diff --git a/lib/tests/parse_key.c b/lib/tests/parse_key.c
index 564352d..dbb6cf3 100644
--- a/lib/tests/parse_key.c
+++ b/lib/tests/parse_key.c
@@ -48,9 +48,10 @@ struct key keys[] = {
 		1}
 };
 
-static int parse_key(ykpiv_state *state, const char *text, const unsigned char *expected, int valid) {
+static int parse_key(const char *text, const unsigned char *expected, int valid) {
 	unsigned char key[24];
-	ykpiv_rc res = ykpiv_parse_key(state, text, key);
+	size_t len = sizeof(key);
+	ykpiv_rc res = ykpiv_hex_decode(text, strlen(text), key, &len);
 	if(res != YKPIV_OK && valid == 1) {
 		printf("key check failed for %s!\n", text);
 		return EXIT_FAILURE;
@@ -67,25 +68,14 @@ static int parse_key(ykpiv_state *state, const char *text, const unsigned char *
 }
 
 int main(void) {
-	ykpiv_state *state;
 	size_t i;
 
-	if(ykpiv_init(&state, 0) != YKPIV_OK) {
-		printf("Failed initializing library!\n");
-		return EXIT_FAILURE;
-	}
-
 	for(i = 0; i < sizeof(keys) / sizeof(struct key); i++) {
-		int res = parse_key(state, keys[i].text, keys[i].formatted, keys[i].valid);
+		int res = parse_key(keys[i].text, keys[i].formatted, keys[i].valid);
 		if(res != EXIT_SUCCESS) {
 			return res;
 		}
 	}
 
-	if(ykpiv_done(state) != YKPIV_OK) {
-		printf("Failed de-initializing library!\n");
-		return EXIT_FAILURE;
-	}
-
 	return EXIT_SUCCESS;
 }
diff --git a/lib/ykpiv.c b/lib/ykpiv.c
index 39e096d..afb9662 100644
--- a/lib/ykpiv.c
+++ b/lib/ykpiv.c
@@ -448,37 +448,31 @@ ykpiv_rc ykpiv_set_mgmkey(ykpiv_state *state, const unsigned char *new_key) {
   return YKPIV_GENERIC_ERROR;
 }
 
-/* FIXME: this function should be removed and replaced by
- * a real hex encoder.. */
-ykpiv_rc ykpiv_parse_key(ykpiv_state *state,
-    const char *key_in, unsigned char *key_out) {
-  unsigned int i;
-  char key_part[4] = {0};
-  int key_len = strlen(key_in);
-  unsigned char tmp_key[DES_KEY_SZ * 3]; /* since sscanf sometimes write 32 bits */
+static char hex_translate[] = "0123456789abcdef";
 
