Re: Problem in trying EVP Key Derivation example in openssl

[Dr Paul Dale <paul.dale@xxxxxxxxxx>]

And done.

This also pointed out a mistake in the man page code.

Pauli

-- 
Dr Paul Dale | Distinguished Architect | Cryptographic Foundations 
Phone +61 7 3031 7217
Oracle Australia

On 15 Sep 2019, at 9:16 am, Dr Paul Dale <paul.dale@xxxxxxxxxx> wrote:

The example is wrong.

The KDF API changed recently to better match the way the rest of the project is moving.

I’ll update the example.

Pauli

-- 
Dr Paul Dale | Distinguished Architect | Cryptographic Foundations 
Phone +61 7 3031 7217
Oracle Australia

On 15 Sep 2019, at 7:28 am, Bhuvan Sharma <erbsharma021@xxxxxxxxx> wrote:

Hey all,

I'm new to openssl community and I don't know much about it. I tried to use openssl on my linux machine. I clone openssl git repo and executed these commands as mentioned in the file "INSTALL": "./config", "make", "make test", "make install". It went alright. Then I tried an "EVP KEY Derivation" example from this link: https://wiki.openssl.org/index.php?title=EVP_Key_Derivation&redirect=no#targetText=HKDF%20was%20designed%20by%20Krawczyk,from%20the%20OpenSSL%20man%20pages. But it gives me some error for undeclared function. 

~/openssl$ gcc -std=c99 test.c -o test.exe -l:libcrypto.a -pthread -ldl
test.c: In function ‘main’:
test.c:12:17: warning: implicit declaration of function ‘EVP_KDF_CTX_new_id’; did you mean ‘EVP_KDF_CTX_new’? [-Wimplicit-function-declaration]
     if ((kctx = EVP_KDF_CTX_new_id(EVP_KDF_HKDF)) == NULL) {
                 ^~~~~~~~~~~~~~~~~~
                 EVP_KDF_CTX_new
test.c:12:36: error: ‘EVP_KDF_HKDF’ undeclared (first use in this function); did you mean ‘EVP_PKEY_HKDF’?
     if ((kctx = EVP_KDF_CTX_new_id(EVP_KDF_HKDF)) == NULL) {
                                    ^~~~~~~~~~~~
                                    EVP_PKEY_HKDF
test.c:12:36: note: each undeclared identifier is reported only once for each function it appears in
test.c:13:9: warning: implicit declaration of function ‘error’; did you mean ‘perror’? [-Wimplicit-function-declaration]
         error("EVP_KDF_CTX_new_id");
         ^~~~~
         perror
test.c:15:9: warning: implicit declaration of function ‘EVP_KDF_ctrl’; did you mean ‘EVP_KDF_size’? [-Wimplicit-function-declaration]
     if (EVP_KDF_ctrl(kctx, EVP_KDF_CTRL_SET_MD, EVP_sha256()) <= 0) {
         ^~~~~~~~~~~~
         EVP_KDF_size

Is there any problem with the installation or am I missing something else?

Your help is much appreciated.

Thanks & Regards,

Bhuvan Sharma