Fix memory leak in EVP_PKEY elements

The cache assumes that all the memory is fixed, which is usually true
because it's block allocated for the config file.  However type
CACHE_PKEY is an exception because they're dynamically allocated, so
add a freeing function callback to make sure they're correctly freed
when no longer in use.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

3 files changed, 9 insertions, 0 deletions

diff --git a/cache.c b/cache.c
index 5d46bb3..b29ce8b 100644
--- a/cache.c
+++ b/cache.c
@@ -106,6 +106,9 @@ static void cache_add_internal(struct s_s *s_s, const char *key,
 	struct kv *kv = kv_get_alloc(s_s, key);
 	if (!kv)
 		return;
+	if (kv->value && kv->len == CACHE_PKEY)
+		/* discard const */
+		crypto_cache_free_pkey((void *)kv->value);
 	if (len == 0)
 		len = strlen(value);
 
diff --git a/crypto.c b/crypto.c
index 22b4caa..6ea738f 100644
--- a/crypto.c
+++ b/crypto.c
@@ -221,6 +221,11 @@ void crypto_free_private_key(int sec_num)
 	cache_add_by_secnum(sec_num, "pkey", NULL, CACHE_PKEY);
 }
 
+void crypto_cache_free_pkey(void *pkey)
+{
+	EVP_PKEY_free(pkey);
+}
+
 static EVP_PKEY_CTX *get_key(int sec_num)
 {
 	EVP_PKEY_CTX *ctx;
diff --git a/openssl-pkcs11.h b/openssl-pkcs11.h
index 1e3d673..f6120d6 100644
--- a/openssl-pkcs11.h
+++ b/openssl-pkcs11.h
@@ -27,6 +27,7 @@
 int crypto_load_public_key(int sec_num, const char *pub);
 int crypto_load_private_key(int sec_num, const unsigned char *pin, int pin_len);
 void crypto_free_private_key(int sec_num);
+void crypto_cache_free_pkey(void *pkey);
 void *crypto_sign_init(int sec_num, CK_MECHANISM_PTR mech);
 int crypto_sign(void *opdata, void *data, unsigned long data_len,
 		void *sig, unsigned long *sig_len);