Add support for keyboard-interactive auth via userAuthCb

src/internal.c

@@ -13349,10 +13349,34 @@ int SendUserAuthKeyboardRequest(WOLFSSH* ssh, WS_UserAuthData* authData)
     }
 
     if (ret == WS_SUCCESS) {
-        ret = ssh->ctx->keyboardAuthCb(&authData->sf.keyboard,
-                                       ssh->keyboardAuthCtx);
+        /* Set responseCount to 0 to indicate this is a prompt setup call */
+        authData->sf.keyboard.responseCount = 0;
+
+        /* First try using userAuthCb if it's set */
+        if (ssh->ctx->userAuthCb != NULL) {
+            WLOG(WS_LOG_DEBUG, "SUAKR: Calling userAuthCb for prompt setup");
+            ret = ssh->ctx->userAuthCb(WOLFSSH_USERAUTH_KEYBOARD,
+                                      authData, ssh->userAuthCtx);
+
+            /* If userAuthCb doesn't return SUCCESS_ANOTHER, fall back to keyboardAuthCb */
+            if (ret != WOLFSSH_USERAUTH_SUCCESS_ANOTHER) {
+                WLOG(WS_LOG_DEBUG, "SUAKR: userAuthCb didn't return SUCCESS_ANOTHER, falling back");
+                ret = ssh->ctx->keyboardAuthCb(&authData->sf.keyboard,
+                                             ssh->keyboardAuthCtx);
+            }
+            else {
+                WLOG(WS_LOG_DEBUG, "SUAKR: userAuthCb returned SUCCESS_ANOTHER, proceeding");
+                ret = WS_SUCCESS;
+            }
+        }
+        else {
+            /* Fall back to keyboardAuthCb if userAuthCb is not set */
+            ret = ssh->ctx->keyboardAuthCb(&authData->sf.keyboard,
+                                         ssh->keyboardAuthCtx);
+        }
     }
 
+    /* Only check for NULL pointers if we actually have prompts */
     if (authData->sf.keyboard.promptCount > 0 &&
         (authData->sf.keyboard.prompts == NULL ||
          authData->sf.keyboard.promptLengths == NULL ||

tests/auth.c

@@ -156,6 +156,7 @@ word32 kbResponseCount;
 byte kbMultiRound = 0;
 byte currentRound = 0;
 byte unbalanced = 0;
+byte useUserAuthCb = 0;  /* Flag to test userAuthCb for keyboard-interactive */
 
 WS_UserAuthData_Keyboard promptData;
 
