mirror of
https://github.com/superseriousbusiness/gotosocial.git
synced 2024-12-05 10:02:47 +00:00
362 lines
14 KiB
Go
362 lines
14 KiB
Go
|
// Implements HTTP request and response signing and verification. Supports the
|
||
|
// major MAC and asymmetric key signature algorithms. It has several safety
|
||
|
// restrictions: One, none of the widely known non-cryptographically safe
|
||
|
// algorithms are permitted; Two, the RSA SHA256 algorithms must be available in
|
||
|
// the binary (and it should, barring export restrictions); Finally, the library
|
||
|
// assumes either the 'Authorizationn' or 'Signature' headers are to be set (but
|
||
|
// not both).
|
||
|
package httpsig
|
||
|
|
||
|
import (
|
||
|
"crypto"
|
||
|
"fmt"
|
||
|
"net/http"
|
||
|
"strings"
|
||
|
"time"
|
||
|
|
||
|
"golang.org/x/crypto/ssh"
|
||
|
)
|
||
|
|
||
|
// Algorithm specifies a cryptography secure algorithm for signing HTTP requests
|
||
|
// and responses.
|
||
|
type Algorithm string
|
||
|
|
||
|
const (
|
||
|
// MAC-based algoirthms.
|
||
|
HMAC_SHA224 Algorithm = hmacPrefix + "-" + sha224String
|
||
|
HMAC_SHA256 Algorithm = hmacPrefix + "-" + sha256String
|
||
|
HMAC_SHA384 Algorithm = hmacPrefix + "-" + sha384String
|
||
|
HMAC_SHA512 Algorithm = hmacPrefix + "-" + sha512String
|
||
|
HMAC_RIPEMD160 Algorithm = hmacPrefix + "-" + ripemd160String
|
||
|
HMAC_SHA3_224 Algorithm = hmacPrefix + "-" + sha3_224String
|
||
|
HMAC_SHA3_256 Algorithm = hmacPrefix + "-" + sha3_256String
|
||
|
HMAC_SHA3_384 Algorithm = hmacPrefix + "-" + sha3_384String
|
||
|
HMAC_SHA3_512 Algorithm = hmacPrefix + "-" + sha3_512String
|
||
|
HMAC_SHA512_224 Algorithm = hmacPrefix + "-" + sha512_224String
|
||
|
HMAC_SHA512_256 Algorithm = hmacPrefix + "-" + sha512_256String
|
||
|
HMAC_BLAKE2S_256 Algorithm = hmacPrefix + "-" + blake2s_256String
|
||
|
HMAC_BLAKE2B_256 Algorithm = hmacPrefix + "-" + blake2b_256String
|
||
|
HMAC_BLAKE2B_384 Algorithm = hmacPrefix + "-" + blake2b_384String
|
||
|
HMAC_BLAKE2B_512 Algorithm = hmacPrefix + "-" + blake2b_512String
|
||
|
BLAKE2S_256 Algorithm = blake2s_256String
|
||
|
BLAKE2B_256 Algorithm = blake2b_256String
|
||
|
BLAKE2B_384 Algorithm = blake2b_384String
|
||
|
BLAKE2B_512 Algorithm = blake2b_512String
|
||
|
// RSA-based algorithms.
|
||
|
RSA_SHA1 Algorithm = rsaPrefix + "-" + sha1String
|
||
|
RSA_SHA224 Algorithm = rsaPrefix + "-" + sha224String
|
||
|
// RSA_SHA256 is the default algorithm.
