我知道验证 WOPI 证明密钥实现起来相当复杂,而从文档中的解释中提取编程逻辑具有挑战性。不幸的是,我不是 PHP 开发人员。但是,我想分享我的生产 C# 代码以防万一。
private async Task<bool> ValidateWopiProof(HttpContext context)
{
// Make sure the request has the correct headers
if (!context.Request.Headers.ContainsKey(WopiRequestHeader.PROOF) ||
!context.Request.Headers.ContainsKey(WopiRequestHeader.TIME_STAMP))
return false;
// TimestampOlderThan20Min
var timeStamp = long.Parse(context.Request.Headers[WopiRequestHeader.TIME_STAMP].ToString());
var timeStampDateTime = new DateTime(timeStamp, DateTimeKind.Utc);
if ((DateTime.UtcNow - timeStampDateTime).TotalMinutes > 20)
return false;
// Set the requested proof values
var requestProof = context.Request.Headers[WopiRequestHeader.PROOF];
var requestProofOld = String.Empty;
if (context.Request.Headers.ContainsKey(WopiRequestHeader.PROOF_OLD))
requestProofOld = context.Request.Headers[WopiRequestHeader.PROOF_OLD];
// Get the WOPI proof info from Wopi discovery
var wopiProofPublicKey = await _wopiDiscovery.GetWopiProof();
// Encode the values into bytes
var accessTokenBytes = Encoding.UTF8.GetBytes(context.Request.Query["access_token"].ToString());
var hostUrl = GetAbsolouteUrl(context);
var hostUrlBytes = Encoding.UTF8.GetBytes(hostUrl.ToUpperInvariant());
var timeStampBytes = BitConverter.GetBytes(Convert.ToInt64(context.Request.Headers[WopiRequestHeader.TIME_STAMP])).Reverse().ToArray();
// Build expected proof
List<byte> expected = new List<byte>(
4 + accessTokenBytes.Length +
4 + hostUrlBytes.Length +
4 + timeStampBytes.Length);
// Add the values to the expected variable
expected.AddRange(BitConverter.GetBytes(accessTokenBytes.Length).Reverse().ToArray());
expected.AddRange(accessTokenBytes);
expected.AddRange(BitConverter.GetBytes(hostUrlBytes.Length).Reverse().ToArray());
expected.AddRange(hostUrlBytes);
expected.AddRange(BitConverter.GetBytes(timeStampBytes.Length).Reverse().ToArray());
expected.AddRange(timeStampBytes);
byte[] expectedBytes = expected.ToArray();
return (VerifyProofKeys(expectedBytes, requestProof, wopiProofPublicKey.Value) ||
VerifyProofKeys(expectedBytes, requestProofOld, wopiProofPublicKey.Value) ||
VerifyProofKeys(expectedBytes, requestProof, wopiProofPublicKey.OldValue));
}
private string GetAbsolouteUrl(HttpContext context)
{
var url = $"{_wopiUrlService.ApiAddress.TrimEnd('/')}{context.Request.Path}{context.Request.QueryString}";
return url.Replace(":44300", "").Replace(":443", "");
}
private bool VerifyProofKeys(byte[] expectedProof, string proofFromRequest, string discoPublicKey)
{
using (RSACryptoServiceProvider rsaProvider = new RSACryptoServiceProvider())
{
try
{
rsaProvider.ImportCspBlob(Convert.FromBase64String(discoPublicKey));
return rsaProvider.VerifyData(expectedProof, "SHA256", Convert.FromBase64String(proofFromRequest));
}
catch (FormatException)
{
return false;
}
catch (CryptographicException)
{
return false;
}
}
}
此实现遵循文档规范。对于方法_wopiDiscovery.GetWopiProof()
,我只是从Wopi Discoveryproof-key
获得部分。
.