OpenSSL版本号

如何兼容历史版本OpenSSL-1.0.2分支

OpenSSL的1.1.0版调整了API接口, 与1.0.2版相比, 删除了成员变量o->data和o->length。
参考:

• https://www.openssl.org/docs/man1.1.0/crypto/OPENSSL_VERSION_NUMBER.html
• https://wiki.openssl.org/index.php/OpenSSL_1.1.0_Changes

 #if OPENSSL_VERSION_NUMBER < 0x10100000L
 #define OBJ_get0_data(o) ((o)->data)
 #define OBJ_length(o) ((o)->length)
 #endif

注意:
OPENSSL_VERSION_NUMBER 的格式应该是0xM-NNFFPPS
最后一个数字S取值0代表dev开发版, 0x1-0xE代表rc1-rc14, 0xF代表release版

• 1.1.0a dev ==0x10100010
• 1.1.0a release==0x1010001f
• 1.0.2g release==0x1000207f

/*-
 * Numeric release version identifier:
 * MNNFFPPS: major minor fix patch status
 * The status nibble has one of the values 0 for development, 1 to e for betas
 * 1 to 14, and f for release.  The patch level is exactly that.
 * For example:
 * 0.9.3-dev      0x00903000
 * 0.9.3-beta1    0x00903001
 * 0.9.3-beta2-dev 0x00903002
 * 0.9.3-beta2    0x00903002 (same as ...beta2-dev)
 * 0.9.3          0x0090300f
 * 0.9.3a         0x0090301f
 * 0.9.4          0x0090400f
 * 1.2.3z         0x102031af
 *
 * For continuity reasons (because 0.9.5 is already out, and is coded
 * 0x00905100), between 0.9.5 and 0.9.6 the coding of the patch level
 * part is slightly different, by setting the highest bit.  This means
 * that 0.9.5a looks like this: 0x0090581f.  At 0.9.6, we can start
 * with 0x0090600S...
 *
 * (Prior to 0.9.3-dev a different scheme was used: 0.9.2b is 0x0922.)
 * (Prior to 0.9.5a beta1, a different scheme was used: MMNNFFRBB for
 *  major minor fix final patch/beta)
 */
# define OPENSSL_VERSION_NUMBER  0x1010004fL
# ifdef OPENSSL_FIPS
#  define OPENSSL_VERSION_TEXT    "GmSSL 2.3.1 - OpenSSL 1.1.0d-fips  30 Mar 2018"
# else
#  define OPENSSL_VERSION_TEXT    "GmSSL 2.3.1 - OpenSSL 1.1.0d  30 Mar 2018"
# endif

ressl

BSD版的libressl目前只提供1.0.x分支的OpenSSL接口, 不支持OBJ_get0_data(o)等新API