【加解密】使用CFSSL生成证书并使用gRPC验证证书
写在前面的话
CFSSL是CloudFlare旗下的PKI/TLS工具。可以用于数字签名,签名验证和TLS证书捆绑的命令行工具和HTTP API服务器。
是使用golang语言开发的证书工具。
官方地址:
github地址:https://github.com/cloudflare/cfssl
下载cfssl工具链
https://github.com/cloudflare/cfssl/releases
下载如下文件
cfssl_1.6.0_darwin_amd64 表示cfssl的工具
cfssljson_1.6.0_darwin_amd64 表示使用json展示的工具
cfssl-certinfo_1.6.0_darwin_amd64 表示证书的查看工具
软连接生成cfssl和cfssljson
ln -s ./cfssl_1.6.0_darwin_amd64 cfssl ln -s ./cfssl-certinfo_1.6.0_darwin_amd64 cfssl-certinfo ln -s ./cfssljson_1.6.0_darwin_amd64 cfssljson
使用cfssl生成证书步骤
1. 编写CA根证书的证书签名请求文件
证书签名请求(Certificate Signing Request)文件,文件格式为ca-csr.json,【文件名含义是CA of Certificate Signing Request】
ca-csr.json文件中包含如下内容简要说明
-
CN: Common Name,表示业务的名称或者对外的域名。
-
C: Country, 表示国家
-
L: Locality,表示地区或城市
-
O: Organization Name,表示组织名称或公司名称
- OU: Organizational Unit 表示组织单元名称
-
ST: State,表示 州,省OU: Organization Unit Name,组织单位名称或者部门
- ca.expiry 表示证书的有效期,此处是20年
- key.algo 表示证书的签名算法,目前cfssl支持的签名算法只有rsa和ecdsa两种。
- hosts 表示要签名的域名,此处是根证书,所以空着,用于签名其他的证书。
ca-csr.json文件内容如下:
➜ certs cat ca-csr.json|python -m json.tool { "CN": "voipman", "ca": { "expiry": "175200h" }, "hosts": [], "key": { "algo": "rsa", "size": 2048 }, "names": [ { "C": "CN", "L": "BeiJing", "O": "MyCompany", "OU": "MyTemp", "ST": "BeiJing" } ] }
如果key的签名算法选择rsa时,size可以取值2048,3072和4096这三个值
如果可用的签名算法选择ecdsa时,将如上内容的key改成如下内容,size可以取值256,384和521三个值
"key":{ "algo":"ecdsa", "size":256 }
2. 使用CA跟证书签名请求文件生成CA根证书。
➜ cfssl gencert -initca ca-csr.json|cfssljson -bare ca 2021/08/18 10:37:00 [INFO] generating a new CA key and certificate from CSR 2021/08/18 10:37:00 [INFO] generate received request 2021/08/18 10:37:00 [INFO] received CSR 2021/08/18 10:37:00 [INFO] generating key: rsa-2048 2021/08/18 10:37:00 [INFO] encoded CSR 2021/08/18 10:37:00 [INFO] signed certificate with serial number 116851465485290360665710914818380982850969052112
通过执行上面的命令,产生如下文件:
ca.pem 表示CA根证书,可以公开
ca-key.pem 表示CA根证书的密钥,不要公开
ca.csr 表示CA证书签名请求
我们主要分析一下ca.pem证书文件中的内容信息
3. 查看 ca.pem CA根证书
里面包含什么信息呢,可以通过cfssl-certinfo工具查看证书内容
cfssl-certinfo -cert ca.pem { "subject": { "common_name": "voipman", "country": "CN", "organization": "MyCompany", "organizational_unit": "MyTemp", "locality": "BeiJing", "province": "BeiJing", "names": [ "CN", "BeiJing", "BeiJing", "MyCompany", "MyTemp", "voipman" ] }, "issuer": { "common_name": "voipman", "country": "CN", "organization": "MyCompany", "organizational_unit": "MyTemp", "locality": "BeiJing", "province": "BeiJing", "names": [ "CN", "BeiJing", "BeiJing", "MyCompany", "MyTemp", "voipman" ] }, "serial_number": "116851465485290360665710914818380982850969052112", "not_before": "2021-08-18T02:32:00Z", "not_after": "2041-08-13T02:32:00Z", "sigalg": "SHA256WithRSA", "authority_key_id": "", "subject_key_id": "34:9C:3B:8B:54:02:6F:2F:D3:F4:29:9B:23:23:6C:47:0D:0A:16:2B", "pem": "-----BEGIN CERTIFICATE-----\n.....\n-----END CERTIFICATE-----\n" }
