refactor cmd/crypto code for SSE handling and parsing (#11045)
This commit refactors the code in `cmd/crypto`
and separates SSE-S3, SSE-C and SSE-KMS.
This commit should not cause any behavior change
except for:
- `IsRequested(http.Header)`
which now returns the requested type {SSE-C, SSE-S3,
SSE-KMS} and does not consider SSE-C copy headers.
However, SSE-C copy headers alone are anyway not valid.
master
Andreas Auernhammer
4 years ago
committed by
GitHub
parent
35fafb837b
commit
8cdf2106b0
@ -0,0 +1,157 @@ |
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/* |
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* Minio Cloud Storage, (C) 2019-2020 Minio, Inc. |
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* |
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* Licensed under the Apache License, Version 2.0 (the "License"); |
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* you may not use this file except in compliance with the License. |
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* You may obtain a copy of the License at |
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* |
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* http://www.apache.org/licenses/LICENSE-2.0
|
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* |
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* Unless required by applicable law or agreed to in writing, software |
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* distributed under the License is distributed on an "AS IS" BASIS, |
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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* See the License for the specific language governing permissions and |
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* limitations under the License. |
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*/ |
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package crypto |
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import ( |
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"bytes" |
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"context" |
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"crypto/md5" |
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"encoding/base64" |
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"net/http" |
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xhttp "github.com/minio/minio/cmd/http" |
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"github.com/minio/minio/cmd/logger" |
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) |
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type ssec struct{} |
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var ( |
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// SSEC represents AWS SSE-C. It provides functionality to handle
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// SSE-C requests.
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SSEC = ssec{} |
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_ Type = SSEC |
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) |
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// String returns the SSE domain as string. For SSE-C the
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// domain is "SSE-C".
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func (ssec) String() string { return "SSE-C" } |
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// IsRequested returns true if the HTTP headers contains
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// at least one SSE-C header. SSE-C copy headers are ignored.
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func (ssec) IsRequested(h http.Header) bool { |
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if _, ok := h[xhttp.AmzServerSideEncryptionCustomerAlgorithm]; ok { |
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return true |
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} |
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if _, ok := h[xhttp.AmzServerSideEncryptionCustomerKey]; ok { |
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return true |
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} |
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if _, ok := h[xhttp.AmzServerSideEncryptionCustomerKeyMD5]; ok { |
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return true |
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} |
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return false |
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} |
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// IsEncrypted returns true if the metadata contains an SSE-C
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// entry inidicating that the object has been encrypted using
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// SSE-C.
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func (ssec) IsEncrypted(metadata map[string]string) bool { |
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if _, ok := metadata[MetaSealedKeySSEC]; ok { |
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return true |
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} |
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return false |
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} |
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// ParseHTTP parses the SSE-C headers and returns the SSE-C client key
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// on success. SSE-C copy headers are ignored.
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func (ssec) ParseHTTP(h http.Header) (key [32]byte, err error) { |
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if h.Get(xhttp.AmzServerSideEncryptionCustomerAlgorithm) != xhttp.AmzEncryptionAES { |
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return key, ErrInvalidCustomerAlgorithm |
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} |
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if h.Get(xhttp.AmzServerSideEncryptionCustomerKey) == "" { |
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return key, ErrMissingCustomerKey |
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} |
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if h.Get(xhttp.AmzServerSideEncryptionCustomerKeyMD5) == "" { |
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return key, ErrMissingCustomerKeyMD5 |
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} |
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clientKey, err := base64.StdEncoding.DecodeString(h.Get(xhttp.AmzServerSideEncryptionCustomerKey)) |
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if err != nil || len(clientKey) != 32 { // The client key must be 256 bits long
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return key, ErrInvalidCustomerKey |
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} |
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keyMD5, err := base64.StdEncoding.DecodeString(h.Get(xhttp.AmzServerSideEncryptionCustomerKeyMD5)) |
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if md5Sum := md5.Sum(clientKey); err != nil || !bytes.Equal(md5Sum[:], keyMD5) { |
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return key, ErrCustomerKeyMD5Mismatch |
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} |
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copy(key[:], clientKey) |
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return key, nil |
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} |
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// UnsealObjectKey extracts and decrypts the sealed object key
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// from the metadata using the SSE-C client key of the HTTP headers
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// and returns the decrypted object key.
