Re: [PATCH v6 3/8] crypto: Introduce x509 utils

[Philippe Mathieu-Daudé]

On 6/9/24 15:50, Daniel P. Berrangé wrote:

On Fri, Sep 06, 2024 at 01:57:30AM +0600, Dorjoy Chowdhury wrote:

An utility function for getting fingerprint from X.509 certificate
has been introduced. Implementation only provided using gnutls.

Signed-off-by: Dorjoy Chowdhury <dorjoychy...@gmail.com>
---
  crypto/meson.build          |  4 ++
  crypto/x509-utils.c         | 75 +++++++++++++++++++++++++++++++++++++
  include/crypto/x509-utils.h | 22 +++++++++++
  3 files changed, 101 insertions(+)
  create mode 100644 crypto/x509-utils.c
  create mode 100644 include/crypto/x509-utils.h

+int qcrypto_get_x509_cert_fingerprint(uint8_t *cert, size_t size,
+                                      QCryptoHashAlgorithm alg,
+                                      uint8_t *result,
+                                      size_t *resultlen,
+                                      Error **errp)
+{
+    int ret;
+    gnutls_x509_crt_t crt;
+    gnutls_datum_t datum = {.data = cert, .size = size};
+
+    if (alg >= G_N_ELEMENTS(qcrypto_to_gnutls_hash_alg_map)) {
+        error_setg(errp, "Unknown hash algorithm");
+        return -1;
+    }
+
+    if (result == NULL) {
+        error_setg(errp, "No valid buffer given");
+        return -1;
+    }
+
+    gnutls_x509_crt_init(&crt);
+
+    if (gnutls_x509_crt_import(crt, &datum, GNUTLS_X509_FMT_PEM) != 0) {
+        error_setg(errp, "Failed to import certificate");
+        goto cleanup;
+    }
+
+    ret = gnutls_hash_get_len(qcrypto_to_gnutls_hash_alg_map[alg]);
+    if (*resultlen < ret) {
+        error_setg(errp,
+                   "Result buffer size %zu is smaller than hash %d",
+                   *resultlen, ret);
+        goto cleanup;
+    }
+
+    if (gnutls_x509_crt_get_fingerprint(crt,
+                                        qcrypto_to_gnutls_hash_alg_map[alg],
+                                        result, resultlen) != 0) {
+        error_setg(errp, "Failed to get fingerprint from certificate");
+        goto cleanup;
+    }
+
+    return 0;
+
+ cleanup:
+    gnutls_x509_crt_deinit(crt);
+    return -1;
+}

This fails to call gnutls_x509_crt_deinit in the success path.

I'm going to squash in the following change:


diff --git a/crypto/x509-utils.c b/crypto/x509-utils.c
index 593eb8968b..6e157af76b 100644
--- a/crypto/x509-utils.c
+++ b/crypto/x509-utils.c
@@ -31,7 +31,8 @@ int qcrypto_get_x509_cert_fingerprint(uint8_t *cert, size_t 
size,
                                        size_t *resultlen,
                                        Error **errp)
  {
-    int ret;
+    int ret = -1;
+    int hlen;
      gnutls_x509_crt_t crt;
      gnutls_datum_t datum = {.data = cert, .size = size};

@@ -52,11 +53,11 @@ int qcrypto_get_x509_cert_fingerprint(uint8_t *cert, size_t size,

          goto cleanup;
      }

- ret = gnutls_hash_get_len(qcrypto_to_gnutls_hash_alg_map[alg]);

-    if (*resultlen < ret) {
+    hlen = gnutls_hash_get_len(qcrypto_to_gnutls_hash_alg_map[alg]);
+    if (*resultlen < hlen) {
          error_setg(errp,
                     "Result buffer size %zu is smaller than hash %d",
-                   *resultlen, ret);
+                   *resultlen, hlen);
          goto cleanup;
      }

@@ -67,9 +68,9 @@ int qcrypto_get_x509_cert_fingerprint(uint8_t *cert, size_t size,

          goto cleanup;
      }

- return 0;

+    ret = 0;

cleanup:

      gnutls_x509_crt_deinit(crt);
-    return -1;
+    return ret;
  }

Reviewed-by: Philippe Mathieu-Daudé <phi...@linaro.org>