[PATCH v4 07/15] crypto/hash: Implement and use new hash API

[Alejandro Zeise]

Changes the public hash API implementation to support accumulative hashing.

Implementations for the public functions are added to call the new
driver functions that implement context creation, updating,
finalization, and destruction.

Additionally changes the "shortcut" functions to use these 4 new core
functions.

Signed-off-by: Alejandro Zeise <alejandro.zeise@seagate.com>
---
 crypto/hash.c | 163 +++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 128 insertions(+), 35 deletions(-)

diff --git a/crypto/hash.c b/crypto/hash.c
index b0f8228bdc..f3c18cdd74 100644
--- a/crypto/hash.c
+++ b/crypto/hash.c
@@ -1,6 +1,7 @@
 /*
  * QEMU Crypto hash algorithms
  *
+ * Copyright (c) 2024 Seagate Technology LLC and/or its Affiliates
  * Copyright (c) 2015 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
@@ -45,23 +46,20 @@ int qcrypto_hash_bytesv(QCryptoHashAlgorithm alg,
                         size_t *resultlen,
                         Error **errp)
 {
-#ifdef CONFIG_AF_ALG
-    int ret;
-    /*
-     * TODO:
-     * Maybe we should treat some afalg errors as fatal
-     */
-    ret = qcrypto_hash_afalg_driver.hash_bytesv(alg, iov, niov,
-                                                result, resultlen,
-                                                NULL);
-    if (ret == 0) {
-        return ret;
+    int fail;
+    QCryptoHash *ctx = qcrypto_hash_new(alg, errp);
+
+    if (ctx) {
+        fail = qcrypto_hash_updatev(ctx, iov, niov, errp) ||
+               qcrypto_hash_finalize_bytes(ctx, result, resultlen, errp);
+
+        /* Ensure context is always freed regardless of error */
+        qcrypto_hash_free(ctx);
+    } else {
+        fail = -1;
     }
-#endif
 
-    return qcrypto_hash_lib_driver.hash_bytesv(alg, iov, niov,
-                                               result, resultlen,
-                                               errp);
+    return fail;
 }
 
 
@@ -77,30 +75,121 @@ int qcrypto_hash_bytes(QCryptoHashAlgorithm alg,
     return qcrypto_hash_bytesv(alg, &iov, 1, result, resultlen, errp);
 }
 
-static const char hex[] = "0123456789abcdef";
-
-int qcrypto_hash_digestv(QCryptoHashAlgorithm alg,
+int qcrypto_hash_updatev(QCryptoHash *hash,
                          const struct iovec *iov,
                          size_t niov,
-                         char **digest,
                          Error **errp)
 {
+#ifdef CONFIG_AF_ALG
+    return qcrypto_hash_afalg_driver.hash_update(hash, iov, niov, errp);
+#else
+    return qcrypto_hash_lib_driver.hash_update(hash, iov, niov, errp);
+#endif /* CONFIG_AF_ALG */
+}
+
+int qcrypto_hash_update(QCryptoHash *hash,
+                        const char *buf,
+                        size_t len,
+                        Error **errp)
+{
+    struct iovec iov = { .iov_base = (char *)buf, .iov_len = len };
+
+    return qcrypto_hash_updatev(hash, &iov, 1, errp);
+}
+
+QCryptoHash *qcrypto_hash_new(QCryptoHashAlgorithm alg, Error **errp)
+{
+#ifdef CONFIG_AF_ALG
+    return qcrypto_hash_afalg_driver.hash_new(alg, errp);
+#else
+    return qcrypto_hash_lib_driver.hash_new(alg, errp);
+#endif /* CONFIG_AF_ALG */
+}
+
+void qcrypto_hash_free(QCryptoHash *hash)
+{
+#ifdef CONFIG_AF_ALG
+    qcrypto_hash_afalg_driver.hash_free(hash);
+#else
+    qcrypto_hash_lib_driver.hash_free(hash);
+#endif /* CONFIG_AF_ALG */
+}
+
+int qcrypto_hash_finalize_bytes(QCryptoHash *hash,
+                                uint8_t **result,
+                                size_t *result_len,
+                                Error **errp)
+{
+#ifdef CONFIG_AF_ALG
+    return qcrypto_hash_afalg_driver.hash_finalize(hash, result, result_len,
+                                                   errp);
+#else
+    return qcrypto_hash_lib_driver.hash_finalize(hash, result, result_len, 
errp);
+#endif /* CONFIG_AF_ALG */
+}
+
+static const char hex[] = "0123456789abcdef";
+
+int qcrypto_hash_finalize_digest(QCryptoHash *hash,
+                                 char **digest,
+                                 Error **errp)
+{
+    int ret;
     uint8_t *result = NULL;
     size_t resultlen = 0;
     size_t i;
 
