Vendor aws-sdk-go (dep ensure) (#178)

vendor/github.com/aws/aws-sdk-go/service/s3/s3crypto/envelope.go

@@ -0,0 +1,37 @@
+package s3crypto
+
+// DefaultInstructionKeySuffix is appended to the end of the instruction file key when
+// grabbing or saving to S3
+const DefaultInstructionKeySuffix = ".instruction"
+
+const (
+	metaHeader                     = "x-amz-meta"
+	keyV1Header                    = "x-amz-key"
+	keyV2Header                    = keyV1Header + "-v2"
+	ivHeader                       = "x-amz-iv"
+	matDescHeader                  = "x-amz-matdesc"
+	cekAlgorithmHeader             = "x-amz-cek-alg"
+	wrapAlgorithmHeader            = "x-amz-wrap-alg"
+	tagLengthHeader                = "x-amz-tag-len"
+	unencryptedMD5Header           = "x-amz-unencrypted-content-md5"
+	unencryptedContentLengthHeader = "x-amz-unencrypted-content-length"
+)
+
+// Envelope encryption starts off by generating a random symmetric key using
+// AES GCM. The SDK generates a random IV based off the encryption cipher
+// chosen. The master key that was provided, whether by the user or KMS, will be used
+// to encrypt the randomly generated symmetric key and base64 encode the iv. This will
+// allow for decryption of that same data later.
+type Envelope struct {
+	// IV is the randomly generated IV base64 encoded.
+	IV string `json:"x-amz-iv"`
+	// CipherKey is the randomly generated cipher key.
+	CipherKey string `json:"x-amz-key-v2"`
+	// MaterialDesc is a description to distinguish from other envelopes.
+	MatDesc               string `json:"x-amz-matdesc"`
+	WrapAlg               string `json:"x-amz-wrap-alg"`
+	CEKAlg                string `json:"x-amz-cek-alg"`
+	TagLen                string `json:"x-amz-tag-len"`
+	UnencryptedMD5        string `json:"x-amz-unencrypted-content-md5"`
+	UnencryptedContentLen string `json:"x-amz-unencrypted-content-length"`
+}