Clean up EVP_PKEY_asn1_find_str()

Use slightly better argument and variable names, do not pointlessly try
to match a string of negative length < -1, use a size_t for the strlen()
and preserve the logic that allows lookup by a string fragment rather
than a full string.

ok jsing

1 files changed, 18 insertions, 9 deletions

diff --git a/src/lib/libcrypto/evp/p_lib.c b/src/lib/libcrypto/evp/p_lib.c
index d9cb66336c..fdddc49b00 100644
--- a/src/lib/libcrypto/evp/p_lib.c
+++ b/src/lib/libcrypto/evp/p_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: p_lib.c,v 1.55 2024/01/04 17:08:57 tb Exp $ */
+/* $OpenBSD: p_lib.c,v 1.56 2024/01/04 17:17:40 tb Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -205,23 +205,32 @@ EVP_PKEY_asn1_find(ENGINE **engine, int pkey_id)
 }
 
 const EVP_PKEY_ASN1_METHOD *
-EVP_PKEY_asn1_find_str(ENGINE **pe, const char *str, int len)
+EVP_PKEY_asn1_find_str(ENGINE **engine, const char *str, int len)
 {
         const EVP_PKEY_ASN1_METHOD *ameth;
+        size_t str_len;
         int i;
 
+        if (engine != NULL)
+                *engine = NULL;
+
+        if (len < -1)
+                return NULL;
         if (len == -1)
-                len = strlen(str);
-        if (pe != NULL)
-                *pe = NULL;
-        for (i = EVP_PKEY_asn1_get_count() - 1; i >= 0; i--) {
-                ameth = EVP_PKEY_asn1_get0(i);
+                str_len = strlen(str);
+        else
+                str_len = len;
+
+        for (i = 0; i < N_ASN1_METHODS; i++) {
+                ameth = asn1_methods[i];
                 if (ameth->pkey_flags & ASN1_PKEY_ALIAS)
                         continue;
-                if (((int)strlen(ameth->pem_str) == len) &&
-                    !strncasecmp(ameth->pem_str, str, len))
+                if (strlen(ameth->pem_str) != str_len)
+                        continue;
+                if (strncasecmp(ameth->pem_str, str, str_len) == 0)
                         return ameth;
         }
+
         return NULL;
 }