Merge pull request #8280 from gilles-peskine-arm/ssl_cache-negative_errors-2.28

Backport 2.28: ssl_cache: misc improvements
diff --git a/ChangeLog.d/mbedtls_ecdsa_can_do-unconditional-define.txt b/ChangeLog.d/mbedtls_ecdsa_can_do-unconditional-define.txt
new file mode 100644
index 0000000..22e8adb
--- /dev/null
+++ b/ChangeLog.d/mbedtls_ecdsa_can_do-unconditional-define.txt
@@ -0,0 +1,3 @@
+Bugfix
+   * Fix an error when MBEDTLS_ECDSA_SIGN_ALT is defined but not
+     MBEDTLS_ECDSA_VERIFY_ALT, causing ecdsa verify to fail. Fixes #7498.
diff --git a/library/ecdsa.c b/library/ecdsa.c
index 3ede933..2fcb2fb 100644
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -240,6 +240,19 @@
 }
 #endif /* ECDSA_DETERMINISTIC || !ECDSA_SIGN_ALT || !ECDSA_VERIFY_ALT */
 
+int mbedtls_ecdsa_can_do(mbedtls_ecp_group_id gid)
+{
+    switch (gid) {
+#ifdef MBEDTLS_ECP_DP_CURVE25519_ENABLED
+        case MBEDTLS_ECP_DP_CURVE25519: return 0;
+#endif
+#ifdef MBEDTLS_ECP_DP_CURVE448_ENABLED
+        case MBEDTLS_ECP_DP_CURVE448: return 0;
+#endif
+        default: return 1;
+    }
+}
+
 #if !defined(MBEDTLS_ECDSA_SIGN_ALT)
 /*
  * Compute ECDSA signature of a hashed message (SEC1 4.1.3)
@@ -379,19 +392,6 @@
     return ret;
 }
 
-int mbedtls_ecdsa_can_do(mbedtls_ecp_group_id gid)
-{
-    switch (gid) {
-#ifdef MBEDTLS_ECP_DP_CURVE25519_ENABLED
-        case MBEDTLS_ECP_DP_CURVE25519: return 0;
-#endif
-#ifdef MBEDTLS_ECP_DP_CURVE448_ENABLED
-        case MBEDTLS_ECP_DP_CURVE448: return 0;
-#endif
-        default: return 1;
-    }
-}
-
 /*
  * Compute ECDSA signature of a hashed message
  */