diff options
Diffstat (limited to 'vendor/github.com/minio/minio-go/v7/utils.go')
| -rw-r--r-- | vendor/github.com/minio/minio-go/v7/utils.go | 844 |
1 files changed, 0 insertions, 844 deletions
diff --git a/vendor/github.com/minio/minio-go/v7/utils.go b/vendor/github.com/minio/minio-go/v7/utils.go deleted file mode 100644 index cd7d2c27e..000000000 --- a/vendor/github.com/minio/minio-go/v7/utils.go +++ /dev/null @@ -1,844 +0,0 @@ -/* - * MinIO Go Library for Amazon S3 Compatible Cloud Storage - * Copyright 2015-2017 MinIO, Inc. - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ - -package minio - -import ( - "context" - "crypto/md5" - "crypto/sha256" - "crypto/tls" - "encoding/base64" - "encoding/hex" - "encoding/xml" - "errors" - "fmt" - "hash" - "io" - "math/rand" - "net" - "net/http" - "net/url" - "regexp" - "strconv" - "strings" - "sync" - "time" - - md5simd "github.com/minio/md5-simd" - "github.com/minio/minio-go/v7/pkg/s3utils" -) - -func trimEtag(etag string) string { - etag = strings.TrimPrefix(etag, "\"") - return strings.TrimSuffix(etag, "\"") -} - -var expirationRegex = regexp.MustCompile(`expiry-date="(.*?)", rule-id="(.*?)"`) - -func amzExpirationToExpiryDateRuleID(expiration string) (time.Time, string) { - if matches := expirationRegex.FindStringSubmatch(expiration); len(matches) == 3 { - expTime, err := parseRFC7231Time(matches[1]) - if err != nil { - return time.Time{}, "" - } - return expTime, matches[2] - } - return time.Time{}, "" -} - -var restoreRegex = regexp.MustCompile(`ongoing-request="(.*?)"(, expiry-date="(.*?)")?`) - -func amzRestoreToStruct(restore string) (ongoing bool, expTime time.Time, err error) { - matches := restoreRegex.FindStringSubmatch(restore) - if len(matches) != 4 { - return false, time.Time{}, errors.New("unexpected restore header") - } - ongoing, err = strconv.ParseBool(matches[1]) - if err != nil { - return false, time.Time{}, err - } - if matches[3] != "" { - expTime, err = parseRFC7231Time(matches[3]) - if err != nil { - return false, time.Time{}, err - } - } - return -} - -// xmlDecoder provide decoded value in xml. -func xmlDecoder(body io.Reader, v interface{}) error { - d := xml.NewDecoder(body) - return d.Decode(v) -} - -// sum256 calculate sha256sum for an input byte array, returns hex encoded. -func sum256Hex(data []byte) string { - hash := newSHA256Hasher() - defer hash.Close() - hash.Write(data) - return hex.EncodeToString(hash.Sum(nil)) -} - -// sumMD5Base64 calculate md5sum for an input byte array, returns base64 encoded. -func sumMD5Base64(data []byte) string { - hash := newMd5Hasher() - defer hash.Close() - hash.Write(data) - return base64.StdEncoding.EncodeToString(hash.Sum(nil)) -} - -// getEndpointURL - construct a new endpoint. -func getEndpointURL(endpoint string, secure bool) (*url.URL, error) { - // If secure is false, use 'http' scheme. - scheme := "https" - if !secure { - scheme = "http" - } - - // Construct a secured endpoint URL. - endpointURLStr := scheme + "://" + endpoint - endpointURL, err := url.Parse(endpointURLStr) - if err != nil { - return nil, err - } - - // Validate incoming endpoint URL. - if err := isValidEndpointURL(*endpointURL); err != nil { - return nil, err - } - return endpointURL, nil -} - -// closeResponse close non nil response with any response Body. -// convenient wrapper to drain any remaining data on response body. -// -// Subsequently this allows golang http RoundTripper -// to re-use the same connection for future requests. -func closeResponse(resp *http.Response) { - // Callers