소개
이 문서에서는 "SSL_ERROR_NO_CIPHER_OVERLAP" 오류를 방지하기 위해 BroadWorks를 구성하고 문제를 해결하는 방법에 대해 설명합니다.
사전 요구 사항
요구 사항
Cisco에서는 BroadWorks 플랫폼에 대해 알고 있는 것이 좋습니다.
배경 정보
BroadWorks 구성
Broadworks 릴리스 22 이상의 경우 프로토콜 및 암호는 서로 다른 컨피그레이션 레벨에서 볼 수 있는 컨텍스트를 통해 CLI를 통해 구성할 수 있습니다.
'Interface/Port specific - low level'
CLI/Interface/Http/HttpServer/SSLSettings/Protocols
CLI/Interface/Http/HttpServer/SSLSettings/Ciphers
'All interfaces - mid level'
CLI/Interface/Http/SSLCommonSettings/Protocols
CLI/Interface/Http/SSLCommonSettings/Ciphers
'Generic system level - high level'
CLI/System/SSLCommonSettings/JSSE/Protocols
CLI/System/SSLCommonSettings/JSSE/Ciphers
SSLCommonSettings라는 컨텍스트는 SSL 계층 구조에서 덜 구체적인 항목을 참조하고 SSLSsettings라는 컨텍스트는 계층 구조에서 더 구체적인 항목을 참조합니다.
기능 실습 예
설정
정의된 암호 없이 특정 인터페이스 및 포트에 연결된 하위 레벨 컨피그레이션:
CLI/Interface/Http/HttpServer/SSLSettings/Protocols> get 172.16.30.146 443
Protocol Name
===============
TLSv1.1
TLSv1.2
TLSv1
CLI/Interface/Http/HttpServer/SSLSettings/Ciphers> get 172.16.30.146 443
Cipher Name
=============
0 entry found.
확인
컨피그레이션을 확인하려면 curl
명령을 사용합니다:
$ curl -v -k https://172.16.30.146
* About to connect() to 172.16.30.146 port 443 (#0)
* Trying 172.16.30.146...
* Connected to 172.16.30.146 (172.16.30.146) port 443 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb
* skipping SSL peer certificate verification
* SSL connection using TLS_RSA_WITH_AES_256_CBC_SHA256 <-----
* Server certificate:
* subject: E=broadworks_tac@cisco.com,CN=*.calo.cisco.com,OU=BroadworksTAC,O=TestIssuer,ST=Veracruz,C=MX
* start date: Apr 04 20:39:56 2022 GMT
* expire date: Apr 04 20:39:56 2023 GMT
* common name: *.calo.cisco.com
* issuer: CN=Root CA test,OU=BroadworksTAC,O=TestIssuer,L=Tecolutla,ST=Veracruz,C=MX
> GET / HTTP/1.1
> User-Agent: curl/7.29.0
> Host: 172.16.30.146
> Accept: */*
>
< HTTP/1.1 302 Found
여기서는 TLSv1.2를 통해 TLS_RSA_WITH_AES_256_CBC_SHA256 암호를 사용하여 성공적으로 연결했습니다.
연결 감사
수락된 프로토콜 및 암호를 확인하려면 다음을 수행합니다.
$ nmap -sV --script ssl-enum-ciphers -p 443 172.16.30.146
Starting Nmap 6.40 ( http://nmap.org ) at 2022-05-09 04:26 EDT
Nmap scan report for r23xsp01.calo.cisco.com (172.16.30.146)
Host is up (0.00013s latency).
PORT STATE SERVICE VERSION
443/tcp open ssl/https?
| ssl-enum-ciphers:
| TLSv1.0:
| ciphers:
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA - strong
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA - strong
| TLS_ECDHE_RSA_WITH_RC4_128_SHA - strong
| TLS_RSA_WITH_AES_128_CBC_SHA - strong
| TLS_RSA_WITH_AES_256_CBC_SHA - strong
| TLS_RSA_WITH_RC4_128_SHA - strong
| compressors:
| NULL
| TLSv1.1:
| ciphers:
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA - strong
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA - strong
| TLS_ECDHE_RSA_WITH_RC4_128_SHA - strong
| TLS_RSA_WITH_AES_128_CBC_SHA - strong
| TLS_RSA_WITH_AES_256_CBC_SHA - strong
| TLS_RSA_WITH_RC4_128_SHA - strong
| compressors:
| NULL
| TLSv1.2:
| ciphers:
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA - strong
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 - strong
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA - strong
| TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 - strong
| TLS_ECDHE_RSA_WITH_RC4_128_SHA - strong
| TLS_RSA_WITH_AES_128_CBC_SHA - strong
| TLS_RSA_WITH_AES_128_CBC_SHA256 - strong
| TLS_RSA_WITH_AES_256_CBC_SHA - strong
| TLS_RSA_WITH_AES_256_CBC_SHA256 - strong
| TLS_RSA_WITH_RC4_128_SHA - strong
| compressors:
| NULL
|_ least strength: strong
오류가 있는 실습 예
문제
브라우저에 "SSL_ERROR_NO_CIPHER_OVERLAP" 오류가 발생했습니다.
