的ASN.1结构迭代器只是声明，但尚未执行

Question

这是我的示例代码：

#include <openssl/asn1.h> 
#include <openssl/asn1t.h> 
#include <openssl/rsa.h> 
#include <openssl/x509.h> 

typedef struct key_st { 
    X509_ALGOR *algorithm_id; 
    RSA *key_material; 
} KEY; 

DECLARE_ASN1_FUNCTIONS(KEY) 

IMPLEMENT_ASN1_FUNCTIONS(KEY) 

int main() 
{ 
    return 0; 
} 

当我编译它，下面的错误报告：

$ gcc -o ssltest ssltest.c -lssl -lcrypto 
/tmp/cch0HA77.o: In function `d2i_KEY': 
ssltest.c:(.text+0x21): undefined reference to `KEY_it' 
/tmp/cch0HA77.o: In function `i2d_KEY': 
ssltest.c:(.text+0x48): undefined reference to `KEY_it' 
/tmp/cch0HA77.o: In function `KEY_new': 
ssltest.c:(.text+0x5e): undefined reference to `KEY_it' 
/tmp/cch0HA77.o: In function `KEY_free': 
ssltest.c:(.text+0x7a): undefined reference to `KEY_it' 
collect2: error: ld returned 1 exit status 

检查宏观后扩展的代码，我发现KEY_it声明为：

extern const ASN1_ITEM KEY_it; 

所以链接器报告未定义的引用。我该如何解决它？非常感谢你！

Answer 1

这是修复后，我添加序列定义为KEY：

ASN1_SEQUENCE(KEY) = { 
    ASN1_SIMPLE(KEY, algorithm_id, X509_ALGOR), 
    ASN1_SIMPLE(KEY, key_material, RSAPublicKey) 
} ASN1_SEQUENCE_END(KEY)