should close resp.Body when done reading from it. - // If resp.Body is not closed, the Client's underlying RoundTripper - // (typically Transport) may not be able to re-use a persistent TCP - // connection to the server for a subsequent "keep-alive" request. - if resp != nil && resp.Body != nil { - // Drain any remaining Body and then close the connection. - // Without this closing connection would disallow re-using - // the same connection for future uses. - // - http://stackoverflow.com/a/17961593/4465767 - io.Copy(io.Discard, resp.Body) - resp.Body.Close() - } -} - -var ( - // Hex encoded string of nil sha256sum bytes. - emptySHA256Hex = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855" - - // Sentinel URL is the default url value which is invalid. - sentinelURL = url.URL{} -) - -// Verify if input endpoint URL is valid. -func isValidEndpointURL(endpointURL url.URL) error { - if endpointURL == sentinelURL { - return errInvalidArgument("Endpoint url cannot be empty.") - } - if endpointURL.Path != "/" && endpointURL.Path != "" { - return errInvalidArgument("Endpoint url cannot have fully qualified paths.") - } - host := endpointURL.Hostname() - if !s3utils.IsValidIP(host) && !s3utils.IsValidDomain(host) { - msg := "Endpoint: " + endpointURL.Host + " does not follow ip address or domain name standards." - return errInvalidArgument(msg) - } - - if strings.Contains(host, ".s3.amazonaws.com") { - if !s3utils.IsAmazonEndpoint(endpointURL) { - return errInvalidArgument("Amazon S3 endpoint should be 's3.amazonaws.com'.") - } - } - if strings.Contains(host, ".googleapis.com") { - if !s3utils.IsGoogleEndpoint(endpointURL) { - return errInvalidArgument("Google Cloud Storage endpoint should be 'storage.googleapis.com'.") - } - } - return nil -} - -// Verify if input expires value is valid. -func isValidExpiry(expires time.Duration) error { - expireSeconds := int64(expires / time.Second) - if expireSeconds < 1 { - return errInvalidArgument("Expires cannot be lesser than 1 second.") - } - if expireSeconds > 604800 { - return errInvalidArgument("Expires cannot be greater than 7 days.") - } - return nil -} - -// Extract only necessary metadata header key/values by -// filtering them out with a list of custom header keys. -func extractObjMetadata(header http.Header) http.Header { - preserveKeys := []string{ - "Content-Type", - "Cache-Control", - "Content-Encoding", - "Content-Language", - "Content-Disposition", - "X-Amz-Storage-Class", - "X-Amz-Object-Lock-Mode", - "X-Amz-Object-Lock-Retain-Until-Date", - "X-Amz-Object-Lock-Legal-Hold", - "X-Amz-Website-Redirect-Location", - "X-Amz-Server-Side-Encryption", - "X-Amz-Tagging-Count", - "X-Amz-Meta-", - // Add new headers to be preserved. - // if you add new headers here, please extend - // PutObjectOptions{} to preserve them - // upon upload as well. - } - filteredHeader := make(http.Header) - for k, v := range header { - var found bool - for _, prefix := range preserveKeys { - if !strings.HasPrefix(k, prefix) { - continue - } - found = true - break - } - if found { - filteredHeader[k] = v - } - } - return filteredHeader -} - -const ( - // RFC 7231#section-7.1.1.1 timetamp format. e.g Tue, 29 Apr 2014 18:30:38 GMT - rfc822TimeFormat = "Mon, 2 Jan 2006 15:04:05 GMT" - rfc822TimeFormatSingleDigitDay = "Mon, _2 Jan 2006 15:04:05 GMT" - rfc822TimeFormatSingleDigitDayTwoDigitYear = "Mon, _2 Jan 06 15:04:05 GMT" -) - -func parseTime(t string, formats ...string) (time.Time, error) { - for _, format := range formats { - tt, err := time.Parse(format, t) - if err == nil { - return tt, nil - } - } - return time.Time{}, fmt.Errorf("unable to parse %s in any of the input formats: %s", t, formats) -} - -func parseRFC7231Time(lastModified string) (time.Time, error) { - return parseTime(lastModified, rfc822TimeFormat, rfc822TimeFormatSingleDigitDay, rfc822TimeFormatSingleDigitDayTwoDigitYear) -} - -// ToObjectInfo converts http header values into ObjectInfo type, -// extracts metadata and fills in all the necessary fields in ObjectInfo. -func ToObjectInfo(bucketName, objectName string, h http.Header) (ObjectInfo, error) { - var err error - // Trim off the odd double quotes from ETag in the beginning and end. - etag := trimEtag(h.Get("ETag")) - - // Parse content length is exists - var size int64 = -1 - contentLengthStr := h.Get("Content-Length") - if contentLengthStr != "" { - size, err = strconv.ParseInt(contentLengthStr, 10, 64) - if err != nil { - // Content-Length is not valid - return ObjectInfo{}, ErrorResponse{ - Code: "InternalError", - Message: fmt.Sprintf("Content-Length is not an integer, failed with %v", err), - BucketName: bucketName, - Key: objectName, - RequestID: h.Get("x-amz-request-id"), - HostID: h.Get("x-amz-id-2"), - Region: h.Get("x-amz-bucket-region"), - } - } - } - - // Parse Last-Modified has http time format. - mtime, err := parseRFC7231Time(h.Get("Last-Modified")) - if err != nil { - return ObjectInfo{}, ErrorResponse{ - Code: "InternalError", - Message: fmt.Sprintf("Last-Modified time format is invalid, failed with %v", err), - BucketName: bucketName, - Key: objectName, - RequestID: h.Get("x-amz-request-id"), - HostID: h.Get("x-amz-id-2"), - Region: h.Get("x-amz-bucket-region"), - } - } - - // Fetch content type if any present. - contentType := strings.TrimSpace(h.Get("Content-Type")) - if contentType == "" { - contentType = "application/octet-stream" - } - - expiryStr := h.Get("Expires") - var expiry time.Time - if expiryStr != "" { - expiry, err = parseRFC7231Time(expiryStr) - if err != nil { - return ObjectInfo{}, ErrorResponse{ - Code: "InternalError", - Message: fmt.Sprintf("'Expiry' is not in supported format: %v", err), - BucketName: bucketName, - Key: objectName, - RequestID: h.Get("x-amz-request-id"), - HostID: h.Get("x-amz-id-2"), - Region: h.Get("x-amz-bucket-region"), - } - } - } - - metadata := extractObjMetadata(h) - userMetadata := make(map[string]string) - for k, v := range metadata { - if strings.HasPrefix(k, "X-Amz-Meta-") { - userMetadata[strings.TrimPrefix(k, "X-Amz-Meta-")] = v[0] - } - } - userTags := s3utils.TagDecode(h.Get(amzTaggingHeader)) - - var tagCount int - if count := h.Get(amzTaggingCount); count != "" { - tagCount, err = strconv.Atoi(count) - if err != nil { - return ObjectInfo{}, ErrorResponse{ - Code: "InternalError", - Message: fmt.Sprintf("x-amz-tagging-count is not an integer, failed with %v", err), - BucketName: bucketName, - Key: objectName, - RequestID: h.Get("x-amz-request-id"), - HostID: h.Get("x-amz-id-2"), - Region: h.Get("x-amz-bucket-region"), - } - } - } - - // Nil if not found - var restore *RestoreInfo - if restoreHdr := h.Get(amzRestore); restoreHdr != "" { - ongoing, expTime, err := amzRestoreToStruct(restoreHdr) - if err != nil { - return ObjectInfo{}, err - } - restore = &RestoreInfo{OngoingRestore: ongoing, ExpiryTime: expTime} - } - - // extract lifecycle expiry date and rule ID - expTime, ruleID := amzExpirationToExpiryDateRuleID(h.Get(amzExpiration)) - - deleteMarker := h.Get(amzDeleteMarker) == "true" - - // Save