Merge pull request #2898 from Infisical/cli-ssh-agent

Add SSH CLI capability to load issued SSH credentials into SSH Agent via addToAgent flag
Infisical · Dec 19, 2024 · 5ab0c66 · 5ab0c66
2 parents 2843818 + f5a0641
commit 5ab0c66
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Showing 4 changed files with 156 additions and 104 deletions.
diff --git a/cli/go.mod b/cli/go.mod
@@ -23,8 +23,8 @@ require (
 	github.com/spf13/cobra v1.6.1
 	github.com/spf13/viper v1.8.1
 	github.com/stretchr/testify v1.9.0
-	golang.org/x/crypto v0.25.0
-	golang.org/x/term v0.22.0
+	golang.org/x/crypto v0.31.0
+	golang.org/x/term v0.27.0
 	gopkg.in/yaml.v2 v2.4.0
 )
 
@@ -93,9 +93,9 @@ require (
 	go.opentelemetry.io/otel/trace v1.24.0 // indirect
 	golang.org/x/net v0.27.0 // indirect
 	golang.org/x/oauth2 v0.21.0 // indirect
-	golang.org/x/sync v0.7.0 // indirect
-	golang.org/x/sys v0.22.0 // indirect
-	golang.org/x/text v0.16.0 // indirect
+	golang.org/x/sync v0.10.0 // indirect
+	golang.org/x/sys v0.28.0 // indirect
+	golang.org/x/text v0.21.0 // indirect
 	golang.org/x/time v0.5.0 // indirect
 	google.golang.org/api v0.188.0 // indirect
 	google.golang.org/genproto/googleapis/api v0.0.0-20240701130421-f6361c86f094 // indirect

