OpenSSL 3.1.0启用FIPS后出现EE Certificate key too weak错误

我通过脚本编译安装了启用FIPS的OpenSSL 3.1.0，安装成功且可正常运行，但启用FIPS后无法建立任何出站连接，出现EE certificate key too weak error。

编译安装脚本 #

wget https://www.openssl.org/source/openssl-3.1.0.tar.gz 
    && tar zxvf openssl-3.1.0.tar.gz 
    && cd openssl-3.1.0 
    && CFLAGS=-fPIC ./config enable-fips --prefix=/usr/local/openssl --openssldir=/usr/local/openssl 
    && make 
    && make test 
    && make install 
    && bash -c "echo '/usr/local/openssl/lib64' >> /etc/ld.so.conf" 
    && ldconfig

版本信息 #

openssl version
OpenSSL 3.1.0 14 Mar 2023 (Library: OpenSSL 3.1.0 14 Mar 2023)

FIPS启用配置 #

.include /usr/local/openssl/fipsmodule.cnf

..
..
..

# List of providers to load
[provider_sect]
default = default_sect

# The fips section name should match the section name inside the
# included fipsmodule.cnf.
fips = fips_sect

FIPS启用验证 #

openssl md5 <file_path>
Error setting digest
40C7F61E7D7F0000:error:0308010C:digital envelope routines:(unknown function):unsupported:crypto/evp/evp_fetch.c:341:Global default library context, Algorithm (MD5 : 100), Properties ()
40C7F61E7D7F0000:error:03000086:digital envelope routines:(unknown function):initialization error:crypto/evp/digest.c:272:
# 
# 
openssl sha256 <file_path>
SHA2-256(openssl)= 49c16340d51eba8d2c31dbe569ad1f686fef571a0a7c9a4545a85c22d4650259
[root@centos7 bin]# 

出站连接错误示例 #

openssl s_client -connect google.com:443

CONNECTED(00000003)
depth=0 CN = *.google.com
verify error:num=66:EE certificate key too weak
verify return:1
depth=0 CN = *.google.com
verify error:num=66:EE certificate key too weak
verify return:1
40D7CF19B37F0000:error:03000072:digital envelope routines:(unknown function):decode error:crypto/x509/x_pubkey.c:458:
40D7CF19B37F0000:error:0A0000EF:SSL routines:(unknown function):unable to find public key parameters:ssl/statem/statem_clnt.c:1905:
---
Certificate chain
 0 s:CN = *.google.com
   i:C = US, O = Google Trust Services LLC, CN = GTS CA 1C3
   v:NotBefore: Mar 28 16:47:33 2023 GMT; NotAfter: Jun 20 16:47:32 2023 GMT
 1 s:C = US, O = Google Trust Services LLC, CN = GTS CA 1C3
   i:C = US, O = Google Trust Services LLC, CN = GTS Root R1
   v:NotBefore: Aug 13 00:00:42 2020 GMT; NotAfter: Sep 30 00:00:42 2027 GMT
 2 s:C = US, O = Google Trust Services LLC, CN = GTS Root R1
   i:C = BE, O = GlobalSign nv-sa, OU = Root CA, CN = GlobalSign Root CA
   v:NotBefore: Jun 19 00:00:42 2020 GMT; NotAfter: Jan 28 00:00:42 2028 GMT
---
no peer certificate available
---
No client certificate CA names sent
Server Temp Key: X25519, 253 bits
---
SSL handshake has read 6777 bytes and written 311 bytes
Verification error: EE certificate key too weak
---
New, TLSv1.3, Cipher is TLS_AES_256_GCM_SHA384
This TLS version forbids renegotiation.
Compression: NONE
Expansion: NONE
No ALPN negotiated
Early data was not sent
Verify return code: 66 (EE certificate key too weak)
---

解决方案 #

这个错误是因为FIPS模式下，OpenSSL默认密钥强度验证规则拒绝了X25519这类未被FIPS模块标记为允许的曲线密钥，导致握手时判定为"密钥太弱"。以下是几种解决方法：

方法1：修改OpenSSL配置允许合规曲线 #

编辑OpenSSL主配置文件（/usr/local/openssl/openssl.cnf），在[provider_sect]后添加FIPS模块的曲线允许规则：

[fips_sect]
activate = 1
ssl_curve_list = X25519:P-256:P-384:P-521

或者直接修改/usr/local/openssl/fipsmodule.cnf的策略部分：

[fips_sect]
policy = fips_policy

[fips_policy]
EC = X25519,P-256,P-384,P-521

方法2：重新编译OpenSSL时启用合规曲线支持 #

清理原有编译文件后，重新编译并启用相关参数：

cd openssl-3.1.0
make clean
CFLAGS=-fPIC ./config enable-fips enable-ec_nistp_64_gcc_128 --prefix=/usr/local/openssl --openssldir=/usr/local/openssl
make && make test && make install
ldconfig

方法3：临时指定合规曲线测试（不推荐生产环境） #

连接时手动指定符合FIPS要求的曲线：

openssl s_client -connect google.com:443 -curves P-256

修改完成后重新运行连接命令，即可正常建立连接。

内容的提问来源于stack exchange，提问作者user1919581