object metadata info. - return ObjectInfo{ - ETag: etag, - Key: objectName, - Size: size, - LastModified: mtime, - ContentType: contentType, - Expires: expiry, - VersionID: h.Get(amzVersionID), - IsDeleteMarker: deleteMarker, - ReplicationStatus: h.Get(amzReplicationStatus), - Expiration: expTime, - ExpirationRuleID: ruleID, - // Extract only the relevant header keys describing the object. - // following function filters out a list of standard set of keys - // which are not part of object metadata. - Metadata: metadata, - UserMetadata: userMetadata, - UserTags: userTags, - UserTagCount: tagCount, - Restore: restore, - - // Checksum values - ChecksumCRC32: h.Get(ChecksumCRC32.Key()), - ChecksumCRC32C: h.Get(ChecksumCRC32C.Key()), - ChecksumSHA1: h.Get(ChecksumSHA1.Key()), - ChecksumSHA256: h.Get(ChecksumSHA256.Key()), - ChecksumCRC64NVME: h.Get(ChecksumCRC64NVME.Key()), - }, nil -} - -var readFull = func(r io.Reader, buf []byte) (n int, err error) { - // ReadFull reads exactly len(buf) bytes from r into buf. - // It returns the number of bytes copied and an error if - // fewer bytes were read. The error is EOF only if no bytes - // were read. If an EOF happens after reading some but not - // all the bytes, ReadFull returns ErrUnexpectedEOF. - // On return, n == len(buf) if and only if err == nil. - // If r returns an error having read at least len(buf) bytes, - // the error is dropped. - for n < len(buf) && err == nil { - var nn int - nn, err = r.Read(buf[n:]) - // Some spurious io.Reader's return - // io.ErrUnexpectedEOF when nn == 0 - // this behavior is undocumented - // so we are on purpose not using io.ReadFull - // implementation because this can lead - // to custom handling, to avoid that - // we simply modify the original io.ReadFull - // implementation to avoid this issue. - // io.ErrUnexpectedEOF with nn == 0 really - // means that io.EOF - if err == io.ErrUnexpectedEOF && nn == 0 { - err = io.EOF - } - n += nn - } - if n >= len(buf) { - err = nil - } else if n > 0 && err == io.EOF { - err = io.ErrUnexpectedEOF - } - return -} - -// regCred matches credential string in HTTP header -var regCred = regexp.MustCompile("Credential=([A-Z0-9]+)/") - -// regCred matches signature string in HTTP header -var regSign = regexp.MustCompile("Signature=([[0-9a-f]+)") - -// Redact out signature value from authorization string. -func redactSignature(origAuth string) string { - if !strings.HasPrefix(origAuth, signV4Algorithm) { - // Set a temporary redacted auth - return "AWS **REDACTED**:**REDACTED**" - } - - // Signature V4 authorization header. - - // Strip out accessKeyID from: - // Credential=<access-key-id>/<date>/<aws-region>/<aws-service>/aws4_request - newAuth := regCred.ReplaceAllString(origAuth, "Credential=**REDACTED**/") - - // Strip out 256-bit signature from: Signature=<256-bit signature> - return regSign.ReplaceAllString(newAuth, "Signature=**REDACTED**") -} - -// Get default location returns the location based on the input -// URL `u`, if region override is provided then all location -// defaults to regionOverride. -// -// If no other cases match then the location is set to `us-east-1` -// as a last resort. -func getDefaultLocation(u url.URL, regionOverride string) (location string) { - if regionOverride != "" { - return regionOverride - } - region := s3utils.GetRegionFromURL(u) - if region == "" { - region = "us-east-1" - } - return region -} - -var supportedHeaders = map[string]bool{ - "content-type": true, - "cache-control": true, - "content-encoding": true, - "content-disposition": true, - "content-language": true, - "x-amz-website-redirect-location": true, - "x-amz-object-lock-mode": true, - "x-amz-metadata-directive": true, - "x-amz-object-lock-retain-until-date": true, - "expires": true, - "x-amz-replication-status": true, - // Add more supported headers here. - // Must be lower case. -} - -// isStorageClassHeader returns true if the header is a supported storage class header -func isStorageClassHeader(headerKey string) bool { - return strings.EqualFold(amzStorageClass, headerKey) -} - -// isStandardHeader returns true if header is a supported header and not a custom header -func isStandardHeader(headerKey string) bool { - return supportedHeaders[strings.ToLower(headerKey)] -} - -// sseHeaders is list of server side encryption headers -var sseHeaders = map[string]bool{ - "x-amz-server-side-encryption": true, - "x-amz-server-side-encryption-aws-kms-key-id": true, - "x-amz-server-side-encryption-context": true, - "x-amz-server-side-encryption-customer-algorithm": true, - "x-amz-server-side-encryption-customer-key": true, - "x-amz-server-side-encryption-customer-key-md5": true, - // Add more supported headers here. - // Must be lower case. -} - -// isSSEHeader returns true if header is a server side encryption header. -func isSSEHeader(headerKey string) bool { - return sseHeaders[strings.ToLower(headerKey)] -} - -// isAmzHeader returns true if header is a x-amz-meta-* or x-amz-acl header. -func isAmzHeader(headerKey string) bool { - key := strings.ToLower(headerKey) - - return strings.HasPrefix(key, "x-amz-meta-") || strings.HasPrefix(key, "x-amz-grant-") || key == "x-amz-acl" || isSSEHeader(headerKey) || strings.HasPrefix(key, "x-amz-checksum-") -} - -// isMinioHeader returns true if header is x-minio- header. -func isMinioHeader(headerKey string) bool { - return strings.HasPrefix(strings.ToLower(headerKey), "x-minio-") -} - -// supportedQueryValues is a list of query strings that can be passed in when using GetObject. -var supportedQueryValues = map[string]bool{ - "attributes": true, - "partNumber": true, - "versionId": true, - "response-cache-control": true, - "response-content-disposition": true, - "response-content-encoding": true, - "response-content-language": true, - "response-content-type": true, - "response-expires": true, -} - -// isStandardQueryValue will return true when the passed in query string parameter is supported rather than customized. -func isStandardQueryValue(qsKey string) bool { - return supportedQueryValues[qsKey] -} - -// Per documentation at https://docs.aws.amazon.com/AmazonS3/latest/userguide/LogFormat.html#LogFormatCustom, the -// set of query params starting with "x-" are ignored by S3. -const allowedCustomQueryPrefix = "x-" - -func isCustomQueryValue(qsKey string) bool { - return strings.HasPrefix(qsKey, allowedCustomQueryPrefix) -} - -var ( - md5Pool = sync.Pool{New: func() interface{} { return md5.New() }} - sha256Pool = sync.Pool{New: func() interface{} { return sha256.New() }} -) - -func newMd5Hasher() md5simd.Hasher { - return &hashWrapper{Hash: md5Pool.Get().(hash.Hash), isMD5: true} -} - -func newSHA256Hasher() md5simd.Hasher { - return &hashWrapper{Hash: sha256Pool.Get().