/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include <CoreFoundation/CoreFoundation.h>
#include <Security/Security.h>
#include <dlfcn.h>

#include "cryptox.h"

// We declare the necessary parts of the Security Transforms API here since
// we're building with the 10.6 SDK, which doesn't know about Security
// Transforms.
#if defined(__cplusplus)
extern "C" {
#endif
const CFStringRef kSecTransformInputAttributeName = CFSTR("INPUT");
typedef CFTypeRef SecTransformRef;
typedef OpaqueSecKeyRef* SecKeyRef;

typedef SecTransformRef (*SecTransformCreateReadTransformWithReadStreamFunc)(
    CFReadStreamRef inputStream);
SecTransformCreateReadTransformWithReadStreamFunc
    SecTransformCreateReadTransformWithReadStreamPtr = nullptr;
typedef CFTypeRef (*SecTransformExecuteFunc)(SecTransformRef transform,
                                             CFErrorRef* error);
SecTransformExecuteFunc SecTransformExecutePtr = nullptr;
typedef SecTransformRef (*SecVerifyTransformCreateFunc)(SecKeyRef key,
                                                        CFDataRef signature,
                                                        CFErrorRef* error);
SecVerifyTransformCreateFunc SecVerifyTransformCreatePtr = nullptr;
typedef Boolean (*SecTransformSetAttributeFunc)(SecTransformRef transform,
                                                CFStringRef key,
                                                CFTypeRef value,
                                                CFErrorRef* error);
SecTransformSetAttributeFunc SecTransformSetAttributePtr = nullptr;
#if defined(__cplusplus)
}
#endif

CryptoX_Result CryptoMac_InitCryptoProvider() {
  if (!SecTransformCreateReadTransformWithReadStreamPtr) {
    SecTransformCreateReadTransformWithReadStreamPtr =
        (SecTransformCreateReadTransformWithReadStreamFunc)dlsym(
            RTLD_DEFAULT, "SecTransformCreateReadTransformWithReadStream");
  }
  if (!SecTransformExecutePtr) {
    SecTransformExecutePtr =
        (SecTransformExecuteFunc)dlsym(RTLD_DEFAULT, "SecTransformExecute");
  }
  if (!SecVerifyTransformCreatePtr) {
    SecVerifyTransformCreatePtr = (SecVerifyTransformCreateFunc)dlsym(
        RTLD_DEFAULT, "SecVerifyTransformCreate");
  }
  if (!SecTransformSetAttributePtr) {
    SecTransformSetAttributePtr = (SecTransformSetAttributeFunc)dlsym(
        RTLD_DEFAULT, "SecTransformSetAttribute");
  }
  if (!SecTransformCreateReadTransformWithReadStreamPtr ||
      !SecTransformExecutePtr || !SecVerifyTransformCreatePtr ||
      !SecTransformSetAttributePtr) {
    return CryptoX_Error;
  }
  return CryptoX_Success;
}

CryptoX_Result CryptoMac_VerifyBegin(CryptoX_SignatureHandle* aInputData) {
  if (!aInputData) {
    return CryptoX_Error;
  }

  void* inputData = CFDataCreateMutable(kCFAllocatorDefault, 0);
  if (!inputData) {
    return CryptoX_Error;
  }

  *aInputData = inputData;
  return CryptoX_Success;
}

CryptoX_Result CryptoMac_VerifyUpdate(CryptoX_SignatureHandle* aInputData,
                                      void* aBuf, unsigned int aLen) {
  if (aLen == 0) {
    return CryptoX_Success;
  }
  if (!aInputData || !*aInputData) {
    return CryptoX_Error;
  }

  CFMutableDataRef inputData = (CFMutableDataRef)*aInputData;

  CFDataAppendBytes(inputData, (const uint8*)aBuf, aLen);
  return CryptoX_Success;
}