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func (s3 ssec) UnsealObjectKey(h http.Header, metadata map[string]string, bucket, object string) (key ObjectKey, err error) { |
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clientKey, err := s3.ParseHTTP(h) |
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if err != nil { |
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return |
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} |
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return unsealObjectKey(clientKey, metadata, bucket, object) |
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} |
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// CreateMetadata encodes the sealed key into the metadata
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// and returns the modified metadata. It allocates a new
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// metadata map if metadata is nil.
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func (ssec) CreateMetadata(metadata map[string]string, sealedKey SealedKey) map[string]string { |
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if sealedKey.Algorithm != SealAlgorithm { |
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logger.CriticalIf(context.Background(), Errorf("The seal algorithm '%s' is invalid for SSE-C", sealedKey.Algorithm)) |
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} |
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if metadata == nil { |
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metadata = make(map[string]string, 3) |
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} |
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metadata[MetaAlgorithm] = SealAlgorithm |
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metadata[MetaIV] = base64.StdEncoding.EncodeToString(sealedKey.IV[:]) |
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metadata[MetaSealedKeySSEC] = base64.StdEncoding.EncodeToString(sealedKey.Key[:]) |
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return metadata |
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} |
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// ParseMetadata extracts all SSE-C related values from the object metadata
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// and checks whether they are well-formed. It returns the sealed object key
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// on success.
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func (ssec) ParseMetadata(metadata map[string]string) (sealedKey SealedKey, err error) { |
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// Extract all required values from object metadata
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b64IV, ok := metadata[MetaIV] |
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if !ok { |
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return sealedKey, errMissingInternalIV |
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} |
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algorithm, ok := metadata[MetaAlgorithm] |
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if !ok { |
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return sealedKey, errMissingInternalSealAlgorithm |
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} |
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b64SealedKey, ok := metadata[MetaSealedKeySSEC] |
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if !ok { |
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return sealedKey, Errorf("The object metadata is missing the internal sealed key for SSE-C") |
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} |
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// Check whether all extracted values are well-formed
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iv, err := base64.StdEncoding.DecodeString(b64IV) |
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if err != nil || len(iv) != 32 { |
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return sealedKey, errInvalidInternalIV |
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} |
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if algorithm != SealAlgorithm && algorithm != InsecureSealAlgorithm { |
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return sealedKey, errInvalidInternalSealAlgorithm |
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} |
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encryptedKey, err := base64.StdEncoding.DecodeString(b64SealedKey) |
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if err != nil || len(encryptedKey) != 64 { |
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return sealedKey, Errorf("The internal sealed key for SSE-C is invalid") |
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} |
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sealedKey.Algorithm = algorithm |
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copy(sealedKey.IV[:], iv) |
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copy(sealedKey.Key[:], encryptedKey) |
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return sealedKey, nil |
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} |
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@ -0,0 +1,201 @@ |
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/* |
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* Minio Cloud Storage, (C) 2019-2020 Minio, Inc. |
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* |
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* Licensed under the Apache License, Version 2.0 (the "License"); |
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* you may not use this file except in compliance with the License. |
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* You may obtain a copy of the License at |
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* |
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* http://www.apache.org/licenses/LICENSE-2.0
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* |
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* Unless required by applicable law or agreed to in writing, software |
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* distributed under the License is distributed on an "AS IS" BASIS, |
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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* See the License for the specific language governing permissions and |
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* limitations under the License. |
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*/ |
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package crypto |
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import ( |
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"context" |
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"encoding/base64" |
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"errors" |
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"net/http" |
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"path" |
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"strings" |
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jsoniter "github.com/json-iterator/go" |
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xhttp "github.com/minio/minio/cmd/http" |
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"github.com/minio/minio/cmd/logger" |
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) |
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type ssekms struct{} |
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var ( |
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// S3KMS represents AWS SSE-KMS. It provides functionality to
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// handle SSE-KMS requests.
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S3KMS = ssekms{} |
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_ Type = S3KMS |
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) |
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// String returns the SSE domain as string. For SSE-KMS the
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// domain is "SSE-KMS".
