commit 88ea71f172930c0445598078ddc30c34a200b430
Author: guessi <guessi@gmail.com>
Date:   Sat Feb 22 23:39:16 2020 +0800

    Initial commit

diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000..6b8710a
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1 @@
+.git
diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..66fd13c
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,15 @@
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/
diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..3cb8775
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,10 @@
+FROM golang:1.13-alpine3.11 AS builder
+RUN apk add --no-cache git
+WORKDIR ${GOPATH}/src/github.com/guessi/ssl-certs-checker
+COPY . .
+RUN go build -o /go/bin/ssl-certs-checker
+
+FROM alpine:3.11
+COPY --from=builder /go/bin/ssl-certs-checker /opt/
+WORKDIR /opt/
+ENTRYPOINT ["/opt/ssl-certs-checker"]
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..a8ed630
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2020 guessi
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..6e47381
--- /dev/null
+++ b/README.md
@@ -0,0 +1,44 @@
+# SSL certificate checker written in golang
+
+
+## Setup Guide
+
+    go get -u github.com/guessi/ssl-certs-checker
+
+## Examples
+ 
+install binary to your ${GOPATH}
+
+    go install github.com/ssl-certs-checker
+
+check single target host certificates infomation
+
+    ${GOPATH}/bin/ssl-certs-checker --hosts "www.google.com"
+
+    +----------------+----------------+-------------------------------+-------------------------------+------------+
+    | Host           | Common Name    | Not Before                    | Not After                     | Issuer     |
+    +----------------+----------------+-------------------------------+-------------------------------+------------+
+    | www.google.com | www.google.com | 2020-02-12 11:47:41 +0000 UTC | 2020-05-06 11:47:41 +0000 UTC | GTS CA 1O1 |
+    +----------------+----------------+-------------------------------+-------------------------------+------------+
+
+check multiple target hosts' certificates at once
+
+    ${GOPATH}/bin/ssl-certs-checker --hosts "www.google.com,www.azure.com,www.amazon.com"
+
+    +----------------+----------------+-------------------------------+-------------------------------+-----------------------+
+    | Host           | Common Name    | Not Before                    | Not After                     | Issuer                |
+    +----------------+----------------+-------------------------------+-------------------------------+-----------------------+
+    | www.google.com | www.google.com | 2020-02-12 11:47:41 +0000 UTC | 2020-05-06 11:47:41 +0000 UTC | GTS CA 1O1            |
+    | www.azure.com  | *.azure.com    | 2019-12-17 19:51:44 +0000 UTC | 2020-12-17 19:51:44 +0000 UTC | Microsoft IT TLS CA 4 |
+    | www.amazon.com | www.amazon.com | 2019-09-18 00:00:00 +0000 UTC | 2020-08-23 12:00:00 +0000 UTC | DigiCert Global CA G2 |
+    +----------------+----------------+-------------------------------+-------------------------------+-----------------------+
+
+run with docker
+
+    docker build -t ssl-certs-checker .
+
+    docker run --rm -it ssl-certs-checker --hosts "www.google.com"
+
+# License
+
+[MIT LICENSE](LICENSE)
diff --git a/config.go b/config.go
new file mode 100644
index 0000000..86a3667
--- /dev/null
+++ b/config.go
@@ -0,0 +1,8 @@
+package main
+
+import "time"
+
+const (
+	dialerTimeout = 10 * time.Second
+	protocol      = "tcp"
+)
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..352108f
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,12 @@
+module github.com/guessi/ssl-certs-checker
+
+go 1.13
+
+require (
+	github.com/go-openapi/strfmt v0.19.4 // indirect
+	github.com/jedib0t/go-pretty v4.3.0+incompatible
+	github.com/mattn/go-runewidth v0.0.8 // indirect
+	github.com/stretchr/testify v1.5.1 // indirect
+	github.com/urfave/cli/v2 v2.1.1
+	golang.org/x/sys v0.0.0-20200219091948-cb0a6d8edb6c // indirect
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..faff6f0
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,47 @@
+github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+github.com/asaskevich/govalidator v0.0.0-20190424111038-f61b66f89f4a h1:idn718Q4B6AGu/h5Sxe66HYVdqdGu2l9Iebqhi/AEoA=
