Amazon.S3.Encryption.EncryptionUtils.BuildInstructionsUsingInstructionFile C# (CSharp) Method

        internal static EncryptionInstructions BuildInstructionsUsingInstructionFile(GetObjectResponse response, EncryptionMaterials materials)
        {
            using (TextReader textReader = new StreamReader(response.ResponseStream))
            {
                JsonData jsonData = JsonMapper.ToObject(textReader);

                var base64EncodedEncryptedEnvelopeKey = jsonData["EncryptedEnvelopeKey"];
                byte[] encryptedEvelopeKey = Convert.FromBase64String((string)base64EncodedEncryptedEnvelopeKey);
                byte[] decryptedEnvelopeKey = DecryptEnvelopeKey(encryptedEvelopeKey, materials);

                var base64EncodedIV = jsonData["IV"];
                byte[] IV = Convert.FromBase64String((string)base64EncodedIV);

                return new EncryptionInstructions(EncryptionMaterials.EmptyMaterialsDescription, decryptedEnvelopeKey, IV);
            }
        }

        /// <summary>
        /// Updates object where the object input stream contains the decrypted contents.
        /// </summary>
        /// <param name="instructionFileResponse">
        /// The getObject response of InstructionFile.
        /// </param>
        /// <param name="response">
        /// The getObject response whose contents are to be decrypted.
        /// </param>
        private void DecryptObjectUsingInstructionFile(GetObjectResponse response, GetObjectResponse instructionFileResponse)
        {
            // Create an instruction object from the instruction file response
            EncryptionInstructions instructions = EncryptionUtils.BuildInstructionsUsingInstructionFile(instructionFileResponse, this.encryptionMaterials);

            // Decrypt the object with the instructions
            EncryptionUtils.DecryptObjectUsingInstructions(response, instructions);
        }