|
||
|
RSA_SHA256 Algorithm = rsaPrefix + "-" + sha256String
|
||
|
RSA_SHA384 Algorithm = rsaPrefix + "-" + sha384String
|
||
|
RSA_SHA512 Algorithm = rsaPrefix + "-" + sha512String
|
||
|
RSA_RIPEMD160 Algorithm = rsaPrefix + "-" + ripemd160String
|
||
|
// ECDSA algorithms
|
||
|
ECDSA_SHA224 Algorithm = ecdsaPrefix + "-" + sha224String
|
||
|
ECDSA_SHA256 Algorithm = ecdsaPrefix + "-" + sha256String
|
||
|
ECDSA_SHA384 Algorithm = ecdsaPrefix + "-" + sha384String
|
||
|
ECDSA_SHA512 Algorithm = ecdsaPrefix + "-" + sha512String
|
||
|
ECDSA_RIPEMD160 Algorithm = ecdsaPrefix + "-" + ripemd160String
|
||
|
// ED25519 algorithms
|
||
|
// can only be SHA512
|
||
|
ED25519 Algorithm = ed25519Prefix
|
||
|
|
||
|
// Just because you can glue things together, doesn't mean they will
|
||
|
// work. The following options are not supported.
|
||
|
rsa_SHA3_224 Algorithm = rsaPrefix + "-" + sha3_224String
|
||
|
rsa_SHA3_256 Algorithm = rsaPrefix + "-" + sha3_256String
|
||
|
rsa_SHA3_384 Algorithm = rsaPrefix + "-" + sha3_384String
|
||
|
rsa_SHA3_512 Algorithm = rsaPrefix + "-" + sha3_512String
|
||
|
rsa_SHA512_224 Algorithm = rsaPrefix + "-" + sha512_224String
|
||
|
rsa_SHA512_256 Algorithm = rsaPrefix + "-" + sha512_256String
|
||
|
rsa_BLAKE2S_256 Algorithm = rsaPrefix + "-" + blake2s_256String
|
||
|
rsa_BLAKE2B_256 Algorithm = rsaPrefix + "-" + blake2b_256String
|
||
|
rsa_BLAKE2B_384 Algorithm = rsaPrefix + "-" + blake2b_384String
|
||
|
rsa_BLAKE2B_512 Algorithm = rsaPrefix + "-" + blake2b_512String
|
||
|
)
|
||
|
|
||
|
// HTTP Signatures can be applied to different HTTP headers, depending on the
|
||
|
// expected application behavior.
|
||
|
type SignatureScheme string
|
||
|
|
||
|
const (
|
||
|
// Signature will place the HTTP Signature into the 'Signature' HTTP
|
||
|
// header.
|
||
|
Signature SignatureScheme = "Signature"
|
||
|
// Authorization will place the HTTP Signature into the 'Authorization'
|
||
|
// HTTP header.
|
||
|
Authorization SignatureScheme = "Authorization"
|
||
|
)
|
||
|
|
||
|
const (
|
||
|
// The HTTP Signatures specification uses the "Signature" auth-scheme
|
||
|
// for the Authorization header. This is coincidentally named, but not
|
||
|
// semantically the same, as the "Signature" HTTP header value.
|
||
|
signatureAuthScheme = "Signature"
|
||
|
)
|
||
|
|
||
|
// There are subtle differences to the values in the header. The Authorization
|
||
|
// header has an 'auth-scheme' value that must be prefixed to the rest of the
|
||
|
// key and values.
|
||
|
func (s SignatureScheme) authScheme() string {
|
||
|
switch s {
|
||
|
case Authorization:
|
||
|
return signatureAuthScheme
|
||
|
default:
|
||
|
return ""
|
||
|
}
|
||
|
}
|
||
|
|
||
|
// Signers will sign HTTP requests or responses based on the algorithms and
|
||
|
// headers selected at creation time.
|
||
|
//
|
||
|
// Signers are not safe to use between multiple goroutines.
|
||
|
//
|
||
|
// Note that signatures do set the deprecated 'algorithm' parameter for
|
||
|
// backwards compatibility.
|
||
|
type Signer interface {
|
||
|
// SignRequest signs the request using a private key. The public key id
|
||
|
// is used by the HTTP server to identify which key to use to verify the
|
||
|
// signature.
|
||
|
//
|
||
|
// If the Signer was created using a MAC based algorithm, then the key
|
||
|
// is expected to be of type []byte. If the Signer was created using an
|
||
|
// RSA based algorithm, then the private key is expected to be of type
|
||
|
// *rsa.PrivateKey.