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func (ssekms) String() string { return "SSE-KMS" } |
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// IsRequested returns true if the HTTP headers contains
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// at least one SSE-KMS header.
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func (ssekms) IsRequested(h http.Header) bool { |
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if _, ok := h[xhttp.AmzServerSideEncryptionKmsID]; ok { |
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return true |
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} |
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if _, ok := h[xhttp.AmzServerSideEncryptionKmsContext]; ok { |
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return true |
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} |
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if _, ok := h[xhttp.AmzServerSideEncryption]; ok { |
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return strings.ToUpper(h.Get(xhttp.AmzServerSideEncryption)) != xhttp.AmzEncryptionAES // Return only true if the SSE header is specified and does not contain the SSE-S3 value
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} |
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return false |
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} |
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// ParseHTTP parses the SSE-KMS headers and returns the SSE-KMS key ID
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// and the KMS context on success.
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func (ssekms) ParseHTTP(h http.Header) (string, Context, error) { |
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algorithm := h.Get(xhttp.AmzServerSideEncryption) |
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if algorithm != xhttp.AmzEncryptionKMS { |
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return "", nil, ErrInvalidEncryptionMethod |
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} |
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var ctx Context |
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if context, ok := h[xhttp.AmzServerSideEncryptionKmsContext]; ok { |
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var json = jsoniter.ConfigCompatibleWithStandardLibrary |
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if err := json.Unmarshal([]byte(context[0]), &ctx); err != nil { |
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return "", nil, err |
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} |
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} |
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return h.Get(xhttp.AmzServerSideEncryptionKmsID), ctx, nil |
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} |
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// IsEncrypted returns true if the object metadata indicates
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// that the object was uploaded using SSE-KMS.
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func (ssekms) IsEncrypted(metadata map[string]string) bool { |
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if _, ok := metadata[MetaSealedKeyKMS]; ok { |
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return true |
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} |
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if _, ok := metadata[MetaKeyID]; ok { |
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return true |
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} |
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if _, ok := metadata[MetaDataEncryptionKey]; ok { |
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return true |
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} |
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return false |
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} |
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// UnsealObjectKey extracts and decrypts the sealed object key
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// from the metadata using KMS and returns the decrypted object
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// key.
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func (s3 ssekms) UnsealObjectKey(kms KMS, metadata map[string]string, bucket, object string) (key ObjectKey, err error) { |
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keyID, kmsKey, sealedKey, err := s3.ParseMetadata(metadata) |
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if err != nil { |
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return key, err |
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} |
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unsealKey, err := kms.UnsealKey(keyID, kmsKey, Context{bucket: path.Join(bucket, object)}) |
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if err != nil { |
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return key, err |
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} |
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err = key.Unseal(unsealKey, sealedKey, s3.String(), bucket, object) |
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return key, err |
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} |
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// CreateMetadata encodes the sealed object key into the metadata and returns
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// the modified metadata. If the keyID and the kmsKey is not empty it encodes
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// both into the metadata as well. It allocates a new metadata map if metadata
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// is nil.
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func (ssekms) CreateMetadata(metadata map[string]string, keyID string, kmsKey []byte, sealedKey SealedKey) map[string]string { |
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if sealedKey.Algorithm != SealAlgorithm { |
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logger.CriticalIf(context.Background(), Errorf("The seal algorithm '%s' is invalid for SSE-S3", sealedKey.Algorithm)) |
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} |
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// There are two possibilites:
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// - We use a KMS -> There must be non-empty key ID and a KMS data key.
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// - We use a K/V -> There must be no key ID and no KMS data key.
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// Otherwise, the caller has passed an invalid argument combination.
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if keyID == "" && len(kmsKey) != 0 { |
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logger.CriticalIf(context.Background(), errors.New("The key ID must not be empty if a KMS data key is present")) |
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} |
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if keyID != "" && len(kmsKey) == 0 { |
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logger.CriticalIf(context.Background(), errors.New("The KMS data key must not be empty if a key ID is present")) |
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} |
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if metadata == nil { |
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metadata = make(map[string]string, 5) |
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} |
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metadata[MetaAlgorithm] = sealedKey.Algorithm |
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metadata[MetaIV] = base64.StdEncoding.EncodeToString(sealedKey.IV[:]) |
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metadata[MetaSealedKeyKMS] = base64.StdEncoding.EncodeToString(sealedKey.Key[:]) |
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if len(kmsKey) > 0 && keyID != "" { // We use a KMS -> Store key ID and sealed KMS data key.
