From c6092083d4fcab034509a9c8136047e4a3abf248 Mon Sep 17 00:00:00 2001 From: Patrick Baker Date: Tue, 14 Jul 2015 13:20:58 -0400 Subject: [PATCH] Add RSASSA-PSS signatures --- rsa_pss.go | 126 ++++++++++++++++++++++++++++++++++++++++++++++++ rsa_pss_test.go | 96 ++++++++++++++++++++++++++++++++++++ 2 files changed, 222 insertions(+) create mode 100644 rsa_pss.go create mode 100644 rsa_pss_test.go diff --git a/rsa_pss.go b/rsa_pss.go new file mode 100644 index 0000000..0cedd5e --- /dev/null +++ b/rsa_pss.go @@ -0,0 +1,126 @@ +// +build go1.4 + +package jwt + +import ( + "crypto" + "crypto/rand" + "crypto/rsa" +) + +// Implements the RSAPSS family of signing methods signing methods +type SigningMethodRSAPSS struct { + *SigningMethodRSA + Options *rsa.PSSOptions +} + +// Specific instances for RS/PS and company +var ( + SigningMethodPS256 *SigningMethodRSAPSS + SigningMethodPS384 *SigningMethodRSAPSS + SigningMethodPS512 *SigningMethodRSAPSS +) + +func init() { + // PS256 + SigningMethodPS256 = &SigningMethodRSAPSS{ + &SigningMethodRSA{ + Name: "PS256", + Hash: crypto.SHA256, + }, + &rsa.PSSOptions{ + SaltLength: rsa.PSSSaltLengthAuto, + Hash: crypto.SHA256, + }, + } + RegisterSigningMethod(SigningMethodPS256.Alg(), func() SigningMethod { + return SigningMethodPS256 + }) + + // PS384 + SigningMethodPS384 = &SigningMethodRSAPSS{ + &SigningMethodRSA{ + Name: "PS384", + Hash: crypto.SHA384, + }, + &rsa.PSSOptions{ + SaltLength: rsa.PSSSaltLengthAuto, + Hash: crypto.SHA384, + }, + } + RegisterSigningMethod(SigningMethodPS384.Alg(), func() SigningMethod { + return SigningMethodPS384 + }) + + // PS512 + SigningMethodPS512 = &SigningMethodRSAPSS{ + &SigningMethodRSA{ + Name: "PS512", + Hash: crypto.SHA512, + }, + &rsa.PSSOptions{ + SaltLength: rsa.PSSSaltLengthAuto, + Hash: crypto.SHA512, + }, + } + RegisterSigningMethod(SigningMethodPS512.Alg(), func() SigningMethod { + return SigningMethodPS512 + }) +} + +// Implements the Verify method from SigningMethod +// For this verify method, key must be an rsa.PrivateKey struct +func (m *SigningMethodRSAPSS) Verify(signingString, signature string, key interface{}) error { + var err error + + // Decode the signature + var sig []byte + if sig, err = DecodeSegment(signature); err != nil { + return err + } + + var rsaKey *rsa.PublicKey + switch k := key.(type) { + case *rsa.PublicKey: + rsaKey = k + default: + return ErrInvalidKey + } + + // Create hasher + if !m.Hash.Available() { + return ErrHashUnavailable + } + hasher := m.Hash.New() + hasher.Write([]byte(signingString)) + + return rsa.VerifyPSS(rsaKey, m.Hash, hasher.Sum(nil), sig, m.Options) +} + +// Implements the Sign method from SigningMethod +// For this signing method, key must be an rsa.PublicKey struct +func (m *SigningMethodRSAPSS) Sign(signingString string, key interface{}) (string, error) { + var rsaKey *rsa.PrivateKey + + switch k := key.(type) { + case *rsa.PrivateKey: + rsaKey = k + default: + return "", ErrInvalidKey + } + + // Create the hasher + if !m.Hash.Available() { + return "", ErrHashUnavailable + } + + hasher := m.Hash.New() + hasher.Write([]byte(signingString)) + + // Sign the string and return the encoded bytes + if sigBytes, err := rsa.SignPSS(rand.Reader, rsaKey, m.Hash, hasher.Sum(nil), m.Options); err == nil { + return EncodeSegment(sigBytes), nil + } else { + return "", err + } +} diff --git a/rsa_pss_test.go b/rsa_pss_test.go new file mode 100644 index 0000000..9045aaf --- /dev/null +++ b/rsa_pss_test.go @@ -0,0 +1,96 @@ +// +build go1.4 + +package jwt_test + +import ( + "crypto/rsa" + "io/ioutil" + "strings" + "testing" + + "github.com/dgrijalva/jwt-go" +) + +var rsaPSSTestData = []struct { + name string + tokenString string + alg string + claims map[string]interface{} + valid bool +}{ + { + "Basic PS256", + "eyJhbGciOiJQUzI1NiIsInR5cCI6IkpXVCJ9.eyJmb28iOiJiYXIifQ.PPG4xyDVY8ffp4CcxofNmsTDXsrVG2npdQuibLhJbv4ClyPTUtR5giNSvuxo03kB6I8VXVr0Y9X7UxhJVEoJOmULAwRWaUsDnIewQa101cVhMa6iR8X37kfFoiZ6NkS-c7henVkkQWu2HtotkEtQvN5hFlk8IevXXPmvZlhQhwzB1sGzGYnoi1zOfuL98d3BIjUjtlwii5w6gYG2AEEzp7HnHCsb3jIwUPdq86Oe6hIFjtBwduIK90ca4UqzARpcfwxHwVLMpatKask00AgGVI0ysdk0BLMjmLutquD03XbThHScC2C2_Pp4cHWgMzvbgLU2RYYZcZRKr46QeNgz9w", + "PS256", + map[string]interface{}{"foo": "bar"}, + true, + }, + { + "Basic PS384", + "eyJhbGciOiJQUzM4NCIsInR5cCI6IkpXVCJ9.eyJmb28iOiJiYXIifQ.w7-qqgj97gK4fJsq_DCqdYQiylJjzWONvD0qWWWhqEOFk2P1eDULPnqHRnjgTXoO4HAw4YIWCsZPet7nR3Xxq4ZhMqvKW8b7KlfRTb9cH8zqFvzMmybQ4jv2hKc3bXYqVow3AoR7hN_CWXI3Dv6Kd2X5xhtxRHI6IL39oTVDUQ74LACe-9t4c3QRPuj6Pq1H4FAT2E2kW_0KOc6EQhCLWEhm2Z2__OZskDC8AiPpP8Kv4k2vB7l0IKQu8Pr4RcNBlqJdq8dA5D3hk5TLxP8V5nG1Ib80MOMMqoS3FQvSLyolFX-R_jZ3-zfq6Ebsqr0yEb0AH2CfsECF7935Pa0FKQ", + "PS384", + map[string]interface{}{"foo": "bar"}, + true, + }, + { + "Basic PS512", + "eyJhbGciOiJQUzUxMiIsInR5cCI6IkpXVCJ9.eyJmb28iOiJiYXIifQ.GX1HWGzFaJevuSLavqqFYaW8_TpvcjQ8KfC5fXiSDzSiT9UD9nB_ikSmDNyDILNdtjZLSvVKfXxZJqCfefxAtiozEDDdJthZ-F0uO4SPFHlGiXszvKeodh7BuTWRI2wL9-ZO4mFa8nq3GMeQAfo9cx11i7nfN8n2YNQ9SHGovG7_T_AvaMZB_jT6jkDHpwGR9mz7x1sycckEo6teLdHRnH_ZdlHlxqknmyTu8Odr5Xh0sJFOL8BepWbbvIIn-P161rRHHiDWFv6nhlHwZnVzjx7HQrWSGb6-s2cdLie9QL_8XaMcUpjLkfOMKkDOfHo6AvpL7Jbwi83Z2ZTHjJWB-A", + "PS512", + map[string]interface{}{"foo": "bar"}, + true, + }, + { + "basic PS256 invalid: foo => bar", + "eyJhbGciOiJQUzI1NiIsInR5cCI6IkpXVCJ9.eyJmb28iOiJiYXIifQ.PPG4xyDVY8ffp4CcxofNmsTDXsrVG2npdQuibLhJbv4ClyPTUtR5giNSvuxo03kB6I8VXVr0Y9X7UxhJVEoJOmULAwRWaUsDnIewQa101cVhMa6iR8X37kfFoiZ6NkS-c7henVkkQWu2HtotkEtQvN5hFlk8IevXXPmvZlhQhwzB1sGzGYnoi1zOfuL98d3BIjUjtlwii5w6gYG2AEEzp7HnHCsb3jIwUPdq86Oe6hIFjtBwduIK90ca4UqzARpcfwxHwVLMpatKask00AgGVI0ysdk0BLMjmLutquD03XbThHScC2C2_Pp4cHWgMzvbgLU2RYYZcZRKr46QeNgz9W", + "PS256", + map[string]interface{}{"foo": "bar"}, + false, + }, +} + +func TestRSAPSSVerify(t *testing.T) { + var err error + + key, _ := ioutil.ReadFile("test/sample_key.pub") + var rsaPSSKey *rsa.PublicKey + if rsaPSSKey, err = jwt.ParseRSAPublicKeyFromPEM(key); err != nil { + t.Errorf("Unable to parse RSA public key: %v", err) + } + + for _, data := range rsaPSSTestData { + parts := strings.Split(data.tokenString, ".") + + method := jwt.GetSigningMethod(data.alg) + err := method.Verify(strings.Join(parts[0:2], "."), parts[2], rsaPSSKey) + if data.valid && err != nil { + t.Errorf("[%v] Error while verifying key: %v", data.name, err) + } + if !data.valid && err == nil { + t.Errorf("[%v] Invalid key passed validation", data.name) + } + } +} + +func TestRSAPSSSign(t *testing.T) { + var err error + + key, _ := ioutil.ReadFile("test/sample_key") + var rsaPSSKey *rsa.PrivateKey + if rsaPSSKey, err = jwt.ParseRSAPrivateKeyFromPEM(key); err != nil { + t.Errorf("Unable to parse RSA private key: %v", err) + } + + for _, data := range rsaPSSTestData { + if data.valid { + parts := strings.Split(data.tokenString, ".") + method := jwt.GetSigningMethod(data.alg) + sig, err := method.Sign(strings.Join(parts[0:2], "."), rsaPSSKey) + if err != nil { + t.Errorf("[%v] Error signing token: %v", data.name, err) + } + if sig == parts[2] { + t.Errorf("[%v] Signatures shouldn't match\nnew:\n%v\noriginal:\n%v", data.name, sig, parts[2]) + } + } + } +}