Implements the new hashing API in the gnutls hash driver.
Supports creating/destroying a context, updating the context
with input data and obtaining an output hash.

Signed-off-by: Alejandro Zeise <alejandro.zeise@seagate.com>
---
 crypto/hash-gnutls.c | 76 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 76 insertions(+)

diff --git a/crypto/hash-gnutls.c b/crypto/hash-gnutls.c
index 84ce7073f5..a2ccd257c7 100644
--- a/crypto/hash-gnutls.c
+++ b/crypto/hash-gnutls.c
@@ -53,8 +53,81 @@ gboolean qcrypto_hash_supports(QCryptoHashAlgorithm alg)
     return false;
 }
 
+static
+QCryptoHash *qcrypto_gnutls_hash_new(QCryptoHashAlgorithm alg, Error **errp)
+{
+    QCryptoHash *hash = NULL;
+
+    if (!qcrypto_hash_supports(alg)) {
+        error_setg(errp,
+                   "Unknown hash algorithm %d",
+                   alg);
+    } else {
+        hash = g_new(QCryptoHash, 1);
+        hash->alg = alg;
+        hash->opaque = g_new(gnutls_hash_hd_t, 1);
+
+        gnutls_hash_init(hash->opaque, qcrypto_hash_alg_map[alg]);
+    }
+
+    return hash;
+}
+
+static
+int qcrypto_gnutls_hash_free(QCryptoHash *hash)
+{
+    gnutls_hash_hd_t *ctx = hash->opaque;
+
+    g_free(ctx);
+    g_free(hash);
+
+    return 0;
+}
 
 
+static
+int qcrypto_gnutls_hash_update(QCryptoHash *hash,
+                               const struct iovec *iov,
+                               size_t niov,
+                               Error **errp)
+{
+    int fail = 0;
+    gnutls_hash_hd_t *ctx = hash->opaque;
+
+    for (int i = 0; i < niov; i++) {
+        fail = gnutls_hash(*ctx, iov[i].iov_base, iov[i].iov_len) || fail;
+    }
+
+    return fail;
+}
+
+static
+int qcrypto_gnutls_hash_finalize(QCryptoHash *hash,
+                                 uint8_t **result,
+                                 size_t *result_len,
+                                 Error **errp)
+{
+    int ret = 0;
+    gnutls_hash_hd_t *ctx = hash->opaque;
+
+    *result_len = gnutls_hash_get_len(qcrypto_hash_alg_map[hash->alg]);
+    if (*result_len == 0) {
+        error_setg(errp, "%s",
+                   "Unable to get hash length");
+        ret = -1;
+    } else {
+        *result = g_new(uint8_t, *result_len);
+
+        gnutls_hash_deinit(*ctx, *result);
+    }
+
+    return ret;
+}
+
 
 QCryptoHashDriver qcrypto_hash_lib_driver = {
+    .hash_new      = qcrypto_gnutls_hash_new,
+    .hash_free     = qcrypto_gnutls_hash_free,
+    .hash_update   = qcrypto_gnutls_hash_update,
+    .hash_finalize = qcrypto_gnutls_hash_finalize
 };
-- 
2.34.1