diff --git a/cli/go.sum b/cli/go.sum
@@ -453,8 +453,8 @@ golang.org/x/crypto v0.0.0-20211215165025-cf75a172585e/go.mod h1:P+XmwS30IXTQdn5
 golang.org/x/crypto v0.0.0-20220622213112-05595931fe9d/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
 golang.org/x/crypto v0.19.0/go.mod h1:Iy9bg/ha4yyC70EfRS8jz+B6ybOBKMaSxLj6P6oBDfU=
 golang.org/x/crypto v0.23.0/go.mod h1:CKFgDieR+mRhux2Lsu27y0fO304Db0wZe70UKqHu0v8=
-golang.org/x/crypto v0.25.0 h1:ypSNr+bnYL2YhwoMt2zPxHFmbAN1KZs/njMG3hxUp30=
-golang.org/x/crypto v0.25.0/go.mod h1:T+wALwcMOSE0kXgUAnPAHqTLW+XHgcELELW8VaDgm/M=
+golang.org/x/crypto v0.31.0 h1:ihbySMvVjLAeSH1IbfcRTkD/iNscyz8rGzjF/E5hV6U=
+golang.org/x/crypto v0.31.0/go.mod h1:kDsLvtWBEx7MV9tJOj9bnXsPbxwJQ6csT/x4KIN4Ssk=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190306152737-a1d7652674e8/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=
 golang.org/x/exp v0.0.0-20190510132918-efd6b22b2522/go.mod h1:ZjyILWgesfNpC6sMxTJOJm9Kp84zZh5NQWvqDGG3Qr8=
@@ -564,8 +564,8 @@ golang.org/x/sync v0.0.0-20201207232520-09787c993a3a/go.mod h1:RxMgew5VJxzue5/jJ
 golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.1.0/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
-golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
-golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+golang.org/x/sync v0.10.0 h1:3NQrjDixjgGwUOCaF8w2+VYHv0Ve/vGYSbdkTa98gmQ=
+golang.org/x/sync v0.10.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20180823144017-11551d06cbcc/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181026203630-95b1ffbd15a5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -620,16 +620,16 @@ golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.8.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.17.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
-golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
-golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+golang.org/x/sys v0.28.0 h1:Fksou7UEQUWlKvIdsqzJmUmCX3cZuD2+P3XyyzwMhlA=
+golang.org/x/sys v0.28.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
 golang.org/x/term v0.5.0/go.mod h1:jMB1sMXY+tzblOD4FWmEbocvup2/aLOaQEp7JmGp78k=
 golang.org/x/term v0.8.0/go.mod h1:xPskH00ivmX89bAKVGSKKtLOWNx2+17Eiy94tnKShWo=
 golang.org/x/term v0.17.0/go.mod h1:lLRBjIVuehSbZlaOtGMbcMncT+aqLLLmKrsjNrUguwk=
 golang.org/x/term v0.20.0/go.mod h1:8UkIAJTvZgivsXaD6/pH6U9ecQzZ45awqEOzuCvwpFY=
-golang.org/x/term v0.22.0 h1:BbsgPEJULsl2fV/AT3v15Mjva5yXKQDyKf+TbDz7QJk=
-golang.org/x/term v0.22.0/go.mod h1:F3qCibpT5AMpCRfhfT53vVJwhLtIVHhB9XDjfFvnMI4=
+golang.org/x/term v0.27.0 h1:WP60Sv1nlK1T6SupCHbXzSaN0b9wUmsPoRS9b61A23Q=
+golang.org/x/term v0.27.0/go.mod h1:iMsnZpn0cago0GOrHO2+Y7u7JPn5AylBrcoWkElMTSM=
 golang.org/x/text v0.0.0-20170915032832-14c0d48ead0c/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.1-0.20180807135948-17ff2d5776d2/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
@@ -643,8 +643,8 @@ golang.org/x/text v0.7.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
 golang.org/x/text v0.9.0/go.mod h1:e1OnstbJyHTd6l/uOt8jFFHp6TRDWZR/bV3emEE/zU8=
 golang.org/x/text v0.14.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 golang.org/x/text v0.15.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
-golang.org/x/text v0.16.0 h1:a94ExnEXNtEwYLGJSIUxnWoxoRz/ZcCsV63ROupILh4=
-golang.org/x/text v0.16.0/go.mod h1:GhwF1Be+LQoKShO3cGOHzqOgRrGaYc9AvblQOmPVHnI=
+golang.org/x/text v0.21.0 h1:zyQAAkrwaneQ066sspRyJaG9VNi/YJ1NfzcGB3hZ/qo=
+golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
 golang.org/x/time v0.0.0-20181108054448-85acf8d2951c/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20190308202827-9d24e82272b4/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=
 golang.org/x/time v0.0.0-20191024005414-555d28b269f0/go.mod h1:tRJNPiyCQ0inRvYxbN9jk5I+vvW/OXSQhTDSoE431IQ=

diff --git a/cli/packages/cmd/ssh.go b/cli/packages/cmd/ssh.go
@@ -6,16 +6,20 @@ package cmd
 import (
 	"context"
 	"fmt"
+	"net"
 	"os"
 	"path/filepath"
 	"strings"
+	"time"
 
 	"github.com/Infisical/infisical-merge/packages/api"
 	"github.com/Infisical/infisical-merge/packages/config"
 	"github.com/Infisical/infisical-merge/packages/util"
 	infisicalSdk "github.com/infisical/go-sdk"
 	infisicalSdkUtil "github.com/infisical/go-sdk/packages/util"
 	"github.com/spf13/cobra"
+	"golang.org/x/crypto/ssh"
+	"golang.org/x/crypto/ssh/agent"
 )
 
 var sshCmd = &cobra.Command{
@@ -52,8 +56,8 @@ var algoToFileName = map[infisicalSdkUtil.CertKeyAlgorithm]string{
 }
 
 func isValidKeyAlgorithm(algo infisicalSdkUtil.CertKeyAlgorithm) bool {
-    _, exists := algoToFileName[algo]
-    return exists
+	_, exists := algoToFileName[algo]
+	return exists
 }
 
 func isValidCertType(certType infisicalSdkUtil.SshCertType) bool {
@@ -81,6 +85,71 @@ func writeToFile(filePath string, content string, perm os.FileMode) error {
 	return nil
 }
 
