1. 已有方案

如下 link 告知在 pcap 文件中如何使用 (Pre)-Master-Secret 文件，以及如何把 pcap 和 (Pre)-Master-Secret 文件转为 pcapng文件。
https://wiki.wireshark.org/TLS
如下 link 在国内打不开：
https://gist.github.com/Lekensteyn/f64ba6d6d2c6229d6ec444647979ea24
不过可以搜索到如下 link，应该可以实现同样的功能：
https://github.com/triplewy/quic/blob/master/inject-tls-secrets.py

2. 新的方案

需要提前了解下 pcapng 规范：
PCAP Next Generation (pcapng) Capture File Format
https://github.com/pcapng/pcapng

该方案可以在输入文件的同路径下生成 pcapng 文件：

源码如下：
inject-tls-secrets-by-pcapng.py

# -*- coding: utf-8 -*-
"""
Created on Sat Dec  3 19:31:06 2022

@author: litao
"""
from tkinter import *
from tkinter import ttk
from tkinter import filedialog
from tkinter.scrolledtext import ScrolledText
import binascii
from scapy.all import *
from pcapng import FileWriter
import pcapng.blocks as blocks
from pcapng.structs import (
    PacketBytes,
)


@blocks.register_block
class DecryptionSecretsBlock(blocks.SectionMemberBlock):
    magic_number = 0x0000000A
    __slots__ = []
    schema = [
        # We don't actually use this field; see _decode()/_encode()
        ("data", PacketBytes("data"), b""),
    ]


class GeneratePcapngWithTLSKey:
    
    def __init__(self):
        pass

    def create_pcapng(self, in_pcap_file, out_pcapng_file, tls_key_file):
        out = open(out_pcapng_file, 'wb')
        shb = blocks.SectionHeader(
            options={
                'shb_hardware': 'Any',
                'shb_os': 'Any OS',
                'shb_userappl': 'Built in TLS password',
            }
        )
        idb_raw = shb.new_member(
            blocks.InterfaceDescription,
            link_type=101,
            snaplen=65535
        )
        idb_user15 = shb.new_member(
            blocks.InterfaceDescription,
            link_type=162,
            snaplen=65535
        )

        writer = FileWriter(out, shb)
        with open(tls_key_file, 'r') as keys:
            dsk = shb.new_member(DecryptionSecretsBlock)
            keys_list = [line.strip() for line in keys.readlines() if line.startswith('CLIENT_RANDOM')]
            data = bytes('\n'.join(keys_list), encoding='utf-8')
            data_len = binascii.a2b_hex(f'{len(data):08x}')[::-1]
            data_type = binascii.a2b_hex('544c534b')[::-1]
            dsk.data = data_type + data_len + data
            writer.write_block(dsk)
        packets = rdpcap(in_pcap_file)
        for count, packet in enumerate(packets):            
            blk = shb.new_member(blocks.EnhancedPacket)
            blk.interface_id = 0
            timestamp_pcap = int(packet.time * 1000000)
            blk.timestamp_high = timestamp_pcap >> 32
            blk.timestamp_low = timestamp_pcap & 0xFFFFFFFF
            blk.packet_data = bytes(packet.payload)
            blk.packet_len = len(bytes(packet.payload))
            writer.write_block(blk)
        out.close()


class UI:

    def __init__(self, root):
        root.title('Inject TLS Keys v0.1')
        root.minsize(960, 508)
        
        mainframe = ttk.Frame(root, padding="3 3 3 3")
        mainframe.grid(column=0, row=0, sticky=(N, W, E, S))
        root.columnconfigure(0, weight=1)
        root.rowconfigure(0, weight=1)

        configlf = ttk.Labelframe(mainframe, text='Settings')
        configlf.grid(column=0, row=0, ipadx=5, ipady=5,padx=5, pady=5, sticky=(W, E))
        mainframe.columnconfigure(0, weight=1)
        keyfilelb = ttk.Label(configlf, text='Key File:')
        keyfilelb.grid(column=0, row=0, padx=5, sticky=(W, E))
        self.keyfileet = ttk.Entry(configlf, width=35)
        self.keyfileet.grid(column=1, row=0, padx=5, sticky=(W, E))
        self.keyfilebn = ttk.Button(configlf, width=5, text='...', command=self.set_key_file_path)
        self.keyfilebn.grid(column=2, row=0, padx=5, sticky=(W, E))
        pcapfilelb = ttk.Label(configlf, text='Pcap FIle:')
        pcapfilelb.grid(column=0, row=2, padx=5, sticky=(W, E))
        self.pcapfileet = ttk.Entry(configlf, width=35)
        self.pcapfileet.grid(column=1, row=2, padx=5, sticky=(W, E))
        self.pcapfilebn = ttk.Button(configlf, width=5, text='...', command=self.set_pcap_file_path)
        self.pcapfilebn.grid(column=2, row=2, padx=5, sticky=(W, E))
        configlf.columnconfigure(1, weight=1)

        resultlf = ttk.Labelframe(mainframe, text='Result')
        resultlf.grid(column=0, row=1, ipadx=5, ipady=5, padx=5, pady=5, sticky=(N, W, E, S))
        self.resulttext = ScrolledText(resultlf, font='TkFixedFont')
        self.resulttext.grid(column=0, row=0, padx=5, pady=2, sticky=(N, S, E, W))
        resultlf.rowconfigure(0, weight=1)
        resultlf.columnconfigure(0, weight=1)
        mainframe.rowconfigure(1, weight=1)

    def set_key_file_path(self):
        self.key_file_name = filedialog.askopenfilename()
        if os.path.exists(self.key_file_name):
            self.keyfileet.delete(0, 'end')
            self.keyfileet.insert(0, self.key_file_name)

    def set_pcap_file_path(self):
        self.pcap_file_name = filedialog.askopenfilename()
        print(os.path.splitext(self.pcap_file_name)[0])
        print(os.path.splitext(self.pcap_file_name)[1])
        if os.path.exists(self.pcap_file_name) and (os.path.splitext(self.pcap_file_name)[-1] in ['.pcap', '.cap']):
            self.pcapfileet.delete(0, 'end')
            self.pcapfileet.insert(0, self.pcap_file_name)
            self.resulttext.delete(1.0,'end')
            self.resulttext.insert(1.0, 'Generate pcapng file, please waiting...')
            self.resulttext.after(10, self.create_pacpng)
    
    def create_pacpng(self):
        gen = GeneratePcapngWithTLSKey()
        pcapng_file_name = os.path.splitext(self.pcap_file_name)[0] + '.pcapng'
        gen.create_pcapng(self.pcap_file_name, pcapng_file_name, self.key_file_name)
        self.resulttext.delete(1.0,'end')
        self.resulttext.insert(1.0, 'Generate completed.')


if __name__ == '__main__':
    root = Tk()
    UI(root)
    root.mainloop()

3. 安装软件

https://pypi.org/project/scapy/
pip install scapy

https://pypi.org/project/python-pcapng/
pip install python-pcapng