From 076687f5f9e7e1fce24f33f498b4e03c4150108e Mon Sep 17 00:00:00 2001 From: Omair Majid Date: Fri, 2 Feb 2024 12:09:52 -0500 Subject: [PATCH] Revert "Disable implicit rejection for RSA PKCS#1 (#95218)" This reverts commit e3500b8e8ad18e8bf067dc5250863b64bb8f0de0. To quote Clemens Lang: > [Disabling implcit rejection] re-enables a Bleichenbacher timing oracle > attack against PKCS#1v1.5 decryption. See > https://people.redhat.com/~hkario/marvin/ for details and > https://github.com/dotnet/runtime/pull/95157#issuecomment-1842784399 for a > comment by the researcher who published the vulnerability and proposed the > change in OpenSSL. For more details, see: https://github.com/dotnet/runtime/pull/95216#issuecomment-1842799314 --- .../RSA/EncryptDecrypt.cs | 49 ++++--------------- .../opensslshim.h | 6 --- .../pal_evp_pkey_rsa.c | 13 ----- 3 files changed, 10 insertions(+), 58 deletions(-) diff --git a/src/libraries/Common/tests/System/Security/Cryptography/AlgorithmImplementations/RSA/EncryptDecrypt.cs b/src/libraries/Common/tests/System/Security/Cryptography/AlgorithmImplementations/RSA/EncryptDecrypt.cs index 55a044d62a6..e72d42e87d2 100644 --- a/src/libraries/Common/tests/System/Security/Cryptography/AlgorithmImplementations/RSA/EncryptDecrypt.cs +++ b/src/libraries/Common/tests/System/Security/Cryptography/AlgorithmImplementations/RSA/EncryptDecrypt.cs @@ -338,10 +338,19 @@ private void RsaCryptRoundtrip(RSAEncryptionPadding paddingMode, bool expectSucc Assert.Equal(TestData.HelloBytes, output); } - [ConditionalFact(nameof(PlatformSupportsEmptyRSAEncryption))] + [ConditionalFact] [SkipOnTargetFramework(TargetFrameworkMonikers.NetFramework)] public void RoundtripEmptyArray() { + if (OperatingSystem.IsIOS() && !OperatingSystem.IsIOSVersionAtLeast(13, 6)) + { + throw new SkipTestException("iOS prior to 13.6 does not reliably support RSA encryption of empty data."); + } + if (OperatingSystem.IsTvOS() && !OperatingSystem.IsTvOSVersionAtLeast(14, 0)) + { + throw new SkipTestException("tvOS prior to 14.0 does not reliably support RSA encryption of empty data."); + } + using (RSA rsa = RSAFactory.Create(TestData.RSA2048Params)) { void RoundtripEmpty(RSAEncryptionPadding paddingMode) @@ -692,26 +701,6 @@ public void NotSupportedValueMethods() } } - [ConditionalTheory] - [InlineData(new byte[] { 1, 2, 3, 4 })] - [InlineData(new byte[0])] - public void Decrypt_Pkcs1_ErrorsForInvalidPadding(byte[] data) - { - if (data.Length == 0 && !PlatformSupportsEmptyRSAEncryption) - { - throw new SkipTestException("Platform does not support RSA encryption of empty data."); - } - - using (RSA rsa = RSAFactory.Create(TestData.RSA2048Params)) - { - byte[] encrypted = Encrypt(rsa, data, RSAEncryptionPadding.Pkcs1); - encrypted[1] ^= 0xFF; - - // PKCS#1, the data, and the key are all deterministic so this should always throw an exception. - Assert.ThrowsAny(() => Decrypt(rsa, encrypted, RSAEncryptionPadding.Pkcs1)); - } - } - [Fact] public void Decrypt_Pkcs1_BadPadding() { @@ -726,23 +715,5 @@ public static IEnumerable OaepPaddingModes } } } - - public static bool PlatformSupportsEmptyRSAEncryption - { - get - { - if (OperatingSystem.IsIOS() && !OperatingSystem.IsIOSVersionAtLeast(13, 6)) - { - return false; - } - - if (OperatingSystem.IsTvOS() && !OperatingSystem.IsTvOSVersionAtLeast(14, 0)) - { - return