[PATCH v4 3/5] ima-avm-utils: Change read_priv_key to use EVP_PKEY API

[Vitaly Chikunov <vt@xxxxxxxxxxxx>]

Introduce read_priv_pkey() to read keys using EVP_PKEY, and change
read_priv_key() to be wrapper for it.

Signed-off-by: Vitaly Chikunov <vt@xxxxxxxxxxxx>
---
 src/libimaevm.c | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/src/libimaevm.c b/src/libimaevm.c
index da0f422..c620c1e 100644
--- a/src/libimaevm.c
+++ b/src/libimaevm.c
@@ -753,10 +753,10 @@ void calc_keyid_v2(uint32_t *keyid, char *str, RSA *key)
 	free(pkey);
 }
 
-static RSA *read_priv_key(const char *keyfile, const char *keypass)
+static EVP_PKEY *read_priv_pkey(const char *keyfile, const char *keypass)
 {
 	FILE *fp;
-	RSA *key;
+	EVP_PKEY *key;
 
 	fp = fopen(keyfile, "r");
 	if (!fp) {
@@ -764,18 +764,40 @@ static RSA *read_priv_key(const char *keyfile, const char *keypass)
 		return NULL;
 	}
 	ERR_load_crypto_strings();
-	key = PEM_read_RSAPrivateKey(fp, NULL, NULL, (void *)keypass);
+	key = PEM_read_PrivateKey(fp, NULL, NULL, (void *)keypass);
 	if (!key) {
 		char str[256];
 
-		ERR_error_string(ERR_get_error(), str);
-		log_err("PEM_read_RSAPrivateKey() failed: %s\n", str);
+		ERR_error_string(ERR_peek_error(), str);
+		log_err("PEM_read_PrivateKey() failed: %s\n", str);
+#ifdef USE_FPRINTF
+		ERR_print_errors_fp(stderr);
+#else
+		ERR_clear_error();
+#endif
 	}
 
 	fclose(fp);
 	return key;
 }
 
+static RSA *read_priv_key(const char *keyfile, const char *keypass)
+{
+	EVP_PKEY *pkey;
+	RSA *key;
+
+	pkey = read_priv_pkey(keyfile, keypass);
+	if (!pkey)
+		return NULL;
+	key = EVP_PKEY_get1_RSA(pkey);
+	EVP_PKEY_free(pkey);
+	if (!key) {
+		log_err("sign_hash_v1: unsupported key type\n");
+		return NULL;
+	}
+	return key;
+}
+
 static int get_hash_algo_v1(const char *algo)
 {
 
-- 
2.11.0