From 3a2c83763200b83d92eaab7c0c980abd0ba97461 Mon Sep 17 00:00:00 2001
From: Chris Conlon <chris@wolfssl.com>
Date: Fri, 14 Aug 2026 10:32:49 -0600
Subject: [PATCH] F-9119: validate min key size range before narrowing to
 word16/short

---
 native/com_wolfssl_WolfSSLContext.c           | 24 ++++++++++++++++---
 .../com/wolfssl/test/WolfSSLContextTest.java  | 21 ++++++++++++++++
 2 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/native/com_wolfssl_WolfSSLContext.c b/native/com_wolfssl_WolfSSLContext.c
index b992ad1..4797821 100644
--- a/native/com_wolfssl_WolfSSLContext.c
+++ b/native/com_wolfssl_WolfSSLContext.c
@@ -7088,11 +7088,17 @@ JNIEXPORT jint JNICALL Java_com_wolfssl_WolfSSLContext_setMinDhKeySz
     WOLFSSL_CTX* ctx = (WOLFSSL_CTX*)(uintptr_t)ctxPtr;
     (void)obj;
 
-    /* wolfSSL_CTX_SetMinDhKey_Sz() sanitizes ctx and keySzBits */
+    /* wolfSSL_CTX_SetMinDhKey_Sz() sanitizes ctx */
     if (jenv == NULL) {
         return (jint)BAD_FUNC_ARG;
     }
 
+    /* Validate range before narrowing to word16, otherwise out of range
+     * value can wrap to a smaller key size */
+    if ((keySzBits < 0) || (keySzBits > (jint)WOLFSSL_MAX_16BIT)) {
+        return (jint)BAD_FUNC_ARG;
+    }
+
     return (jint)wolfSSL_CTX_SetMinDhKey_Sz(ctx, (word16)keySzBits);
 #else
     (void)jenv;
@@ -7110,11 +7116,17 @@ JNIEXPORT jint JNICALL Java_com_wolfssl_WolfSSLContext_setMinRsaKeySz
     WOLFSSL_CTX* ctx = (WOLFSSL_CTX*)(uintptr_t)ctxPtr;
     (void)obj;
 
-    /* wolfSSL_CTX_SetMinRsaKey_Sz() sanitizes ctx and keySzBits */
+    /* wolfSSL_CTX_SetMinRsaKey_Sz() sanitizes ctx */
     if (jenv == NULL) {
         return (jint)BAD_FUNC_ARG;
     }
 
+    /* Validate range before narrowing to short, otherwise out of range value
+     * can wrap to a smaller key size */
+    if ((keySzBits < 0) || (keySzBits > INT16_MAX)) {
+        return (jint)BAD_FUNC_ARG;
+    }
+
     return (jint)wolfSSL_CTX_SetMinRsaKey_Sz(ctx, (short)keySzBits);
 #else
     (void)jenv;
@@ -7132,11 +7144,17 @@ JNIEXPORT jint JNICALL Java_com_wolfssl_WolfSSLContext_setMinEccKeySz
     WOLFSSL_CTX* ctx = (WOLFSSL_CTX*)(uintptr_t)ctxPtr;
     (void)obj;
 
-    /* wolfSSL_CTX_SetMinEccKey_Sz() sanitizes ctx and keySzBits */
+    /* wolfSSL_CTX_SetMinEccKey_Sz() sanitizes ctx */
     if (jenv == NULL) {
         return (jint)BAD_FUNC_ARG;
     }
 
+    /* Validate range before narrowing to short, otherwise out of range value
+     * can wrap to a smaller key size */
+    if ((keySzBits < 0) || (keySzBits > INT16_MAX)) {
+        return (jint)BAD_FUNC_ARG;
+    }
+
     return (jint)wolfSSL_CTX_SetMinEccKey_Sz(ctx, (short)keySzBits);
 #else
     (void)jenv;
diff --git a/src/test/com/wolfssl/test/WolfSSLContextTest.java b/src/test/com/wolfssl/test/WolfSSLContextTest.java
index 71e492b..534a4b2 100644
--- a/src/test/com/wolfssl/test/WolfSSLContextTest.java
+++ b/src/test/com/wolfssl/test/WolfSSLContextTest.java
@@ -762,6 +762,13 @@ public class WolfSSLContextTest {
                 fail("setMinRSAKeySize should fail with negative key size");
             }
 
+            /* value that wraps across the 16-bit boundary should fail,
+             * 66560 wraps to 1024. */
+            ret = ctx.setMinRSAKeySize(66560);
+            if (ret != WolfSSL.BAD_FUNC_ARG) {
+                fail("setMinRSAKeySize should fail for out-of-range value");
+            }
+
             /* key length not % 8 should fail */
             ret = ctx.setMinRSAKeySize(1023);
             if (ret != WolfSSL.BAD_FUNC_ARG) {
@@ -814,6 +821,13 @@ public class WolfSSLContextTest {
                 fail("setMinECCKeySize should fail with negative key size");
             }
 
+            /* value that wraps across the 16-bit boundary should fail,
+             * 66048 narrows to 512. */
+            ret = ctx.setMinECCKeySize(66048);
+            if (ret != WolfSSL.BAD_FUNC_ARG) {
+                fail("setMinECCKeySize should fail for out-of-range value");
+            }
+
             /* valid key length should succeed */
             ret = ctx.setMinECCKeySize(128);
             if (ret != WolfSSL.SSL_SUCCESS) {
@@ -868,6 +882,13 @@ public class WolfSSLContextTest {
                 fail("setMinDHKeySize should fail with key size too large");
             }
 
+            /* value that wraps across the 16-bit boundary should fail,
+             * 66560 narrows to 1024. */
+            ret = ctx.setMinDHKeySize(66560);
+            if (ret != WolfSSL.BAD_FUNC_ARG) {
+                fail("setMinDHKeySize should fail for out-of-range value");
+            }
+
             /* key length not % 8 should fail */
             ret = ctx.setMinDHKeySize(1023);
             if (ret != WolfSSL.BAD_FUNC_ARG) {