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metadata[MetaKeyID] = keyID |
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metadata[MetaDataEncryptionKey] = base64.StdEncoding.EncodeToString(kmsKey) |
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} |
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return metadata |
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} |
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// ParseMetadata extracts all SSE-KMS related values from the object metadata
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// and checks whether they are well-formed. It returns the sealed object key
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// on success. If the metadata contains both, a KMS master key ID and a sealed
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// KMS data key it returns both. If the metadata does not contain neither a
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// KMS master key ID nor a sealed KMS data key it returns an empty keyID and
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// KMS data key. Otherwise, it returns an error.
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func (ssekms) ParseMetadata(metadata map[string]string) (keyID string, kmsKey []byte, sealedKey SealedKey, err error) { |
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// Extract all required values from object metadata
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b64IV, ok := metadata[MetaIV] |
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if !ok { |
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return keyID, kmsKey, sealedKey, errMissingInternalIV |
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} |
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algorithm, ok := metadata[MetaAlgorithm] |
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if !ok { |
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return keyID, kmsKey, sealedKey, errMissingInternalSealAlgorithm |
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} |
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b64SealedKey, ok := metadata[MetaSealedKeyKMS] |
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if !ok { |
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return keyID, kmsKey, sealedKey, Errorf("The object metadata is missing the internal sealed key for SSE-S3") |
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} |
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// There are two possibilites:
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// - We use a KMS -> There must be a key ID and a KMS data key.
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// - We use a K/V -> There must be no key ID and no KMS data key.
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// Otherwise, the metadata is corrupted.
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keyID, idPresent := metadata[MetaKeyID] |
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b64KMSSealedKey, kmsKeyPresent := metadata[MetaDataEncryptionKey] |
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if !idPresent && kmsKeyPresent { |
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return keyID, kmsKey, sealedKey, Errorf("The object metadata is missing the internal KMS key-ID for SSE-S3") |
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} |
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if idPresent && !kmsKeyPresent { |
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return keyID, kmsKey, sealedKey, Errorf("The object metadata is missing the internal sealed KMS data key for SSE-S3") |
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} |
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// Check whether all extracted values are well-formed
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iv, err := base64.StdEncoding.DecodeString(b64IV) |
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if err != nil || len(iv) != 32 { |
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return keyID, kmsKey, sealedKey, errInvalidInternalIV |
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} |
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if algorithm != SealAlgorithm { |
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return keyID, kmsKey, sealedKey, errInvalidInternalSealAlgorithm |
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} |
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encryptedKey, err := base64.StdEncoding.DecodeString(b64SealedKey) |
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if err != nil || len(encryptedKey) != 64 { |
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return keyID, kmsKey, sealedKey, Errorf("The internal sealed key for SSE-S3 is invalid") |
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} |
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if idPresent && kmsKeyPresent { // We are using a KMS -> parse the sealed KMS data key.
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kmsKey, err = base64.StdEncoding.DecodeString(b64KMSSealedKey) |
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if err != nil { |
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return keyID, kmsKey, sealedKey, Errorf("The internal sealed KMS data key for SSE-S3 is invalid") |
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} |
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} |
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sealedKey.Algorithm = algorithm |
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copy(sealedKey.IV[:], iv) |
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copy(sealedKey.Key[:], encryptedKey) |
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return keyID, kmsKey, sealedKey, nil |
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} |
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@ -0,0 +1,181 @@ |
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/* |
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* Minio Cloud Storage, (C) 2019-2020 Minio, Inc. |
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* |
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* Licensed under the Apache License, Version 2.0 (the "License"); |
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* you may not use this file except in compliance with the License. |
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* You may obtain a copy of the License at |
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* |
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* http://www.apache.org/licenses/LICENSE-2.0
|
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* |
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* Unless required by applicable law or agreed to in writing, software |
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* distributed under the License is distributed on an "AS IS" BASIS, |
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
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* See the License for the specific language governing permissions and |
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* limitations under the License. |
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*/ |
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|
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package crypto |
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import ( |
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"context" |
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"encoding/base64" |
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"errors" |
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"net/http" |
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"path" |
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"strings" |
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|
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xhttp "github.com/minio/minio/cmd/http" |
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"github.com/minio/minio/cmd/logger" |
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) |
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type sses3 struct{} |
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var ( |
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// S3 represents AWS SSE-S3. It provides functionality to handle
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// SSE-S3 requests.
