Xcode无法处理密钥加密Ed25519

为了解决这个问题，需要使用OpenSSL库来生成并处理Ed25519密钥。以下是一些参考代码：

1. 生成Ed25519密钥对：

#include <openssl/evp.h>
#include <openssl/ed25519.h>

/* generate a Ed25519 keypair */
void generate_ed25519_keypair() {
  unsigned char pk[ED25519_PUBLIC_KEY_LEN], sk[ED25519_SECRET_KEY_LEN];
  int res;

  res = ED25519_keypair(pk, sk);
  if (res != 1) {
    printf("Failed to generate Ed25519 keypair.\n");
    return;
  }

  /* pk: public key, sk: secret key */
  printf("Public key:\n");
  for (int i = 0; i < ED25519_PUBLIC_KEY_LEN; i++) {
    printf("%02x", pk[i]);
  }
  printf("\n");

  printf("Secret key:\n");
  for (int i = 0; i < ED25519_SECRET_KEY_LEN; i++) {
    printf("%02x", sk[i]);
  }
  printf("\n");
}

2. 加密消息：

/* encrypt data with Ed25519 public key */
void encrypt_with_ed25519(const unsigned char *pk, const unsigned char *data, size_t data_len,
                          unsigned char *encrypted_data, size_t *encrypted_len) {
  EVP_PKEY *pkey = EVP_PKEY_new_raw_public_key(EVP_PKEY_ED25519, NULL, pk, ED25519_PUBLIC_KEY_LEN);
  if (!pkey) {
    printf("Failed to create EVP_PKEY object with Ed25519 public key.\n");
    return;
  }

  EVP_PKEY_CTX *ctx = EVP_PKEY_CTX_new(pkey, NULL);
  if (!ctx) {
    printf("Failed to create EVP_PKEY_CTX object.\n");
    EVP_PKEY_free(pkey);
    return;
  }

  int res = EVP_PKEY_encrypt_init(ctx);
  if (res != 1) {
    printf("Failed to initialize EVP_PKEY_CTX for encryption.\n");
    EVP_PKEY_free(pkey);
    EVP_PKEY_CTX_free(ctx);