ssh-ident/identity.go

package main

import (
	"os"
	"path"
	"regexp"
	"strings"
)

type Identity struct {
	Name string
	Path string
}

func newIdentity(config Config, name string) Identity {
	return Identity{
		Name: name,
		Path: "",
	}
}

var hostRegexps = map[string]*regexp.Regexp{
	"ssh": regexp.MustCompile("(?P<user>.*@)?(?P<host>.*)"),
	"scp": regexp.MustCompile("(?P<user>.*@)?(?P<host>.*):(?P<file>.*)"),
}

func extractHost(prog string, args []string) string {
	args = removeOptions(prog, args)
	switch prog {
	case "ssh":
		if len(args) == 0 {
			return ""
		}
		re := hostRegexps["ssh"]
		arg := args[0]
		p := matchParams(re, arg)
		return p["host"]
	case "scp":
		re := hostRegexps["scp"]
		for _, arg := range args {
			if p := matchParams(re, arg); p != nil {
				return p["host"]
			}
		}
	}
	return ""
}

func findIdentityName(config Config, prog string, args []string) string {
	name := os.Getenv("SSH_IDENTITY")
	if name != "" {
		return name
	}
	identities := config.Identities
	host := extractHost(prog, args)
	for match, name := range identities {
		if strings.Contains(host, match) {
			return name
		}
	}

	return config.DefaultIdentity
}

func FindIdentity(config Config, prog string, args []string) Identity {
	name := findIdentityName(config, prog, args)
	path := path.Join(config.IdentitiesDir, name)
	return Identity{
		Name: name,
		Path: path,
	}
}