|
||
|
//
|
||
|
// A Digest (RFC 3230) will be added to the request. The body provided
|
||
|
// must match the body used in the request, and is allowed to be nil.
|
||
|
// The Digest ensures the request body is not tampered with in flight,
|
||
|
// and if the signer is created to also sign the "Digest" header, the
|
||
|
// HTTP Signature will then ensure both the Digest and body are not both
|
||
|
// modified to maliciously represent different content.
|
||
|
SignRequest(pKey crypto.PrivateKey, pubKeyId string, r *http.Request, body []byte) error
|
||
|
// SignResponse signs the response using a private key. The public key
|
||
|
// id is used by the HTTP client to identify which key to use to verify
|
||
|
// the signature.
|
||
|
//
|
||
|
// If the Signer was created using a MAC based algorithm, then the key
|
||
|
// is expected to be of type []byte. If the Signer was created using an
|
||
|
// RSA based algorithm, then the private key is expected to be of type
|
||
|
// *rsa.PrivateKey.
|
||
|
//
|
||
|
// A Digest (RFC 3230) will be added to the response. The body provided
|
||
|
// must match the body written in the response, and is allowed to be
|
||
|
// nil. The Digest ensures the response body is not tampered with in
|
||
|
// flight, and if the signer is created to also sign the "Digest"
|
||
|
// header, the HTTP Signature will then ensure both the Digest and body
|
||
|
// are not both modified to maliciously represent different content.
|
||
|
SignResponse(pKey crypto.PrivateKey, pubKeyId string, r http.ResponseWriter, body []byte) error
|
||
|
}
|
||
|
|
||
|
// NewSigner creates a new Signer with the provided algorithm preferences to
|
||
|
// make HTTP signatures. Only the first available algorithm will be used, which
|
||
|
// is returned by this function along with the Signer. If none of the preferred
|
||
|
// algorithms were available, then the default algorithm is used. The headers
|
||
|
// specified will be included into the HTTP signatures.
|
||
|
//
|
||
|
// The Digest will also be calculated on a request's body using the provided
|
||
|
// digest algorithm, if "Digest" is one of the headers listed.
|
||
|
//
|
||
|
// The provided scheme determines which header is populated with the HTTP
|
||
|
// Signature.
|
||
|
//
|
||
|
// An error is returned if an unknown or a known cryptographically insecure
|
||
|
// Algorithm is provided.
|
||
|
func NewSigner(prefs []Algorithm, dAlgo DigestAlgorithm, headers []string, scheme SignatureScheme, expiresIn int64) (Signer, Algorithm, error) {
|
||
|
for _, pref := range prefs {
|
||
|
s, err := newSigner(pref, dAlgo, headers, scheme, expiresIn)
|
||
|
if err != nil {
|
||
|
continue
|
||
|
}
|
||
|
return s, pref, err
|
||
|
}
|
||
|
s, err := newSigner(defaultAlgorithm, dAlgo, headers, scheme, expiresIn)
|
||
|
return s, defaultAlgorithm, err
|
||
|
}
|
||
|
|
||
|
// Signers will sign HTTP requests or responses based on the algorithms and
|
||
|
// headers selected at creation time.
|
||
|
//
|
||
|
// Signers are not safe to use between multiple goroutines.
|
||
|
//
|
||
|
// Note that signatures do set the deprecated 'algorithm' parameter for
|
||
|
// backwards compatibility.
|
||
|
type SSHSigner interface {
|
||
|
// SignRequest signs the request using ssh.Signer.
|
||
|
// The public key id is used by the HTTP server to identify which key to use
|
||
|
// to verify the signature.
|
||
|
//
|
||
|
// A Digest (RFC 3230) will be added to the request. The body provided
|
||
|
// must match the body used in the request, and is allowed to be nil.
|
||
|
// The Digest ensures the request body is not tampered with in flight,
|
||
|
// and if the signer is created to also sign the "Digest" header, the
|
||
|
// HTTP Signature will then ensure both the Digest and body are not both
|
||
|
// modified to maliciously represent different content.
