Openssl compile error

Question

I have included the following header files in a C code using openssl libraries.

#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <time.h>
#ifdef __VMS
#include <in.h>
#include <inet.h>
#else
#include <netinet/in.h>
#include <arpa/inet.h>
#endif
#include <openssl/crypto.h>
#include <openssl/ssl.h>
#include <openssl/err.h>

Then I compiled the program using gcc -o openssl -lssl -lcrypt openssl.c In my office this code compiled and run fine but in my house system(both are linux- debian 6 in office and Ubuntu 12.04 at home), it gave the following error:

/tmp/ccZcmLk4.o: In function `main':
server.c:(.text+0x3d): undefined reference to `SSL_library_init'
server.c:(.text+0x42): undefined reference to `SSL_load_error_strings'
server.c:(.text+0x47): undefined reference to `SSLv3_method'
server.c:(.text+0x57): undefined reference to `SSL_CTX_new'
server.c:(.text+0x6f): undefined reference to `ERR_print_errors_fp'
server.c:(.text+0x97): undefined reference to `SSL_CTX_use_certificate_file'
server.c:(.text+0xa8): undefined reference to `ERR_print_errors_fp'
server.c:(.text+0xd0): undefined reference to `SSL_CTX_use_PrivateKey_file'
server.c:(.text+0xe1): undefined reference to `ERR_print_errors_fp'
server.c:(.text+0xf9): undefined reference to `SSL_CTX_check_private_key'
server.c:(.text+0x154): undefined reference to `SSL_CTX_load_verify_locations'
server.c:(.text+0x165): undefined reference to `ERR_print_errors_fp'
server.c:(.text+0x18d): undefined reference to `SSL_CTX_set_verify'
server.c:(.text+0x1a1): undefined reference to `SSL_CTX_set_verify_depth'
server.c:(.text+0x397): undefined reference to `SSL_new'
server.c:(.text+0x3c2): undefined reference to `SSL_set_fd'
server.c:(.text+0x3ce): undefined reference to `SSL_accept'
server.c:(.text+0x3e6): undefined reference to `ERR_print_errors_fp'
server.c:(.text+0x3fe): undefined reference to `SSL_get_current_cipher'
server.c:(.text+0x406): undefined reference to `SSL_CIPHER_get_name'
server.c:(.text+0x42e): undefined reference to `SSL_get_peer_certificate'
server.c:(.text+0x455): undefined reference to `X509_get_subject_name'
server.c:(.text+0x46d): undefined reference to `X509_NAME_oneline'
server.c:(.text+0x4b1): undefined reference to `X509_get_issuer_name'
server.c:(.text+0x4c9): undefined reference to `X509_NAME_oneline'
server.c:(.text+0x50d): undefined reference to `X509_free'
server.c:(.text+0x593): undefined reference to `SSL_write'
server.c:(.text+0x5ab): undefined reference to `ERR_print_errors_fp'
server.c:(.text+0x5d3): undefined reference to `SSL_read'
server.c:(.text+0x5eb): undefined reference to `ERR_print_errors_fp'
collect2: ld returned 1 exit status

I understand that this is due to the absence of certain libraries in my home PC. But can anyone tell me which libraries I need to install for this? Thanks in advance.

Solution 1

Put the libraries after the source file:

gcc -o openssl openssl.c -lssl -lcrypto

See: http://www.network-theory.co.uk/docs/gccintro/gccintro_18.html

Solution 2

put the file name before -l option

Comments

[Harikrishnan]

Well, that worked. But it returned a warning which i didn't get at office. server.c: In function ‘main’: server.c:55:7: warning: assignment discards ‘const’ qualifier from pointer target type [enabled by default] I am afraid I will have to paste the entire code to show you where the problem is. But it was certainly not at office.

[HonkyTonk]

@Hari You are using different compiler versions, yes? Either adjust the flags during compilation to harmonize the warnings or get used to different compiler output. Preferably you should use the same compiler version on both locations.

[Orion Lawlor]

I had to do -lssl -lcrypto (note the 'o'!) to avoid a mysterious undefined reference to symbol PEM_read_bio_DHparams