forked from paultag/go-debian
/
sigcheck.go
50 lines (44 loc) · 1.18 KB
/
sigcheck.go
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package deb // import "github.com/systemos-linux/go-debian/deb"
import (
"fmt"
"io"
"strings"
"golang.org/x/crypto/openpgp"
)
const (
SigTypeArchive = `archive`
SigTypeMaint = `maint`
SigTypeOrigin = `origin`
)
func (deb *Deb) CheckDebsig(validKeys openpgp.EntityList, sigType string) (signer *openpgp.Entity, err error) {
sig, ok := deb.ArContent[`_gpg`+sigType]
if !ok {
return nil, fmt.Errorf("no signature of type %v present", sigType)
}
binaryFlag, ok := deb.ArContent[`debian-binary`]
if !ok {
return nil, fmt.Errorf("archive does not contain a debian-binary flag")
}
var control, data *ArEntry
for _, member := range deb.ArContent {
if strings.HasPrefix(member.Name, "control.") {
control = member
if data != nil {
break
}
} else if strings.HasPrefix(member.Name, "data.") {
data = member
if control != nil {
break
}
}
}
if control == nil || data == nil {
return nil, fmt.Errorf("unable to find signed data")
}
binaryFlag.Data.Seek(0, 0)
control.Data.Seek(0, 0)
data.Data.Seek(0, 0)
signedData := io.MultiReader(binaryFlag.Data, control.Data, data.Data)
return openpgp.CheckDetachedSignature(validKeys, signedData, sig.Data)
}