从如上的ca.pem中可以看到
签名算法:"sigalg": "SHA256WithRSA"
如果选择ecdsa签名算法,签名算法就是: "sigalg": "ECDSAWithSHA256"
证书生效时间:"not_before": "2021-08-18T02:32:00Z"
证书失效时间:"not_after": "2041-08-13T02:32:00Z",说明证书签名请求文件中设置的20年的证书有效期。
序列化:"serial_number": "116851465485290360665710914818380982850969052112",在前面生成证书时会打印出来。
证书内容:"pem": "-----BEGIN CERTIFICATE-----...,此处省调证书内容信息。
其他字段在证书签名请求时已经做过介绍,此处忽略。
4. 编写CA签名配置文件ca-config.json
cat ca-config.json |python -m json.tool { "signing": { "default": { "expiry": "175200h" }, "profiles": { "client": { "expiry": "175200h", "usages": [ "signing", "key encipherment", "client auth" ] }, "peer": { "expiry": "175200h", "usages": [ "signing", "key encipherment", "client auth", "server auth" ] }, "server": { "expiry": "175200h", "usages": [ "signing", "key encipherment", "server auth" ] } } } }
字段说明如下
-
signing, 表示ca.pem证书可用于签名其它证书
- profile中的peer配置的client auth 和 server auth
- profile中的client配置的client auth
- profile中的server配置的server auth
- server auth:表示 客户端client 可以用 CA证书 对 服务端server的证书进行签名验证。
- client auth:表示 服务端server 可以用 CA证书 对 客户端client 提供的证书进行签名验证。
- server auth和client auth都存在时,说明客户端和服务端双向验证。
如下业务域名证书生成选择的profle是peer,表示双向验证。
同样证书的失效日期是20年。
5. 编写业务域名的证书签名请求文件 voipman-csr.json
cat voipman-csr.json |python -m json.tool { "CN": "voipman", "hosts": [ "127.0.0.1", "*.voipman.com", "localhost", "voipman.com", "*.vipman.com", "vipman.com" ], "key": { "algo": "rsa", "size": 2048 }, "names": [ { "C": "CN", "L": "BeiJing", "O": "voipman", "OU": "MyTeam", "ST": "BeiJing" } ] }
这个业务域名签名请求文件的内容和ca-csr.json内容含义类似,关键部分是增加了hosts的配置,将需要签名认证的ip地址和域名增加到hosts列表中。
6. 生成业务域名的证书和私钥
cfssl gencert -ca=ca.pem -ca-key=ca-key.pem -config=ca-config.json -profile=peer voipman-csr.json|cfssljson -bare voipman-peer 2021/08/18 11:15:09 [INFO] generate received request 2021/08/18 11:15:09 [INFO] received CSR 2021/08/18 11:15:09 [INFO] generating key: rsa-2048 2021/08/18 11:15:09 [INFO] encoded CSR 2021/08/18 11:15:09 [INFO] signed certificate with serial number 178028283460672116734375677106692089761404461988
此命令的参数说明
生成证书命令:cfssh gencerts
使用ca证书:-ca=ca.pem
使用ca的密钥:-ca-key=ca-key.pem
使用ca签名证书的配置:-config=ca-config.json
选择ca签名证书配置的profile项:-profile=peer
选择业务域名的证书签名请求文件:voipman-csr.json
生成业务域名的私钥和证书文件:cfssljson -bare voipman-peer 会生成voipman-peer.pem证书文件和voipman-peer-key.pem的私钥文件。
执行如上命令后,产生如下文件
voipman-peer.pem 业务域名的证书文件,可以直接公开给请求端使用。
voipman-peer-key.pem 业务域名的私钥,不可公开。
voipman-peer.csr 业务域名的证书签名请求文件。
查看 业务域名的证书文件voipman-peer.pem的内容
