Function sha_update

src/common/sha.cpp:260–294

// update the SHA digest

void sha_update(SHA_INFO *sha_info, const BYTE *buffer, size_t count)
{
	const Sha1::LONG clo = T32(sha_info->count_lo + ((Sha1::LONG) count << 3));
	if (clo < sha_info->count_lo) {
		++sha_info->count_hi;
	}
	sha_info->count_lo = clo;
	sha_info->count_hi += (Sha1::LONG) count >> 29;
	if (sha_info->local)
	{
		size_t i = SHA_BLOCKSIZE - sha_info->local;
		if (i > count) {
			i = count;
		}
		memcpy(sha_info->data + sha_info->local, buffer, i);
		count -= i;
		buffer += i;
		sha_info->local += i;
		if (sha_info->local == SHA_BLOCKSIZE) {
			sha_transform(sha_info);
		}
		else {
			return;
		}
	}
	while (count >= SHA_BLOCKSIZE)
	{
		memcpy(sha_info->data, buffer, SHA_BLOCKSIZE);
		buffer += SHA_BLOCKSIZE;
		count -= SHA_BLOCKSIZE;
		sha_transform(sha_info);
	}
	memcpy(sha_info->data, buffer, count);
	sha_info->local = count;
}

// finish computing the SHA digest