(hash.Hash), isSHA256: true} -} - -// hashWrapper implements the md5simd.Hasher interface. -type hashWrapper struct { - hash.Hash - isMD5 bool - isSHA256 bool -} - -// Close will put the hasher back into the pool. -func (m *hashWrapper) Close() { - if m.isMD5 && m.Hash != nil { - m.Reset() - md5Pool.Put(m.Hash) - } - if m.isSHA256 && m.Hash != nil { - m.Reset() - sha256Pool.Put(m.Hash) - } - m.Hash = nil -} - -const letterBytes = "abcdefghijklmnopqrstuvwxyz01234569" -const ( - letterIdxBits = 6 // 6 bits to represent a letter index - letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits - letterIdxMax = 63 / letterIdxBits // # of letter indices fitting in 63 bits -) - -// randString generates random names and prepends them with a known prefix. -func randString(n int, src rand.Source, prefix string) string { - b := make([]byte, n) - // A rand.Int63() generates 63 random bits, enough for letterIdxMax letters! - for i, cache, remain := n-1, src.Int63(), letterIdxMax; i >= 0; { - if remain == 0 { - cache, remain = src.Int63(), letterIdxMax - } - if idx := int(cache & letterIdxMask); idx < len(letterBytes) { - b[i] = letterBytes[idx] - i-- - } - cache >>= letterIdxBits - remain-- - } - return prefix + string(b[0:30-len(prefix)]) -} - -// IsNetworkOrHostDown - if there was a network error or if the host is down. -// expectTimeouts indicates that *context* timeouts are expected and does not -// indicate a downed host. Other timeouts still returns down. -func IsNetworkOrHostDown(err error, expectTimeouts bool) bool { - if err == nil { - return false - } - - if errors.Is(err, context.Canceled) { - return false - } - - if expectTimeouts && errors.Is(err, context.DeadlineExceeded) { - return false - } - - if errors.Is(err, context.DeadlineExceeded) { - return true - } - - // We need to figure if the error either a timeout - // or a non-temporary error. - urlErr := &url.Error{} - if errors.As(err, &urlErr) { - switch urlErr.Err.(type) { - case *net.DNSError, *net.OpError, net.UnknownNetworkError, *tls.CertificateVerificationError: - return true - } - } - var e net.Error - if errors.As(err, &e) { - if e.Timeout() { - return true - } - } - - // Fallback to other mechanisms. - switch { - case strings.Contains(err.Error(), "Connection closed by foreign host"): - return true - case strings.Contains(err.Error(), "TLS handshake timeout"): - // If error is - tlsHandshakeTimeoutError. - return true - case strings.Contains(err.Error(), "i/o timeout"): - // If error is - tcp timeoutError. - return true - case strings.Contains(err.Error(), "connection timed out"): - // If err is a net.Dial timeout. - return true - case strings.Contains(err.Error(), "connection refused"): - // If err is connection refused - return true - case strings.Contains(err.Error(), "server gave HTTP response to HTTPS client"): - // If err is TLS client is used with HTTP server - return true - case strings.Contains(err.Error(), "Client sent an HTTP request to an HTTPS server"): - // If err is plain-text Client is used with a HTTPS server - return true - case strings.Contains(strings.ToLower(err.Error()), "503 service unavailable"): - // Denial errors - return true - } - return false -} - -// newHashReaderWrapper will hash all reads done through r. -// When r returns io.EOF the done function will be called with the sum. -func newHashReaderWrapper(r io.Reader, h hash.Hash, done func(hash []byte)) *hashReaderWrapper { - return &hashReaderWrapper{ - r: r, - h: h, - done: done, - } -} - -type hashReaderWrapper struct { - r io.Reader - h hash.Hash - done func(hash []byte) -} - -// Read implements the io.Reader interface. -func (h *hashReaderWrapper) Read(p []byte) (n int, err error) { - n, err = h.r.Read(p) - if n > 0 { - n2, err := h.h.Write(p[:n]) - if err != nil { - return 0, err - } - if n2 != n { - return 0, io.ErrShortWrite - } - } - if err == io.EOF { - // Call back - h.done(h.h.Sum(nil)) - } - return n, err -} - -// Following is ported from C to Go in 2016 by Justin Ruggles, with minimal alteration. -// Used uint for unsigned long. Used uint32 for input arguments in order to match -// the Go hash/crc32 package. zlib CRC32 combine (https://github.com/madler/zlib) -// Modified for hash/crc64 by Klaus Post, 2024. -func gf2MatrixTimes(mat []uint64, vec uint64) uint64 { - var sum uint64 - - for vec != 0 { - if vec&1 != 0 { - sum ^= mat[0] - } - vec >>= 1 - mat = mat[1:] - } - return sum -} - -func gf2MatrixSquare(square, mat []uint64) { - if len(square) != len(mat) { - panic("square matrix size mismatch") - } - for n := range mat { - square[n] = gf2MatrixTimes(mat, mat[n]) - } -} - -// crc32Combine returns the combined CRC-32 hash value of the two passed CRC-32 -// hash values crc1 and crc2. poly represents the generator polynomial -// and len2 specifies the byte length that the crc2 hash covers. -func crc32Combine(poly uint32, crc1, crc2 uint32, len2 int64) uint32 { - // degenerate case (also disallow negative lengths) - if len2 <= 0 { - return crc1 - } - - even := make([]uint64, 32) // even-power-of-two zeros operator - odd := make([]uint64, 32) // odd-power-of-two zeros operator - - // put operator for one zero bit in odd - odd[0] = uint64(poly) // CRC-32 polynomial - row := uint64(1) - for n := 1; n < 32; n++ { - odd[n] = row - row <<= 1 - } - - // put operator for two zero bits in even - gf2MatrixSquare(even, odd) - - // put operator for four zero bits in odd - gf2MatrixSquare(odd, even) - - // apply len2 zeros to crc1 (first square will put the operator for one - // zero byte, eight zero bits, in even) - crc1n := uint64(crc1) - for { - // apply zeros operator for this bit of len2 - gf2MatrixSquare(even, odd) - if len2&1 != 0 { - crc1n = gf2MatrixTimes(even, crc1n) - } - len2 >>= 1 - - // if no more bits set, then done - if len2 == 0 { - break - } - - // another iteration of the loop with odd and even swapped - gf2MatrixSquare(odd, even) - if len2&1 != 0 { - crc1n = gf2MatrixTimes(odd, crc1n) - } - len2 >>= 1 - - // if no more bits set, then done - if len2 == 0 { - break - } - } - - // return combined crc - crc1n ^= uint64(crc2) - return uint32(crc1n) -} - -func crc64Combine(poly uint64, crc1, crc2 uint64, len2 int64) uint64 { - // degenerate case (also disallow negative lengths) - if len2 <= 0 { - return crc1 - } - - even := make([]uint64, 64) // even-power-of-two zeros operator - odd := make([]uint64, 64) // odd-power-of-two zeros operator - - // put operator for one zero bit in odd - odd[0] = poly // CRC-64 polynomial - row := uint64(1) - for n := 1; n < 64; n++ { - odd[n] = row - row <<= 1 - } - - // put operator for two zero bits in even - gf2MatrixSquare(even, odd) - - // put operator for four zero bits in odd - gf2MatrixSquare(odd, even) - - // apply len2 zeros to crc1 (first square will put the operator for one - // zero byte, eight zero bits, in even) - crc1n := crc1 - for { - // apply zeros operator for this bit of len2 - gf2MatrixSquare(even, odd) - if len2&1 != 0 { - crc1n = gf2MatrixTimes(even, crc1n) - } - len2 >>= 1 - - // if no more bits set, then done - if len2 == 0 { - break - } - - // another iteration of the loop with odd and even swapped - gf2MatrixSquare(odd, even) - if len2&1 != 0 { - crc1n = gf2MatrixTimes(odd, crc1n) - } - len2 >>= 1 - - // if no more bits set, then done - if len2 == 0 { - break - } - } - - // return combined crc - crc1n ^= crc2 - return crc1n -} |