+func addCredentialsToAgent(privateKeyContent, certContent string) error {
+	// Parse the private key
+	privateKey, err := ssh.ParseRawPrivateKey([]byte(privateKeyContent))
+	if err != nil {
+		return fmt.Errorf("failed to parse private key: %w", err)
+	}
+
+	// Parse the certificate
+	pubKey, _, _, _, err := ssh.ParseAuthorizedKey([]byte(certContent))
+	if err != nil {
+		return fmt.Errorf("failed to parse certificate: %w", err)
+	}
+
+	cert, ok := pubKey.(*ssh.Certificate)
+	if !ok {
+		return fmt.Errorf("parsed key is not a certificate")
+	}
+	// Calculate LifetimeSecs based on certificate's valid-to time
+	validUntil := time.Unix(int64(cert.ValidBefore), 0)
+	now := time.Now()
+
+	// Handle ValidBefore as either a timestamp or an enumeration
+	// SSH certificates use ValidBefore as a timestamp unless set to 0 or ~0
+	if cert.ValidBefore == ssh.CertTimeInfinity {
+		// If certificate never expires, set default lifetime to 1 year (can adjust as needed)
+		validUntil = now.Add(365 * 24 * time.Hour)
+	}
+
+	// Calculate the duration until expiration
+	lifetime := validUntil.Sub(now)
+	if lifetime <= 0 {
+		return fmt.Errorf("certificate is already expired")
+	}
+
+	// Convert duration to seconds
+	lifetimeSecs := uint32(lifetime.Seconds())
+
+	// Connect to the SSH agent
+	socket := os.Getenv("SSH_AUTH_SOCK")
+	if socket == "" {
+		return fmt.Errorf("SSH_AUTH_SOCK not set")
+	}
+
+	conn, err := net.Dial("unix", socket)
+	if err != nil {
+		return fmt.Errorf("failed to connect to SSH agent: %w", err)
+	}
+	defer conn.Close()
+
+	agentClient := agent.NewClient(conn)
+
+	// Add the key with certificate to the agent
+	err = agentClient.Add(agent.AddedKey{
+		PrivateKey:   privateKey,
+		Certificate:  cert,
+		Comment:      "Added via Infisical CLI",
+		LifetimeSecs: lifetimeSecs,
+	})
+	if err != nil {
+		return fmt.Errorf("failed to add key to agent: %w", err)
+	}
+
+	return nil
+}
+
 func issueCredentials(cmd *cobra.Command, args []string) {
 
 	token, err := util.GetInfisicalToken(cmd)
@@ -166,21 +235,23 @@ func issueCredentials(cmd *cobra.Command, args []string) {
 		util.HandleError(err, "Unable to parse flag")
 	}
 
+	addToAgent, err := cmd.Flags().GetBool("addToAgent")
+	if err != nil {
+		util.HandleError(err, "Unable to parse addToAgent flag")
+	}
+
+	if outFilePath == "" && addToAgent == false {
+		util.PrintErrorMessageAndExit("You must provide either --outFilePath or --addToAgent flag to use this command")
+	}
+
 	var (
 		outputDir      string
 		privateKeyPath string
 		publicKeyPath  string
 		signedKeyPath  string
 	)
 
-	if outFilePath == "" {
-		// Use current working directory
-		cwd, err := os.Getwd()
-		if err != nil {
-			util.HandleError(err, "Failed to get current working directory")
-		}
-		outputDir = cwd
-	} else {
+	if outFilePath != "" {
 		// Expand ~ to home directory if present
 		if strings.HasPrefix(outFilePath, "~") {
 			homeDir, err := os.UserHomeDir()
@@ -264,34 +335,47 @@ func issueCredentials(cmd *cobra.Command, args []string) {
 		util.HandleError(err, "Failed to issue SSH credentials")
 	}
 
-	// If signedKeyPath wasn't set in the directory scenario, set it now
-	if signedKeyPath == "" {
-		fileName := algoToFileName[infisicalSdkUtil.CertKeyAlgorithm(keyAlgorithm)]
-		signedKeyPath = filepath.Join(outputDir, fileName+"-cert.pub")
-	}
+	if outFilePath != "" {
+		// If signedKeyPath wasn't set in the directory scenario, set it now
+		if signedKeyPath == "" {
+			fileName := algoToFileName[infisicalSdkUtil.CertKeyAlgorithm(keyAlgorithm)]
+			signedKeyPath = filepath.Join(outputDir, fileName+"-cert.pub")
+		}
 
