EVP_MD_CTX “error: storage size of ‘ctx’ isn’t known”

Question

My system is Ubuntu16.04 LTS. when I use the OpenSSL EVP_MD_CTX, this error appeared. Can anyone help me?

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CODE:

Answer 1

I had a similar error but with EVP_CIPHER_CTX

error: storage size of ‘ctx’ isn’t known
       EVP_CIPHER_CTX ctx;

I solved with this:

EVP_CIPHER_CTX *ctx;
ctx = EVP_CIPHER_CTX_new();

I hope this helps somebody with the same problem I had.

Answer 2

You are using OpenSSL 1.1.0 which made this structure (and many others) opaque - which means you cannot stack allocate it. Instead do this:

EVP_MD_CTX *md_ctx;

md_ctx = EVP_MD_CTX_new();
if (md_ctx == NULL)
    ...
...
EVP_MD_CTX_free(md_ctx);