PEM_def_callback(): don't loop because of too short password given

That error is already caught by EVP_read_pw_string_min, and causes
this function to return -1, so the code detecting too short passwords
in this function is practically dead.

Fixes #5465

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6080)

(cherry picked from commit 4977b4e9281c981efcf6a8b31378b8bbd6a8a96f)

1 files changed, 12 insertions, 29 deletions

diff --git a/crypto/pem/pem_lib.c b/crypto/pem/pem_lib.c
index 4d5f053e46..c6cf63a24e 100644
--- a/crypto/pem/pem_lib.c
+++ b/crypto/pem/pem_lib.c
@@ -84,14 +84,7 @@ int pem_check_suffix(const char *pem_str, const char *suffix);
 
 int PEM_def_callback(char *buf, int num, int w, void *key)
 {
-#ifdef OPENSSL_NO_FP_API
-    /*
-     * We should not ever call the default callback routine from windows.
-     */
-    PEMerr(PEM_F_PEM_DEF_CALLBACK, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
-    return (-1);
-#else
-    int i, j;
+    int i, min_len;
     const char *prompt;
     if (key) {
         i = strlen(key);
@@ -104,29 +97,19 @@ int PEM_def_callback(char *buf, int num, int w, void *key)
     if (prompt == NULL)
         prompt = "Enter PEM pass phrase:";
 
-    for (;;) {
-        /*
-         * We assume that w == 0 means decryption,
-         * while w == 1 means encryption
-         */
-        int min_len = w ? MIN_LENGTH : 0;
+    /*
+     * We assume that w == 0 means decryption,
+     * while w == 1 means encryption
+     */
+    min_len = w ? MIN_LENGTH : 0;
 
-        i = EVP_read_pw_string_min(buf, min_len, num, prompt, w);
-        if (i != 0) {
-            PEMerr(PEM_F_PEM_DEF_CALLBACK, PEM_R_PROBLEMS_GETTING_PASSWORD);
-            memset(buf, 0, (unsigned int)num);
-            return (-1);
-        }
-        j = strlen(buf);
-        if (min_len && j < min_len) {
-            fprintf(stderr,
-                    "phrase is too short, needs to be at least %d chars\n",
-                    min_len);
-        } else
-            break;
+    i = EVP_read_pw_string_min(buf, min_len, num, prompt, w);
+    if (i != 0) {
+        PEMerr(PEM_F_PEM_DEF_CALLBACK, PEM_R_PROBLEMS_GETTING_PASSWORD);
+        memset(buf, 0, (unsigned int)num);
+        return -1;
     }
-    return (j);
-#endif
+    return strlen(buf);
 }
 
 void PEM_proc_type(char *buf, int type)