+github.com/asaskevich/govalidator v0.0.0-20190424111038-f61b66f89f4a/go.mod h1:lB+ZfQJz7igIIfQNfa7Ml4HSf2uFQQRzpGGRXenZAgY=
+github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d h1:U+s90UTSYgptZMwQh2aRr3LuazLJIa+Pg3Kc1ylSYVY=
+github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/go-openapi/errors v0.19.2 h1:a2kIyV3w+OS3S97zxUndRVD46+FhGOUBDFY7nmu4CsY=
+github.com/go-openapi/errors v0.19.2/go.mod h1:qX0BLWsyaKfvhluLejVpVNwNRdXZhEbTA4kxxpKBC94=
+github.com/go-openapi/strfmt v0.19.4 h1:eRvaqAhpL0IL6Trh5fDsGnGhiXndzHFuA05w6sXH6/g=
+github.com/go-openapi/strfmt v0.19.4/go.mod h1:eftuHTlB/dI8Uq8JJOyRlieZf+WkkxUuk0dgdHXr2Qk=
+github.com/go-stack/stack v1.8.0 h1:5SgMzNM5HxrEjV0ww2lTmX6E2Izsfxas4+YHWRs3Lsk=
+github.com/go-stack/stack v1.8.0/go.mod h1:v0f6uXyyMGvRgIKkXu+yp6POWl0qKG85gN/melR3HDY=
+github.com/google/go-cmp v0.3.0 h1:crn/baboCvb5fXaQ0IJ1SGTsTVrWpDsCWC8EGETZijY=
+github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
+github.com/google/uuid v1.1.1 h1:Gkbcsh/GbpXz7lPftLA3P6TYMwjCLYm83jiFQZF/3gY=
+github.com/google/uuid v1.1.1/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/jedib0t/go-pretty v4.3.0+incompatible h1:CGs8AVhEKg/n9YbUenWmNStRW2PHJzaeDodcfvRAbIo=
+github.com/jedib0t/go-pretty v4.3.0+incompatible/go.mod h1:XemHduiw8R651AF9Pt4FwCTKeG3oo7hrHJAoznj9nag=
+github.com/mattn/go-runewidth v0.0.8 h1:3tS41NlGYSmhhe/8fhGRzc+z3AYCw1Fe1WAyLuujKs0=
+github.com/mattn/go-runewidth v0.0.8/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
+github.com/mitchellh/mapstructure v1.1.2 h1:fmNYVwqnSfB9mZU6OS2O6GsXM+wcskZDuKQzvN1EDeE=
+github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/russross/blackfriday/v2 v2.0.1 h1:lPqVAte+HuHNfhJ/0LC98ESWRz8afy9tM/0RK8m9o+Q=
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+github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
+github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/objx v0.2.0/go.mod h1:qt09Ya8vawLte6SNmTgCsAVtYtaKzEcn8ATUoHMkEqE=
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+golang.org/x/sys v0.0.0-20200219091948-cb0a6d8edb6c/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
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diff --git a/main.go b/main.go
new file mode 100644
index 0000000..e9354a6
--- /dev/null
+++ b/main.go
@@ -0,0 +1,32 @@
+package main
+
+import (
+	"os"
+
+	"github.com/urfave/cli/v2"
+)
+
+func main() {
+	app := &cli.App{
+		Name:  "SSL Certificate Checker",
+		Usage: "check SSL certificates at once",
+		Flags: []cli.Flag{
+			&cli.StringFlag{
+				Name:     "hosts",
+				Aliases:  []string{"H"},
+				Value:    "",
+				Usage:    "target hosts, splits by comma",
+				Required: true,
+			},
+		},
+		Action: func(c *cli.Context) error {
+			prettyPrintCertsInfo(c.String("hosts"))
+			return nil
+		},
+	}
+
+	err := app.Run(os.Args)
+	if err != nil {
+		os.Exit(1)
+	}
+}
diff --git a/utils.go b/utils.go
new file mode 100644
index 0000000..2a8bb37
--- /dev/null
+++ b/utils.go
@@ -0,0 +1,71 @@
+package main
+
+import (
+	"crypto/tls"
+	"crypto/x509"
+	"net"
+	"os"
+	"strconv"
+	"strings"
+
+	"github.com/jedib0t/go-pretty/table"
+	"github.com/jedib0t/go-pretty/text"
+)
+
+func getPeerCertificates(h string, port int) ([]*x509.Certificate, error) {
+	conn, err := tls.DialWithDialer(
+		&net.Dialer{
+			Timeout: dialerTimeout,
+		},
+		protocol,
+		h+":"+strconv.Itoa(port),
+		&tls.Config{
+			ServerName: h,
+		})
+	if err != nil {
+		return nil, err
+	}
+	defer conn.Close()
+
+	if err := conn.Handshake(); err != nil {
+		return nil, err
+	}
+	return conn.ConnectionState().PeerCertificates, nil
+}
+
+func getCells(t table.Writer, h string) {
+	certs, err := getPeerCertificates(h, 443)
+	if err != nil {
+		return // skip if target host invalid
+	}
+
+	for _, c := range certs {
+		if c.IsCA {
+			continue
+		}
+		t.AppendRows([]table.Row{
+			{h, (*c).Subject.CommonName, (*c).NotBefore, (*c).NotAfter, (*c).Issuer.CommonName},
+		})
+	}
+}
+
+func prettyPrintCertsInfo(h string) {
+	targets := strings.Split(h, ",")
+
+	t := table.NewWriter()
+	t.SetOutputMirror(os.Stdout)
+	t.AppendHeader(table.Row{
+		"Host",
+		"Common Name",
+		"Not Before",
+		"Not After",
+		"Issuer",
+	})
+
+	for _, target := range targets {
+		getCells(t, target)
+	}
+
+	t.Style().Format.Header = text.FormatDefault
+	t.Render()
+}