OpenSSL 3.1.2自定义签名Provider未触发签名回调问题求助

我为OpenSSL v3.1.2编写了一个基础签名Provider，代码如下：

#include <openssl/core_dispatch.h>
#include <openssl/core_names.h>
#include <openssl/params.h>
#include <openssl/evp.h>

struct rsa_sign_ctx
{
   EVP_PKEY *pkey;
};

static void *rsa_sign_newctx(void *provctx);
static void rsa_sign_freectx(void *ctx);
static int rsa_sign_init(void *ctx, void *provkey);
static int rsa_sign(void *ctx, unsigned char *sig, size_t *siglen, size_t sigsize, const unsigned char *tbs, size_t tbslen);


// here comes basic implementation of the above callback with log printouts
////////////////////

const OSSL_DISPATCH rsa_signature_functions[] = {
  {OSSL_FUNC_SIGNATURE_NEWCTX, (void (*)(void))rsa_sign_newctx},
  {OSSL_FUNC_SIGNATURE_FREECTX, (void (*)(void))rsa_sign_freectx},
  {OSSL_FUNC_SIGNATURE_SIGN_INIT, (void (*)(void))rsa_sign_init},
  {OSSL_FUNC_SIGNATURE_SIGN, (void (*)(void))rsa_sign},
  {0, NULL}};

const OSSL_ALGORITHM my_rsa_algorithm[] = {
  { "RSA", "provider=p_hsmpoc", rsa_signature_functions },
  {NULL, NULL, NULL}};

const OSSL_ALGORITHM *my_provider_query(void *provctx, int operation_id, int *no_cache)
{
   *no_cache = 0;

   switch (operation_id)
   {
   case OSSL_OP_SIGNATURE:
      return my_rsa_algorithm;
   }
   return NULL;
}

const OSSL_DISPATCH my_provider_functions[] = {
   {OSSL_FUNC_PROVIDER_QUERY_OPERATION, (void (*)(void))my_provider_query},
   {0, NULL}};

int OSSL_provider_init(const OSSL_CORE_HANDLE *handle, const OSSL_DISPATCH *in,
                   const OSSL_DISPATCH **out, void **provctx)
{
   *provctx = NULL;
   *out = my_provider_functions;
   return 1;
}

已执行的操作及现象：

• 将生成的SO文件复制到共享模块目录/usr/local/lib64/ossl-modules
• 更新openssl.cnf后执行openssl list -provider <my-prov>无报错，可确认OSSL_provider_init函数被调用
• 启动s_server和s_client（使用自定义SSL密钥对）时，my_provider_query查询函数按预期调用并注册了签名回调，但TLS握手过程中签名回调并未触发
• 在Nginx中加载该Provider时，出现完全相同的问题

请求指点遗漏的配置步骤。

内容的提问来源于stack exchange，提问作者eagle_bear