Add ssh host host ca public key endpoint

backend/src/ee/routes/v1/ssh-host-router.ts

@@ -460,4 +460,25 @@ export const registerSshHostRouter = async (server: FastifyZodProvider) => {
       return publicKey;
     }
   });
+
+  server.route({
+    method: "GET",
+    url: "/:sshHostId/host-ca-public-key",
+    config: {
+      rateLimit: publicSshCaLimit
+    },
+    schema: {
+      description: "Get public key of the host SSH CA linked to the host",
+      params: z.object({
+        sshHostId: z.string().trim().describe(SSH_HOSTS.GET_USER_CA_PUBLIC_KEY.sshHostId)
+      }),
+      response: {
+        200: z.string()
+      }
+    },
+    handler: async (req) => {
+      const publicKey = await server.services.sshHost.getSshHostHostCaPk(req.params.sshHostId);
+      return publicKey;
+    }
+  });
 };

backend/src/ee/services/ssh-host/ssh-host-service.ts

@@ -590,6 +590,30 @@ export const sshHostServiceFactory = ({
     return publicKey;
   };
 
+  const getSshHostHostCaPk = async (sshHostId: string) => {
+    const host = await sshHostDAL.findById(sshHostId);
+    if (!host) {
+      throw new NotFoundError({
+        message: `SSH host with ID ${sshHostId} not found`
+      });
+    }
+
+    const sshCaSecret = await sshCertificateAuthoritySecretDAL.findOne({ sshCaId: host.hostSshCaId });
+
+    const { decryptor: secretManagerDecryptor } = await kmsService.createCipherPairWithDataKey({
+      type: KmsDataKey.SecretManager,
+      projectId: host.projectId
+    });
+
+    const decryptedCaPrivateKey = secretManagerDecryptor({
+      cipherTextBlob: sshCaSecret.encryptedPrivateKey
+    });
+
+    const publicKey = await getSshPublicKey(decryptedCaPrivateKey.toString("utf-8"));
+
+    return publicKey;
+  };
+
   return {
     listSshHosts,
     createSshHost,
@@ -598,6 +622,7 @@ export const sshHostServiceFactory = ({
     getSshHost,
     issueSshHostUserCert,
     issueSshHostHostCert,
-    getSshHostUserCaPk
+    getSshHostUserCaPk,
+    getSshHostHostCaPk
   };
 };

backend/src/lib/api-docs/constants.ts

@@ -1363,6 +1363,9 @@ export const SSH_HOSTS = {
   },
   GET_USER_CA_PUBLIC_KEY: {
     sshHostId: "The ID of the SSH host to get the user SSH CA public key for."
+  },
+  GET_HOST_CA_PUBLIC_KEY: {
+    sshHostId: "The ID of the SSH host to get the host SSH CA public key for."
   }
 };