diff --git a/README.md b/README.md index c25e21cb9..42dd89fe8 100644 --- a/README.md +++ b/README.md @@ -263,7 +263,6 @@ The following open source libraries, frameworks, and tools are used by GoToSocia - [gin-contrib/gzip](https://github.com/gin-contrib/gzip); Gin gzip middleware. [MIT License](https://spdx.org/licenses/MIT.html). - [gin-contrib/sessions](https://github.com/gin-contrib/sessions); Gin sessions middleware. [MIT License](https://spdx.org/licenses/MIT.html). - [gin-gonic/gin](https://github.com/gin-gonic/gin); speedy router engine. [MIT License](https://spdx.org/licenses/MIT.html). -- [go-fed/httpsig](https://github.com/go-fed/httpsig); secure HTTP signature library. [BSD-3-Clause License](https://spdx.org/licenses/BSD-3-Clause.html). - [google/uuid](https://github.com/google/uuid); UUID generation. [BSD-3-Clause License](https://spdx.org/licenses/BSD-3-Clause.html). - [google/wuffs](https://github.com/google/wuffs); png-stripping code. [Apache-2.0 License](https://spdx.org/licenses/Apache-2.0.html). - Go-Playground: @@ -306,6 +305,7 @@ The following open source libraries, frameworks, and tools are used by GoToSocia - superseriousbusiness: - [superseriousbusiness/activity](https://github.com/superseriousbusiness/activity) forked from [go-fed/activity](https://github.com/go-fed/activity); Golang ActivityPub/ActivityStreams library. [BSD-3-Clause License](https://spdx.org/licenses/BSD-3-Clause.html). - [superseriousbusiness/exif-terminator](https://codeberg.org/superseriousbusiness/exif-terminator); EXIF data removal. [GNU AGPL v3 LICENSE](https://spdx.org/licenses/AGPL-3.0-or-later.html). + - [superseriousbusiness/httpsig](https://github.com/superseriousbusiness/httpsig) forked from [go-fed/httpsig](https://github.com/go-fed/httpsig); secure HTTP signature library. [BSD-3-Clause License](https://spdx.org/licenses/BSD-3-Clause.html). - [superseriousbusiness/oauth2](https://github.com/superseriousbusiness/oauth2) forked from [go-oauth2/oauth2](https://github.com/go-oauth2/oauth2); OAuth server framework and token handling. [MIT License](https://spdx.org/licenses/MIT.html). - [tdewolff/minify](https://github.com/tdewolff/minify); HTML minification for Markdown-submitted posts. [MIT License](https://spdx.org/licenses/MIT.html). - [uber-go/automaxprocs](https://github.com/uber-go/automaxprocs); GOMAXPROCS automation. [MIT License](https://spdx.org/licenses/MIT.html). diff --git a/docs/federation/federating_with_gotosocial.md b/docs/federation/federating_with_gotosocial.md index 3f4458f71..563536556 100644 --- a/docs/federation/federating_with_gotosocial.md +++ b/docs/federation/federating_with_gotosocial.md @@ -10,7 +10,7 @@ GoToSocial will also sign all outgoing `GET` and `POST` requests that it makes t This behavior is the equivalent of Mastodon's [AUTHORIZED_FETCH / "secure mode"](https://docs.joinmastodon.org/admin/config/#authorized_fetch). -GoToSocial uses the [go-fed/httpsig](https://github.com/go-fed/httpsig) library for signing outgoing requests, and for parsing and validating the signatures of incoming requests. This library strictly follows the [Cavage http signature RFC](https://datatracker.ietf.org/doc/html/draft-cavage-http-signatures-12), which is the same RFC used by other implementations like Mastodon, Pixelfed, Akkoma/Pleroma, etc. (This RFC has since been superceded by the [httpbis http signature RFC](https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-message-signatures), but this is not yet widely implemented.) +GoToSocial uses the [superseriousbusiness/httpsig](https://github.com/superseriousbusiness/httpsign) library (forked from go-fed) for signing outgoing requests, and for parsing and validating the signatures of incoming requests. This library strictly follows the [Cavage http signature RFC](https://datatracker.ietf.org/doc/html/draft-cavage-http-signatures-12), which is the same RFC used by other implementations like Mastodon, Pixelfed, Akkoma/Pleroma, etc. (This RFC has since been superceded by the [httpbis http signature RFC](https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-message-signatures), but this is not yet widely implemented.) ### Incoming Requests diff --git a/go.mod b/go.mod index 82ab66209..5afb0cb45 100644 --- a/go.mod +++ b/go.mod @@ -31,7 +31,6 @@ require ( github.com/gin-contrib/gzip v0.0.6 github.com/gin-contrib/sessions v0.0.5 github.com/gin-gonic/gin v1.9.1 - github.com/go-fed/httpsig v1.1.0 github.com/go-playground/form/v4 v4.2.1 github.com/google/uuid v1.5.0 github.com/gorilla/feeds v1.1.2 @@ -48,6 +47,7 @@ require ( github.com/spf13/viper v1.18.2 github.com/stretchr/testify v1.8.4 github.com/superseriousbusiness/activity v1.4.0-gts + github.com/superseriousbusiness/httpsig v1.2.0-SSB github.com/superseriousbusiness/oauth2/v4 v4.3.2-SSB.0.20230227143000-f4900831d6c8 github.com/tdewolff/minify/v2 v2.20.14 github.com/technologize/otel-go-contrib v1.1.0 @@ -106,6 +106,7 @@ require ( github.com/gabriel-vasile/mimetype v1.4.2 // indirect github.com/gin-contrib/sse v0.1.0 // indirect github.com/go-errors/errors v1.4.1 // indirect + github.com/go-fed/httpsig v1.1.0 // indirect github.com/go-jose/go-jose/v3 v3.0.1 // indirect github.com/go-logr/logr v1.4.1 // indirect github.com/go-logr/stdr v1.2.2 // indirect diff --git a/go.sum b/go.sum index 12fc8916b..306599665 100644 --- a/go.sum +++ b/go.sum @@ -489,6 +489,8 @@ github.com/superseriousbusiness/go-jpeg-image-structure/v2 v2.0.0-20220321154430 github.com/superseriousbusiness/go-jpeg-image-structure/v2 v2.0.0-20220321154430-d89a106fdabe/go.mod h1:gH4P6gN1V+wmIw5o97KGaa1RgXB/tVpC2UNzijhg3E4= github.com/superseriousbusiness/go-png-image-structure/v2 v2.0.1-SSB h1:8psprYSK1KdOSH7yQ4PbJq0YYaGQY+gzdW/B0ExDb/8= github.com/superseriousbusiness/go-png-image-structure/v2 v2.0.1-SSB/go.mod h1:ymKGfy9kg4dIdraeZRAdobMS/flzLk3VcRPLpEWOAXg= +github.com/superseriousbusiness/httpsig v1.2.0-SSB h1:BinBGKbf2LSuVT5+MuH0XynHN9f0XVshx2CTDtkaWj0= +github.com/superseriousbusiness/httpsig v1.2.0-SSB/go.mod h1:+rxfATjFaDoDIVaJOTSP0gj6UrbicaYPEptvCLC9F28= github.com/superseriousbusiness/oauth2/v4 v4.3.2-SSB.0.20230227143000-f4900831d6c8 h1:nTIhuP157oOFcscuoK1kCme1xTeGIzztSw70lX9NrDQ= github.com/superseriousbusiness/oauth2/v4 v4.3.2-SSB.0.20230227143000-f4900831d6c8/go.mod h1:uYC/W92oVRJ49Vh1GcvTqpeFqHi+Ovrl2sMllQWRAEo= github.com/tdewolff/minify/v2 v2.20.14 h1:sktSuVixRwk0ryQjqvKBu/uYS+MWmkwEFMEWtFZ+TdE= diff --git a/internal/federation/authenticate.go b/internal/federation/authenticate.go index fe611af8c..6899e5ad3 100644 --- a/internal/federation/authenticate.go +++ b/internal/federation/authenticate.go @@ -28,7 +28,6 @@ import ( "time" "codeberg.org/gruf/go-kv" - "github.com/go-fed/httpsig" "github.com/superseriousbusiness/activity/streams" "github.com/superseriousbusiness/gotosocial/internal/ap" "github.com/superseriousbusiness/gotosocial/internal/config" @@ -37,6 +36,7 @@ import ( "github.com/superseriousbusiness/gotosocial/internal/gtserror" "github.com/superseriousbusiness/gotosocial/internal/gtsmodel" "github.com/superseriousbusiness/gotosocial/internal/log" + "github.com/superseriousbusiness/httpsig" ) var ( @@ -509,24 +509,62 @@ var signingAlgorithms = []httpsig.Algorithm{ httpsig.ED25519, // Try ED25519 as a long shot. } -// verifyAuth verifies auth using generated verifier, according to pubkey and our supported signing algorithms. -func verifyAuth(l *log.Entry, verifier httpsig.Verifier, pubKey *rsa.PublicKey) bool { +// Cheeky type to wrap a signing option with a +// description of that option for logging purposes. +type signingOption struct { + desc string // Description of this options set. + sigOpt httpsig.SignatureOption // The options themselves. +} + +var signingOptions = []signingOption{ + { + // Prefer include query params. + desc: "include query params", + sigOpt: httpsig.SignatureOption{ + ExcludeQueryStringFromPathPseudoHeader: false, + }, + }, + { + // Fall back to exclude query params. + desc: "exclude query params", + sigOpt: httpsig.SignatureOption{ + ExcludeQueryStringFromPathPseudoHeader: true, + }, + }, +} + +// verifyAuth verifies auth using generated verifier, +// according to pubkey, our supported signing algorithms, +// and signature options. The loops in the function are +// arranged in such a way that the most common combos are +// tried first, so that we can hopefully succeed quickly +// without wasting too many CPU cycles. +func verifyAuth( + l *log.Entry, + verifier httpsig.VerifierWithOptions, + pubKey *rsa.PublicKey, +) bool { if pubKey == nil { return false } - // Loop through all supported algorithms. + // Loop through supported algorithms. for _, algo := range signingAlgorithms { - // Verify according to pubkey and algo. - err := verifier.Verify(pubKey, algo) - if err != nil { - l.Tracef("authentication NOT PASSED with %s: %v", algo, err) - continue - } + // Loop through signing options. + for _, opt := range signingOptions { - l.Tracef("authenticated PASSED with %s", algo) - return true + // Try to verify according to this pubkey, + // algo, and signing options combination. + err := verifier.VerifyWithOptions(pubKey, algo, opt.sigOpt) + if err != nil { + l.Tracef("authentication NOT PASSED with %s (%s): %v", algo, opt.desc, err) + continue + } + + l.Tracef("authenticated PASSED with %s (%s)", algo, opt.desc) + return true + } } return false diff --git a/internal/federation/federatingprotocol_test.go b/internal/federation/federatingprotocol_test.go index 7a8343048..999569c85 100644 --- a/internal/federation/federatingprotocol_test.go +++ b/internal/federation/federatingprotocol_test.go @@ -27,12 +27,12 @@ import ( "net/url" "testing" - "github.com/go-fed/httpsig" "github.com/stretchr/testify/suite" "github.com/superseriousbusiness/gotosocial/internal/ap" "github.com/superseriousbusiness/gotosocial/internal/gtscontext" "github.com/superseriousbusiness/gotosocial/internal/gtsmodel" "github.com/superseriousbusiness/gotosocial/testrig" + "github.com/superseriousbusiness/httpsig" ) type FederatingProtocolTestSuite struct { diff --git a/internal/gtscontext/context.go b/internal/gtscontext/context.go index 46f2899fa..0d5ed5340 100644 --- a/internal/gtscontext/context.go +++ b/internal/gtscontext/context.go @@ -21,8 +21,8 @@ import ( "context" "net/url" - "github.com/go-fed/httpsig" "github.com/superseriousbusiness/gotosocial/internal/gtsmodel" + "github.com/superseriousbusiness/httpsig" ) // package private context key type. @@ -129,8 +129,8 @@ func SetOtherIRIs(ctx context.Context, iris []*url.URL) context.Context { // HTTPSignatureVerifier returns an http signature verifier for the current ActivityPub // request chain. This verifier can be called to authenticate the current request. -func HTTPSignatureVerifier(ctx context.Context) httpsig.Verifier { - verifier, _ := ctx.Value(httpSigVerifierKey).(httpsig.Verifier) +func HTTPSignatureVerifier(ctx context.Context) httpsig.VerifierWithOptions { + verifier, _ := ctx.Value(httpSigVerifierKey).(httpsig.VerifierWithOptions) return verifier } diff --git a/internal/middleware/signaturecheck.go b/internal/middleware/signaturecheck.go index 87c7aac01..ea63ec4f0 100644 --- a/internal/middleware/signaturecheck.go +++ b/internal/middleware/signaturecheck.go @@ -26,7 +26,7 @@ import ( "github.com/superseriousbusiness/gotosocial/internal/log" "github.com/gin-gonic/gin" - "github.com/go-fed/httpsig" + "github.com/superseriousbusiness/httpsig" ) const ( diff --git a/internal/transport/signing.go b/internal/transport/signing.go index a9eafeb54..dcd8e206f 100644 --- a/internal/transport/signing.go +++ b/internal/transport/signing.go @@ -18,7 +18,7 @@ package transport import ( - "github.com/go-fed/httpsig" + "github.com/superseriousbusiness/httpsig" ) var ( diff --git a/internal/transport/transport.go b/internal/transport/transport.go index ac56c73cb..558e187f0 100644 --- a/internal/transport/transport.go +++ b/internal/transport/transport.go @@ -27,10 +27,10 @@ import ( "sync" "time" - "github.com/go-fed/httpsig" "github.com/superseriousbusiness/gotosocial/internal/gtscontext" "github.com/superseriousbusiness/gotosocial/internal/gtsmodel" "github.com/superseriousbusiness/gotosocial/internal/httpclient" + "github.com/superseriousbusiness/httpsig" ) // Transport implements the pub.Transport interface with some additional functionality for fetching remote media. diff --git a/vendor/github.com/superseriousbusiness/httpsig/LICENSE b/vendor/github.com/superseriousbusiness/httpsig/LICENSE new file mode 100644 index 000000000..a9e8aefad --- /dev/null +++ b/vendor/github.com/superseriousbusiness/httpsig/LICENSE @@ -0,0 +1,29 @@ +BSD 3-Clause License + +Copyright (c) 2018, go-fed +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + +* Redistributions of source code must retain the above copyright notice, this + list of conditions and the following disclaimer. + +* Redistributions in binary form must reproduce the above copyright notice, + this list of conditions and the following disclaimer in the documentation + and/or other materials provided with the distribution. + +* Neither the name of the copyright holder nor the names of its + contributors may be used to endorse or promote products derived from + this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE +DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE +FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR +SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, +OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/vendor/github.com/superseriousbusiness/httpsig/README.md b/vendor/github.com/superseriousbusiness/httpsig/README.md new file mode 100644 index 000000000..8e45e8d38 --- /dev/null +++ b/vendor/github.com/superseriousbusiness/httpsig/README.md @@ -0,0 +1,101 @@ +# httpsig + +**THIS IS A FORK OF https://github.com/go-fed/httpsig, WHICH WAS NO LONGER MAINTAINED. THANK YOU TO [cjslep](https://github.com/cjslep) FOR ALL YOUR HARD WORK!