-	if privateKeyPath == "" {
-		privateKeyPath = filepath.Join(outputDir, algoToFileName[infisicalSdkUtil.CertKeyAlgorithm(keyAlgorithm)])
-	}
-	err = writeToFile(privateKeyPath, creds.PrivateKey, 0600)
-	if err != nil {
-		util.HandleError(err, "Failed to write Private Key to file")
-	}
+		if privateKeyPath == "" {
+			privateKeyPath = filepath.Join(outputDir, algoToFileName[infisicalSdkUtil.CertKeyAlgorithm(keyAlgorithm)])
+		}
+		err = writeToFile(privateKeyPath, creds.PrivateKey, 0600)
+		if err != nil {
+			util.HandleError(err, "Failed to write Private Key to file")
+		}
 
-	if publicKeyPath == "" {
-		publicKeyPath = privateKeyPath + ".pub"
-	}
-	err = writeToFile(publicKeyPath, creds.PublicKey, 0644)
-	if err != nil {
-		util.HandleError(err, "Failed to write Public Key to file")
-	}
+		if publicKeyPath == "" {
+			publicKeyPath = privateKeyPath + ".pub"
+		}
+		err = writeToFile(publicKeyPath, creds.PublicKey, 0644)
+		if err != nil {
+			util.HandleError(err, "Failed to write Public Key to file")
+		}
 
-	err = writeToFile(signedKeyPath, creds.SignedKey, 0644)
-	if err != nil {
-		util.HandleError(err, "Failed to write Signed Key to file")
+		err = writeToFile(signedKeyPath, creds.SignedKey, 0644)
+		if err != nil {
+			util.HandleError(err, "Failed to write Signed Key to file")
+		}
+
+		fmt.Println("Successfully wrote SSH certificate to:", signedKeyPath)
 	}
 
-	fmt.Println("Successfully wrote SSH certificate to:", signedKeyPath)
+	// Add SSH credentials to the SSH agent if needed
+	if addToAgent {
+		// Call the helper function to handle add-to-agent flow
+		err := addCredentialsToAgent(creds.PrivateKey, creds.SignedKey)
+		if err != nil {
+			util.HandleError(err, "Failed to add keys to SSH agent")
+		} else {
+			fmt.Println("The SSH key and certificate have been successfully added to your ssh-agent.")
+		}
+	}
 }
 
 func signKey(cmd *cobra.Command, args []string) {
@@ -519,6 +603,7 @@ func init() {
 	sshIssueCredentialsCmd.Flags().String("ttl", "", "The ttl to issue SSH credentials for")
 	sshIssueCredentialsCmd.Flags().String("keyId", "", "The keyId to issue SSH credentials for")
 	sshIssueCredentialsCmd.Flags().String("outFilePath", "", "The path to write the SSH credentials to such as ~/.ssh, ./some_folder, ./some_folder/id_rsa-cert.pub. If not provided, the credentials will be saved to the current working directory")
+	sshIssueCredentialsCmd.Flags().Bool("addToAgent", false, "Whether to add issued SSH credentials to the SSH agent")
 	sshCmd.AddCommand(sshIssueCredentialsCmd)
 	rootCmd.AddCommand(sshCmd)
 }
diff --git a/docs/documentation/platform/ssh.mdx b/docs/documentation/platform/ssh.mdx
@@ -159,7 +159,19 @@ as part of the SSH operation.
 
