SAN 证书如何降低性能？

Question

我听说当许多名称添加到单个 SAN 证书（主题备用名称）时，性能开始下降。

有人可以解释如何处理 SAN 证书，以便我了解是什么导致了 SAN 上名称增加时的性能成本？

Answer 1

一些肤浅的测试似乎确实表明我被喂了一堆马拉奇。

我像这样生成了证书：

openssl genrsa -out www.domain.tld.key 2048

[kbrandt@alpine: ~/sancrt] openssl req -new -key www.domain.tld.key -out www.domain.tld.csr
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [AU]:US
State or Province Name (full name) [Some-State]:NY
Locality Name (eg, city) []:New York
Organization Name (eg, company) [Internet Widgits Pty Ltd]:LOTA-SAN
Organizational Unit Name (eg, section) []:SANSRUS
Common Name (e.g. server FQDN or YOUR name) []:www.domain.tld
Email Address []:kyle@SANRUS.com
....

echo -n "subjectAltName=DNS:www.domain.tld," > www.domain.tld.cnf;for i in {1..2500}; do echo -n "DNS:www$i.domain.tld,"; done >> www.domain.tld.cnf   

#manually delete comma at the end of the .cnf

openssl x509 -req -days 365 \
>   -in www.domain.tld.csr \
>   -signkey www.domain.tld.key \
>   -text \
>   -extfile  www.domain.tld.cnf \
>   -out www.domain.tld.crt
Signature ok
subject=/C=US/ST=NY/L=New York/O=LOTA-SAN/OU=SANSRUS/CN=www.domain.tld/emailAddress=kyle@SANRUS.com
Getting Private key

cat *.key *.crt > sillysan.pem

当我尝试 curl 和 wget 时，我看不到任何明显的差异：

time curl -ssl3 --noproxy \* -D - --insecure http://www2500.domain.tld
curl -ssl3 --noproxy \* -D - --insecure http://www2500.domain.tld  0.01s user 0.00s system 69% cpu 0.012 total

www 与 www2500 的结果相同。我想 --insecure 有可能完全绕过检查，但现在我将给出一个非常不科学的测试的标准印章：