valgrind informa problemas con libcurl al usar https

Question

Así que tengo un ejemplo muy básico de hablar con un servidor de Facebook sobre https, pero valgrind se queja con tristeza. Así que supongo que no estoy configurando algo incorrectamente ... ¿Alguien sabe lo que estoy haciendo mal?

Aquí está mi código:

#include <string> 
#include <iostream> 
#include <curl/curl.h> 

size_t write_fn_impl(void* ptr, size_t size, size_t nmemb, void * data) 
{ 
    std::string * result = static_cast<std::string*>(data); 
    *result += std::string((char*)ptr, size*nmemb); 
    return size*nmemb; 
} 

int main() 
{ 
    std::string url_full="https://graph.facebook.com/me"; 
    std::string useragent = "Facebook API C++ Client (curl)"; 

    CURL * ch_ = curl_easy_init(); 
    char error_buffer[CURL_ERROR_SIZE]; 
    curl_easy_setopt(ch_, CURLOPT_ERRORBUFFER, error_buffer); 
    curl_easy_setopt(ch_, CURLOPT_WRITEFUNCTION, &write_fn_impl); 
    std::string result; 
    curl_easy_setopt(ch_, CURLOPT_WRITEDATA, &result); 
    int id = 1; 
    curl_easy_setopt(ch_, CURLOPT_VERBOSE, id); 

    curl_easy_setopt(ch_, CURLOPT_URL, url_full.c_str()); 
    curl_easy_setopt(ch_, CURLOPT_USERAGENT, useragent.c_str()); 
    curl_easy_setopt(ch_, CURLOPT_CONNECTTIMEOUT, 10); 
    curl_easy_setopt(ch_, CURLOPT_TIMEOUT, 30); 
    curl_easy_perform(ch_); 
    curl_easy_cleanup(ch_); 

    std::cout<< result<<std::endl; 
} 

Y lo que dice es valgrind:

==14149== Memcheck, a memory error detector 
==14149== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et al. 
==14149== Using Valgrind-3.5.0-Debian and LibVEX; rerun with -h for copyright info 
==14149== Command: ./a.out 
==14149== 
* About to connect() to graph.facebook.com port 443 (#0) 
* Trying 66.220.146.47... * connected 
* Connected to graph.facebook.com (66.220.146.47) port 443 (#0) 
* successfully set certificate verify locations: 
* CAfile: none 
    CApath: /etc/ssl/certs 
==14149== Syscall param write(buf) points to uninitialised byte(s) 
==14149== at 0x4268113: __write_nocancel (in /lib/tls/i686/cmov/libc-2.10.1.so) 
==14149== by 0x44A5A8E: BIO_write (in /lib/i686/cmov/libcrypto.so.0.9.8) 
==14149== by 0x43E49B8: ssl23_write_bytes (in /lib/i686/cmov/libssl.so.0.9.8) 
==14149== by 0x43E39AB: ssl23_connect (in /lib/i686/cmov/libssl.so.0.9.8) 
==14149== by 0x43F0D49: SSL_connect (in /lib/i686/cmov/libssl.so.0.9.8) 
==14149== by 0x4050EB0: ossl_connect_common (in /usr/lib/libcurl.so.4.1.1) 
==14149== by 0x4052202: Curl_ossl_connect (in /usr/lib/libcurl.so.4.1.1) 
==14149== by 0x406597F: Curl_ssl_connect (in /usr/lib/libcurl.so.4.1.1) 
==14149== by 0x403FF1B: Curl_http_connect (in /usr/lib/libcurl.so.4.1.1) 
==14149== by 0x4046F6D: Curl_protocol_connect (in /usr/lib/libcurl.so.4.1.1) 
==14149== by 0x404C396: Curl_connect (in /usr/lib/libcurl.so.4.1.1) 
==14149== by 0x4059B23: Curl_perform (in /usr/lib/libcurl.so.4.1.1) 
==14149== Address 0x47e92df is 15 bytes inside a block of size 21,848 alloc'd 
==14149== at 0x4024C1C: malloc (vg_replace_malloc.c:195) 
==14149== by 0x4446EFD: ??? (in /lib/i686/cmov/libcrypto.so.0.9.8) 
==14149== by 0x444755B: CRYPTO_malloc (in /lib/i686/cmov/libcrypto.so.0.9.8) 
==14149== by 0x44A4EF7: BUF_MEM_grow (in /lib/i686/cmov/libcrypto.so.0.9.8) 
==14149== by 0x43E3BAB: ssl23_connect (in /lib/i686/cmov/libssl.so.0.9.8) 
==14149== by 0x43F0D49: SSL_connect (in /lib/i686/cmov/libssl.so.0.9.8) 
==14149== by 0x4050EB0: ossl_connect_common (in /usr/lib/libcurl.so.4.1.1) 
==14149== by 0x4052202: Curl_ossl_connect (in /usr/lib/libcurl.so.4.1.1) 
==14149== by 0x406597F: Curl_ssl_connect (in /usr/lib/libcurl.so.4.1.1) 
==14149== by 0x403FF1B: Curl_http_connect (in /usr/lib/libcurl.so.4.1.1) 
==14149== by 0x4046F6D: Curl_protocol_connect (in /usr/lib/libcurl.so.4.1.1) 
==14149== by 0x404C396: Curl_connect (in /usr/lib/libcurl.so.4.1.1) 

