From: Vladimirs Ambrosovs <rodriguez.twister@gmail.com>
Date: Wed, 1 Nov 2023 11:18:14 +0000 (+0200)
Subject: Bugfixes for params to legacy control translations for EC parameters
X-Git-Tag: openssl-3.5.0-alpha1~934
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=2aaef03339a88e5d693f278406a889657b10fd2d;p=thirdparty%2Fopenssl.git

Bugfixes for params to legacy control translations for EC parameters

param->ctrl translation: Fix fix_ecdh_cofactor()

In POST_PARAMS_TO_CTRL state the fix_ecdh_cofactor() function should
return value in ctx->p1

param->ctrl translation: fix evp_pkey_ctx_setget_params_to_ctrl
 return

Since some of the ctrl operations may return 0 as valid value
(e.g. ecdh_cofactor value 0 is valid setting), before colling
POST_PARAMS_TO_CTRL, we need to check return value for 0 as well
otherwise the evp_pkey_ctx_setget_params_to_ctrl function fails
without a chance to fix the return value

param->ctrl translation: Set ecdh_cofactor default action_type GET

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/22587)
---

diff --git a/crypto/evp/ctrl_params_translate.c b/crypto/evp/ctrl_params_translate.c
index 406343f0a81..a932d38c060 100644
--- a/crypto/evp/ctrl_params_translate.c
+++ b/crypto/evp/ctrl_params_translate.c
@@ -1208,6 +1208,8 @@ static int fix_ecdh_cofactor(enum state state,
         /* The initial value for |ctx->action_type| must not be zero. */
         if (!ossl_assert(ctx->action_type != NONE))
             return 0;
+    } else if (state == POST_PARAMS_TO_CTRL && ctx->action_type == NONE) {
+        ctx->action_type = GET;
     }
 
     if ((ret = default_check(state, translation, ctx)) <= 0)
@@ -1233,6 +1235,8 @@ static int fix_ecdh_cofactor(enum state state,
         }
     } else if (state == PRE_PARAMS_TO_CTRL && ctx->action_type == GET) {
         ctx->p1 = -2;
+    } else if (state == POST_PARAMS_TO_CTRL && ctx->action_type == GET) {
+        ctx->p1 = ret;
     }
 
     return ret;
@@ -2868,8 +2872,14 @@ static int evp_pkey_ctx_setget_params_to_ctrl(EVP_PKEY_CTX *pctx,
         /*
          * In POST, we pass the return value as p1, allowing the fixup_args
          * function to put it to good use, or maybe affect it.
+         *
+         * NOTE: even though EVP_PKEY_CTX_ctrl return value is documented
+         * as return positive on Success and 0 or negative on falure. There
+         * maybe parameters (e.g. ecdh_cofactor), which actually return 0
+         * as success value. That is why we do POST_PARAMS_TO_CTRL for 0
+         * value as well
          */
-        if (ret > 0) {
+        if (ret >= 0) {
             ctx.p1 = ret;
             fixup(POST_PARAMS_TO_CTRL, translation, &ctx);
             ret = ctx.p1;