** + +> HTTP Signatures made simple + +`go get github.com/superseriousbusiness/httpsig` + +Implementation of [HTTP Signatures](https://tools.ietf.org/html/draft-cavage-http-signatures). + +Supports many different combinations of MAC, HMAC signing of hash, or RSA +signing of hash schemes. Its goals are: + +* Have a very simple interface for signing and validating +* Support a variety of signing algorithms and combinations +* Support setting either headers (`Authorization` or `Signature`) +* Remaining flexible with headers included in the signing string +* Support both HTTP requests and responses +* Explicitly not support known-cryptographically weak algorithms +* Support automatic signing and validating Digest headers + +## How to use + +`import "github.com/superseriousbusiness/httpsig"` + +### Signing + +Signing a request or response requires creating a new `Signer` and using it: + +```go +func sign(privateKey crypto.PrivateKey, pubKeyId string, r *http.Request) error { + prefs := []httpsig.Algorithm{httpsig.RSA_SHA512, httpsig.RSA_SHA256} + digestAlgorithm := DigestSha256 + // The "Date" and "Digest" headers must already be set on r, as well as r.URL. + headersToSign := []string{httpsig.RequestTarget, "date", "digest"} + signer, chosenAlgo, err := httpsig.NewSigner(prefs, digestAlgorithm, headersToSign, httpsig.Signature) + if err != nil { + return err + } + // To sign the digest, we need to give the signer a copy of the body... + // ...but it is optional, no digest will be signed if given "nil" + body := ... + // If r were a http.ResponseWriter, call SignResponse instead. + return signer.SignRequest(privateKey, pubKeyId, r, body) +} +``` + +`Signer`s are not safe for concurrent use by goroutines, so be sure to guard +access: + +```go +type server struct { + signer httpsig.Signer + mu *sync.Mutex +} + +func (s *server) handlerFunc(w http.ResponseWriter, r *http.Request) { + privateKey := ... + pubKeyId := ... + // Set headers and such on w + s.mu.Lock() + defer s.mu.Unlock() + // To sign the digest, we need to give the signer a copy of the response body... + // ...but it is optional, no digest will be signed if given "nil" + body := ... + err := s.signer.SignResponse(privateKey, pubKeyId, w, body) + if err != nil { + ... + } + ... +} +``` + +The `pubKeyId` will be used at verification time. + +### Verifying + +Verifying requires an application to use the `pubKeyId` to both retrieve the key +needed for verification as well as determine the algorithm to use. Use a +`Verifier`: + +```go +func verify(r *http.Request) error { + verifier, err := httpsig.NewVerifier(r) + if err != nil { + return err + } + pubKeyId := verifier.KeyId() + var algo httpsig.Algorithm = ... + var pubKey crypto.PublicKey = ... + // The verifier will verify the Digest in addition to the HTTP signature + return verifier.Verify(pubKey, algo) +} +``` + +`Verifier`s are not safe for concurrent use by goroutines, but since they are +constructed on a per-request or per-response basis it should not be a common +restriction. + +[License-Image]: https://img.shields.io/github/license/go-fed/httpsig?color=blue +[License-Url]: https://opensource.org/licenses/BSD-3-Clause diff --git a/vendor/github.com/superseriousbusiness/httpsig/algorithms.go b/vendor/github.com/superseriousbusiness/httpsig/algorithms.go new file mode 100644 index 000000000..9595941be --- /dev/null +++ b/vendor/github.com/superseriousbusiness/httpsig/algorithms.go @@ -0,0 +1,532 @@ +package httpsig + +import ( + "crypto" + "crypto/ecdsa" + "crypto/hmac" + "crypto/rsa" + "crypto/sha1" + "crypto/sha256" + "crypto/sha512" + "crypto/subtle" // Use should trigger great care + "encoding/asn1" + "errors" + "fmt" + "hash" + "io" + "math/big" + "strings" + + "golang.org/x/crypto/blake2b" + "golang.org/x/crypto/blake2s" + "golang.org/x/crypto/ed25519" + "golang.org/x/crypto/ripemd160" + "golang.org/x/crypto/sha3" + "golang.org/x/crypto/ssh" +) + +const ( + hmacPrefix = "hmac" + rsaPrefix = "rsa" + sshPrefix = "ssh" + ecdsaPrefix = "ecdsa" + ed25519Prefix = "ed25519" + md4String = "md4" + md5String = "md5" + sha1String = "sha1" + sha224String = "sha224" + sha256String = "sha256" + sha384String = "sha384" + sha512String = "sha512" + md5sha1String = "md5sha1" + ripemd160String = "ripemd160" + sha3_224String = "sha3-224" + sha3_256String = "sha3-256" + sha3_384String = "sha3-384" + sha3_512String = "sha3-512" + sha512_224String = "sha512-224" + sha512_256String = "sha512-256" + blake2s_256String = "blake2s-256" + blake2b_256String = "blake2b-256" + blake2b_384String = "blake2b-384" + blake2b_512String = "blake2b-512" +) + +var blake2Algorithms = map[crypto.Hash]bool{ + crypto.BLAKE2s_256: true, + crypto.BLAKE2b_256: true, + crypto.BLAKE2b_384: true, + crypto.BLAKE2b_512: true, +} + +var hashToDef = map[crypto.Hash]struct { + name string + new func(key []byte) (hash.Hash, error) // Only MACers will accept a key +}{ + // Which standard names these? + // The spec lists the following as a canonical reference, which is dead: + // http://www.iana.org/assignments/signature-algorithms + // + // Note that the forbidden hashes have an invalid 'new' function. + crypto.MD4: {md4String, func(key []byte) (hash.Hash, error) { return nil, nil }}, + crypto.MD5: {md5String, func(key []byte) (hash.Hash, error) { return nil, nil }}, + // Temporarily enable SHA1 because of issue https://github.com/golang/go/issues/37278 + crypto.SHA1: {sha1String, func(key []byte) (hash.Hash, error) { return sha1.New(), nil }}, + crypto.SHA224: {sha224String, func(key []byte) (hash.Hash, error) { return sha256.New224(), nil }}, + crypto.SHA256: {sha256String, func(key []byte) (hash.Hash, error) { return sha256.New(), nil }}, + crypto.SHA384: {sha384String, func(key []byte) (hash.Hash, error) { return sha512.New384(), nil }}, + crypto.SHA512: {sha512String, func(key []byte) (hash.Hash, error) { return sha512.New(), nil }}, + crypto.MD5SHA1: {md5sha1String, func(key []byte) (hash.Hash, error) { return nil, nil }}, + crypto.RIPEMD160: {ripemd160String, func(key []byte) (hash.Hash, error) { return ripemd160.New(), nil }}, + crypto.SHA3_224: {sha3_224String, func(key []byte) (hash.Hash, error) { return sha3.New224(), nil }}, + crypto.SHA3_256: {sha3_256String, func(key []byte) (hash.Hash, error) { return sha3.New256(), nil }}, + crypto.SHA3_384: {sha3_384String, func(key []byte) (hash.Hash, error) { return sha3.New384(), nil }}, + crypto.SHA3_512: {sha3_512String, func(key []byte) (hash.Hash, error) { return sha3.New512(), nil }}, + crypto.SHA512_224: {sha512_224String, func(key []byte) (hash.Hash, error) { return sha512.New512_224(), nil }}, + crypto.SHA512_256: {sha512_256String, func(key []byte) (hash.Hash, error) { return sha512.New512_256(), nil }}, + crypto.BLAKE2s_256: {blake2s_256String, func(key []byte) (hash.Hash, error) { return blake2s.New256(key) }}, + crypto.BLAKE2b_256: {blake2b_256String, func(key []byte) (hash.Hash, error) { return blake2b.New256(key) }}, + crypto.BLAKE2b_384: {blake2b_384String, func(key []byte) (hash.Hash, error) { return blake2b.New384(key) }}, + crypto.BLAKE2b_512: {blake2b_512String, func(key []byte) (hash.Hash, error) { return blake2b.New512(key) }}, +} + +var stringToHash map[string]crypto.Hash + +const ( + defaultAlgorithm = RSA_SHA256 + defaultAlgorithmHashing = sha256String +) + +func init() { + stringToHash = make(map[string]crypto.Hash, len(hashToDef)) + for k, v := range hashToDef { + stringToHash[v.name] = k + } + // This should guarantee that at runtime the defaultAlgorithm will not + // result in errors when fetching a macer or signer (see algorithms.go) + if ok, err := isAvailable(string(defaultAlgorithmHashing)); err != nil { + panic(err) + } else if !ok { + panic(fmt.Sprintf("the default httpsig algorithm is unavailable: %q", defaultAlgorithm)) + } +} + +func isForbiddenHash(h crypto.Hash) bool { + switch h { + // Not actually cryptographically secure + case crypto.MD4: + fallthrough + case crypto.MD5: + fallthrough + case crypto.MD5SHA1: // shorthand for crypto/tls, not actually implemented + return true + } + // Still cryptographically secure + return false +} + +// signer is an internally public type. +type signer interface { + Sign(rand io.Reader, p crypto.PrivateKey, sig []byte) ([]byte, error) + Verify(pub crypto.PublicKey, toHash, signature []byte) error + String() string +} + +// macer is an internally public type. +type macer interface { + Sign(sig, key []byte) ([]byte, error) + Equal(sig, actualMAC, key []byte) (bool, error) + String() string +} + +var _ macer = &hmacAlgorithm{} + +type hmacAlgorithm struct { + fn func(key []byte) (hash.Hash, error) + kind crypto.Hash +} + +func (h *hmacAlgorithm) Sign(sig, key []byte) ([]byte, error) { + hs, err := h.fn(key) + if err = setSig(hs, sig); err != nil { + return nil, err + } + return hs.Sum(nil), nil +} + +func (h *hmacAlgorithm) Equal(sig, actualMAC, key []byte) (bool, error) { + hs, err := h.fn(key) + if err != nil { + return false, err + } + defer hs.Reset() + err = setSig(hs, sig) + if err != nil { + return false, err + } + expected := hs.Sum(nil) + return hmac.Equal(actualMAC, expected), nil +} + +func (h *hmacAlgorithm) String() string { + return fmt.Sprintf("%s-%s", hmacPrefix, hashToDef[h.kind].name) +} + +var _ signer = &rsaAlgorithm{} + +type rsaAlgorithm struct { + hash.Hash + kind crypto.Hash + sshSigner ssh.Signer +} + +func (r *rsaAlgorithm) setSig(b []byte) error { + n, err := r.Write(b) + if err != nil { + r.Reset() + return err + } else if n != len(b) { + r.Reset() + return fmt.Errorf("could only write %d of %d bytes of signature to hash", n, len(b)) + } + return nil +} + +func (r *rsaAlgorithm) Sign(rand io.Reader, p crypto.PrivateKey, sig []byte) ([]byte, error) { + if r.sshSigner != nil { + sshsig, err := r.sshSigner.Sign(rand, sig) + if err != nil { + return nil, err + } + + return sshsig.Blob, nil + } + defer r.Reset() + + if err := r.setSig(sig); err != nil { + return nil, err + } + rsaK, ok := p.(*rsa.PrivateKey) + if !ok { + return nil, errors.New("crypto.PrivateKey is not *rsa.PrivateKey") + } + return rsa.SignPKCS1v15(rand, rsaK, r.kind, r.Sum(nil)) +} + +func (r *rsaAlgorithm) Verify(pub crypto.PublicKey, toHash, signature []byte) error { + defer r.Reset() + rsaK, ok := pub.(*rsa.PublicKey) + if !ok { + return errors.New("crypto.PublicKey is not *rsa.PublicKey") + } + if err := r.setSig(toHash); err != nil { + return err + } + return rsa.VerifyPKCS1v15(rsaK, r.kind, r.Sum(nil), signature) +} + +func (r *rsaAlgorithm) String() string { + return fmt.Sprintf("%s-%s", rsaPrefix, hashToDef[r.kind].name) +} + +var _ signer = &ed25519Algorithm{} + +type ed25519Algorithm struct { + sshSigner ssh.Signer +} + +func (r *ed25519Algorithm) Sign(rand io.Reader, p crypto.PrivateKey, sig []byte) ([]byte, error) { + if r.sshSigner != nil { + sshsig, err := r.sshSigner.Sign(rand, sig) + if err != nil { + return nil, err + } + + return sshsig.Blob, nil + } + ed25519K, ok := p.(ed25519.PrivateKey) + if !ok { + return nil, errors.New("crypto.PrivateKey is not ed25519.PrivateKey") + } + return ed25519.Sign(ed25519K, sig), nil +} + +func (r *ed25519Algorithm) Verify(pub crypto.PublicKey, toHash, signature []byte) error { + ed25519K, ok := pub.(ed25519.PublicKey) + if !ok { + return errors.New("crypto.PublicKey is not ed25519.PublicKey") + } + + if ed25519.Verify(ed25519K, toHash, signature) { + return nil + } + + return errors.New("ed25519 verify failed") +} + +func (r *ed25519Algorithm) String() string { + return fmt.Sprintf("%s", ed25519Prefix) +} + +var _ signer = &ecdsaAlgorithm{} + +type ecdsaAlgorithm struct { + hash.Hash + kind crypto.Hash +} + +func (r *ecdsaAlgorithm) setSig(b []byte) error { + n, err := r.Write(b) + if err != nil { + r.Reset() + return err + } else if n != len(b) { + r.Reset() + return fmt.Errorf("could only write %d of %d bytes of signature to hash", n, len(b)) + } + return nil +} + +type ECDSASignature struct { + R, S *big.Int +} + +func (r *ecdsaAlgorithm) Sign(rand io.Reader, p crypto.PrivateKey, sig []byte) ([]byte, error) { + defer r.Reset() + if err := r.setSig(sig); err != nil { + return nil, err + } + ecdsaK, ok := p.(*ecdsa.PrivateKey) + if !ok { + return nil, errors.New("crypto.PrivateKey is not *ecdsa.PrivateKey") + } + R, S, err := ecdsa.Sign(rand, ecdsaK, r.Sum(nil)) + if err != nil { + return nil, err + } + + signature := ECDSASignature{R: R, S: S} + bytes, err := asn1.Marshal(signature) + + return bytes, err +} + +func (r *ecdsaAlgorithm) Verify(pub crypto.PublicKey, toHash, signature []byte) error { + defer r.Reset() + ecdsaK, ok := pub.