使用OS提供的API在MacOS上散列

经过大量研究后，事实证明，尽管没有记录，但可以使用Security Transforms API。为了使其工作，精制而成的样品AES加密与SecDigestTransformCreate和可用的散列算法的使用的列表存在。

这是C和C ++友好的解决方案：

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

#ifdef __cplusplus
#include <vector>
#else // C
#include <stdbool.h> // For adding boolean support
#endif // __cplusplus

// Convenience define for cleanup
#define _CLEANUP_IF(a) if ((a)) goto Cleanup;

#ifdef __cplusplus
// Wrap into class in case of C++

class Sha256Calculator {
public:
#endif // __cplusplus

    // Calculates SHA256 hash from given array of data and returns array
    // Note: Parameter "outHash" is manually allocated so consider calling free(outHash) after using it
    static bool calculateSha256(uint8_t** outHash, size_t* outHashSize, const uint8_t *data, const size_t dataSize)
    {
        bool result = false;
        CFErrorRef error = NULL;

        SecTransformRef digestTransform = NULL;

        CFDataRef sourceData = NULL;
        CFDataRef outDataRef = NULL;
        const UInt8 * outData = NULL;
        CFIndex outDataSize = 0;


        // Create a CFData object from the source
        sourceData = CFDataCreate(kCFAllocatorDefault, (const UInt8*)data, dataSize);
        _CLEANUP_IF(!sourceData);

        digestTransform = SecDigestTransformCreate(kSecDigestSHA2, 256, &error);
        _CLEANUP_IF(error);

        SecTransformSetAttribute(digestTransform, kSecTransformInputAttributeName, (CFDataRef)sourceData, &error);
        _CLEANUP_IF(error);

        outDataRef = (CFDataRef)SecTransformExecute(digestTransform, &error);
        _CLEANUP_IF(error);
        _CLEANUP_IF(!outDataRef);


        // Extract data from CFDataRef to array
        outData = CFDataGetBytePtr(outDataRef);     // Returns read-only (UInt8*) pointer to the data
        outDataSize = CFDataGetLength(outDataRef);


        if (outHash) {
            *outHash = (uint8_t*)malloc(outDataSize);
            if (*outHash) {
                memcpy(*outHash, outData, outDataSize);
                if (outHashSize) {
                    *outHashSize = (size_t)outDataSize;
                }
                result = true;
            }
        }

        // Notes:
        //   * All the objects are released except "outData" since it's handled and cleaned by using outDataRef
        //   * CFRelease throws error if the passed object is NULL, so check objects before releasing

    Cleanup:
        // Use CFShow(error) for getting details about error
        if (error) { CFRelease(error); }
        if (digestTransform) { CFRelease(digestTransform); }
        if (sourceData) { CFRelease(sourceData); }
        if (outDataRef) { CFRelease(outDataRef); }

        return result;
    }

#ifdef __cplusplus
    // Convenience method for cpp using vectors
    static bool calculateSha256(std::vector<uint8_t>& outHash, const std::vector<uint8_t>& data)
    {
        // Call original method
        uint8_t * outHashArray = nullptr;
        size_t outHashSize;
        bool result;
        result = calculateSha256(&outHashArray, &outHashSize, data.data(), data.size());
        if (!result)
            return false;

        // Put resulting array in vector
        outHash.clear();
        outHash.insert(outHash.end(), &outHashArray[0], &outHashArray[outHashSize]);

        // Clean allocated array
        if (outHashArray)
            free(outHashArray);

        return result;
    }
};
#endif // __cplusplus

注意：
为了使用任何其他哈希算法而不是SHA256，请随意修改该行：
SecDigestTransformCreate(kSecDigestSHA2, 256, &error);
具有所需的可用哈希算法名称和适当的长度。

PS Hope，苹果公司将更新他们的文档...