Found the following significant warnings:
  pki-x509.c:179:5: warning: 'EVP_PKEY_get1_RSA' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:182:2: warning: 'i2d_RSAPrivateKey' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:187:2: warning: 'i2d_RSAPrivateKey' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:195:2: warning: 'i2d_RSA_PUBKEY' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:200:2: warning: 'i2d_RSA_PUBKEY' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:376:5: warning: 'EVP_PKEY_get1_RSA' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:379:5: warning: 'RSA_public_encrypt' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:422:5: warning: 'EVP_PKEY_get1_RSA' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:425:5: warning: 'RSA_private_decrypt' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:463:2: warning: 'MD5' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:507:5: warning: 'EVP_PKEY_get1_RSA' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:510:5: warning: 'RSA_sign' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:548:5: warning: 'EVP_PKEY_get1_RSA' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:553:9: warning: 'RSA_verify' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:569:2: warning: 'd2i_RSAPrivateKey' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:573:2: warning: 'EVP_PKEY_assign' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:595:5: warning: 'd2i_RSA_PUBKEY' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:599:5: warning: 'EVP_PKEY_assign' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:616:5: warning: 'RSA_new' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:622:13: warning: 'RSA_free' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:626:2: warning: 'RSA_generate_key_ex' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:628:6: warning: 'RSA_free' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
  pki-x509.c:636:5: warning: 'EVP_PKEY_assign' is deprecated: Since OpenSSL 3.0 [-Wdeprecated-declarations]
See 'C:/r_packages/pkgcheck/CRAN/PKI/PKI.Rcheck/00install.out' for details.