(*ecdsa.PublicKey) + if !ok { + return errors.New("crypto.PublicKey is not *ecdsa.PublicKey") + } + if err := r.setSig(toHash); err != nil { + return err + } + + sig := new(ECDSASignature) + _, err := asn1.Unmarshal(signature, sig) + if err != nil { + return err + } + + if ecdsa.Verify(ecdsaK, r.Sum(nil), sig.R, sig.S) { + return nil + } else { + return errors.New("Invalid signature") + } +} + +func (r *ecdsaAlgorithm) String() string { + return fmt.Sprintf("%s-%s", ecdsaPrefix, hashToDef[r.kind].name) +} + +var _ macer = &blakeMacAlgorithm{} + +type blakeMacAlgorithm struct { + fn func(key []byte) (hash.Hash, error) + kind crypto.Hash +} + +func (r *blakeMacAlgorithm) Sign(sig, key []byte) ([]byte, error) { + hs, err := r.fn(key) + if err != nil { + return nil, err + } + if err = setSig(hs, sig); err != nil { + return nil, err + } + return hs.Sum(nil), nil +} + +func (r *blakeMacAlgorithm) Equal(sig, actualMAC, key []byte) (bool, error) { + hs, err := r.fn(key) + if err != nil { + return false, err + } + defer hs.Reset() + err = setSig(hs, sig) + if err != nil { + return false, err + } + expected := hs.Sum(nil) + return subtle.ConstantTimeCompare(actualMAC, expected) == 1, nil +} + +func (r *blakeMacAlgorithm) String() string { + return fmt.Sprintf("%s", hashToDef[r.kind].name) +} + +func setSig(a hash.Hash, b []byte) error { + n, err := a.Write(b) + if err != nil { + a.Reset() + return err + } else if n != len(b) { + a.Reset() + return fmt.Errorf("could only write %d of %d bytes of signature to hash", n, len(b)) + } + return nil +} + +// IsSupportedHttpSigAlgorithm returns true if the string is supported by this +// library, is not a hash known to be weak, and is supported by the hardware. +func IsSupportedHttpSigAlgorithm(algo string) bool { + a, err := isAvailable(algo) + return a && err == nil +} + +// isAvailable is an internally public function +func isAvailable(algo string) (bool, error) { + c, ok := stringToHash[algo] + if !ok { + return false, fmt.Errorf("no match for %q", algo) + } + if isForbiddenHash(c) { + return false, fmt.Errorf("forbidden hash type in %q", algo) + } + return c.Available(), nil +} + +func newAlgorithmConstructor(algo string) (fn func(k []byte) (hash.Hash, error), c crypto.Hash, e error) { + ok := false + c, ok = stringToHash[algo] + if !ok { + e = fmt.Errorf("no match for %q", algo) + return + } + if isForbiddenHash(c) { + e = fmt.Errorf("forbidden hash type in %q", algo) + return + } + algoDef, ok := hashToDef[c] + if !ok { + e = fmt.Errorf("have crypto.Hash %v but no definition", c) + return + } + fn = func(key []byte) (hash.Hash, error) { + h, err := algoDef.new(key) + if err != nil { + return nil, err + } + return h, nil + } + return +} + +func newAlgorithm(algo string, key []byte) (hash.Hash, crypto.Hash, error) { + fn, c, err := newAlgorithmConstructor(algo) + if err != nil { + return nil, c, err + } + h, err := fn(key) + return h, c, err +} + +func signerFromSSHSigner(sshSigner ssh.Signer, s string) (signer, error) { + switch { + case strings.HasPrefix(s, rsaPrefix): + return &rsaAlgorithm{ + sshSigner: sshSigner, + }, nil + case strings.HasPrefix(s, ed25519Prefix): + return &ed25519Algorithm{ + sshSigner: sshSigner, + }, nil + default: + return nil, fmt.Errorf("no signer matching %q", s) + } +} + +// signerFromString is an internally public method constructor +func signerFromString(s string) (signer, error) { + s = strings.ToLower(s) + isEcdsa := false + isEd25519 := false + var algo string = "" + if strings.HasPrefix(s, ecdsaPrefix) { + algo = strings.TrimPrefix(s, ecdsaPrefix+"-") + isEcdsa = true + } else if strings.HasPrefix(s, rsaPrefix) { + algo = strings.TrimPrefix(s, rsaPrefix+"-") + } else if strings.HasPrefix(s, ed25519Prefix) { + isEd25519 = true + algo = "sha512" + } else { + return nil, fmt.Errorf("no signer matching %q", s) + } + hash, cHash, err := newAlgorithm(algo, nil) + if err != nil { + return nil, err + } + if isEd25519 { + return &ed25519Algorithm{}, nil + } + if isEcdsa { + return &ecdsaAlgorithm{ + Hash: hash, + kind: cHash, + }, nil + } + return &rsaAlgorithm{ + Hash: hash, + kind: cHash, + }, nil +} + +// macerFromString is an internally public method constructor +func macerFromString(s string) (macer, error) { + s = strings.ToLower(s) + if strings.HasPrefix(s, hmacPrefix) { + algo := strings.TrimPrefix(s, hmacPrefix+"-") + hashFn, cHash, err := newAlgorithmConstructor(algo) + if err != nil { + return nil, err + } + // Ensure below does not panic + _, err = hashFn(nil) + if err != nil { + return nil, err + } + return &hmacAlgorithm{ + fn: func(key []byte) (hash.Hash, error) { + return hmac.New(func() hash.Hash { + h, e := hashFn(nil) + if e != nil { + panic(e) + } + return h + }, key), nil + }, + kind: cHash, + }, nil + } else if bl, ok := stringToHash[s]; ok && blake2Algorithms[bl] { + hashFn, cHash, err := newAlgorithmConstructor(s) + if err != nil { + return nil, err + } + return &blakeMacAlgorithm{ + fn: hashFn, + kind: cHash, + }, nil + } else { + return nil, fmt.Errorf("no MACer matching %q", s) + } +} diff --git a/vendor/github.com/superseriousbusiness/httpsig/digest.go b/vendor/github.com/superseriousbusiness/httpsig/digest.go new file mode 100644 index 000000000..bf9e3a914 --- /dev/null +++ b/vendor/github.com/superseriousbusiness/httpsig/digest.go @@ -0,0 +1,120 @@ +package httpsig + +import ( + "bytes" + "crypto" + "encoding/base64" + "fmt" + "hash" + "net/http" + "strings" +) + +type DigestAlgorithm string + +const ( + DigestSha256 DigestAlgorithm = "SHA-256" + DigestSha512 = "SHA-512" +) + +var digestToDef = map[DigestAlgorithm]crypto.Hash{ + DigestSha256: crypto.SHA256, + DigestSha512: crypto.SHA512, +} + +// IsSupportedDigestAlgorithm returns true if hte string is supported by this +// library, is not a hash known to be weak, and is supported by the hardware. +func IsSupportedDigestAlgorithm(algo string) bool { + uc := DigestAlgorithm(strings.ToUpper(algo)) + c, ok := digestToDef[uc] + return ok && c.Available() +} + +func getHash(alg DigestAlgorithm) (h hash.Hash, toUse DigestAlgorithm, err error) { + upper := DigestAlgorithm(strings.ToUpper(string(alg))) + c, ok := digestToDef[upper] + if !ok { + err = fmt.Errorf("unknown or unsupported Digest algorithm: %s", alg) + } else if !c.Available() { + err = fmt.Errorf("unavailable Digest algorithm: %s", alg) + } else { + h = c.New() + toUse = upper + } + return +} + +const ( + digestHeader = "Digest" + digestDelim = "=" +) + +func addDigest(r *http.Request, algo DigestAlgorithm, b []byte) (err error) { + _, ok := r.Header[digestHeader] + if ok { + err = fmt.Errorf("cannot add Digest: Digest is already set") + return + } + var h hash.Hash + var a DigestAlgorithm + h, a, err = getHash(algo) + if err != nil { + return + } + h.Write(b) + sum := h.Sum(nil) + r.Header.Add(digestHeader, + fmt.Sprintf("%s%s%s", + a, + digestDelim, + base64.StdEncoding.EncodeToString(sum[:]))) + return +} + +func addDigestResponse(r http.ResponseWriter, algo DigestAlgorithm, b []byte) (err error) { + _, ok := r.Header()[digestHeader] + if ok { + err = fmt.Errorf("cannot add Digest: Digest is already set") + return + } + var h hash.Hash + var a DigestAlgorithm + h, a, err = getHash(algo) + if err != nil { + return + } + h.Write(b) + sum := h.Sum(nil) + r.Header().Add(digestHeader, + fmt.Sprintf("%s%s%s", + a, + digestDelim, + base64.StdEncoding.EncodeToString(sum[:]))) + return +} + +func verifyDigest(r *http.Request, body *bytes.Buffer) (err error) { + d := r.Header.Get(digestHeader) + if len(d) == 0 { + err = fmt.Errorf("cannot verify Digest: request has no Digest header") + return + } + elem := strings.SplitN(d, digestDelim, 2) + if len(elem) != 2 { + err = fmt.Errorf("cannot verify Digest: malformed Digest: %s", d) + return + } + var h hash.Hash + h, _, err = getHash(DigestAlgorithm(elem[0])) + if err != nil { + return + } + h.Write(body.Bytes()) + sum := h.Sum(nil) + encSum := base64.StdEncoding.EncodeToString(sum[:]) + if encSum != elem[1] { + err = fmt.Errorf("cannot verify Digest: header Digest does not match the digest of the request body") + return + } + return +} diff --git a/vendor/github.com/superseriousbusiness/httpsig/httpsig.go b/vendor/github.com/superseriousbusiness/httpsig/httpsig.go new file mode 100644 index 000000000..8864da055 --- /dev/null +++ b/vendor/github.com/superseriousbusiness/httpsig/httpsig.go @@ -0,0 +1,413 @@ +// 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 "" + } +} + +type SignatureOption struct { + // ExcludeQueryStringFromPathPseudoHeader omits the query parameters from the + // `:path` pseudo-header in the HTTP signature. + // + // The query string is optional in the `:path` pseudo-header. + // https://www.rfc-editor.org/rfc/rfc9113#section-8.3.1-2.4.1 + ExcludeQueryStringFromPathPseudoHeader bool +} + +// 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 +} + +type SignerWithOptions interface { + Signer + + // SignRequestWithOptions 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. + SignRequestWithOptions(pKey crypto.PrivateKey, pubKeyId string, r *http.Request, body []byte, opts SignatureOption) error + // SignResponseWithOptions 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. + SignResponseWithOptions(pKey crypto.PrivateKey, pubKeyId string, r http.ResponseWriter, body []byte, opts SignatureOption) 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) (SignerWithOptions, 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 +} + +type VerifierWithOptions interface { + Verifier + + VerifyWithOptions(pKey crypto.PublicKey, algo Algorithm, opts SignatureOption) 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) (VerifierWithOptions, 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, opts SignatureOption) (string, error) { + return signatureString(h, toInclude, addRequestTarget(r, opts), 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, _ SignatureOption) (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: %s", algo, err) + } + + 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) (SignerWithOptions, 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: %s", algo, err) + } + c := &macSigner{ + m: m, + dAlgo: dAlgo, + headers: headers, + targetHeader: scheme, + prefix: scheme.authScheme(), + created: created, + expires: expires, + } + return c, nil +} diff --git a/vendor/github.com/superseriousbusiness/httpsig/signing.go b/vendor/github.com/superseriousbusiness/httpsig/signing.go new file mode 100644 index 000000000..a2fa38c5b --- /dev/null +++ b/vendor/github.com/superseriousbusiness/httpsig/signing.go @@ -0,0 +1,350 @@ +package httpsig + +import ( + "bytes" + "crypto" + "crypto/rand" + "encoding/base64" + "fmt" + "net/http" + "net/textproto" + "strconv" + "strings" +) + +const ( + // Signature Parameters + keyIdParameter = "keyId" + algorithmParameter = "algorithm" + headersParameter = "headers" + signatureParameter = "signature" + prefixSeparater = " " + parameterKVSeparater = "=" + parameterValueDelimiter = "\"" + parameterSeparater = "," + headerParameterValueDelim = " " + // RequestTarget specifies to include the http request method and + // entire URI in the signature. Pass it as a header to NewSigner. + RequestTarget = "(request-target)" + createdKey = "created" + expiresKey = "expires" + dateHeader = "date" + + // Signature String Construction + headerFieldDelimiter = ": " + headersDelimiter = "\n" + headerValueDelimiter = ", " + requestTargetSeparator = " " +) + +var defaultHeaders = []string{dateHeader} + +var _ SignerWithOptions = &macSigner{} + +type macSigner struct { + m macer + makeDigest bool + dAlgo DigestAlgorithm + headers []string + targetHeader SignatureScheme + prefix string + created int64 + expires int64 +} + +func (m *macSigner) SignRequest(pKey crypto.PrivateKey, pubKeyId string, r *http.Request, body []byte) error { + return m.SignRequestWithOptions(pKey, pubKeyId, r, body, SignatureOption{}) +} + +func (m *macSigner) SignRequestWithOptions(pKey crypto.PrivateKey, pubKeyId string, r *http.Request, body []byte, opts SignatureOption) error { + if body != nil { + err := addDigest(r, m.dAlgo, body) + if err != nil { + return err + } + } + s, err := m.signatureString(r, opts) + if err != nil { + return err + } + enc, err := m.signSignature(pKey, s) + if err != nil { + return err + } + setSignatureHeader(r.Header, string(m.targetHeader), m.prefix, pubKeyId, m.m.String(), enc, m.headers, m.created, m.expires) + return nil +} + +func (m *macSigner) SignResponse(pKey crypto.PrivateKey, pubKeyId string, r http.ResponseWriter, body []byte) error { + return m.SignResponseWithOptions(pKey, pubKeyId, r, body, SignatureOption{}) +} + +func (m *macSigner) SignResponseWithOptions(pKey crypto.PrivateKey, pubKeyId string, r http.ResponseWriter, body []byte, _ SignatureOption) error { + if body != nil { + err := addDigestResponse(r, m.dAlgo, body) + if err != nil { + return err + } + } + s, err := m.signatureStringResponse(r) + if err != nil { + return err + } + enc, err := m.signSignature(pKey, s) + if err != nil { + return err + } + setSignatureHeader(r.Header(), string(m.targetHeader), m.prefix, pubKeyId, m.m.String(), enc, m.headers, m.created, m.expires) + return nil +} + +func (m *macSigner) signSignature(pKey crypto.PrivateKey, s string) (string, error) { + pKeyBytes, ok := pKey.