 ## Guide to Using Infisical SSH to Access a Host
 
-We show how to obtain a SSH certificate (and optionally a new SSH key pair) for a client to access a host via CLI:
+We show how to obtain a SSH certificate and use it for a client to access a host via CLI:
+
+<Note>
+  The subsequent guide assumes the following prerequisites:
+
+- SSH Agent is running: The `ssh-agent` must be actively running on the host machine.
+- OpenSSH is installed: The system should have OpenSSH installed; this includes
+  both the `ssh` client and `ssh-agent`.
+- `SSH_AUTH_SOCK` environment variable
+  is set; the `SSH_AUTH_SOCK` variable should point to the UNIX socket that
+  `ssh-agent` uses for communication.
+
+</Note>
 
 <Steps>
   <Step title="Authenticate with Infisical">
@@ -169,70 +181,25 @@ infisical login
 ```
 
   </Step>
-  <Step title="Obtain a SSH certificate (and optionally new key-pair)">
-    Depending on the use-case, a client may either request a SSH certificate along with a new SSH key pair or obtain a SSH certificate for an existing SSH key pair to access a host.
-
-    <AccordionGroup>
-      <Accordion title="Using New Key Pair (Recommended)">
-        If you wish to obtain a new SSH key pair in conjunction with the SSH certificate, then you can use the `infisical ssh issue-credentials` command.
-
-        ```bash
-        infisical ssh issue-credentials --certificateTemplateId=<certificate-template-id> --principals=<username>
-        ```
-
-        The following flags may be relevant:
-
-        - `certificateTemplateId`: The ID of the certificate template to use for issuing the SSH certificate.
-        - `principals`: The comma-delimited username(s) or hostname(s) to include in the SSH certificate.
-        - `outFilePath` (optional): The path to the file to write the SSH certificate to.
-
-        <Note>
-          If `outFilePath` is not specified, the SSH certificate will be written to the current working directory where the command is run.
-        </Note>
-
-      </Accordion>
-      <Accordion title="Using Existing Key Pair">
-        If you have an existing SSH key pair, then you can use the `infisical ssh sign-key` command with either
-        the `--publicKey` flag or the `--publicKeyFilePath` flag to obtain a SSH certificate corresponding to
-        the existing credential.
-
-        ```bash
-        infisical ssh sign-key --publicKeyFilePath=<public-key-file-path> --certificateTemplateId=<certificate-template-id> --principals=<username>
-        ```
-
-        The following flags may be relevant:
-
-        - `publicKey`: The public key to sign.
-        - `publicKeyFilePath`: The path to the public key file to sign.
-        - `certificateTemplateId`: The ID of the certificate template to use for issuing the SSH certificate.
-        - `principals`: The comma-delimited username(s) or hostname(s) to include in the SSH certificate.
-        - `outFilePath` (optional): The path to the file to write the SSH certificate to.
-
-        <Note>
-          If `outFilePath` is not specified but `publicKeyFilePath` is then the SSH certificate will be written to the directory of the public key file; if the public key file is called `id_rsa.pub`, then the file containing the SSH certificate will be called `id_rsa-cert.pub`.
+  <Step title="Obtain a SSH certificate and load it into the SSH agent">
+    Run the `infisical ssh issue-credentials` command, specifying the `--addToAgent` flag to automatically load the SSH certificate into the SSH agent.
+    ```bash
+    infisical ssh issue-credentials --certificateTemplateId=<certificate-template-id> --principals=<username> --addToAgent
+    ```
 
-          Otherwise, if `outFilePath` is not specified, the SSH certificate will be written to the current working directory where the command is run.
-        </Note>
+    Here's some guidance on each flag:
 
-      </Accordion>
-    </AccordionGroup>
+    - `certificateTemplateId`: The ID of the certificate template to use for issuing the SSH certificate.
+    - `principals`: The comma-delimited username(s) or hostname(s) to include in the SSH certificate.
 
   </Step>
   <Step title="SSH into the host">
-    Once you have obtained the SSH certificate, you can use it to SSH into the desired host.
+    Finally, SSH into the desired host; the SSH operation will be performed using the SSH certificate loaded into the SSH agent.
 
     ```bash
-    ssh -i /path/to/private_key.pem \
-    -o CertificateFile=/path/to/ssh-cert.pub \
-    username@hostname
+    ssh username@hostname
     ```
 
-    <Note>
-      We recommend setting up aliases so you can more easily SSH into the desired host.
-
-      For example, you may set up an SSH alias using the SSH client configuration file (usually `~/.ssh/config`), defining a host alias including the file path to the issued SSH credential(s).
-    </Note>
-
   </Step>
 </Steps>