From 0879fac692cb1bff0ec4c196cb364d970ad3ecec Mon Sep 17 00:00:00 2001
From: Clemens Lang <cllang@redhat.com>
Date: Mon, 21 Nov 2022 14:33:57 +0100
Subject: [PATCH 2/3] Obtain PSS salt length from provider

Rather than computing the PSS salt length again in core using
ossl_rsa_ctx_to_pss_string, which calls rsa_ctx_to_pss and computes the
salt length, obtain it from the provider using the
OSSL_SIGNATURE_PARAM_ALGORITHM_ID param to handle the case where the
interpretation of the magic constants in the provider differs from that
of OpenSSL core.

Signed-off-by: Clemens Lang <cllang@redhat.com>
---
 crypto/cms/cms_rsa.c   | 19 +++++++++++++++----
 crypto/rsa/rsa_ameth.c | 34 +++++++++++++++++++++-------------
 2 files changed, 36 insertions(+), 17 deletions(-)

diff --git a/crypto/cms/cms_rsa.c b/crypto/cms/cms_rsa.c
index 20ed816918..997567fdbf 100644
--- a/crypto/cms/cms_rsa.c
+++ b/crypto/cms/cms_rsa.c
@@ -10,6 +10,7 @@
 #include <assert.h>
 #include <openssl/cms.h>
 #include <openssl/err.h>
+#include <openssl/core_names.h>
 #include "crypto/asn1.h"
 #include "crypto/rsa.h"
 #include "cms_local.h"
@@ -191,7 +192,10 @@ static int rsa_cms_sign(CMS_SignerInfo *si)
     int pad_mode = RSA_PKCS1_PADDING;
     X509_ALGOR *alg;
     EVP_PKEY_CTX *pkctx = CMS_SignerInfo_get0_pkey_ctx(si);
-    ASN1_STRING *os = NULL;
+    unsigned char aid[128];
+    const unsigned char *pp = aid;
+    size_t aid_len = 0;
+    OSSL_PARAM params[2];
 
     CMS_SignerInfo_get0_algs(si, NULL, NULL, NULL, &alg);
     if (pkctx != NULL) {
@@ -205,10 +209,17 @@ static int rsa_cms_sign(CMS_SignerInfo *si)
     /* We don't support it */
     if (pad_mode != RSA_PKCS1_PSS_PADDING)
         return 0;
-    os = ossl_rsa_ctx_to_pss_string(pkctx);
-    if (os == NULL)
+
+    params[0] = OSSL_PARAM_construct_octet_string(
+        OSSL_SIGNATURE_PARAM_ALGORITHM_ID, aid, sizeof(aid));
+    params[1] = OSSL_PARAM_construct_end();
+
+    if (EVP_PKEY_CTX_get_params(pkctx, params) <= 0)
+        return 0;
+    if ((aid_len = params[0].return_size) == 0)
+        return 0;
+    if (d2i_X509_ALGOR(&alg, &pp, aid_len) == NULL)
         return 0;
-    X509_ALGOR_set0(alg, OBJ_nid2obj(EVP_PKEY_RSA_PSS), V_ASN1_SEQUENCE, os);
     return 1;
 }
 
diff --git a/crypto/rsa/rsa_ameth.c b/crypto/rsa/rsa_ameth.c
index c15554505b..61ec53d424 100644
--- a/crypto/rsa/rsa_ameth.c
+++ b/crypto/rsa/rsa_ameth.c
@@ -637,22 +637,30 @@ static int rsa_item_sign(EVP_MD_CTX *ctx, const ASN1_ITEM *it, const void *asn,
     if (pad_mode == RSA_PKCS1_PADDING)
         return 2;
     if (pad_mode == RSA_PKCS1_PSS_PADDING) {
-        ASN1_STRING *os1 = NULL;
-        os1 = ossl_rsa_ctx_to_pss_string(pkctx);
-        if (!os1)
+        unsigned char aid[128];
+        size_t aid_len = 0;
+        OSSL_PARAM params[2];
+
+        params[0] = OSSL_PARAM_construct_octet_string(
+            OSSL_SIGNATURE_PARAM_ALGORITHM_ID, aid, sizeof(aid));
+        params[1] = OSSL_PARAM_construct_end();
+
+        if (EVP_PKEY_CTX_get_params(pkctx, params) <= 0)
             return 0;
-        /* Duplicate parameters if we have to */
-        if (alg2) {
-            ASN1_STRING *os2 = ASN1_STRING_dup(os1);
-            if (!os2) {
-                ASN1_STRING_free(os1);
+        if ((aid_len = params[0].return_size) == 0)
+            return 0;
+
+        if (alg1 != NULL) {
+            const unsigned char *pp = aid;
+            if (d2i_X509_ALGOR(&alg1, &pp, aid_len) == NULL)
+                return 0;
+        }
+        if (alg2 != NULL) {
+            const unsigned char *pp = aid;
+            if (d2i_X509_ALGOR(&alg2, &pp, aid_len) == NULL)
                 return 0;
-            }
-            X509_ALGOR_set0(alg2, OBJ_nid2obj(EVP_PKEY_RSA_PSS),
-                            V_ASN1_SEQUENCE, os2);
         }
-        X509_ALGOR_set0(alg1, OBJ_nid2obj(EVP_PKEY_RSA_PSS),
-                        V_ASN1_SEQUENCE, os1);
+
         return 3;
     }
     return 2;
-- 
2.38.1