Aws-sdk-cpp: Segmentation fault in S3EncryptionClient.PutObject()

[jakelawcheukwun]

Hello, I encountered a segmentation fault while i was running the example code in https://aws.amazon.com/blogs/developer/amazon-s3-encryption-client-is-now-available-for-c/

My code is as the following:
https://pastebin.com/jad8QdKf
Where the constants KEY is the KMS key for the S3 bucket, BUCKET is the bucket name, FILE_NAME is the path to local file.

Thank you for your help! ;)

What platform/OS are you using?

Amazon Linux 2 LTS Candidate AMI 2017.12.0.20180115 x86_64 HVM GP2

What compiler are you using? what version?

gcc (GCC) 7.2.1 20170915 (Red Hat 7.2.1-2)

What's your CMake arguments?

cmake -Daws-sdk-cpp_DIR=~/sdk_build ../s3encryption/

Can you provide a TRACE level log? (sanitize any sensitive information)

Here's the debug log from GNU gdb (GDB) Red Hat Enterprise Linux 8.0.1-30.amzn2.0.1
https://pastebin.com/WpnFhF2x
`Thread 1 "s3_encrypt_clie" received signal SIGSEGV, Segmentation fault.
0x00007ffff5f24ca6 in EVP_EncryptFinal_ex (ctx=0x67eba0, out=0x67f2e0 "0\352g", outl=0x7fffffffc4fc) at evp_enc.c:456
456 if (ctx->cipher->flags & EVP_CIPH_FLAG_CUSTOM_CIPHER) {
(gdb) bt

0 0x00007ffff5f24ca6 in EVP_EncryptFinal_ex (ctx=0x67eba0, out=0x67f2e0 "0\352g", outl=0x7fffffffc4fc) at evp_enc.c:456

1 0x00007ffff6b690ba in Aws::Utils::Crypto::OpenSSLCipher::FinalizeEncryption() () from /home/ec2-user/sdk_build/aws-cpp-sdk-core/libaws-cpp-sdk-core.so

2 0x00007ffff6b69bdc in Aws::Utils::Crypto::AES_GCM_Cipher_OpenSSL::FinalizeEncryption() () from /home/ec2-user/sdk_build/aws-cpp-sdk-core/libaws-cpp-sdk-core.so

3 0x00007ffff7bb0bd0 in Aws::S3Encryption::Modules::AES_GCM_AppendedTag::FinalizeEncryption() () from /home/ec2-user/sdk_build/aws-cpp-sdk-s3-encryption/libaws-cpp-sdk-s3-encryption.so

4 0x00007ffff6b5154d in Aws::Utils::Crypto::SymmetricCryptoBufSrc::FinalizeCipher() () from /home/ec2-user/sdk_build/aws-cpp-sdk-core/libaws-cpp-sdk-core.so

5 0x00007ffff6b52072 in Aws::Utils::Crypto::SymmetricCryptoBufSrc::Finalize() () from /home/ec2-user/sdk_build/aws-cpp-sdk-core/libaws-cpp-sdk-core.so

6 0x00007ffff6b53751 in Aws::Utils::Crypto::SymmetricCryptoStream::Finalize() () from /home/ec2-user/sdk_build/aws-cpp-sdk-core/libaws-cpp-sdk-core.so

7 0x00007ffff6b53685 in Aws::Utils::Crypto::SymmetricCryptoStream::~SymmetricCryptoStream() () from /home/ec2-user/sdk_build/aws-cpp-sdk-core/libaws-cpp-sdk-core.so

8 0x00007ffff7bb50c1 in void __gnu_cxx::new_allocator::destroy(Aws::Utils::Crypto::SymmetricCryptoStream*) ()

from /home/ec2-user/sdk_build/aws-cpp-sdk-s3-encryption/libaws-cpp-sdk-s3-encryption.so

9 0x00007ffff7bb5074 in decltype (({parm#1}.destroy)({parm#2})) std::allocator_traits >::_S_destroy, Aws::Utils::Crypto::SymmetricCryptoStream>(Aws::Allocator&, Aws::Utils::Crypto::SymmetricCryptoStream*, int) ()

from /home/ec2-user/sdk_build/aws-cpp-sdk-s3-encryption/libaws-cpp-sdk-s3-encryption.so

10 0x00007ffff7bb5006 in void std::allocator_traits >::destroy(Aws::Allocator&, Aws::Utils::Crypto::SymmetricCryptoStream*) () from /home/ec2-user/sdk_build/aws-cpp-sdk-s3-encryption/libaws-cpp-sdk-s3-encryption.so

11 0x00007ffff7bb4ec9 in std::_Sp_counted_ptr_inplace, (__gnu_cxx::_Lock_policy)2>::_M_dispose() ()

from /home/ec2-user/sdk_build/aws-cpp-sdk-s3-encryption/libaws-cpp-sdk-s3-encryption.so

12 0x000000000041e594 in std::_Sp_counted_base<(__gnu_cxx::_Lock_policy)2>::_M_release() ()

13 0x000000000041d50b in std::__shared_count<(__gnu_cxx::_Lock_policy)2>::~__shared_count() ()

14 0x000000000041c560 in std::__shared_ptr::~__shared_ptr() ()

15 0x000000000041c57c in std::shared_ptr::~shared_ptr() ()

16 0x00007ffff6b19544 in Aws::AmazonStreamingWebServiceRequest::~AmazonStreamingWebServiceRequest() () from /home/ec2-user/sdk_build/aws-cpp-sdk-core/libaws-cpp-sdk-core.so

17 0x0000000000421de0 in Aws::S3::Model::PutObjectRequest::~PutObjectRequest() ()

18 0x00007ffff7bae44e in Aws::S3Encryption::Modules::CryptoModule::PutObjectSecurely(Aws::S3::Model::PutObjectRequest const&, std::function > (Aws::S3::Model::PutObjectRequest const&)> const&) () from /home/ec2-user/sdk_build/aws-cpp-sdk-s3-encryption/libaws-cpp-sdk-s3-encryption.so

19 0x00007ffff7b9bfcb in Aws::S3Encryption::S3EncryptionClient::PutObject(Aws::S3::Model::PutObjectRequest const&) const ()

from /home/ec2-user/sdk_build/aws-cpp-sdk-s3-encryption/libaws-cpp-sdk-s3-encryption.so

20 0x000000000041b675 in main ()`

[singku]

From frame 0, It seems the ctx is still valid, but ctx->cipher is not, which caused memory access violation when calling ctx->cipher->flag. Is that possible for you to verify that?

[singku]

BTW, line 22 of the code should be updated to:
auto simpleMaterials = Aws::MakeShared<SimpleEncryptionMaterials>("s3Encryption", masterKey);

[jakelawcheukwun]

Thanks for the reminder, I made a mistake when I was pasting the code, I was using this code in line 22
auto simpleMaterials = Aws::MakeShared<Aws::S3Encryption::Materials::SimpleEncryptionMaterials>("s3Encryption", masterKey);

[jakelawcheukwun]

Sorry for the inconvenience, how do I verify the

ctx->cipher is not valid

?

Do I use GDB or any recommended tools? Thanks!

[singku]

Yes, gdb is recommended.

[cedral]

it is the ctx-cipher issue. You can see it in the call stack. #841 should fix it.