Openssl 编译错误

Question

我使用 openssl 库在 C 代码中包含以下头文件。

#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>

然后我使用gcc -o openssl -lssl -lcrypt openssl.c 编译了程序 在我的办公室里，这段代码编译并运行良好，但在我家的系统中（办公室里都是 linux-debian 6，家里是 Ubuntu 12.04），它给出了以下错误：

/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

我了解这是因为我的家用电脑中缺少某些库。但是谁能告诉我需要为此安装哪些库？提前致谢。

Answer 1

将库放在源文件之后：

gcc -o openssl openssl.c -lssl -lcrypto

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

Answer 2

将文件名放在 -l 选项之前