编译带OpenSSL的Android版PJSIP时出现Duplicate symbol错误

我正在尝试使用支持OpenSSL的PJSIP库构建用于SIP连接的Android应用。先完成了带OpenSSL的PJSIP编译，接着尝试生成SWIG Java绑定，执行make命令时，在aes_icm.c和aes_icm_ossl.c文件中出现三个重复符号错误。不使用OpenSSL时，所有编译流程均正常。

编译环境：

• MacOS
• PJSIP版本2.14.1
• NDK版本22.1.7171670
• OpenSSL版本3.3.1

错误信息：

ld: error: duplicate symbol: srtp_aes_icm_128
>>> defined at aes_icm.c
>>>            aes_icm.o:(srtp_aes_icm_128) in archive /pjproject/third_party/lib/libsrtp-aarch64-unknown-linux-android.a
>>> defined at aes_icm_ossl.c
>>>            aes_icm_ossl.o:(.data.rel.ro.srtp_aes_icm_128+0x0) in archive /pjproject/third_party/lib/libsrtp-aarch64-unknown-linux-android.a

ld: error: duplicate symbol: srtp_aes_icm_256
>>> defined at aes_icm.c
>>>            aes_icm.o:(srtp_aes_icm_256) in archive /pjproject/third_party/lib/libsrtp-aarch64-unknown-linux-android.a
>>> defined at aes_icm_ossl.c
>>>            aes_icm_ossl.o:(.data.rel.ro.srtp_aes_icm_256+0x0) in archive /pjproject/third_party/lib/libsrtp-aarch64-unknown-linux-android.a

ld: error: duplicate symbol: srtp_mod_aes_icm
>>> defined at aes_icm.c
>>>            aes_icm.o:(srtp_mod_aes_icm) in archive /pjproject/third_party/lib/libsrtp-aarch64-unknown-linux-android.a
>>> defined at aes_icm_ossl.c
>>>            aes_icm_ossl.o:(.data.srtp_mod_aes_icm+0x0) in archive /pjproject/third_party/lib/libsrtp-aarch64-unknown-linux-android.a
clang++: error: linker command failed with exit code 1 (use -v to see invocation)
make[1]: *** [android/pjsua2/src/main/jniLibs/arm64-v8a/libpjsua2.so] Error 1
make: *** [java] Error 2

这个问题是因为编译SRTP时同时包含了默认AES实现和OpenSSL实现，导致符号重复。按以下步骤解决：

1. 清理旧编译产物
   进入PJProject根目录，执行：

   make clean
   rm -rf third_party/build/srtp
   rm third_party/lib/libsrtp-*.a
   

2. 重新配置PJSIP，明确启用OpenSSL
   使用configure-android脚本时，添加OpenSSL相关参数，替换/path/to/your/openssl为你实际的OpenSSL编译目录：

   ./configure-android --enable-openssl --with-openssl=/path/to/your/openssl
   

3. 强制SRTP只使用OpenSSL实现（若配置后仍报错）
   进入third_party/build/srtp目录，修改Makefile：

   • 确保编译列表中移除aes_icm.c，只保留aes_icm_ossl.c
   • 或者在编译CFLAGS中添加-DUSE_OPENSSL，让SRTP自动切换到OpenSSL实现

4. 重新编译

   make dep && make
   make java
   

注意：确保OpenSSL是用对应Android NDK工具链编译的，避免兼容性问题。

内容的提问来源于stack exchange，提问作者Змей Горыныч