# curl -v https://172.16.30.146
* About to connect() to 172.16.30.146 port 443 (#0)
* Trying 172.16.30.146...
* Connected to 172.16.30.146 (172.16.30.146) port 443 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb * CAfile: /etc/pki/tls/certs/ca-bundle.crt CApath: none
* NSS error -12286 (SSL_ERROR_NO_CYPHER_OVERLAP)
* Cannot communicate securely with peer: no common encryption algorithm(s).
* Closing connection 0 curl: (35) Cannot communicate securely with peer: no common encryption algorithm(s).
설정
TLSv1.0 Cipher TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256 집합과 함께 TLSv1.2 프로토콜이 설정된 특정 인터페이스 및 포트에 연결된 하위 레벨 컨피그레이션:
CLI/Interface/Http/HttpServer/SSLSettings/Protocols> get 172.16.30.146 443
Protocol Name
===============
TLSv1.2
CLI/Interface/Http/SSLCommonSettings/Ciphers> get
Cipher Name
======================================
TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256
확인
컨피그레이션을 확인하려면 curl
명령을 사용합니다:
$ curl -v -k https://172.16.30.146
* About to connect() to 172.16.30.146 port 443 (#0)
* Trying 172.16.30.146...
* Connected to 172.16.30.146 (172.16.30.146) port 443 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb
* NSS error -12286 (SSL_ERROR_NO_CYPHER_OVERLAP)
* Cannot communicate securely with peer: no common encryption algorithm(s).
* Closing connection 0
curl: (35) Cannot communicate securely with peer: no common encryption algorithm(s).
연결 감사
수락된 프로토콜 및 암호를 확인하려면 다음을 수행합니다.
$ nmap -sV --script ssl-enum-ciphers -p 443 172.16.30.146
Starting Nmap 6.40 ( http://nmap.org ) at 2022-05-09 05:31 EDT
Nmap scan report for r23xsp01.calo.cisco.com (172.16.30.146)
Host is up (0.000049s latency).
PORT STATE SERVICE VERSION
443/tcp open https?
| ssl-enum-ciphers:
|_ TLSv1.2: No supported ciphers found
이 툴의 결과에서 TLSv1.2 프로토콜을 사용할 수 있지만 지원되는 암호가 없는 것으로 확인되었습니다.
해결
아래에서 TLSv1.1 암호를 삭제합니다 CLI/Interface/Http/SSLCommonSettings/Ciphers
를 클릭한 다음 모든 TLSv1.2 암호를 다시 열거나 TLSv1.2 암호를 추가합니다.
CLI/Interface/Http/HttpServer/SSLSettings/Protocols> get 172.16.30.146 443
Protocol Name
===============
TLSv1.2
CLI/Interface/Http/HttpServer/SSLSettings/Ciphers> get 172.16.30.146 443
Cipher Name
=============
0 entry found.
CLI/Interface/Http/SSLCommonSettings/Ciphers> get
Cipher Name
=============
0 entry found.
해결 확인
$ curl -v -k https://172.16.30.146
* About to connect() to 172.16.30.146 port 443 (#0)
* Trying 172.16.30.146...
* Connected to 172.16.30.146 (172.16.30.146) port 443 (#0)
* Initializing NSS with certpath: sql:/etc/pki/nssdb
* skipping SSL peer certificate verification
* SSL connection using TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 <-----
* Server certificate:
* subject: E=broadworks_tac@cisco.com,CN=*.calo.cisco.com,OU=BroadworksTAC,O=TestIssuer,ST=Veracruz,C=MX
* start date: Apr 04 20:39:56 2022 GMT
* expire date: Apr 04 20:39:56 2023 GMT
* common name: *.calo.cisco.com
* issuer: CN=Root CA test,OU=BroadworksTAC,O=TestIssuer,L=Tecolutla,ST=Veracruz,C=MX
> GET / HTTP/1.1
> User-Agent: curl/7.29.0
> Host: 172.16.30.146
> Accept: */*
>
< HTTP/1.1 302 Found
$ nmap -sV --script ssl-enum-ciphers -p 443 172.16.30.146
Starting Nmap 6.40 ( http://nmap.org ) at 2022-05-09 05:44 EDT
Nmap scan report for r23xsp01.calo.cisco.com (172.16.30.146)
Host is up (0.000063s latency).
PORT STATE SERVICE VERSION
443/tcp open https?
| ssl-enum-ciphers:
| TLSv1.2:
| ciphers:
| TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 - strong
| TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 - strong
| TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 - strong
| TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 - strong