diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index d28a751ebd..5b2a58cdcd 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1648,6 +1648,7 @@ virConfWriteMem;
 # util/vircrypto.h
 virCryptoEncryptData;
 virCryptoGenerateRandom;
+virCryptoHashBuf;
 virCryptoHashString;
 virCryptoHaveCipher;
 
diff --git a/src/util/vircrypto.c b/src/util/vircrypto.c
index 48b04fc8ce..1a2dcc28b7 100644
--- a/src/util/vircrypto.c
+++ b/src/util/vircrypto.c
@@ -53,6 +53,26 @@ struct virHashInfo {
 
 verify(ARRAY_CARDINALITY(hashinfo) == VIR_CRYPTO_HASH_LAST);
 
+int
+virCryptoHashBuf(virCryptoHash hash,
+                 const char *input,
+                 unsigned char *output)
+{
+    if (hash >= VIR_CRYPTO_HASH_LAST) {
+        virReportError(VIR_ERR_INVALID_ARG,
+                       _("Unknown crypto hash %d"), hash);
+        return -1;
+    }
+
+    if (!(hashinfo[hash].func(input, strlen(input), output))) {
+        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
+                       _("Unable to compute hash of data"));
+        return -1;
+    }
+
+    return 0;
+}
+
 int
 virCryptoHashString(virCryptoHash hash,
                     const char *input,
@@ -62,20 +82,11 @@ virCryptoHashString(virCryptoHash hash,
     size_t hashstrlen;
     size_t i;
 
-    if (hash >= VIR_CRYPTO_HASH_LAST) {
-        virReportError(VIR_ERR_INVALID_ARG,
-                       _("Unknown crypto hash %d"), hash);
+    if (virCryptoHashBuf(hash, input, buf) < 0)
         return -1;
-    }
 
     hashstrlen = (hashinfo[hash].hashlen * 2) + 1;
 
-    if (!(hashinfo[hash].func(input, strlen(input), buf))) {
-        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
-                       _("Unable to compute hash of data"));
-        return -1;
-    }
-
     if (VIR_ALLOC_N(*output, hashstrlen) < 0)
         return -1;
 
diff --git a/src/util/vircrypto.h b/src/util/vircrypto.h
index 81743d2f74..64984006be 100644
--- a/src/util/vircrypto.h
+++ b/src/util/vircrypto.h
@@ -41,6 +41,13 @@ typedef enum {
     VIR_CRYPTO_CIPHER_LAST
 } virCryptoCipher;
 
+int
+virCryptoHashBuf(virCryptoHash hash,
+                 const char *input,
+                 unsigned char *output)
+    ATTRIBUTE_NONNULL(2) ATTRIBUTE_NONNULL(3)
+    ATTRIBUTE_RETURN_CHECK;
+
 int
 virCryptoHashString(virCryptoHash hash,
                     const char *input,