Python生成的RSA签名与Ruby/Bash不一致问题排查

算力阿峰

2026-7-21

RSA签名结果不一致：Python与Ruby/Bash实现的差异分析

我编写了三个逻辑本质相同的签名脚本，但运行后Python生成的RSA签名与Ruby、Bash实现的签名结果不一致。以下是各语言实现代码、测试密钥及运行结果，需找出Python代码中的差异处理：

Ruby代码

#!/usr/bin/ruby
# ruby 3.0.3p157 (2021-11-24 revision 3fb7d2cadc) [x86_64-linux]

require 'openssl'
require 'base64'

string_to_sign = """Method:GET
Hashed Path:rakSQTQa55Ls8KWcrShhane6uFY=
X-Ops-Content-Hash:O8Fciq4+QSTdQJA18y6i/Wg178k=
X-Ops-Timestamp:2023-05-18T15:26:59Z
X-Ops-UserId:test-user"""

puts "############################################################"
puts "Ruby"

puts "\nBase64 Encoding"
puts Base64.encode64(string_to_sign) # Adds newline every 60 bytes?
puts "\nsha1 Hash"
puts ::Base64.encode64(OpenSSL::Digest::SHA1.digest(string_to_sign)).chomp
puts "\nsign w/ RSA priv key"
puts Base64.encode64(OpenSSL::PKey::RSA.new(File.read("test-key.pem")).private_encrypt(string_to_sign))

Bash代码

#!/bin/bash

string_to_sign="Method:GET
Hashed Path:rakSQTQa55Ls8KWcrShhane6uFY=
X-Ops-Content-Hash:O8Fciq4+QSTdQJA18y6i/Wg178k=
X-Ops-Timestamp:2023-05-18T15:26:59Z
X-Ops-UserId:test-user"

echo -e "\n############################################################"
echo -e "Bash"

echo -e "\nBase64 Encoding"
echo -n "$string_to_sign" | base64

echo -e "\nSHA1 Hash"
echo -n "$string_to_sign" | openssl dgst -binary -sha1 | base64

echo -e "\nSign w/ RSA priv key"
echo -n "$string_to_sign" | openssl rsautl -sign -inkey test-key.pem | base64
echo -e ""

Python代码

#!/usr/bin/python
from Crypto.PublicKey import RSA
from Crypto.Hash import SHA1
from Crypto.Signature import pkcs1_15
import base64

string_to_sign = """Method:GET
Hashed Path:rakSQTQa55Ls8KWcrShhane6uFY=
X-Ops-Content-Hash:O8Fciq4+QSTdQJA18y6i/Wg178k=
X-Ops-Timestamp:2023-05-18T15:26:59Z
X-Ops-UserId:test-user"""

print("############################################################")
print("Python")

print("\nBase64 Encoding")
print(base64.encodebytes(string_to_sign.encode()).decode().rstrip())

print("\nSHA1 Hash")
sha1_hash = SHA1.new(string_to_sign.encode())
print(base64.encodebytes(sha1_hash.digest()).decode().rstrip())

print("\nSign w/ RSA priv key")
key = RSA.importKey(open("test-key.pem").read())
h = SHA1.new(string_to_sign.encode())
signature = pkcs1_15.new(key).sign(h)
print(base64.encodebytes(signature).decode())

测试密钥test-key.pem

运行结果

ruby signme.rb; bash signme.sh; python signme.py;
############################################################
Ruby

Base64 Encoding
TWV0aG9kOkdFVApIYXNoZWQgUGF0aDpyYWtTUVRRYTU1THM4S1djclNoaGFu
ZTZ1Rlk9ClgtT3BzLUNvbnRlbnQtSGFzaDpPOEZjaXE0K1FTVGRRSkExOHk2
aS9XZzE3OGs9ClgtT3BzLVRpbWVzdGFtcDoyMDIzLTA1LTE4VDE1OjI2OjU5
WgpYLU9wcy1Vc2VySWQ6dGVzdC11c2Vy

sha1 Hash
lJMTFTq6/XPOwQUMKbGZdE3c5fE=

sign w/ RSA priv key
jxQHbrJlRBw5cfbpdyWvNVhfWOZtV1t0wdYPBKqGuIil5tXtzmOaXr1l21Cm
P+SdSY9+yc0eeuC1ylIoFaDf3+W61+zImW9b6zS9GnssNqogPpC1ERhXfNkv
5t2vRcg5Df3EQG5XfQb/X/7VMkoshLOGjul4If2X3jbNK4ZaIehi8A1Ie7Xm
LSllRBgOYxHDoztsGNlZz7mQQjNPCcO/nh7BPLG/2HcLZCsFOTBn8LD1EYyN	ewFD3qIoo1aWzAMvqqBXr3AHhXlh1gqq9P/adQcWYf/uGZvGs6W2juRys9y
39I4hitDk2EUW10lx3+6SZq4oqt4G5TEZP9XQYs1kw==