@@ -223,38 +224,73 @@ static int load_key(byte isEcc, byte* buf, word32 bufSz)
 static int serverUserAuth(byte authType, WS_UserAuthData* authData, void* ctx)
 {
     (void) ctx;
-    if (authType != WOLFSSH_USERAUTH_KEYBOARD) {
-        return WOLFSSH_USERAUTH_FAILURE;
-    }
-
-    if (authData->sf.keyboard.responseCount != kbResponseCount) {
-        return WOLFSSH_USERAUTH_FAILURE;
-    }
-
-    for (word32 resp = 0; resp < kbResponseCount; resp++) {
-        if (authData->sf.keyboard.responseLengths[resp] !=
-                kbResponseLengths[resp]) {
+
+    /* Handle keyboard-interactive auth */
+    if (authType == WOLFSSH_USERAUTH_KEYBOARD) {
+        /* If responseCount is 0, this is a prompt setup call */
+        if (authData->sf.keyboard.responseCount == 0) {
+            /* Set up prompts - only copy the necessary fields, not the entire structure */
+            authData->sf.keyboard.promptCount = promptData.promptCount;
+            authData->sf.keyboard.promptName = promptData.promptName;
+            authData->sf.keyboard.promptNameSz = promptData.promptNameSz;
+            authData->sf.keyboard.promptInstruction = promptData.promptInstruction;
+            authData->sf.keyboard.promptInstructionSz = promptData.promptInstructionSz;
+            authData->sf.keyboard.promptLanguage = promptData.promptLanguage;
+            authData->sf.keyboard.promptLanguageSz = promptData.promptLanguageSz;
+            authData->sf.keyboard.prompts = promptData.prompts;
+            authData->sf.keyboard.promptLengths = promptData.promptLengths;
+            authData->sf.keyboard.promptEcho = promptData.promptEcho;
+
+            /* Return SUCCESS_ANOTHER to proceed with sending prompts */
+            if (useUserAuthCb) {
+                return WOLFSSH_USERAUTH_SUCCESS_ANOTHER;
+            }
+            /* When not testing userAuthCb, return FAILURE to fall back to keyboardAuthCb */
             return WOLFSSH_USERAUTH_FAILURE;
-
         }
-        if (WSTRCMP((const char*)authData->sf.keyboard.responses[resp],
-                    (const char*)kbResponses[resp]) != 0) {
+
+        /* Validate responses */
+        if (authData->sf.keyboard.responseCount != kbResponseCount) {
             return WOLFSSH_USERAUTH_FAILURE;
         }
+
+        for (word32 resp = 0; resp < kbResponseCount; resp++) {
+            if (authData->sf.keyboard.responseLengths[resp] !=
+                    kbResponseLengths[resp]) {
+                return WOLFSSH_USERAUTH_FAILURE;
+
+            }
+            if (WSTRCMP((const char*)authData->sf.keyboard.responses[resp],
+                        (const char*)kbResponses[resp]) != 0) {
+                return WOLFSSH_USERAUTH_FAILURE;
+            }
+        }
+        if (kbMultiRound && currentRound == 0) {
+            currentRound++;
+            kbResponses[0] = (byte*)testText2;
+            kbResponseLengths[0] = 8;
+            return WOLFSSH_USERAUTH_SUCCESS_ANOTHER;
+        }
+        return WOLFSSH_USERAUTH_SUCCESS;
     }
-    if (kbMultiRound && currentRound == 0) {
-        currentRound++;
-        kbResponses[0] = (byte*)testText2;
-        kbResponseLengths[0] = 8;
-        return WOLFSSH_USERAUTH_SUCCESS_ANOTHER;
-    }
-    return WOLFSSH_USERAUTH_SUCCESS;
+
+    return WOLFSSH_USERAUTH_FAILURE;
 }
 
 static int serverKeyboardCallback(WS_UserAuthData_Keyboard *kbAuth, void *ctx)
 {
     (void) ctx;
-    WMEMCPY(kbAuth, &promptData, sizeof(WS_UserAuthData_Keyboard));
+    /* Copy individual fields instead of the entire structure to avoid memory issues */
+    kbAuth->promptCount = promptData.promptCount;
+    kbAuth->promptName = promptData.promptName;
+    kbAuth->promptNameSz = promptData.promptNameSz;
+    kbAuth->promptInstruction = promptData.promptInstruction;
+    kbAuth->promptInstructionSz = promptData.promptInstructionSz;
+    kbAuth->promptLanguage = promptData.promptLanguage;
+    kbAuth->promptLanguageSz = promptData.promptLanguageSz;
+    kbAuth->prompts = promptData.prompts;
+    kbAuth->promptLengths = promptData.promptLengths;
+    kbAuth->promptEcho = promptData.promptEcho;
 
     return WS_SUCCESS;
 }
@@ -332,7 +368,12 @@ static THREAD_RETURN WOLFSSH_THREAD server_thread(void* args)
     }
 
     wolfSSH_SetUserAuth(ctx, serverUserAuth);
-    wolfSSH_SetKeyboardAuthPrompts(ctx, serverKeyboardCallback);
+
+    /* Only set keyboard auth callback when not testing userAuthCb */
+    if (!useUserAuthCb) {
+        wolfSSH_SetKeyboardAuthPrompts(ctx, serverKeyboardCallback);
+    }
+
     ssh = wolfSSH_new(ctx);
     if (ssh == NULL) {
         ES_ERROR("Couldn't allocate SSH data.\n");
@@ -394,16 +435,24 @@ static int keyboardUserAuth(byte authType, WS_UserAuthData* authData, void* ctx)
 