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S3 = sses3{} |
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_ Type = S3 |
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) |
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// String returns the SSE domain as string. For SSE-S3 the
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// domain is "SSE-S3".
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func (sses3) String() string { return "SSE-S3" } |
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func (sses3) IsRequested(h http.Header) bool { |
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_, ok := h[xhttp.AmzServerSideEncryption] |
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return ok && strings.ToLower(h.Get(xhttp.AmzServerSideEncryption)) != xhttp.AmzEncryptionKMS // Return only true if the SSE header is specified and does not contain the SSE-KMS value
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} |
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// ParseHTTP parses the SSE-S3 related HTTP headers and checks
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// whether they contain valid values.
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func (sses3) ParseHTTP(h http.Header) error { |
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if h.Get(xhttp.AmzServerSideEncryption) != xhttp.AmzEncryptionAES { |
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return ErrInvalidEncryptionMethod |
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} |
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return nil |
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} |
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|
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// IsEncrypted returns true if the object metadata indicates
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// that the object was uploaded using SSE-S3.
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func (sses3) IsEncrypted(metadata map[string]string) bool { |
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if _, ok := metadata[MetaSealedKeyS3]; ok { |
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return true |
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} |
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if _, ok := metadata[MetaKeyID]; ok { |
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return true |
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} |
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if _, ok := metadata[MetaDataEncryptionKey]; ok { |
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return true |
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} |
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return false |
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} |
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|
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// UnsealObjectKey extracts and decrypts the sealed object key
|
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// from the metadata using KMS and returns the decrypted object
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// key.
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func (s3 sses3) UnsealObjectKey(kms KMS, metadata map[string]string, bucket, object string) (key ObjectKey, err error) { |
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keyID, kmsKey, sealedKey, err := s3.ParseMetadata(metadata) |
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if err != nil { |
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return key, err |
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} |
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unsealKey, err := kms.UnsealKey(keyID, kmsKey, Context{bucket: path.Join(bucket, object)}) |
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if err != nil { |
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return key, err |
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} |
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err = key.Unseal(unsealKey, sealedKey, s3.String(), bucket, object) |
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return key, err |
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} |
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|
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// CreateMetadata encodes the sealed object key into the metadata and returns
|
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// the modified metadata. If the keyID and the kmsKey is not empty it encodes
|
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// both into the metadata as well. It allocates a new metadata map if metadata
|
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// is nil.
|
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func (sses3) CreateMetadata(metadata map[string]string, keyID string, kmsKey []byte, sealedKey SealedKey) map[string]string { |
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if sealedKey.Algorithm != SealAlgorithm { |
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logger.CriticalIf(context.Background(), Errorf("The seal algorithm '%s' is invalid for SSE-S3", sealedKey.Algorithm)) |
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} |
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|
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// There are two possibilites:
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// - We use a KMS -> There must be non-empty key ID and a KMS data key.
|
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// - We use a K/V -> There must be no key ID and no KMS data key.
|
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// Otherwise, the caller has passed an invalid argument combination.
|
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if keyID == "" && len(kmsKey) != 0 { |
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logger.CriticalIf(context.Background(), errors.New("The key ID must not be empty if a KMS data key is present")) |
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} |
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if keyID != "" && len(kmsKey) == 0 { |
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logger.CriticalIf(context.Background(), errors.New("The KMS data key must not be empty if a key ID is present")) |
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} |
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|
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if metadata == nil { |
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metadata = make(map[string]string, 5) |
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} |
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|
||||
metadata[MetaAlgorithm] = sealedKey.Algorithm |
||||
metadata[MetaIV] = base64.StdEncoding.EncodeToString(sealedKey.IV[:]) |
||||
metadata[MetaSealedKeyS3] = base64.StdEncoding.EncodeToString(sealedKey.Key[:]) |
||||
if len(kmsKey) > 0 && keyID != "" { // We use a KMS -> Store key ID and sealed KMS data key.