false; - } - - return true; - } - } } } diff --git a/src/libraries/Native/Unix/System.Security.Cryptography.Native/opensslshim.h b/src/libraries/Native/Unix/System.Security.Cryptography.Native/opensslshim.h index 050df1193ff..dad18ebd9a1 100644 --- a/src/libraries/Native/Unix/System.Security.Cryptography.Native/opensslshim.h +++ b/src/libraries/Native/Unix/System.Security.Cryptography.Native/opensslshim.h @@ -272,10 +272,8 @@ const EVP_CIPHER* EVP_chacha20_poly1305(void); REQUIRED_FUNCTION(ERR_peek_error) \ REQUIRED_FUNCTION(ERR_peek_error_line) \ REQUIRED_FUNCTION(ERR_peek_last_error) \ - REQUIRED_FUNCTION(ERR_pop_to_mark) \ FALLBACK_FUNCTION(ERR_put_error) \ REQUIRED_FUNCTION(ERR_reason_error_string) \ - REQUIRED_FUNCTION(ERR_set_mark) \ LIGHTUP_FUNCTION(ERR_set_debug) \ LIGHTUP_FUNCTION(ERR_set_error) \ REQUIRED_FUNCTION(EVP_aes_128_cbc) \ @@ -330,7 +328,6 @@ const EVP_CIPHER* EVP_chacha20_poly1305(void); REQUIRED_FUNCTION(EVP_PKCS82PKEY) \ REQUIRED_FUNCTION(EVP_PKEY2PKCS8) \ REQUIRED_FUNCTION(EVP_PKEY_CTX_ctrl) \ - REQUIRED_FUNCTION(EVP_PKEY_CTX_ctrl_str) \ REQUIRED_FUNCTION(EVP_PKEY_CTX_free) \ REQUIRED_FUNCTION(EVP_PKEY_CTX_get0_pkey) \ REQUIRED_FUNCTION(EVP_PKEY_CTX_new) \ @@ -728,10 +725,8 @@ FOR_ALL_OPENSSL_FUNCTIONS #define ERR_peek_error_line ERR_peek_error_line_ptr #define ERR_peek_last_error ERR_peek_last_error_ptr #define ERR_put_error ERR_put_error_ptr -#define ERR_pop_to_mark ERR_pop_to_mark_ptr #define ERR_reason_error_string ERR_reason_error_string_ptr #define ERR_set_debug ERR_set_debug_ptr -#define ERR_set_mark ERR_set_mark_ptr #define ERR_set_error ERR_set_error_ptr #define EVP_aes_128_cbc EVP_aes_128_cbc_ptr #define EVP_aes_128_cfb8 EVP_aes_128_cfb8_ptr @@ -785,7 +780,6 @@ FOR_ALL_OPENSSL_FUNCTIONS #define EVP_PKCS82PKEY EVP_PKCS82PKEY_ptr #define EVP_PKEY2PKCS8 EVP_PKEY2PKCS8_ptr #define EVP_PKEY_CTX_ctrl EVP_PKEY_CTX_ctrl_ptr -#define EVP_PKEY_CTX_ctrl_str EVP_PKEY_CTX_ctrl_str_ptr #define EVP_PKEY_CTX_free EVP_PKEY_CTX_free_ptr #define EVP_PKEY_CTX_get0_pkey EVP_PKEY_CTX_get0_pkey_ptr #define EVP_PKEY_CTX_new EVP_PKEY_CTX_new_ptr diff --git a/src/libraries/Native/Unix/System.Security.Cryptography.Native/pal_evp_pkey_rsa.c b/src/libraries/Native/Unix/System.Security.Cryptography.Native/pal_evp_pkey_rsa.c index c3e491a868f..36924abb505 100644 --- a/src/libraries/Native/Unix/System.Security.Cryptography.Native/pal_evp_pkey_rsa.c +++ b/src/libraries/Native/Unix/System.Security.Cryptography.Native/pal_evp_pkey_rsa.c @@ -63,19 +63,6 @@ static bool ConfigureEncryption(EVP_PKEY_CTX* ctx, RsaPaddingMode padding, const { return false; } - - // OpenSSL 3.2 introduced a change where PKCS#1 RSA decryption does not fail for invalid padding. - // If the padding is invalid, the decryption operation returns random data. - // See https://github.com/openssl/openssl/pull/13817 for background. - // Some Linux distributions backported this change to previous versions of OpenSSL. - // Here we do a best-effort to set a flag to revert the behavior to failing if the padding is invalid. - ERR_set_mark(); - - EVP_PKEY_CTX_ctrl_str(ctx, "rsa_pkcs1_implicit_rejection", "0"); - - // Undo any changes to the error queue that may have occured while configuring implicit rejection if the - // current version does not support implicit rejection. - ERR_pop_to_mark(); } else { -- 2.43.0