openssl / valgrind

Question

我有一个必须计算文件的MD5的应用程序，我已经使用了openssl库，valgrind抱怨一些块仍然可以访问。

编译以下代码：

#include <openssl/bio.h>

int main(int, char**)
{
   BIO * mem = BIO_new(BIO_s_mem());
   BIO_vfree(mem);
   return 0;
}

使用valgrind运行它，这是我得到的结果：

==23597== 220 bytes in 6 blocks are still reachable in loss record 1 of 1
==23597==    at 0x4022D78: malloc (vg_replace_malloc.c:207)
==23597==    by 0x432FD0D: (within /usr/lib/i686/cmov/libcrypto.so.0.9.8)
==23597==    by 0x433036E: CRYPTO_malloc (in /usr/lib/i686/cmov/libcrypto.so.0.9.8)
==23597==    by 0x43989C9: lh_new (in /usr/lib/i686/cmov/libcrypto.so.0.9.8)
==23597==    by 0x4332025: (within /usr/lib/i686/cmov/libcrypto.so.0.9.8)
==23597==    by 0x433249B: (within /usr/lib/i686/cmov/libcrypto.so.0.9.8)
==23597==    by 0x4332B5D: CRYPTO_new_ex_data (in /usr/lib/i686/cmov/libcrypto.so.0.9.8)
==23597==    by 0x438E053: BIO_set (in /usr/lib/i686/cmov/libcrypto.so.0.9.8)
==23597==    by 0x438E0E9: BIO_new (in /usr/lib/i686/cmov/libcrypto.so.0.9.8)
==23597==    by 0x80485E1: main (in /home/kalman/cxx_test/md5test/a.out)

有没有人有过同样的经历？

Answer 1

当不使用-DPURIFY编译时，OpenSSL具有混淆Valgrind的操作。Is this the error you are seeing?

Answer 2

我相信这些都是openssl分配的静态结构。我运行了你的代码，我运行了下面的代码，valgrind报告说两者都有相同数量的未释放内存：

#include <openssl/bio.h>

int main(int, char**)
{
   BIO * mem = BIO_new(BIO_s_mem());
   BIO * mem2 = BIO_new(BIO_s_mem());
   BIO * mem3 = BIO_new(BIO_s_mem());
   BIO * mem4 = BIO_new(BIO_s_mem());
   BIO_vfree(mem);
   BIO_vfree(mem2);
   BIO_vfree(mem3);
   BIO_vfree(mem4);
   return 0;
}

~

Answer 3

BIO_new() -> BIO_set() -> CRYPTO_new_ex_data() -> int_new_ex_data() -> def_get_class()

int_new_ex_data()不释放def_get_class错误定位的内存。

请参阅：http://openssl.6102.n7.nabble.com/memory-leak-in-engine-cleanup-td30935.html http://rt.openssl.org/Ticket/Display.html?id=2673&user=guest&pass=guest