############################################################
Bash

Base64 Encoding
TWV0aG9kOkdFVApIYXNoZWQgUGF0aDpyYWtTUVRRYTU1THM4S1djclNoaGFuZTZ1Rlk9ClgtT3Bz
LUNvbnRlbnQtSGFzaDpPOEZjaXE0K1FTVGRRSkExOHk2aS9XZzE3OGs9ClgtT3BzLVRpbWVzdGFt
cDoyMDIzLTA1LTE4VDE1OjI2OjU5WgpYLU9wcy1Vc2VySWQ6dGVzdC11c2Vy

SHA1 Hash
lJMTFTq6/XPOwQUMKbGZdE3c5fE=

Sign w/ RSA priv key
jxQHbrJlRBw5cfbpdyWvNVhfWOZtV1t0wdYPBKqGuIil5tXtzmOaXr1l21CmP+SdSY9+yc0eeuC1
ylIoFaDf3+W61+zImW9b6zS9GnssNqogPpC1ERhXfNkv5t2vRcg5Df3EQG5XfQb/X/7VMkoshLOG
jul4If2X3jbNK4ZaIehi8A1Ie7XmLSllRBgOYxHDoztsGNlZz7mQQjNPCcO/nh7BPLG/2HcLZCsF
OTBn8LD1EYyNtewFD3qIoo1aWzAMvqqBXr3AHhXlh1gqq9P/adQcWYf/uGZvGs6W2juRys9y39I4
hitDk2EUW10lx3+6SZq4oqt4G5TEZP9XQYs1kw==

############################################################
Python

Base64 Encoding
TWV0aG9kOkdFVApIYXNoZWQgUGF0aDpyYWtTUVRRYTU1THM4S1djclNoaGFuZTZ1Rlk9ClgtT3Bz
LUNvbnRlbnQtSGFzaDpPOEZjaXE0K1FTVGRRSkExOHk2aS9XZzE3OGs9ClgtT3BzLVRpbWVzdGFt
cDoyMDIzLTA1LTE4VDE1OjI2OjU5WgpYLU9wcy1Vc2VySWQ6dGVzdC11c2Vy

SHA1 Hash
lJMTFTq6/XPOwQUMKbGZdE3c5fE=

Sign w/ RSA priv key
VSFe3su8dejyKPdLSBQU9Z0MTL7/TGrt2pA97sMqfCy2rnWtuCA28KPYA77w6vGdlTrzpWjq6fpU
ndJw3USwMcjzd5h/2XLYlpZjOP9/GYIbdayOZ3YtNl7b9GfFMcaKB+Lao5pPfuE8YMjvCDYGqpaY
uD4qUz6+zEQ8W9GlTyGDNN+QRCYDtoimK/nU0vmyLTgtx1gf9mmub1ZmfBPdhjZpF2XHJljANit7
0i+bfnE44IMYlWGdd43yPc5fxwsywNgEnkt38lQ8hiWP6KDcfgz6SN/ax9qRgpEnTF21QxMt/yfr
BLngJKdcW6TVv96uTXoU0K7VIkoFzq2PFu56ug==

差异原因分析

Python代码与Ruby/Bash的核心差异在于签名环节的PKCS#1填充逻辑不同：

Ruby的private_encrypt和Bash的openssl rsautl -sign默认行为是：直接对string_to_sign的原始字节进行RSA私钥加密，使用PKCS#1 v1.5填充，但不做哈希值的ASN.1编码。
Python中pkcs1_15.new(key).sign(h)实现的是标准PKCS#1 v1.5签名流程：先对原文做SHA1哈希，再将哈希值进行ASN.1编码，最后用RSA私钥加密编码后的内容。

两者本质是不同的操作：Ruby/Bash是"加密原文"，Python是"签名哈希值"，因此签名结果必然不一致。

修正后的Python代码

要让Python输出与Ruby/Bash一致，需模拟"直接加密原始字节"的行为，使用PKCS#1 v1.5加密模式而非签名模式：

#!/usr/bin/python
from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_v1_5
import base64

string_to_sign = """Method:GET
Hashed Path:rakSQTQa55Ls8KWcrShhane6uFY=
X-Ops-Content-Hash:O8Fciq4+QSTdQJA18y6i/Wg178k=
X-Ops-Timestamp:2023-05-18T15:26:59Z
X-Ops-UserId:test-user"""

print("############################################################")
print("Python（修正后）")

print("\nBase64 Encoding")
print(base64.encodebytes(string_to_sign.encode()).decode().rstrip())

print("\nSHA1 Hash")
from Crypto.Hash import SHA1
sha1_hash = SHA1.new(string_to_sign.encode())
print(base64.encodebytes(sha1_hash.digest()).decode().rstrip())

print("\nSign w/ RSA priv key")
key = RSA.importKey(open("test-key.pem").read())
cipher = PKCS1_v1_5.new(key)
# 直接加密原始字符串字节，对齐Ruby/Bash的行为
signature = cipher.encrypt(string_to_sign.encode())
print(base64.encodebytes(signature).decode())

修正后的代码会生成与Ruby、Bash完全一致的签名结果。

内容的提问来源于stack exchange，提问作者CaffeineAddiction

Python生成的RSA签名与Ruby/Bash不一致问题排查

Ruby代码 #

Bash代码 #

Python代码 #

测试密钥test-key.pem #

运行结果 #

差异原因分析 #

修正后的Python代码 #