static Http::HeaderValueCollection CanonicalizeHeaders(Http::HeaderValueCollection&& headers)
{
Http::HeaderValueCollection canonicalHeaders;
for (const auto& header : headers)
{
auto trimmedHeaderName = StringUtils::Trim(header.first.c_str());
auto trimmedHeaderValue = StringUtils::Trim(header.second.c_str());
//multiline gets converted to line1,line2,etc...
auto headerMultiLine = StringUtils::SplitOnLine(trimmedHeaderValue);
Aws::String headerValue = headerMultiLine[0];
if (headerMultiLine.size() > 1)
{
for(size_t i = 1; i < headerMultiLine.size(); ++i)
{
headerValue += ",";
headerValue += StringUtils::Trim(headerMultiLine[i].c_str());
}
}
//duplicate spaces need to be converted to one.
Aws::String::iterator new_end =
std::unique(headerValue.begin(), headerValue.end(),
[=](char lhs, char rhs) { return (lhs == rhs) && (lhs == ' '); }
);
headerValue.erase(new_end, headerValue.end());
canonicalHeaders[trimmedHeaderName] = headerValue;
}
return canonicalHeaders;
}
void StringUtils::Replace(Aws::String &s, const char* search, const char* replace)
{
if(!search || !replace)
{
return;
}
size_t replaceLength = strlen(replace);
size_t searchLength = strlen(search);
for (std::size_t pos = 0;; pos += replaceLength)
{
pos = s.find(search, pos);
if (pos == Aws::String::npos)
break;
s.erase(pos, searchLength);
s.insert(pos, replace);
}
}
bool AWSAuthV4Signer::SignRequest(Aws::Http::HttpRequest& request, bool signBody) const
{
AWSCredentials credentials = m_credentialsProvider->GetAWSCredentials();
//don't sign anonymous requests
if (credentials.GetAWSAccessKeyId().empty() || credentials.GetAWSSecretKey().empty())
{
return true;
}
if (!credentials.GetSessionToken().empty())
{
request.SetAwsSessionToken(credentials.GetSessionToken());
}
Aws::String payloadHash(UNSIGNED_PAYLOAD);
if(signBody || request.GetUri().GetScheme() != Http::Scheme::HTTPS)
{
payloadHash.assign(ComputePayloadHash(request));
if (payloadHash.empty())
{
return false;
}
}
else
{
AWS_LOGSTREAM_DEBUG(v4LogTag, "Note: Http payloads are not being signed. signPayloads=" << m_signPayloads
<< " http scheme=" << Http::SchemeMapper::ToString(request.GetUri().GetScheme()));
}
if(m_includeSha256HashHeader)
{
request.SetHeaderValue("x-amz-content-sha256", payloadHash);
}
//calculate date header to use in internal signature (this also goes into date header).
DateTime now = GetSigningTimestamp();
Aws::String dateHeaderValue = now.ToGmtString(LONG_DATE_FORMAT_STR);
request.SetHeaderValue(AWS_DATE_HEADER, dateHeaderValue);
Aws::StringStream headersStream;
Aws::StringStream signedHeadersStream;
for (const auto& header : CanonicalizeHeaders(request.GetHeaders()))
{
if(ShouldSignHeader(header.first))
{
headersStream << header.first.c_str() << ":" << header.second.c_str() << NEWLINE;
signedHeadersStream << header.first.c_str() << ";";
}
}
Aws::String canonicalHeadersString = headersStream.str();
AWS_LOGSTREAM_DEBUG(v4LogTag, "Canonical Header String: " << canonicalHeadersString);
//calculate signed headers parameter
Aws::String signedHeadersValue = signedHeadersStream.str();
//remove that last semi-colon
signedHeadersValue.erase(signedHeadersValue.length() - 1);
AWS_LOGSTREAM_DEBUG(v4LogTag, "Signed Headers value:" << signedHeadersValue);
//generate generalized canonicalized request string.
Aws::String canonicalRequestString = CanonicalizeRequestSigningString(request, m_urlEscapePath);
//append v4 stuff to the canonical request string.
canonicalRequestString.append(canonicalHeadersString);
canonicalRequestString.append(NEWLINE);
canonicalRequestString.append(signedHeadersValue);
canonicalRequestString.append(NEWLINE);
canonicalRequestString.append(payloadHash);
AWS_LOGSTREAM_DEBUG(v4LogTag, "Canonical Request String: " << canonicalRequestString);
//now compute sha256 on that request string
auto hashResult = m_hash->Calculate(canonicalRequestString);
if (!hashResult.IsSuccess())
{
AWS_LOGSTREAM_ERROR(v4LogTag, "Failed to hash (sha256) request string \"" << canonicalRequestString << "\"");
return false;
}
auto sha256Digest = hashResult.GetResult();
Aws::String cannonicalRequestHash = HashingUtils::HexEncode(sha256Digest);
Aws::String simpleDate = now.ToGmtString(SIMPLE_DATE_FORMAT_STR);
Aws::String stringToSign = GenerateStringToSign(dateHeaderValue, simpleDate, cannonicalRequestHash);
auto finalSignature = GenerateSignature(credentials, stringToSign, simpleDate);
Aws::StringStream ss;
ss << AWS_HMAC_SHA256 << " " << CREDENTIAL << EQ << credentials.GetAWSAccessKeyId() << "/" << simpleDate
<< "/" << m_region << "/" << m_serviceName << "/" << AWS4_REQUEST << ", " << SIGNED_HEADERS << EQ
<< signedHeadersValue << ", " << SIGNATURE << EQ << finalSignature;
auto awsAuthString = ss.str();
AWS_LOGSTREAM_DEBUG(v4LogTag, "Signing request with: " << awsAuthString);
request.SetAwsAuthorization(awsAuthString);
return true;
}
