boxbackup: error: field has incomplete type 'EVP_CIPHER_CTX' (aka 'evp_cipher_ctx_st')

[ryandesign (Ryan Carsten Schmidt)]

​boxbackup does not build:

Random.cpp:113:5: warning: 'RAND_pseudo_bytes' is deprecated [-Wdeprecated-declarations]
        if(RAND_pseudo_bytes((uint8_t*)pOutput, Length) == -1)
           ^
/opt/local/include/openssl/rand.h:44:24: note: 'RAND_pseudo_bytes' declared here
DEPRECATEDIN_1_1_0(int RAND_pseudo_bytes(unsigned char *buf, int num))
                       ^
/opt/local/include/openssl/opensslconf.h:158:53: note: expanded from macro 'DEPRECATEDIN_1_1_0'
# define DEPRECATEDIN_1_1_0(f)   DECLARE_DEPRECATED(f)
                                                    ^
/opt/local/include/openssl/opensslconf.h:121:37: note: expanded from macro 'DECLARE_DEPRECATED'
#   define DECLARE_DEPRECATED(f)    f __attribute__ ((deprecated));
                                    ^
In file included from CipherContext.cpp:73:
./CipherContext.h:130:17: error: field has incomplete type 'EVP_CIPHER_CTX' (aka 'evp_cipher_ctx_st')
        EVP_CIPHER_CTX ctx;
                       ^
/opt/local/include/openssl/ossl_typ.h:90:16: note: forward declaration of 'evp_cipher_ctx_st'
typedef struct evp_cipher_ctx_st EVP_CIPHER_CTX;
               ^
CipherContext.cpp:537:7: warning: unused variable 'outs' [-Wunused-variable]
                int outs = OutLength;
                    ^
1 warning and 1 error generated.
*** Error code 1
1 warning generated.
1 error
*** Error code 2

Stop.
*** Error code 1