Add support getting raw private/public keys

Only applies to algorithms that support it. Both raw private and public
keys can be obtained for X25519, Ed25519, X448, Ed448. Raw private keys
only can be obtained for HMAC, Poly1305 and SipHash

Fixes #6259

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6394)

1 files changed, 34 insertions, 0 deletions

diff --git a/crypto/evp/p_lib.c b/crypto/evp/p_lib.c
index e4d2bb1835..d78f1d2d84 100644
--- a/crypto/evp/p_lib.c
+++ b/crypto/evp/p_lib.c
@@ -280,6 +280,40 @@ EVP_PKEY *EVP_PKEY_new_raw_public_key(int type, ENGINE *e,
     return NULL;
 }
 
+int EVP_PKEY_get_raw_private_key(const EVP_PKEY *pkey, unsigned char *priv,
+                                 size_t *len)
+{
+     if (pkey->ameth->get_priv_key == NULL) {
+        EVPerr(EVP_F_EVP_PKEY_GET_RAW_PRIVATE_KEY,
+               EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
+        return 0;
+    }
+
+    if (!pkey->ameth->get_priv_key(pkey, priv, len)) {
+        EVPerr(EVP_F_EVP_PKEY_GET_RAW_PRIVATE_KEY, EVP_R_GET_RAW_KEY_FAILED);
+        return 0;
+    }
+
+    return 1;
+}
+
+int EVP_PKEY_get_raw_public_key(const EVP_PKEY *pkey, unsigned char *pub,
+                                size_t *len)
+{
+     if (pkey->ameth->get_pub_key == NULL) {
+        EVPerr(EVP_F_EVP_PKEY_GET_RAW_PUBLIC_KEY,
+               EVP_R_OPERATION_NOT_SUPPORTED_FOR_THIS_KEYTYPE);
+        return 0;
+    }
+
+    if (!pkey->ameth->get_pub_key(pkey, pub, len)) {
+        EVPerr(EVP_F_EVP_PKEY_GET_RAW_PUBLIC_KEY, EVP_R_GET_RAW_KEY_FAILED);
+        return 0;
+    }
+
+    return 1;
+}
+
 EVP_PKEY *EVP_PKEY_new_CMAC_key(ENGINE *e, const unsigned char *priv,
                                 size_t len, const EVP_CIPHER *cipher)
 {