cfssl-certinfo -cert voipman-peer.pem { "subject": { "common_name": "voipman", "country": "CN", "organization": "voipman", "organizational_unit": "MyTeam", "locality": "BeiJing", "province": "BeiJing", "names": [ "CN", "BeiJing", "BeiJing", "voipman", "MyTeam", "voipman" ] }, "issuer": { "common_name": "voipman", "country": "CN", "organization": "MyCompany", "organizational_unit": "MyTemp", "locality": "BeiJing", "province": "BeiJing", "names": [ "CN", "BeiJing", "BeiJing", "MyCompany", "MyTemp", "voipman" ] }, "serial_number": "178028283460672116734375677106692089761404461988", "sans": [ "*.voipman.com", "localhost", "voipman.com", "*.vipman.com", "vipman.com", "127.0.0.1" ], "not_before": "2021-08-18T03:10:00Z", "not_after": "2041-08-13T03:10:00Z", "sigalg": "SHA256WithRSA", "authority_key_id": "34:9C:3B:8B:54:02:6F:2F:D3:F4:29:9B:23:23:6C:47:0D:0A:16:2B", "subject_key_id": "AD:54:74:A0:BF:67:E7:B7:18:50:20:0A:77:57:F7:16:D3:62:80:F6", "pem": "-----BEGIN CERTIFICATE-----\n......\n-----END CERTIFICATE-----\n" }
如上可以看到,证书文件的内容中
sans表示证书的支持的域名列表
authority_key_id 表示是本证书是从哪个CA证书签名生成的证书,业务域名正式的authority_key_id等于CA证书的subject_key_id。
其他字段说明见签名对CA证书的字段说明。
使用如下命令查询业务域名的证书签名请求信息
如下内容省略了部分内容,重点说明一下内容中的公钥PublicKey(N模数,E公钥指数)
cfssl certinfo -csr voipman-peer.csr { "Raw": "xxx", "RawTBSCertificateRequest": "xxx, "RawSubject": "xxx", "Version": 0, "Signature": "xxx", "SignatureAlgorithm": 4, "PublicKeyAlgorithm": 1, "PublicKey": { "N": 252598034519828318357090360116071250272xxxxxxxxxxxxxx....xxxxx7, "E": 65537 } "Subject": { }, "DNSNames": [ "*.voipman.com", "localhost", "voipman.com", "*.vipman.com", "vipman.com" ], "EmailAddresses": null, "IPAddresses": [ "127.0.0.1" ], "URIs": null }
如果选择ecdsa签名算法时,公钥PublicKey信息为如下形式
"PublicKey": { "Curve": { "P": 11579xxxxx1, "N": 11579xxxxxx8, "B": 410583xxxx1, "Gx": 484395xxx6, "Gy": 36134xxxxx09, "BitSize": 256, "Name": "P-256" }, "X": 1069xx854, "Y": 1105xx971 }
P: 代表有限域Fp的那个质数
G: 椭圆曲线上的一个基点G = (Gx, Gy)
N:G在Fp中规定的序号
7. 使用golang的grpc验证业务域名的证书和私钥
编写proto接口文件,文件命名为test.proto,定义一个EchoService接口,服务端实现时,将请求数据转成大写返回。
syntax = "proto3"; package test; service EchoService { rpc Echo (Request) returns (Response) {} } message Request { string data = 1; } message Response { string data = 1; }
生成go的grpc代码
mkdir -p ../src/test && protoc --go_out=plugins=grpc:../src/test/ ./test.proto
会生成 src/test/test.pb.go代码文件。
编写gRPC的服务端验证代码,配置证书voipman-peer.pem和私钥voipman-peer-key.pem
代码如下所示
package main import ( "cert-verify/src/test" "context" "fmt" "google.golang.org/grpc" "google.golang.org/grpc/credentials" "google.golang.org/grpc/reflection" "log" "net" "strings" ) type EchoServer struct{ } func (s *EchoServer) Echo(ctx context.Context, in *test.Request) (*test.Response, error) { fmt.Println("RequestData: " + in.Data) return &test.Response{Data: strings.ToUpper(in.Data)}, nil } func main() { listen, err := net.Listen("tcp", "0.0.0.0:9025") if err != nil { log.Fatalf("Failed to listen: %v", err) } creds, cerErr := credentials.NewServerTLSFromFile("./certs/voipman-peer.pem", "./certs/voipman-peer-key.pem") if cerErr != nil { log.Fatalf("Failed to load cert error: %v", cerErr) } var grpcServer *grpc.Server grpcServer = grpc.NewServer(grpc.Creds(creds)) test.RegisterEchoServiceServer(grpcServer, &EchoServer{}) reflection.Register(grpcServer) grpcServer.Serve(listen) }
