Linking issues using OpenSSL in Ubuntu - c++

Question

I have installed OpenSSL using sudo apt-get install openssl-dev. When I try to compile it using Netbeans it gives following errors. How can I fix this problem?
g++ -lssl -o dist/Debug/GNU-Linux-x86/cppapplication_2 build/Debug/GNU-Linux-x86/main.o -L/home/sercan/Desktop/openssl-0.9.8h-1-lib/lib
build/Debug/GNU-Linux-x86/main.o: In function `main':
/home/sercan/NetBeansProjects/CppApplication_2/main.cpp:46: undefined reference to `OPENSSL_add_all_algorithms_noconf'
/home/sercan/NetBeansProjects/CppApplication_2/main.cpp:48: undefined reference to `ERR_load_crypto_strings'
/home/sercan/NetBeansProjects/CppApplication_2/main.cpp:58: undefined reference to `d2i_PKCS12_fp'
/home/sercan/NetBeansProjects/CppApplication_2/main.cpp:66: undefined reference to `ERR_print_errors_fp'
/home/sercan/NetBeansProjects/CppApplication_2/main.cpp:72: undefined reference to `PKCS12_parse'
/home/sercan/NetBeansProjects/CppApplication_2/main.cpp:76: undefined reference to `ERR_print_errors_fp'
/home/sercan/NetBeansProjects/CppApplication_2/main.cpp:82: undefined reference to `PKCS12_free'
/home/sercan/NetBeansProjects/CppApplication_2/main.cpp:96: undefined reference to `PEM_write_PrivateKey'
/home/sercan/NetBeansProjects/CppApplication_2/main.cpp:104: undefined reference to `PEM_write_X509_AUX'
/home/sercan/NetBeansProjects/CppApplication_2/main.cpp:108: undefined reference to `sk_num'
/home/sercan/NetBeansProjects/CppApplication_2/main.cpp:114: undefined reference to `sk_value'
/home/sercan/NetBeansProjects/CppApplication_2/main.cpp:114: undefined reference to `PEM_write_X509_AUX'
/home/sercan/NetBeansProjects/CppApplication_2/main.cpp:112: undefined reference to `sk_num'
My code is here:
#include <stdio.h>
#include <stdlib.h>
#include <openssl/pem.h>
#include <openssl/err.h>
#include <openssl/pkcs12.h>
/* Simple PKCS#12 file reader */
int main(int argc, char **argv)
{
FILE *fp;
EVP_PKEY *pkey;
X509 *cert;
STACK_OF(X509) *ca = NULL;
PKCS12 *p12;
int i;
if (argc != 4) {
fprintf(stderr, "Usage: pkread p12file password opfile\n");
exit(1);
}
OpenSSL_add_all_algorithms();
ERR_load_crypto_strings();
if (!(fp = fopen(argv[1], "rb"))) {
fprintf(stderr, "Error opening file %s\n", argv[1]);
exit(1);
}
p12 = d2i_PKCS12_fp(fp, NULL);
fclose(fp);
if (!p12) {
fprintf(stderr, "Error reading PKCS#12 file\n");
ERR_print_errors_fp(stderr);
exit(1);
}
if (!PKCS12_parse(p12, argv[2], &pkey, &cert, &ca)) {
fprintf(stderr, "Error parsing PKCS#12 file\n");
ERR_print_errors_fp(stderr);
exit(1);
}
PKCS12_free(p12);
if (!(fp = fopen(argv[3], "w"))) {
fprintf(stderr, "Error opening file %s\n", argv[1]);
exit(1);
}
if (pkey) {
fprintf(fp, "***Private Key***\n");
PEM_write_PrivateKey(fp, pkey, NULL, NULL, 0, NULL, NULL);
}
if (cert) {
fprintf(fp, "***User Certificate***\n");
PEM_write_X509_AUX(fp, cert);
}
if (ca && sk_X509_num(ca)) {
fprintf(fp, "***Other Certificates***\n");
for (i = 0; i < sk_X509_num(ca); i++)
PEM_write_X509_AUX(fp, sk_X509_value(ca, i));
}
fclose(fp);
return 0;
}

Answer 1

you need to link to libcrypto as well - add -lcrypto to the link line and your code should link correctly.
natsu:~/openssl% gcc -o test test.c -L/usr/lib -lssl -lcrypto
links correctly, while:
natsu:~/openssl% gcc -o test test.c -L/usr/lib -lssl
/tmp/ccvA7iNe.o: In function `main':
test.c:(.text+0x4c): undefined reference to `OPENSSL_add_all_algorithms_noconf'
test.c:(.text+0x51): undefined reference to `ERR_load_crypto_strings'
test.c:(.text+0xb9): undefined reference to `d2i_PKCS12_fp'
test.c:(.text+0x103): undefined reference to `ERR_print_errors_fp'
test.c:(.text+0x133): undefined reference to `PKCS12_parse'
test.c:(.text+0x16a): undefined reference to `ERR_print_errors_fp'
test.c:(.text+0x180): undefined reference to `PKCS12_free'
test.c:(.text+0x22c): undefined reference to `PEM_write_PrivateKey'
test.c:(.text+0x266): undefined reference to `PEM_write_X509_AUX'
test.c:(.text+0x27b): undefined reference to `sk_num'
test.c:(.text+0x2b7): undefined reference to `sk_value'
test.c:(.text+0x2c9): undefined reference to `PEM_write_X509_AUX'
test.c:(.text+0x2d9): undefined reference to `sk_num'
collect2: ld returned 1 exit status
does not.