| 1 | // Package signtest stands in for AWS's instance-identity signer: one key, |
| 2 | // one self-signed certificate, and identity documents signed with them. It |
| 3 | // imports nothing from boxid, so both boxid's own tests (package boxid) and |
| 4 | // boxid/boxidtest wrap it without an import cycle. |
| 5 | package signtest |
| 6 | |
| 7 | import ( |
| 8 | "crypto" |
| 9 | "crypto/rand" |
| 10 | "crypto/rsa" |
| 11 | "crypto/sha256" |
| 12 | "crypto/x509" |
| 13 | "crypto/x509/pkix" |
| 14 | "encoding/json" |
| 15 | "math/big" |
| 16 | "testing" |
| 17 | "time" |
| 18 | ) |
| 19 | |
| 20 | // Signer is one test's AWS. |
| 21 | type Signer struct { |
| 22 | Key *rsa.PrivateKey |
| 23 | Cert *x509.Certificate |
| 24 | } |
| 25 | |
| 26 | // New makes a fresh key and a certificate for it, valid for an hour either |
| 27 | // side of now. |
| 28 | func New(t testing.TB) *Signer { |
| 29 | t.Helper() |
| 30 | key, err := rsa.GenerateKey(rand.Reader, 2048) |
| 31 | if err != nil { |
| 32 | t.Fatal(err) |
| 33 | } |
| 34 | tmpl := &x509.Certificate{SerialNumber: big.NewInt(1), Subject: pkix.Name{CommonName: "test"}, |
| 35 | NotBefore: time.Now().Add(-time.Hour), NotAfter: time.Now().Add(time.Hour)} |
| 36 | der, err := x509.CreateCertificate(rand.Reader, tmpl, tmpl, &key.PublicKey, key) |
| 37 | if err != nil { |
| 38 | t.Fatal(err) |
| 39 | } |
| 40 | cert, err := x509.ParseCertificate(der) |
| 41 | if err != nil { |
| 42 | t.Fatal(err) |
| 43 | } |
| 44 | return &Signer{Key: key, Cert: cert} |
| 45 | } |
| 46 | |
| 47 | // Sign returns an identity document for instance in account and region and |
| 48 | // its PKCS #1 v1.5 SHA-256 signature, the pair AWS's IMDS serves. |
| 49 | func (s *Signer) Sign(t testing.TB, account, region, instance string) (doc, sig []byte) { |
| 50 | t.Helper() |
| 51 | doc, err := json.Marshal(map[string]string{"accountId": account, "region": region, "instanceId": instance}) |
| 52 | if err != nil { |
| 53 | t.Fatal(err) |
| 54 | } |
| 55 | sum := sha256.Sum256(doc) |
| 56 | sig, err = rsa.SignPKCS1v15(rand.Reader, s.Key, crypto.SHA256, sum[:]) |
| 57 | if err != nil { |
| 58 | t.Fatal(err) |
| 59 | } |
| 60 | return doc, sig |
| 61 | } |
| 62 | |
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