From 298839b69f04d01ec5ba2e77c3b9f7d351384809 Mon Sep 17 00:00:00 2001
From: Jacob Champion <jacob.champion@enterprisedb.com>
Date: Thu, 6 Feb 2025 14:56:04 -0800
Subject: [PATCH v47 07/11] fixup! Add OAUTHBEARER SASL mechanism

---
 src/interfaces/libpq/fe-auth-oauth-curl.c | 48 +++++++++++++++++------
 1 file changed, 37 insertions(+), 11 deletions(-)

diff --git a/src/interfaces/libpq/fe-auth-oauth-curl.c b/src/interfaces/libpq/fe-auth-oauth-curl.c
index 6c8333789f1..993ca3bdab9 100644
--- a/src/interfaces/libpq/fe-auth-oauth-curl.c
+++ b/src/interfaces/libpq/fe-auth-oauth-curl.c
@@ -1329,8 +1329,9 @@ static int
 debug_callback(CURL *handle, curl_infotype type, char *data, size_t size,
 			   void *clientp)
 {
-	const char *const end = data + size;
 	const char *prefix;
+	bool		printed_prefix = false;
+	PQExpBufferData buf;
 
 	/* Prefixes are modeled off of the default libcurl debug output. */
 	switch (type)
@@ -1353,25 +1354,50 @@ debug_callback(CURL *handle, curl_infotype type, char *data, size_t size,
 			return 0;
 	}
 
+	initPQExpBuffer(&buf);
+
 	/*
 	 * Split the output into lines for readability; sometimes multiple headers
-	 * are included in a single call.
+	 * are included in a single call. We also don't allow unprintable ASCII
+	 * through without a basic <XX> escape.
 	 */
-	while (data < end)
+	for (int i = 0; i < size; i++)
 	{
-		size_t		len = end - data;
-		char	   *eol = memchr(data, '\n', len);
+		char		c = data[i];
 
-		if (eol)
-			len = eol - data + 1;
+		if (!printed_prefix)
+		{
+			appendPQExpBuffer(&buf, "%s ", prefix);
+			printed_prefix = true;
+		}
 
-		/* TODO: handle unprintables */
-		fprintf(stderr, "%s %.*s%s", prefix, (int) len, data,
-				eol ? "" : "\n");
+		if (c >= 0x20 && c <= 0x7E)
+			appendPQExpBufferChar(&buf, c);
+		else if ((type == CURLINFO_HEADER_IN
+				  || type == CURLINFO_HEADER_OUT
+				  || type == CURLINFO_TEXT)
+				 && (c == '\r' || c == '\n'))
+		{
+			/*
+			 * Don't bother emitting <0D><0A> for headers and text; it's not
+			 * helpful noise.
+			 */
+		}
+		else
+			appendPQExpBuffer(&buf, "<%02X>", c);
 
-		data += len;
+		if (c == '\n')
+		{
+			appendPQExpBufferChar(&buf, c);
+			printed_prefix = false;
+		}
 	}
 
+	if (printed_prefix)
+		appendPQExpBufferChar(&buf, '\n');	/* finish the line */
+
+	fprintf(stderr, "%s", buf.data);
+	termPQExpBuffer(&buf);
 	return 0;
 }
 
-- 
2.34.1