-  if(key_len != DES_KEY_SZ * 3 * 2) {
-    if(state->verbose) {
-      fprintf(stderr, "Wrong key size, should be %lu characters (was %d).\n", DES_KEY_SZ * 3 * 2, key_len);
-    }
+ykpiv_rc ykpiv_hex_decode(const char *hex_in, size_t in_len,
+    unsigned char *hex_out, size_t *out_len) {
+
+  size_t i;
+  bool first = true;
+  if(*out_len < in_len / 2) {
+    return YKPIV_SIZE_ERROR;
+  } else if(in_len % 2 != 0) {
     return YKPIV_SIZE_ERROR;
   }
-  for(i = 0; i < DES_KEY_SZ * 3; i++) {
-    key_part[0] = *key_in++;
-    key_part[1] = *key_in++;
-    if(sscanf(key_part, "%hhx", &tmp_key[i]) != 1) {
-      if(state->verbose) {
-	fprintf(stderr, "Failed parsing key at position %d.\n", i);
-      }
-      return YKPIV_KEY_ERROR;
+  *out_len = in_len / 2;
+  for(i = 0; i < in_len; i++) {
+    char *ind_ptr = strchr(hex_translate, *hex_in++);
+    int index = 0;
+    if(ind_ptr) {
+      index = ind_ptr - hex_translate;
     }
-  }
-  memcpy(key_out, tmp_key, DES_KEY_SZ * 3);
-
-  if(state->verbose > 1) {
-    fprintf(stderr, "parsed key: ");
-    dump_hex(key_out, DES_KEY_SZ * 3);
-    fprintf(stderr, "\n");
+    if(first) {
+      *hex_out = index << 4;
+    } else {
+      *hex_out++ |= index;
+    }
+    first = !first;
   }
   return YKPIV_OK;
 }
diff --git a/lib/ykpiv.h b/lib/ykpiv.h
index afb64a2..b4051b5 100644
--- a/lib/ykpiv.h
+++ b/lib/ykpiv.h
@@ -70,8 +70,8 @@ extern "C"
 			unsigned char *out_data, unsigned long *out_len, int *sw);
 	ykpiv_rc ykpiv_authenticate(ykpiv_state *state, const unsigned char *key);
 	ykpiv_rc ykpiv_set_mgmkey(ykpiv_state *state, const unsigned char *new_key);
-	ykpiv_rc ykpiv_parse_key(ykpiv_state *state,
-			const char *key_in, unsigned char *key_out);
+	ykpiv_rc ykpiv_hex_decode(const char *hex_in, size_t in_len,
+	            unsigned char *hex_out, size_t *out_len);
 	ykpiv_rc ykpiv_sign_data(ykpiv_state *state, const unsigned char *sign_in,
 			size_t in_len,unsigned char *sign_out, size_t *out_len,
 			unsigned char algorithm, unsigned char key);
diff --git a/lib/ykpiv.map b/lib/ykpiv.map
index fc97ac0..2b7a333 100644
--- a/lib/ykpiv.map
+++ b/lib/ykpiv.map
@@ -37,12 +37,12 @@ global:
 	ykpiv_transfer_data;
 	ykpiv_authenticate;
 	ykpiv_set_mgmkey;
-	ykpiv_parse_key;
 	ykpiv_sign_data;
 	ykpiv_get_version;
 	ykpiv_verify;
 	ykpiv_fetch_object;
   ykpiv_save_object;
+	ykpiv_hex_decode;
 
 local:
 	*;
diff --git a/tool/yubico-piv-tool.c b/tool/yubico-piv-tool.c
index 12c4ac5..7a50f48 100644
--- a/tool/yubico-piv-tool.c
+++ b/tool/yubico-piv-tool.c
@@ -822,6 +822,7 @@ int main(int argc, char *argv[]) {
   struct gengetopt_args_info args_info;
   ykpiv_state *state;
   unsigned char key[KEY_LEN];
+  size_t key_len = sizeof(key);
   int verbosity;
   enum enum_action action;
   unsigned int i;
@@ -843,7 +844,7 @@ int main(int argc, char *argv[]) {
     return EXIT_FAILURE;
   }
 
-  if(ykpiv_parse_key(state, args_info.key_arg, key) != YKPIV_OK) {
+  if(ykpiv_hex_decode(args_info.key_arg, strlen(args_info.key_arg), key, &key_len) != YKPIV_OK) {
     return EXIT_FAILURE;
   }
 
@@ -880,7 +881,8 @@ int main(int argc, char *argv[]) {
       case action_arg_setMINUS_mgmMINUS_key:
         if(args_info.new_key_arg) {
           unsigned char new_key[KEY_LEN];
-          if(ykpiv_parse_key(state, args_info.new_key_arg, new_key) != YKPIV_OK) {
+          size_t new_key_len = sizeof(new_key);
+          if(ykpiv_hex_decode(args_info.new_key_arg, strlen(args_info.new_key_arg), new_key, &new_key_len) != YKPIV_OK) {
             ret = EXIT_FAILURE;
           } else if(ykpiv_set_mgmkey(state, new_key) != YKPIV_OK) {
             ret = EXIT_FAILURE;