-    if (qcrypto_hash_bytesv(alg, iov, niov, &result, &resultlen, errp) < 0) {
-        return -1;
+    ret = qcrypto_hash_finalize_bytes(hash, &result, &resultlen, errp);
+    if (ret == 0) {
+        *digest = g_new0(char, (resultlen * 2) + 1);
+        for (i = 0 ; i < resultlen ; i++) {
+            (*digest)[(i * 2)] = hex[(result[i] >> 4) & 0xf];
+            (*digest)[(i * 2) + 1] = hex[result[i] & 0xf];
+        }
+        (*digest)[resultlen * 2] = '\0';
+        g_free(result);
+    }
+
+    return ret;
+}
+
+int qcrypto_hash_finalize_base64(QCryptoHash *hash,
+                                 char **base64,
+                                 Error **errp)
+{
+    int ret;
+    uint8_t *result = NULL;
+    size_t resultlen = 0;
+
+    ret = qcrypto_hash_finalize_bytes(hash, &result, &resultlen, errp);
+    if (ret == 0) {
+        *base64 = g_base64_encode(result, resultlen);
+        g_free(result);
     }
 
-    *digest = g_new0(char, (resultlen * 2) + 1);
-    for (i = 0 ; i < resultlen ; i++) {
-        (*digest)[(i * 2)] = hex[(result[i] >> 4) & 0xf];
-        (*digest)[(i * 2) + 1] = hex[result[i] & 0xf];
+    return ret;
+}
+
+int qcrypto_hash_digestv(QCryptoHashAlgorithm alg,
+                         const struct iovec *iov,
+                         size_t niov,
+                         char **digest,
+                         Error **errp)
+{
+    bool fail;
+    QCryptoHash *ctx = qcrypto_hash_new(alg, errp);
+
+    if (ctx) {
+        fail = qcrypto_hash_updatev(ctx, iov, niov, errp) ||
+               qcrypto_hash_finalize_digest(ctx, digest, errp);
+
+        /* Ensure context is always freed regardless of error */
+        qcrypto_hash_free(ctx);
+    } else {
+        fail = false;
     }
-    (*digest)[resultlen * 2] = '\0';
-    g_free(result);
-    return 0;
+
+    return fail;
 }
 
 int qcrypto_hash_digest(QCryptoHashAlgorithm alg,
@@ -120,16 +209,20 @@ int qcrypto_hash_base64v(QCryptoHashAlgorithm alg,
                          char **base64,
                          Error **errp)
 {
-    uint8_t *result = NULL;
-    size_t resultlen = 0;
+    bool fail;
+    QCryptoHash *ctx = qcrypto_hash_new(alg, errp);
+
+    if (ctx) {
+        fail = qcrypto_hash_updatev(ctx, iov, niov, errp) ||
+               qcrypto_hash_finalize_base64(ctx, base64, errp);
 
-    if (qcrypto_hash_bytesv(alg, iov, niov, &result, &resultlen, errp) < 0) {
-        return -1;
+        /* Ensure context is always freed regardless of error */
+        qcrypto_hash_free(ctx);
+    } else {
+        fail = 1;
     }
 
-    *base64 = g_base64_encode(result, resultlen);
-    g_free(result);
-    return 0;
+    return fail;
 }
 
 int qcrypto_hash_base64(QCryptoHashAlgorithm alg,
-- 
2.34.1