([]byte) + if !ok { + return "", fmt.Errorf("private key for MAC signing must be of type []byte") + } + sig, err := m.m.Sign([]byte(s), pKeyBytes) + if err != nil { + return "", err + } + enc := base64.StdEncoding.EncodeToString(sig) + return enc, nil +} + +func (m *macSigner) signatureString(r *http.Request, opts SignatureOption) (string, error) { + return signatureString(r.Header, m.headers, addRequestTarget(r, opts), m.created, m.expires) +} + +func (m *macSigner) signatureStringResponse(r http.ResponseWriter) (string, error) { + return signatureString(r.Header(), m.headers, requestTargetNotPermitted, m.created, m.expires) +} + +var _ SignerWithOptions = &asymmSigner{} + +type asymmSigner struct { + s signer + makeDigest bool + dAlgo DigestAlgorithm + headers []string + targetHeader SignatureScheme + prefix string + created int64 + expires int64 +} + +func (a *asymmSigner) SignRequest(pKey crypto.PrivateKey, pubKeyId string, r *http.Request, body []byte) error { + return a.SignRequestWithOptions(pKey, pubKeyId, r, body, SignatureOption{}) +} + +func (a *asymmSigner) SignRequestWithOptions(pKey crypto.PrivateKey, pubKeyId string, r *http.Request, body []byte, opts SignatureOption) error { + if body != nil { + err := addDigest(r, a.dAlgo, body) + if err != nil { + return err + } + } + s, err := a.signatureString(r, opts) + if err != nil { + return err + } + enc, err := a.signSignature(pKey, s) + if err != nil { + return err + } + setSignatureHeader(r.Header, string(a.targetHeader), a.prefix, pubKeyId, a.s.String(), enc, a.headers, a.created, a.expires) + return nil +} + +func (a *asymmSigner) SignResponse(pKey crypto.PrivateKey, pubKeyId string, r http.ResponseWriter, body []byte) error { + return a.SignResponseWithOptions(pKey, pubKeyId, r, body, SignatureOption{}) +} + +func (a *asymmSigner) SignResponseWithOptions(pKey crypto.PrivateKey, pubKeyId string, r http.ResponseWriter, body []byte, _ SignatureOption) error { + if body != nil { + err := addDigestResponse(r, a.dAlgo, body) + if err != nil { + return err + } + } + s, err := a.signatureStringResponse(r) + if err != nil { + return err + } + enc, err := a.signSignature(pKey, s) + if err != nil { + return err + } + setSignatureHeader(r.Header(), string(a.targetHeader), a.prefix, pubKeyId, a.s.String(), enc, a.headers, a.created, a.expires) + return nil +} + +func (a *asymmSigner) signSignature(pKey crypto.PrivateKey, s string) (string, error) { + sig, err := a.s.Sign(rand.Reader, pKey, []byte(s)) + if err != nil { + return "", err + } + enc := base64.StdEncoding.EncodeToString(sig) + return enc, nil +} + +func (a *asymmSigner) signatureString(r *http.Request, opts SignatureOption) (string, error) { + return signatureString(r.Header, a.headers, addRequestTarget(r, opts), a.created, a.expires) +} + +func (a *asymmSigner) signatureStringResponse(r http.ResponseWriter) (string, error) { + return signatureString(r.Header(), a.headers, requestTargetNotPermitted, a.created, a.expires) +} + +var _ SSHSigner = &asymmSSHSigner{} + +type asymmSSHSigner struct { + *asymmSigner +} + +func (a *asymmSSHSigner) SignRequest(pubKeyId string, r *http.Request, body []byte) error { + return a.asymmSigner.SignRequest(nil, pubKeyId, r, body) +} + +func (a *asymmSSHSigner) SignResponse(pubKeyId string, r http.ResponseWriter, body []byte) error { + return a.asymmSigner.SignResponse(nil, pubKeyId, r, body) +} + +func setSignatureHeader(h http.Header, targetHeader, prefix, pubKeyId, algo, enc string, headers []string, created int64, expires int64) { + if len(headers) == 0 { + headers = defaultHeaders + } + var b bytes.Buffer + // KeyId + b.WriteString(prefix) + if len(prefix) > 0 { + b.WriteString(prefixSeparater) + } + b.WriteString(keyIdParameter) + b.WriteString(parameterKVSeparater) + b.WriteString(parameterValueDelimiter) + b.WriteString(pubKeyId) + b.WriteString(parameterValueDelimiter) + b.WriteString(parameterSeparater) + // Algorithm + b.WriteString(algorithmParameter) + b.WriteString(parameterKVSeparater) + b.WriteString(parameterValueDelimiter) + b.WriteString("hs2019") //real algorithm is hidden, see newest version of spec draft + b.WriteString(parameterValueDelimiter) + b.WriteString(parameterSeparater) + + hasCreated := false + hasExpires := false + for _, h := range headers { + val := strings.ToLower(h) + if val == "("+createdKey+")" { + hasCreated = true + } else if val == "("+expiresKey+")" { + hasExpires = true + } + } + + // Created + if hasCreated == true { + b.WriteString(createdKey) + b.WriteString(parameterKVSeparater) + b.WriteString(strconv.FormatInt(created, 10)) + b.WriteString(parameterSeparater) + } + + // Expires + if hasExpires == true { + b.WriteString(expiresKey) + b.WriteString(parameterKVSeparater) + b.WriteString(strconv.FormatInt(expires, 10)) + b.WriteString(parameterSeparater) + } + + // Headers + b.WriteString(headersParameter) + b.WriteString(parameterKVSeparater) + b.WriteString(parameterValueDelimiter) + for i, h := range headers { + b.WriteString(strings.ToLower(h)) + if i != len(headers)-1 { + b.WriteString(headerParameterValueDelim) + } + } + b.WriteString(parameterValueDelimiter) + b.WriteString(parameterSeparater) + // Signature + b.WriteString(signatureParameter) + b.WriteString(parameterKVSeparater) + b.WriteString(parameterValueDelimiter) + b.WriteString(enc) + b.WriteString(parameterValueDelimiter) + h.Add(targetHeader, b.String()) +} + +func requestTargetNotPermitted(b *bytes.Buffer) error { + return fmt.Errorf("cannot sign with %q on anything other than an http request", RequestTarget) +} + +func addRequestTarget(r *http.Request, opts SignatureOption) func(b *bytes.Buffer) error { + return func(b *bytes.Buffer) error { + b.WriteString(RequestTarget) + b.WriteString(headerFieldDelimiter) + b.WriteString(strings.ToLower(r.Method)) + b.WriteString(requestTargetSeparator) + b.WriteString(r.URL.Path) + + if !opts.ExcludeQueryStringFromPathPseudoHeader && r.URL.RawQuery != "" { + b.WriteString("?") + b.WriteString(r.URL.RawQuery) + } + + return nil + } +} + +func signatureString(values http.Header, include []string, requestTargetFn func(b *bytes.Buffer) error, created int64, expires int64) (string, error) { + if len(include) == 0 { + include = defaultHeaders + } + var b bytes.Buffer + for n, i := range include { + i := strings.ToLower(i) + if i == RequestTarget { + err := requestTargetFn(&b) + if err != nil { + return "", err + } + } else if i == "("+expiresKey+")" { + if expires == 0 { + return "", fmt.Errorf("missing expires value") + } + b.WriteString(i) + b.WriteString(headerFieldDelimiter) + b.WriteString(strconv.FormatInt(expires, 