Add error checking for EVP_Digest*() to snmp(1).

ok martijn

diff --git a/usr.bin/snmp/usm.c b/usr.bin/snmp/usm.c
index d0a207a..ceb607f 100644 (file)
--- a/usr.bin/snmp/usm.c
+++ b/usr.bin/snmp/usm.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: usm.c,v 1.6 2022/01/05 10:59:21 tb Exp $      */
+/*     $OpenBSD: usm.c,v 1.7 2022/01/05 16:41:07 tb Exp $      */
 
 /*
  * Copyright (c) 2019 Martijn van Duren <martijn@openbsd.org>
@@ -632,7 +632,11 @@ usm_passwd2mkey(const EVP_MD *md, const char *passwd)
 
        if ((ctx = EVP_MD_CTX_new()) == NULL)
                return NULL;
-       EVP_DigestInit_ex(ctx, md, NULL);
+       if (!EVP_DigestInit_ex(ctx, md, NULL)) {
+               EVP_MD_CTX_free(ctx);
+               return NULL;
+       }
+
        pw = (const u_char *)passwd;
        for (count = 0; count < 1048576; count += 64) {
                c = keybuf;
@@ -641,9 +645,15 @@ usm_passwd2mkey(const EVP_MD *md, const char *passwd)
                                pw = (const u_char *)passwd;
                        *c++ = *pw++;
                }
-               EVP_DigestUpdate(ctx, keybuf, 64);
+               if (!EVP_DigestUpdate(ctx, keybuf, 64)) {
+                       EVP_MD_CTX_free(ctx);
+                       return NULL;
+               }
+       }
+       if (!EVP_DigestFinal_ex(ctx, keybuf, &dlen)) {
+               EVP_MD_CTX_free(ctx);
+               return NULL;
        }
-       EVP_DigestFinal_ex(ctx, keybuf, &dlen);
        EVP_MD_CTX_free(ctx);
 
        if ((key = malloc(dlen)) == NULL)
@@ -662,13 +672,16 @@ usm_mkey2lkey(struct usm_sec *usm, const EVP_MD *md, const char *mkey)
 
        if ((ctx = EVP_MD_CTX_new()) == NULL)
                return NULL;
-       EVP_DigestInit_ex(ctx, md, NULL);
 
-       EVP_DigestUpdate(ctx, mkey, EVP_MD_size(md));
-       EVP_DigestUpdate(ctx, usm->engineid, usm->engineidlen);
-       EVP_DigestUpdate(ctx, mkey, EVP_MD_size(md));
+       if (!EVP_DigestInit_ex(ctx, md, NULL) ||
+           !EVP_DigestUpdate(ctx, mkey, EVP_MD_size(md)) ||
+           !EVP_DigestUpdate(ctx, usm->engineid, usm->engineidlen) ||
+           !EVP_DigestUpdate(ctx, mkey, EVP_MD_size(md)) ||
+           !EVP_DigestFinal_ex(ctx, buf, &lklen)) {
+               EVP_MD_CTX_free(ctx);
+               return NULL;
+       }
 
-       EVP_DigestFinal_ex(ctx, buf, &lklen);
        EVP_MD_CTX_free(ctx);
 
        if ((lkey = malloc(lklen)) == NULL)