y las páginas más ....

Answer 1

MK es parcialmente correcto. Valgrind lanza muchas advertencias basura sobre OpenSSL. Pero en mi caso, los bloqueos que estaba viendo se debieron a algunos problemas con la forma en que usaba openSSL. En particular, no se estaba configurando correctamente para el uso de subprocesos múltiples. Los documentos curl cubren lo que tienes que hacer ... pero de alguna manera debo haberlo perdido)

De todos modos aquí está el archivo de supresión que me ayudó a encontrarlo ... puede ser útil para alguien ... Pero ten cuidado, probablemente no sea así ' coger todo lo que se desea capturar, y es probable que las capturas de algunas cosas que no quiero ...

{ 
    openssl-rand-write 
    Memcheck:Param 
    write(buf) 
    fun:__write_nocancel 
    fun:BIO_write 
    fun:ssl23_write_bytes 
    fun:ssl23_connect 
    fun:SSL_connect 
    fun:ossl_connect_common 
} 
{ 
    openssl-rand-write2 
    Memcheck:Param 
    write(buf) 
    fun:__write_nocancel 
    fun:BIO_write 
    fun:ssl3_write_pending 
    obj:/lib/i686/cmov/libssl.so.0.9.8 
    fun:ssl3_write_bytes 
    fun:ssl3_write 
    fun:SSL_write 
} 
{ 
    openssl-rand-write3 
    Memcheck:Param 
    write(buf) 
    fun:__write_nocancel 
    fun:BIO_write 
    ... 
    fun:ossl_connect_common 
} 
{ 
    openssl-rand-uninit_mod_inverse 
    Memcheck:Cond 
    fun:BN_mod_inverse 
    ... 
    obj:/lib/i686/cmov/libcrypto.so.0.9.8 
} 
{ 
    openssl-rand-uninit_div 
    Memcheck:Cond 
    fun:BN_div 
    ... 
    obj:/lib/i686/cmov/libcrypto.so.0.9.8 
} 
{ 
    openssl-uninit-padding 
    Memcheck:Cond 
    fun:RSA_padding_add_PKCS1_type_2 
    obj:/lib/i686/cmov/libcrypto.so.0.9.8 
} 
{ 
    openssl-uninit-ucmp 
    Memcheck:Cond 
    fun:BN_ucmp 
    obj:/lib/i686/cmov/libcrypto.so.0.9.8 
} 
{ 
    openssl-uninit-encrypt 
    Memcheck:Cond 
    obj:/lib/i686/cmov/libcrypto.so.0.9.8 
    fun:RSA_public_encrypt 
} 
{ 
    openssl-uninit-ssl3_read_bytes 
    Memcheck:Cond 
    fun:ssl3_read_bytes 
    fun:ssl3_read 
    fun:SSL_read 
} 
{ 
    openssl-uninit-get_finished 
    Memcheck:Cond 
    fun:ssl3_get_finished 
    fun:ssl3_connect 
    fun:SSL_connect 
    fun:ossl_connect_common 
} 
{ 
    openssl-uninit-read_bytes 
    Memcheck:Cond 
    ... 
    fun:ossl_connect_common 
} 
{ 
    openssl-value4-connect_common 
    Memcheck:Value4 
    ... 
    fun:ossl_connect_common 
} 
{ 
    openssl-uninit-encrypt 
    Memcheck:Cond 
    ...  
    fun:RSA_public_encrypt 
} 

Answer 2

Última vez que alguien trató de asegurarse OpenSSL corre limpio debajo valgrind Cosas malas (tm) sucedieron: http://blogs.fsfe.org/tonnerre/archives/24

Así que simplemente ignoraría cualquier advertencia de vlagrind sobre OpenSSL.