|
||||
metadata[MetaKeyID] = keyID |
||||
metadata[MetaDataEncryptionKey] = base64.StdEncoding.EncodeToString(kmsKey) |
||||
} |
||||
return metadata |
||||
} |
||||
|
||||
// ParseMetadata extracts all SSE-S3 related values from the object metadata
|
||||
// and checks whether they are well-formed. It returns the sealed object key
|
||||
// on success. If the metadata contains both, a KMS master key ID and a sealed
|
||||
// KMS data key it returns both. If the metadata does not contain neither a
|
||||
// KMS master key ID nor a sealed KMS data key it returns an empty keyID and
|
||||
// KMS data key. Otherwise, it returns an error.
|
||||
func (sses3) ParseMetadata(metadata map[string]string) (keyID string, kmsKey []byte, sealedKey SealedKey, err error) { |
||||
// Extract all required values from object metadata
|
||||
b64IV, ok := metadata[MetaIV] |
||||
if !ok { |
||||
return keyID, kmsKey, sealedKey, errMissingInternalIV |
||||
} |
||||
algorithm, ok := metadata[MetaAlgorithm] |
||||
if !ok { |
||||
return keyID, kmsKey, sealedKey, errMissingInternalSealAlgorithm |
||||
} |
||||
b64SealedKey, ok := metadata[MetaSealedKeyS3] |
||||
if !ok { |
||||
return keyID, kmsKey, sealedKey, Errorf("The object metadata is missing the internal sealed key for SSE-S3") |
||||
} |
||||
|
||||
// There are two possibilites:
|
||||
// - We use a KMS -> There must be a key ID and a KMS data key.
|
||||
// - We use a K/V -> There must be no key ID and no KMS data key.
|
||||
// Otherwise, the metadata is corrupted.
|
||||
keyID, idPresent := metadata[MetaKeyID] |
||||
b64KMSSealedKey, kmsKeyPresent := metadata[MetaDataEncryptionKey] |
||||
if !idPresent && kmsKeyPresent { |
||||
return keyID, kmsKey, sealedKey, Errorf("The object metadata is missing the internal KMS key-ID for SSE-S3") |
||||
} |
||||
if idPresent && !kmsKeyPresent { |
||||
return keyID, kmsKey, sealedKey, Errorf("The object metadata is missing the internal sealed KMS data key for SSE-S3") |
||||
} |
||||
|
||||
// Check whether all extracted values are well-formed
|
||||
iv, err := base64.StdEncoding.DecodeString(b64IV) |
||||
if err != nil || len(iv) != 32 { |
||||
return keyID, kmsKey, sealedKey, errInvalidInternalIV |
||||
} |
||||
if algorithm != SealAlgorithm { |
||||
return keyID, kmsKey, sealedKey, errInvalidInternalSealAlgorithm |
||||
} |
||||
encryptedKey, err := base64.StdEncoding.DecodeString(b64SealedKey) |
||||
if err != nil || len(encryptedKey) != 64 { |
||||
return keyID, kmsKey, sealedKey, Errorf("The internal sealed key for SSE-S3 is invalid") |
||||
} |
||||
if idPresent && kmsKeyPresent { // We are using a KMS -> parse the sealed KMS data key.
|
||||
kmsKey, err = base64.StdEncoding.DecodeString(b64KMSSealedKey) |
||||
if err != nil { |
||||
return keyID, kmsKey, sealedKey, Errorf("The internal sealed KMS data key for SSE-S3 is invalid") |
||||
} |
||||
} |
||||
|
||||
sealedKey.Algorithm = algorithm |
||||
copy(sealedKey.IV[:], iv) |
||||
copy(sealedKey.Key[:], encryptedKey) |
||||
return keyID, kmsKey, sealedKey, nil |
||||
} |
||||
Loading…
Reference in new issue