|
||
|
SignRequest(pubKeyId string, r *http.Request, body []byte) error
|
||
|
// SignResponse signs the response using ssh.Signer. The public key
|
||
|
// id is used by the HTTP client to identify which key to use to verify
|
||
|
// the signature.
|
||
|
//
|
||
|
// A Digest (RFC 3230) will be added to the response. The body provided
|
||
|
// must match the body written in the response, and is allowed to be
|
||
|
// nil. The Digest ensures the response body is not tampered with in
|
||
|
// flight, and if the signer is created to also sign the "Digest"
|
||
|
// header, the HTTP Signature will then ensure both the Digest and body
|
||
|
// are not both modified to maliciously represent different content.
|
||
|
SignResponse(pubKeyId string, r http.ResponseWriter, body []byte) error
|
||
|
}
|
||
|
|
||
|
// NewwSSHSigner creates a new Signer using the specified ssh.Signer
|
||
|
// At the moment only ed25519 ssh keys are supported.
|
||
|
// The headers specified will be included into the HTTP signatures.
|
||
|
//
|
||
|
// The Digest will also be calculated on a request's body using the provided
|
||
|
// digest algorithm, if "Digest" is one of the headers listed.
|
||
|
//
|
||
|
// The provided scheme determines which header is populated with the HTTP
|
||
|
// Signature.
|
||
|
func NewSSHSigner(s ssh.Signer, dAlgo DigestAlgorithm, headers []string, scheme SignatureScheme, expiresIn int64) (SSHSigner, Algorithm, error) {
|
||
|
sshAlgo := getSSHAlgorithm(s.PublicKey().Type())
|
||
|
if sshAlgo == "" {
|
||
|
return nil, "", fmt.Errorf("key type: %s not supported yet.", s.PublicKey().Type())
|
||
|
}
|
||
|
|
||
|
signer, err := newSSHSigner(s, sshAlgo, dAlgo, headers, scheme, expiresIn)
|
||
|
if err != nil {
|
||
|
return nil, "", err
|
||
|
}
|
||
|
|
||
|
return signer, sshAlgo, nil
|
||
|
}
|
||
|
|
||
|
func getSSHAlgorithm(pkType string) Algorithm {
|
||
|
switch {
|
||
|
case strings.HasPrefix(pkType, sshPrefix+"-"+ed25519Prefix):
|
||
|
return ED25519
|
||
|
case strings.HasPrefix(pkType, sshPrefix+"-"+rsaPrefix):
|
||
|
return RSA_SHA1
|
||
|
}
|
||
|
|
||
|
return ""
|
||
|
}
|
||
|
|
||
|
// Verifier verifies HTTP Signatures.
|
||
|
//
|
||
|
// It will determine which of the supported headers has the parameters
|
||
|
// that define the signature.
|
||
|
//
|
||
|
// Verifiers are not safe to use between multiple goroutines.
|
||
|
//
|
||
|
// Note that verification ignores the deprecated 'algorithm' parameter.
|
||
|
type Verifier interface {
|
||
|
// KeyId gets the public key id that the signature is signed with.
|
||
|
//
|
||
|
// Note that the application is expected to determine the algorithm
|
||
|
// used based on metadata or out-of-band information for this key id.
|
||
|
KeyId() string
|
||
|
// Verify accepts the public key specified by KeyId and returns an
|
||
|
// error if verification fails or if the signature is malformed. The
|
||
|
// algorithm must be the one used to create the signature in order to
|
||
|
// pass verification. The algorithm is determined based on metadata or
|
||
|
// out-of-band information for the key id.
|
||
|
//
|
||
|
// If the signature was created using a MAC based algorithm, then the
|
||
|
// key is expected to be of type []byte. If the signature was created
|
||
|
// using an RSA based algorithm, then the public key is expected to be
|
||
|
// of type *rsa.PublicKey.
|
||
|
Verify(pKey crypto.PublicKey, algo Algorithm) error
|
||
|
}
|
||
|
|
||
|
const (
|
||
|
// host is treated specially because golang may not include it in the
|
||
|
// request header map on the server side of a request.
