python 将十六进制字符串写入二进制文件

发布于 2021-07-15 13:27:22 浏览：1150 订阅该版

这几天遇到一个问题，要检查一串字符串组成的证书文件内容是不是x509证书文件，需要在win10 写到一个二进制文件中，不想用c 来实现，想用python 来写二进制文件。实现一个简单例子，觉得很方便，分享给大家。
filetest.py
```python
 import struct
t= "308201b83082015ea00302010202090093741f63c0d348c2300a06082a8648ce3d040302301d311b30190\
    6035504030c124d4f434b2d4341522d524f4f542d43412d45301e170d3231303531383032353134335a170d\
    3236303531373032353134335a30263124302206035504030c1b446576696365204f454d20526f6f74204365\
    7274696669636174653059301306072a8648ce3d020106082a8648ce3d030107034200049076ead5ced3dc6b8\
    2c17ee0aa23d9a80b7adcee968ae0841db5c01aa092d1447aadcbcfa2dbe60607690e5abe2c84a55f730a1d01e\
    67a9ede4f2edcd3879707a37e307c301d0603551d0e041604140b3f8afa130735b3641bb81d3129ffba7445445\
    3301f0603551d230418301680144f7e2ff298a4860254dd2e0fe59a2c89d5928eb230120603551d130101ff0408\
    30060101ff020101300e0603551d0f0101ff0404030202043016060a2b0601040182c46905020101ff040530030\
    20101300a06082a8648ce3d0403020348003045022068a0d7fdd996f1a91f1ccc4d7b00bb6ed4d9bc68556253532\
    c377b18e2da95aa022100ab6833c1a5f6618e4e3bc82a39f1908c897c92726d9ee353988f5b1f24bebf1c"
#写二进制文件 
strY = ''
i = 0
with open("./x509.der","wb") as f:                                         
    for x in t:
        if x != ' ' and x!= '\n' and x!= '\r' and x!= '\t':
            strY += x
            i+=1
            if (i%2 == 0):
                xHex = int(strY, 16)
                xHex = struct.pack("B",xHex)
                f.write(xHex)
                strY = ''

print("done")
```