10)) + } else if i == "("+createdKey+")" { + if created == 0 { + return "", fmt.Errorf("missing created value") + } + b.WriteString(i) + b.WriteString(headerFieldDelimiter) + b.WriteString(strconv.FormatInt(created, 10)) + } else { + hv, ok := values[textproto.CanonicalMIMEHeaderKey(i)] + if !ok { + return "", fmt.Errorf("missing header %q", i) + } + b.WriteString(i) + b.WriteString(headerFieldDelimiter) + for i, v := range hv { + b.WriteString(strings.TrimSpace(v)) + if i < len(hv)-1 { + b.WriteString(headerValueDelimiter) + } + } + } + if n < len(include)-1 { + b.WriteString(headersDelimiter) + } + } + return b.String(), nil +} diff --git a/vendor/github.com/superseriousbusiness/httpsig/verifying.go b/vendor/github.com/superseriousbusiness/httpsig/verifying.go new file mode 100644 index 000000000..52a142ac1 --- /dev/null +++ b/vendor/github.com/superseriousbusiness/httpsig/verifying.go @@ -0,0 +1,188 @@ +package httpsig + +import ( + "crypto" + "encoding/base64" + "errors" + "fmt" + "net/http" + "strconv" + "strings" + "time" +) + +var _ VerifierWithOptions = &verifier{} + +type verifier struct { + header http.Header + kId string + signature string + created int64 + expires int64 + headers []string + sigStringFn func(http.Header, []string, int64, int64, SignatureOption) (string, error) +} + +func newVerifier(h http.Header, sigStringFn func(http.Header, []string, int64, int64, SignatureOption) (string, error)) (*verifier, error) { + scheme, s, err := getSignatureScheme(h) + if err != nil { + return nil, err + } + kId, sig, headers, created, expires, err := getSignatureComponents(scheme, s) + if created != 0 { + //check if created is not in the future, we assume a maximum clock offset of 10 seconds + now := time.Now().Unix() + if created-now > 10 { + return nil, errors.New("created is in the future") + } + } + if expires != 0 { + //check if expires is in the past, we assume a maximum clock offset of 10 seconds + now := time.Now().Unix() + if now-expires > 10 { + return nil, errors.New("signature expired") + } + } + if err != nil { + return nil, err + } + return &verifier{ + header: h, + kId: kId, + signature: sig, + created: created, + expires: expires, + headers: headers, + sigStringFn: sigStringFn, + }, nil +} + +func (v *verifier) KeyId() string { + return v.kId +} + +func (v *verifier) Verify(pKey crypto.PublicKey, algo Algorithm) error { + return v.VerifyWithOptions(pKey, algo, SignatureOption{}) +} + +func (v *verifier) VerifyWithOptions(pKey crypto.PublicKey, algo Algorithm, opts SignatureOption) error { + s, err := signerFromString(string(algo)) + if err == nil { + return v.asymmVerify(s, pKey, opts) + } + m, err := macerFromString(string(algo)) + if err == nil { + return v.macVerify(m, pKey, opts) + } + return fmt.Errorf("no crypto implementation available for %q: %s", algo, err) +} + +func (v *verifier) macVerify(m macer, pKey crypto.PublicKey, opts SignatureOption) error { + key, ok := pKey.([]byte) + if !ok { + return fmt.Errorf("public key for MAC verifying must be of type []byte") + } + signature, err := v.sigStringFn(v.header, v.headers, v.created, v.expires, opts) + if err != nil { + return err + } + actualMAC, err := base64.StdEncoding.DecodeString(v.signature) + if err != nil { + return err + } + ok, err = m.Equal([]byte(signature), actualMAC, key) + if err != nil { + return err + } else if !ok { + return fmt.Errorf("invalid http signature") + } + return nil +} + +func (v *verifier) asymmVerify(s signer, pKey crypto.PublicKey, opts SignatureOption) error { + toHash, err := v.sigStringFn(v.header, v.headers, v.created, v.expires, opts) + if err != nil { + return err + } + signature, err := base64.StdEncoding.DecodeString(v.signature) + if err != nil { + return err + } + err = s.Verify(pKey, []byte(toHash), signature) + if err != nil { + return err + } + return nil +} + +func getSignatureScheme(h http.Header) (scheme SignatureScheme, val string, err error) { + s := h.Get(string(Signature)) + sigHasAll := strings.Contains(s, keyIdParameter) || + strings.Contains(s, headersParameter) || + strings.Contains(s, signatureParameter) + a := h.Get(string(Authorization)) + authHasAll := strings.Contains(a, keyIdParameter) || + strings.Contains(a, headersParameter) || + strings.Contains(a, signatureParameter) + if sigHasAll && authHasAll { + err = fmt.Errorf("both %q and %q have signature parameters", Signature, Authorization) + return + } else if !sigHasAll && !authHasAll { + err = fmt.Errorf("neither %q nor %q have signature parameters", Signature, Authorization) + return + } else if sigHasAll { + val = s + scheme = Signature + return + } else { // authHasAll + val = a + scheme = Authorization + return + } +} + +func getSignatureComponents(scheme SignatureScheme, s string) (kId, sig string, headers []string, created int64, expires int64, err error) { + if as := scheme.authScheme(); len(as) > 0 { + s = strings.TrimPrefix(s, as+prefixSeparater) + } + params := strings.Split(s, parameterSeparater) + for _, p := range params { + kv := strings.SplitN(p, parameterKVSeparater, 2) + if len(kv) != 2 { + err = fmt.Errorf("malformed http signature parameter: %v", kv) + return + } + k := kv[0] + v := strings.Trim(kv[1], parameterValueDelimiter) + switch k { + case keyIdParameter: + kId = v + case createdKey: + created, err = strconv.ParseInt(v, 10, 64) + if err != nil { + return + } + case expiresKey: + expires, err = strconv.ParseInt(v, 10, 64) + if err != nil { + return + } + case algorithmParameter: + // Deprecated, ignore + case headersParameter: + headers = strings.Split(v, headerParameterValueDelim) + case signatureParameter: + sig = v + default: + // Ignore unrecognized parameters + } + } + if len(kId) == 0 { + err = fmt.Errorf("missing %q parameter in http signature", keyIdParameter) + } else if len(sig) == 0 { + err = fmt.Errorf("missing %q parameter in http signature", signatureParameter) + } else if len(headers) == 0 { // Optional + headers = defaultHeaders + } + return +} diff --git a/vendor/modules.txt b/vendor/modules.txt index de5d99d68..a9dd0bc6e 100644 --- a/vendor/modules.txt +++ b/vendor/modules.txt @@ -676,6 +676,9 @@ github.com/superseriousbusiness/go-jpeg-image-structure/v2 # github.com/superseriousbusiness/go-png-image-structure/v2 v2.0.1-SSB ## explicit; go 1.12 github.com/superseriousbusiness/go-png-image-structure/v2 +# github.com/superseriousbusiness/httpsig v1.2.0-SSB +## explicit; go 1.21 +github.com/superseriousbusiness/httpsig # github.com/superseriousbusiness/oauth2/v4 v4.3.2-SSB.0.20230227143000-f4900831d6c8 ## explicit; go 1.13 github.com/superseriousbusiness/oauth2/v4