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author | 2021-08-12 21:03:24 +0200 | |
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committer | 2021-08-12 21:03:24 +0200 | |
commit | 98263a7de64269898a2f81207e38943b5c8e8653 (patch) | |
tree | 743c90f109a6c5d27832d1dcef2388d939f0f77a /vendor/github.com/go-fed/httpsig/verifying.go | |
parent | Text duplication fix (#137) (diff) | |
download | gotosocial-98263a7de64269898a2f81207e38943b5c8e8653.tar.xz |
Grand test fixup (#138)
* start fixing up tests
* fix up tests + automate with drone
* fiddle with linting
* messing about with drone.yml
* some more fiddling
* hmmm
* add cache
* add vendor directory
* verbose
* ci updates
* update some little things
* update sig
Diffstat (limited to 'vendor/github.com/go-fed/httpsig/verifying.go')
-rw-r--r-- | vendor/github.com/go-fed/httpsig/verifying.go | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/vendor/github.com/go-fed/httpsig/verifying.go b/vendor/github.com/go-fed/httpsig/verifying.go new file mode 100644 index 000000000..6d8df02ce --- /dev/null +++ b/vendor/github.com/go-fed/httpsig/verifying.go @@ -0,0 +1,184 @@ +package httpsig + +import ( + "crypto" + "encoding/base64" + "errors" + "fmt" + "net/http" + "strconv" + "strings" + "time" +) + +var _ Verifier = &verifier{} + +type verifier struct { + header http.Header + kId string + signature string + created int64 + expires int64 + headers []string + sigStringFn func(http.Header, []string, int64, int64) (string, error) +} + +func newVerifier(h http.Header, sigStringFn func(http.Header, []string, int64, int64) (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 { + s, err := signerFromString(string(algo)) + if err == nil { + return v.asymmVerify(s, pKey) + } + m, err := macerFromString(string(algo)) + if err == nil { + return v.macVerify(m, pKey) + } + return fmt.Errorf("no crypto implementation available for %q", algo) +} + +func (v *verifier) macVerify(m macer, pKey crypto.PublicKey) 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) + 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) error { + toHash, err := v.sigStringFn(v.header, v.headers, v.created, v.expires) + 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 +} |