编写gRPC的客户端代码,使用voipman-peer.pem证书请求如上的gRPC服务端
package main import ( "cert-verify/src/test" "golang.org/x/net/context" "google.golang.org/grpc" "google.golang.org/grpc/credentials" "log" ) func main() { hostNameList := []string { "dev.voipman.com", "test.voipman.com", "voipman.com", "127.0.0.1", "localhost", "dev.vipman.com", "test.vipman.com", "vipman.com", "dev.unknown.com", } for _, hostName := range hostNameList { url := "127.0.0.1:9025" creds, err := credentials.NewClientTLSFromFile("./certs/voipman-peer.pem", hostName) if err != nil { log.Printf("new rpc client tls fail %v", err) } clientConn, err := grpc.DialContext(context.Background(), url, grpc.WithTransportCredentials(creds)) if err != nil { log.Printf("dail rpc server fail url:%v, err:%v", url, err) } if err != nil { log.Printf(err.Error()) } defer clientConn.Close() cli := test.NewEchoServiceClient(clientConn) response, err := cli.Echo(context.Background(), &test.Request{Data: hostName}) if err != nil { log.Fatalf("could not greet: %v", err) } log.Printf("HostName:%v, Response: %s", hostName, response.Data) } }
如上代码中,我们验证voipman-csr.json中定义的hosts列表,如下测试域名应该可以通过证书的验证。
"dev.voipman.com",
"test.voipman.com",
"voipman.com",
"127.0.0.1",
"localhost",
"dev.vipman.com",
"test.vipman.com",
"vipman.com",
另外增加一条错误的域名地址,使用证书验证应该不成功。
运行结果如下
2021/08/18 13:38:12 HostName:dev.voipman.com, Response: DEV.VOIPMAN.COM 2021/08/18 13:38:12 HostName:test.voipman.com, Response: TEST.VOIPMAN.COM 2021/08/18 13:38:12 HostName:voipman.com, Response: VOIPMAN.COM 2021/08/18 13:38:12 HostName:127.0.0.1, Response: 127.0.0.1 2021/08/18 13:38:12 HostName:localhost, Response: LOCALHOST 2021/08/18 13:38:12 HostName:dev.vipman.com, Response: DEV.VIPMAN.COM 2021/08/18 13:38:12 HostName:test.vipman.com, Response: TEST.VIPMAN.COM 2021/08/18 13:38:12 HostName:vipman.com, Response: VIPMAN.COM 2021/08/18 13:38:12 could not greet: rpc error: code = Unavailable desc = connection error: desc = "transport: authentication handshake failed: x509: certificate is valid for *.voipman.com, localhost, voipman.com, *.vipman.com, vipman.com, not dev.unknown.com"
从运行的结果来看,最后一条域名,使用证书和服务端建立认证时出现错误
could not greet: rpc error: code = Unavailable desc = connection error: desc = "transport: authentication handshake failed: x509: certificate is valid for *.voipman.com, localhost, voipman.com, *.vipman.com, vipman.com, not dev.unknown.com"
这就说明了证书voipman.pem中的hosts含义所在。
另外,在cfssl中hosts支持 ip地址,DNS域名,email地址和URI这四类。
如下:
"cloudflare.com" "www.cloudflare.com" "192.168.0.1" "jdoe@example.com" "https://www.cloudflare.com"
祝玩的开心~
done.