From bdcd6075bd4593c8f67722ce075c9519faec58b7 Mon Sep 17 00:00:00 2001 From: Greg Hudson Date: Fri, 9 Feb 2024 17:57:40 -0500 Subject: Correct PKINIT EC cert signature metadata When generating CMS SignedData in PKINIT, check the certificate's public key type and set the signatureAlgorithm field appropriately. (This field is currently ignored by OpenSSL when verifying CMS SignedData.) ticket: 9111 (new) --- src/plugins/preauth/pkinit/pkinit_crypto_openssl.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) diff --git a/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c b/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c index ae78181..25796fd 100644 --- a/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c +++ b/src/plugins/preauth/pkinit/pkinit_crypto_openssl.c @@ -1662,7 +1662,22 @@ cleanup: return retval; } +/* Return the name ID of the signature algorithm for cert, assuming that the + * digest used is SHA-256 and the cert uses either an RSA or EC public key. */ +static int +cert_sig_alg(X509 *cert) +{ + /* Use X509_get0_pubkey() when OpenSSL 1.0 support is removed. */ + EVP_PKEY *pkey = X509_get_pubkey(cert); + int id; + if (pkey != NULL && EVP_PKEY_get_base_id(pkey) == EVP_PKEY_EC) + id = NID_ecdsa_with_SHA256; + else + id = NID_sha256WithRSAEncryption; + EVP_PKEY_free(pkey); + return id; +} krb5_error_code cms_signeddata_create(krb5_context context, @@ -1695,6 +1710,7 @@ cms_signeddata_create(krb5_context context, unsigned int alg_len = 0, digest_len = 0; unsigned char *y = NULL; ASN1_OBJECT *oid = NULL, *oid_copy; + int sig_alg_id; /* Start creating PKCS7 data. */ if ((p7 = PKCS7_new()) == NULL) @@ -1782,8 +1798,8 @@ cms_signeddata_create(krb5_context context, /* Set sig algs */ if (p7si->digest_enc_alg->parameter != NULL) ASN1_TYPE_free(p7si->digest_enc_alg->parameter); - p7si->digest_enc_alg->algorithm = - OBJ_nid2obj(NID_sha256WithRSAEncryption); + sig_alg_id = cert_sig_alg(id_cryptoctx->my_cert); + p7si->digest_enc_alg->algorithm = OBJ_nid2obj(sig_alg_id); if (!(p7si->digest_enc_alg->parameter = ASN1_TYPE_new())) goto cleanup; p7si->digest_enc_alg->parameter->type = V_ASN1_NULL; -- cgit v1.1