add encryptedcontent to functioncalloutput (#23500)

add new `EncryptedContent` variant to `FunctionCallOutputContentItem`
ahead of standalone websearch.

we need to be able to receive and pass encrypted function call output
from the new web search endpoint back to responsesapi, as we cannot
expose direct search results.

codex-rs/core/src/context_manager/history.rs

@@ -504,6 +504,10 @@ fn estimate_reasoning_length(encoded_len: usize) -> usize {
         .saturating_sub(650)
 }
 
+fn estimate_encrypted_function_output_length(encoded_len: usize) -> usize {
+    encoded_len.saturating_mul(9).div_ceil(16)
+}
+
 fn estimate_item_token_count(item: &ResponseItem) -> i64 {
     let model_visible_bytes = estimate_response_item_model_visible_bytes(item);
     approx_tokens_from_byte_count_i64(model_visible_bytes)
@@ -547,16 +551,18 @@ pub(crate) fn estimate_response_item_model_visible_bytes(item: &ResponseItem) ->
             let raw = serde_json::to_string(item)
                 .map(|serialized| i64::try_from(serialized.len()).unwrap_or(i64::MAX))
                 .unwrap_or_default();
-            let (payload_bytes, replacement_bytes) = image_data_url_estimate_adjustment(item);
-            if payload_bytes == 0 || replacement_bytes == 0 {
-                raw
-            } else {
-                // Replace raw base64 payload bytes with a per-image estimate.
-                // We intentionally preserve the data URL prefix and JSON
-                // wrapper bytes already included in `raw`.
-                raw.saturating_sub(payload_bytes)
-                    .saturating_add(replacement_bytes)
-            }
+            let (image_payload_bytes, image_replacement_bytes) =
+                image_data_url_estimate_adjustment(item);
+            let (encrypted_payload_bytes, encrypted_replacement_bytes) =
+                encrypted_function_output_estimate_adjustment(item);
+            // Replace raw base64 payload bytes with a per-image estimate.
+            // We intentionally preserve the data URL prefix and JSON
+            // wrapper bytes already included in `raw`.
+            let raw = raw
+                .saturating_sub(image_payload_bytes)
+                .saturating_add(image_replacement_bytes);
+            raw.saturating_sub(encrypted_payload_bytes)
+                .saturating_add(encrypted_replacement_bytes)
         }
     }
 }
@@ -678,6 +684,31 @@ fn image_data_url_estimate_adjustment(item: &ResponseItem) -> (i64, i64) {
     (payload_bytes, replacement_bytes)
 }
 
+fn encrypted_function_output_estimate_adjustment(item: &ResponseItem) -> (i64, i64) {
+    let ResponseItem::FunctionCallOutput { output, .. } = item else {
+        return (0, 0);
+    };
+    let FunctionCallOutputBody::ContentItems(items) = &output.body else {
+        return (0, 0);
+    };
+
+    items.iter().fold((0i64, 0i64), |acc, item| {
+        let FunctionCallOutputContentItem::EncryptedContent { encrypted_content } = item else {
+            return acc;
+        };
+        let payload_bytes = acc
+            .0
+            .saturating_add(i64::try_from(encrypted_content.len()).unwrap_or(i64::MAX));
+        let replacement_bytes = acc.1.saturating_add(
+            i64::try_from(estimate_encrypted_function_output_length(
+                encrypted_content.len(),
+            ))
+            .unwrap_or(i64::MAX),
+        );
+        (payload_bytes, replacement_bytes)
+    })
+}
+
 fn is_model_generated_item(item: &ResponseItem) -> bool {
     match item {
         ResponseItem::Message { role, .. } => role == "assistant",

codex-rs/core/src/context_manager/history_tests.rs

@@ -1754,6 +1754,26 @@ fn non_base64_image_urls_are_unchanged() {
     );
 }
 
+#[test]
+fn encrypted_function_output_uses_plaintext_byte_estimate() {
+    let encrypted_content = "A".repeat(1_868);
+    let item = ResponseItem::FunctionCallOutput {
+        call_id: "call-encrypted".to_string(),
+        output: FunctionCallOutputPayload::from_content_items(vec![
+            FunctionCallOutputContentItem::EncryptedContent {
+                encrypted_content: encrypted_content.clone(),
+            },
+        ]),
+    };
+
+    let raw_len = serde_json::to_string(&item).unwrap().len() as i64;
+    let estimated = estimate_response_item_model_visible_bytes(&item);
+    let expected = raw_len - encrypted_content.len() as i64
+        + estimate_encrypted_function_output_length(encrypted_content.len()) as i64;
+
+    assert_eq!(estimated, expected);
+}
+
 #[test]
 fn data_url_without_base64_marker_is_unchanged() {
     let item = ResponseItem::Message {