SSE-C

Functions

With SSE-C used, OBS uses the keys and MD5 values provided by customers for server-side encryption.

Newly Added Headers

OBS does not store your encryption keys. If you lost them, you lost the objects. Six headers are added to support SSE-C.

The following table lists headers that are required when you use SSE-C to encrypt objects.

**Table 1** Header fields used for encrypting objects in SSE-C mode
Element	Description
x-obs-server-side-encryption-customer-algorithm	Indicates the encryption algorithm for the object when SSE-C is used. Example: x-obs-server-side-encryption-customer-algorithm: AES256
x-obs-server-side-encryption-customer-key	Indicates the key for encrypting objects when SSE-C is used. Its value is a Base64-encoded 256-bit key. Example: x-obs-server-side-encryption-customer-key:K7QkYpBkM5+hca27fsNkUnNVaobncnLht/rCB2o/9Cw=
x-obs-server-side-encryption-customer-key-MD5	Indicates the MD5 value of the key for encrypting objects when SSE-C is used. Its value is a Base64-encoded MD5 hash. The MD5 value is used to check whether any error occurs during the transmission of the key. Example: x-obs-server-side-encryption-customer-key-MD5:4XvB3tbNTN+tIEVa0/fGaQ==

APIs where the newly added headers apply:

Uploading an Object - PUT
Uploading an Object - POST
Copying an Object: The newly added headers apply to the object copy.
Querying Object Metadata
Downloading an Object
Initiating a Multipart Upload
Uploading Parts
Copying Parts: The newly added headers apply to target parts.

The following table lists three headers that are added for CopyObject and UploadPart-Copy operations to support source objects encrypted using SSE-C.

**Table 2** Header fields for source objects encrypted by the SSE-C
Element	Description
x-obs-copy-source-server-side-encryption-customer-algorithm	Indicates the algorithm for decrypting the source object when SSE-C is used. Example: x-obs-server-side-encryption-customer-algorithm: AES256
x-obs-copy-source-server-side-encryption-customer-key	Indicates the key for decrypting the source object when SSE-C is used. Example: x-obs-copy-source-server-side-encryption-customer-algorithm: K7QkYpBkM5+hca27fsNkUnNVaobncnLht/rCB2o/9Cw=
x-obs-copy-source-server-side-encryption-customer-key-MD5	Indicates the MD5 value of the key for decrypting the source object when SSE-C is used. The MD5 value is used to check whether any error occurs during the transmission of the key. Example: x-obs-copy-source-server-side-encryption-customer-key:4XvB3tbNTN+tIEVa0/fGaQ==

Sample Request: Uploading an Object Encrypted with SSE-C

    
         PUT /encryp2 HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.example.com
Accept: */*
Date: Wed, 06 Jun 2018 09:12:00 GMT
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:mZSfafoM+llApk0HGOThlqeccu0=
x-obs-server-side-encryption-customer-algorithm:AES256
x-obs-server-side-encryption-customer-key:K7QkYpBkM5+hca27fsNkUnNVaobncnLht/rCB2o/9Cw=
x-obs-server-side-encryption-customer-key-MD5:4XvB3tbNTN+tIEVa0/fGaQ==
Content-Length: 5242

[5242 Byte object contents]

Sample Response: Uploading an Object Encrypted with SSE-C

    
         HTTP/1.1 200 OK
Server: OBS
x-obs-request-id: 8DF400000163D45E0017055619BD02B8
ETag: "0f91242c7f3d86f98ae572a686d0696e"
x-obs-server-side-encryption-customer-algorithm: AES256
x-obs-server-side-encryption-customer-key-MD5: 4XvB3tbNTN+tIEVa0/fGaQ==
x-obs-id-2: 32AAAUgAIAABAAAQAAEAABAAAQAAEAABCSSAJ8bTNJV0X+Ote1PtuWecqyMh6zBJ
Date: Wed, 06 Jun 2018 09:12:00 GMT
Content-Length: 0

Sample Request: Copying an SSE-C Encrypted Object and Saving It as a KMS Encrypted Object

    
         PUT /kmsobject HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.example.com
Accept: */*
Date: Wed, 06 Jun 2018 09:20:10 GMT
Authorization: OBS H4IPJX0TQTHTHEBQQCEC:mZSfafoM+llApk0HGOThlqeccu0=
x-obs-copy-source-server-side-encryption-customer-algorithm:AES256
x-obs-copy-source-server-side-encryption-customer-key:K7QkYpBkM5+hca27fsNkUnNVaobncnLht/rCB2o/9Cw=
x-obs-copy-source-server-side-encryption-customer-key-MD5:4XvB3tbNTN+tIEVa0/fGaQ==
x-obs-server-side-encryption: kms
x-obs-copy-source: /examplebucket/encryp2
Content-Length: 5242

[5242 Byte object contents]

Sample Response: Copying an SSE-C Encrypted Object and Saving It as a KMS Encrypted Object

    
         HTTP/1.1 200 OK
Server: OBS
x-obs-request-id: BB7800000164848E0FC70528B9D92C41
ETag: "1072e1b96b47d7ec859710068aa70d57"
x-obs-server-side-encryption: kms
x-obs-server-side-encryption-kms-key-id: region:783fc6652cf246c096ea836694f71855:key/522d6070-5ad3-4765-9737-9312ddc72cdb
x-obs-id-2: 32AAAUJAIAABAAAQAAEAABAAAQAAEAABCTkkRzQXs9ECzZcavVRncBqqYNkoAEsr
Date: Wed, 06 Jun 2018 09:20:10 GMT
Content-Length: 0

Sample Request: Uploading an SSE-C Encrypted Object Using a Signed URL

PUT /encrypobject?AccessKeyId=H4IPJX0TQTHTHEBQQCEC&Expires=1532688887&Signature=EQmDuOhaLUrzrzRNZxwS72CXeXM%3D HTTP/1.1
User-Agent: curl/7.29.0
Host: examplebucket.obs.region.example.com
Accept: */*
x-obs-server-side-encryption-customer-algorithm: AES256
x-obs-server-side-encryption-customer-key:K7QkYpBkM5+hca27fsNkUnNVaobncnLht/rCB2o/9Cw=
x-obs-server-side-encryption-customer-key-MD5:4XvB3tbNTN+tIEVa0/fGaQ==
Content-Length: 5242
Expect: 100-continue

[5242 Byte object contents]

Sample Response: Uploading an SSE-C Encrypted Object Using a Signed URL

    
         HTTP/1.1 100 Continue
HTTP/1.1 200 OK
Server: OBS
x-obs-request-id: 804F00000164DB5E5B7FB908D3BA8E00
ETag: "1072e1b96b47d7ec859710068aa70d57"
x-obs-server-side-encryption-customer-algorithm: AES256
x-obs-server-side-encryption-customer-key-MD5: 4XvB3tbNTN+tIEVa0/fGaQ==
x-obs-id-2: 32AAAUJAIAABAAAQAAEAABAAAQAAEAABCTlpxILjhVK/heKOWIP8Wn2IWmQoerfw
Content-Length: 0