     if (authType == WOLFSSH_USERAUTH_KEYBOARD) {
         AssertIntEQ(kbResponseCount, authData->sf.keyboard.promptCount);
-        for (word32 prompt = 0; prompt < kbResponseCount; prompt++) {
-            AssertStrEQ("Password: ", authData->sf.keyboard.prompts[prompt]);
+
+        /* Only check prompts if there are any */
+        if (kbResponseCount > 0) {
+            for (word32 prompt = 0; prompt < kbResponseCount; prompt++) {
+                AssertStrEQ("Password: ", authData->sf.keyboard.prompts[prompt]);
+            }
         }
 
         authData->sf.keyboard.responseCount = kbResponseCount;
         if (unbalanced) {
             authData->sf.keyboard.responseCount++;
         }
-        authData->sf.keyboard.responseLengths = kbResponseLengths;
-        authData->sf.keyboard.responses = (byte**)kbResponses;
+
+        /* Only set response pointers if there are responses */
+        if (kbResponseCount > 0) {
+            authData->sf.keyboard.responseLengths = kbResponseLengths;
+            authData->sf.keyboard.responses = (byte**)kbResponses;
+        }
         ret = WS_SUCCESS;
     }
     return ret;
@@ -574,6 +623,34 @@ static void test_unbalanced_client_KeyboardInteractive(void)
     test_client();
     unbalanced = 0;
 }
+
+static void test_userAuthCb_KeyboardInteractive(void)
+{
+    printf("Testing keyboard-interactive auth via userAuthCb\n");
+    kbResponses[0] = (byte*)testText1;
+    kbResponseLengths[0] = 4;
+    kbResponseCount = 1;
+    useUserAuthCb = 1;
+
+    test_client();
+    useUserAuthCb = 0;
+}
+
+static void test_userAuthCb_multi_round_KeyboardInteractive(void)
+{
+    printf("Testing multiple prompt rounds via userAuthCb\n");
+    kbResponses[0] = (byte*)testText1;
+    kbResponseLengths[0] = 4;
+    kbResponseCount = 1;
+    kbMultiRound = 1;
+    useUserAuthCb = 1;
+
+    test_client();
+    AssertIntEQ(currentRound, 1);
+    currentRound = 0;
+    kbMultiRound = 0;
+    useUserAuthCb = 0;
+}
 #endif /* WOLFSSH_TEST_BLOCK */
 
 int wolfSSH_AuthTest(int argc, char** argv)
@@ -603,6 +680,8 @@ int wolfSSH_AuthTest(int argc, char** argv)
     test_multi_prompt_KeyboardInteractive();
     test_multi_round_KeyboardInteractive();
     test_unbalanced_client_KeyboardInteractive();
+    test_userAuthCb_KeyboardInteractive();
+    test_userAuthCb_multi_round_KeyboardInteractive();
 
     AssertIntEQ(wolfSSH_Cleanup(), WS_SUCCESS);
 

wolfssh/ssh.h

@@ -360,6 +360,13 @@ typedef struct WS_UserAuthData {
     } sf;
 } WS_UserAuthData;
 
+/* User Authentication callback
+ * For keyboard-interactive authentication:
+ * - When responseCount is 0, the callback is being called to set up prompts
+ *   Return WOLFSSH_USERAUTH_SUCCESS_ANOTHER to proceed with sending prompts
+ * - When responseCount > 0, the callback is being called to validate responses
+ *   Return WOLFSSH_USERAUTH_SUCCESS_ANOTHER to request more prompts
+ */
 typedef int (*WS_CallbackUserAuth)(byte, WS_UserAuthData*, void*);
 WOLFSSH_API void wolfSSH_SetUserAuth(WOLFSSH_CTX*, WS_CallbackUserAuth);
 typedef int (*WS_CallbackUserAuthTypes)(WOLFSSH* ssh, void* ctx);