|
||
|
hostHeader = "Host"
|
||
|
)
|
||
|
|
||
|
// NewVerifier verifies the given request. It returns an error if the HTTP
|
||
|
// Signature parameters are not present in any headers, are present in more than
|
||
|
// one header, are malformed, or are missing required parameters. It ignores
|
||
|
// unknown HTTP Signature parameters.
|
||
|
func NewVerifier(r *http.Request) (Verifier, error) {
|
||
|
h := r.Header
|
||
|
if _, hasHostHeader := h[hostHeader]; len(r.Host) > 0 && !hasHostHeader {
|
||
|
h[hostHeader] = []string{r.Host}
|
||
|
}
|
||
|
return newVerifier(h, func(h http.Header, toInclude []string, created int64, expires int64) (string, error) {
|
||
|
return signatureString(h, toInclude, addRequestTarget(r), created, expires)
|
||
|
})
|
||
|
}
|
||
|
|
||
|
// NewResponseVerifier verifies the given response. It returns errors under the
|
||
|
// same conditions as NewVerifier.
|
||
|
func NewResponseVerifier(r *http.Response) (Verifier, error) {
|
||
|
return newVerifier(r.Header, func(h http.Header, toInclude []string, created int64, expires int64) (string, error) {
|
||
|
return signatureString(h, toInclude, requestTargetNotPermitted, created, expires)
|
||
|
})
|
||
|
}
|
||
|
|
||
|
func newSSHSigner(sshSigner ssh.Signer, algo Algorithm, dAlgo DigestAlgorithm, headers []string, scheme SignatureScheme, expiresIn int64) (SSHSigner, error) {
|
||
|
var expires, created int64 = 0, 0
|
||
|
|
||
|
if expiresIn != 0 {
|
||
|
created = time.Now().Unix()
|
||
|
expires = created + expiresIn
|
||
|
}
|
||
|
|
||
|
s, err := signerFromSSHSigner(sshSigner, string(algo))
|
||
|
if err != nil {
|
||
|
return nil, fmt.Errorf("no crypto implementation available for ssh algo %q", algo)
|
||
|
}
|
||
|
|
||
|
a := &asymmSSHSigner{
|
||
|
asymmSigner: &asymmSigner{
|
||
|
s: s,
|
||
|
dAlgo: dAlgo,
|
||
|
headers: headers,
|
||
|
targetHeader: scheme,
|
||
|
prefix: scheme.authScheme(),
|
||
|
created: created,
|
||
|
expires: expires,
|
||
|
},
|
||
|
}
|
||
|
|
||
|
return a, nil
|
||
|
}
|
||
|
|
||
|
func newSigner(algo Algorithm, dAlgo DigestAlgorithm, headers []string, scheme SignatureScheme, expiresIn int64) (Signer, error) {
|
||
|
|
||
|
var expires, created int64 = 0, 0
|
||
|
if expiresIn != 0 {
|
||
|
created = time.Now().Unix()
|
||
|
expires = created + expiresIn
|
||
|
}
|
||
|
|
||
|
s, err := signerFromString(string(algo))
|
||
|
if err == nil {
|
||
|
a := &asymmSigner{
|
||
|
s: s,
|
||
|
dAlgo: dAlgo,
|
||
|
headers: headers,
|
||
|
targetHeader: scheme,
|
||
|
prefix: scheme.authScheme(),
|
||
|
created: created,
|
||
|
expires: expires,
|
||
|
}
|
||
|
return a, nil
|
||
|
}
|
||
|
m, err := macerFromString(string(algo))
|
||
|
if err != nil {
|
||
|
return nil, fmt.Errorf("no crypto implementation available for %q", algo)
|
||
|
}
|
||
|
c := &macSigner{
|
||
|
m: m,
|
||
|
dAlgo: dAlgo,
|
||
|
headers: headers,
|
||
|
targetHeader: scheme,
|
||
|
prefix: scheme.authScheme(),
|
||
|
created: created,
|
||
|
expires: expires,
|
||
|
}
|
||
|
return c, nil
|
||
|
}
|