CryptoX_Result CryptoMac_LoadPublicKey(const unsigned char* aCertData,
                                       unsigned int aDataSize,
                                       CryptoX_PublicKey* aPublicKey) {
  if (!aCertData || aDataSize == 0 || !aPublicKey) {
    return CryptoX_Error;
  }
  *aPublicKey = nullptr;
  CFDataRef certData = CFDataCreate(kCFAllocatorDefault, aCertData, aDataSize);
  if (!certData) {
    return CryptoX_Error;
  }

  SecCertificateRef cert =
      SecCertificateCreateWithData(kCFAllocatorDefault, certData);
  CFRelease(certData);
  if (!cert) {
    return CryptoX_Error;
  }

  OSStatus status = SecCertificateCopyPublicKey(cert, (SecKeyRef*)aPublicKey);
  CFRelease(cert);
  if (status != 0) {
    return CryptoX_Error;
  }

  return CryptoX_Success;
}

CryptoX_Result CryptoMac_VerifySignature(CryptoX_SignatureHandle* aInputData,
                                         CryptoX_PublicKey* aPublicKey,
                                         const unsigned char* aSignature,
                                         unsigned int aSignatureLen) {
  if (!aInputData || !*aInputData || !aPublicKey || !*aPublicKey ||
      !aSignature || aSignatureLen == 0) {
    return CryptoX_Error;
  }

  CFDataRef signatureData =
      CFDataCreate(kCFAllocatorDefault, aSignature, aSignatureLen);
  if (!signatureData) {
    return CryptoX_Error;
  }

  CFErrorRef error;
  SecTransformRef verifier = SecVerifyTransformCreatePtr((SecKeyRef)*aPublicKey,
                                                         signatureData, &error);
  if (!verifier || error) {
    if (error) {
      CFRelease(error);
    }
    CFRelease(signatureData);
    return CryptoX_Error;
  }

  SecTransformSetAttributePtr(verifier, kSecDigestTypeAttribute, kSecDigestSHA2,
                              &error);
  if (error) {
    CFRelease(error);
    CFRelease(signatureData);
    CFRelease(verifier);
    return CryptoX_Error;
  }

  int digestLength = 384;
  CFNumberRef dLen =
      CFNumberCreate(kCFAllocatorDefault, kCFNumberIntType, &digestLength);
  SecTransformSetAttributePtr(verifier, kSecDigestLengthAttribute, dLen,
                              &error);
  CFRelease(dLen);
  if (error) {
    CFRelease(error);
    CFRelease(signatureData);
    CFRelease(verifier);
    return CryptoX_Error;
  }

  SecTransformSetAttributePtr(verifier, kSecTransformInputAttributeName,
                              (CFDataRef)*aInputData, &error);
  if (error) {
    CFRelease(error);
    CFRelease(signatureData);
    CFRelease(verifier);
    return CryptoX_Error;
  }

  CryptoX_Result result = CryptoX_Error;
  CFTypeRef rv = SecTransformExecutePtr(verifier, &error);
  if (error) {
    CFRelease(error);
    CFRelease(signatureData);
    CFRelease(verifier);
    return CryptoX_Error;
  }

  if (CFGetTypeID(rv) == CFBooleanGetTypeID() &&
      CFBooleanGetValue((CFBooleanRef)rv) == true) {
    result = CryptoX_Success;
  }

  CFRelease(signatureData);
  CFRelease(verifier);

  return result;
}

void CryptoMac_FreeSignatureHandle(CryptoX_SignatureHandle* aInputData) {
  if (!aInputData || !*aInputData) {
    return;
  }

  CFMutableDataRef inputData = nullptr;
  inputData = (CFMutableDataRef)*aInputData;

  CFRelease(inputData);
}

void CryptoMac_FreePublicKey(CryptoX_PublicKey* aPublicKey) {
  if (!aPublicKey || !*aPublicKey) {
    return;
  }

  CFRelease((SecKeyRef)*aPublicKey);
}