lekkit/sha256

SHA-256 algorithm implementation (С/С++)

sha256

SHA-256 algorithm implementation (С/С++)

• Pure C with no platform or architecture dependencies
• Easy to use - just include sha256.h and add sha256.c to your project source files
• Can be used in C++, extends API appropriately
• Two types of API: easy - for hashing strings, etc in a single call; extended - for hashing files, streams, etc
• Based on the pseudocode algorithm from Wikipedia
• Pretty fast, comparable to sha256sum in speed

Usage

Easy API - String hashing example

const char* str = "test";
char hash[65] = {0}; // Notice the additional null-byte
sha256_easy_hash_hex(str, strlen(str), hash);
printf("%s\n", hash);

Extended API - File hashing example

FILE* file = fopen("test", "rb");
char buffer[1024];
size_t size;
struct sha256_buff buff;
sha256_init(&buff);
while (!feof(file)) {
    // Hash file by 1kb chunks, instead of loading into RAM at once
    size = fread(buffer, 1, 1024, file);
    sha256_update(&buff, buffer, size);
}
char hash[65] = {0};
sha256_finalize(&buff);
sha256_read_hex(&buff, hash);
printf("%s\n", hash);

C++

std::cout << SHA256::hashString("test") << std::endl;

SHA256 buff;
buff.update("test", 4);
std::cout << buff.hash() << std::endl;

sha256's Issues

Error: #268: declaration may not appear after executable statement in block

Under the scenario using LLVM for cross-compilation, "Error: #268: Declaration may not Appear after Executable Statement in block" will be prompted. It is recommended that variables be declared in advance at the beginning.
For example:

// old:
void sha256_read(const struct sha256_buff *buff, uint8_t *hash)
{
    for (uint32_t i = 0; i < 8; i++)
    {
        hash[i * 4] = (buff->h[i] >> 24) & 255;
        hash[i * 4 + 1] = (buff->h[i] >> 16) & 255;
        hash[i * 4 + 2] = (buff->h[i] >> 8) & 255;
        hash[i * 4 + 3] = buff->h[i] & 255;
    }
}

// new 
void sha256_read(const struct sha256_buff *buff, uint8_t *hash)
{
    uint32_t i = 0;
    for (/*uint32_t*/ i = 0; i < 8; i++)
    {
        hash[i * 4] = (buff->h[i] >> 24) & 255;
        hash[i * 4 + 1] = (buff->h[i] >> 16) & 255;
        hash[i * 4 + 2] = (buff->h[i] >> 8) & 255;
        hash[i * 4 + 3] = buff->h[i] & 255;
    }
}

Provide a complete SHA256 project

Your sha256 's API implementation is awesome, thank you very much.
It would be even better to provide a complete project。