
• certifi==2022.6.15