Mark pop/clear error stack in der2key_decode_p8

This commit sets the error mark before calling d2i_X509_SIG and clear it if that function call is successful. The motivation for this is that if d2i_X509_SIG returns NULL then the else clause will be entered and d2i_PKCS8_PRIV_KEY_INFO will be called. If d2i_X509_SIG raised any errors those error will be on the error stack when d2i_PKCS8_PRIV_KEY_INFO gets called, and even if it returns successfully those errors will still be on the error stack. We ran into this issue when upgrading Node.js to 3.0.0-alpha15. More details can be found in the ref links below. Refs: nodejs/node#38373 Refs: https://github.com/danbev/learning-libcrypto/blob/master/notes/wrong-tag-issue2.md Reviewed-by: Richard Levitte <levitte@openssl.org> Reviewed-by: Tomas Mraz <tomas@openssl.org> Reviewed-by: Ben Kaduk <kaduk@mit.edu> (Merged from openssl#15067)
devnexen · Jul 7, 2021 · ad0d311 · ad0d311
1 parent df6c904
commit ad0d311
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diff --git a/providers/implementations/encode_decode/decode_der2key.c b/providers/implementations/encode_decode/decode_der2key.c
@@ -124,10 +124,13 @@ static void *der2key_decode_p8(const unsigned char **input_der,
 
     ctx->flag_fatal = 0;
 
+    ERR_set_mark();
     if ((p8 = d2i_X509_SIG(NULL, input_der, input_der_len)) != NULL) {
         char pbuf[PEM_BUFSIZE];
         size_t plen = 0;
 
+        ERR_clear_last_mark();
+
         if (!pw_cb(pbuf, sizeof(pbuf), &plen, NULL, pw_cbarg))
             ERR_raise(ERR_LIB_PROV, PROV_R_UNABLE_TO_GET_PASSPHRASE);
         else
@@ -136,6 +139,8 @@ static void *der2key_decode_p8(const unsigned char **input_der,
             ctx->flag_fatal = 1;
         X509_SIG_free(p8);
     } else {
+        /* Pop any errors that might have been raised by d2i_X509_SIG. */
+        ERR_pop_to_mark();
         p8inf = d2i_PKCS8_PRIV_KEY_INFO(NULL, input_der, input_der_len);
     }
     if (p8inf != NULL

diff --git a/test/evp_extra_test.c b/test/evp_extra_test.c
@@ -1177,7 +1177,41 @@ static int test_EVP_PKCS82PKEY(void)
 
     return ret;
 }
+
 #endif
+static int test_EVP_PKCS82PKEY_wrong_tag(void)
+{
+    EVP_PKEY *pkey = NULL;
+    EVP_PKEY *pkey2 = NULL;
+    BIO *membio = NULL;
+    char *membuf = NULL;
+    PKCS8_PRIV_KEY_INFO *p8inf = NULL;
+    int ok = 0;
+
+    if (testctx != NULL)
+        /* test not supported with non-default context */
+        return 1;
+
+    if (!TEST_ptr(membio = BIO_new(BIO_s_mem()))
+        || !TEST_ptr(pkey = load_example_rsa_key())
+        || !TEST_int_gt(i2d_PKCS8PrivateKey_bio(membio, pkey, NULL,
+                                                NULL, 0, NULL, NULL),
+                        0)
+        || !TEST_int_gt(BIO_get_mem_data(membio, &membuf), 0)
+        || !TEST_ptr(p8inf = d2i_PKCS8_PRIV_KEY_INFO_bio(membio, NULL))
+        || !TEST_ptr(pkey2 = EVP_PKCS82PKEY(p8inf))
+        || !TEST_int_eq(ERR_get_error(), 0)) {
+        goto done;
+    }
+
+    ok = 1;
+ done:
+    EVP_PKEY_free(pkey);
+    EVP_PKEY_free(pkey2);
+    PKCS8_PRIV_KEY_INFO_free(p8inf);
+    BIO_free_all(membio);
+    return ok;
+}
 
 /* This uses kExampleRSAKeyDER and kExampleRSAKeyPKCS8 to verify encoding */
 static int test_privatekey_to_pkcs8(void)
@@ -2899,6 +2933,7 @@ int setup_tests(void)
     ADD_TEST(test_EVP_Enveloped);
     ADD_ALL_TESTS(test_d2i_AutoPrivateKey, OSSL_NELEM(keydata));
     ADD_TEST(test_privatekey_to_pkcs8);
+    ADD_TEST(test_EVP_PKCS82PKEY_wrong_tag);
 #ifndef OPENSSL_NO_EC
     ADD_TEST(test_EVP_PKCS82PKEY);
 #endif