From fa5937aaed0268286faecf193ebdaa862118f207 Mon Sep 17 00:00:00 2001
From: Marcin Niestroj <m.niestroj@emb.dev>
Date: Wed, 15 Jun 2022 00:22:03 +0200
Subject: [PATCH] modules: mbedtls: support stripping newline from debug log
 messages

Debug log messages generated by mbedTLS library contain newline at the end
of log string. Remove this newline, if it exists, so that log output is
much more user friendly.

Add a dedicated Kconfig option for that, so it can be disabled on request.

Signed-off-by: Marcin Niestroj <m.niestroj@emb.dev>
---
 modules/mbedtls/Kconfig |  7 +++++++
 modules/mbedtls/debug.c | 18 ++++++++++++++----
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/modules/mbedtls/Kconfig b/modules/mbedtls/Kconfig
index 9474941cbf3..ced8519ba2d 100644
--- a/modules/mbedtls/Kconfig
+++ b/modules/mbedtls/Kconfig
@@ -146,6 +146,13 @@ config MBEDTLS_DEBUG_EXTRACT_BASENAME_DISABLED
 
 endchoice
 
+config MBEDTLS_DEBUG_STRIP_NEWLINE
+	bool "Strip newlines"
+	default y
+	help
+	  Attempt to strip last character from logged string when it is a
+	  newline.
+
 endif # MBEDTLS_DEBUG
 
 config MBEDTLS_MEMORY_DEBUG
diff --git a/modules/mbedtls/debug.c b/modules/mbedtls/debug.c
index 170400264af..69bafc9c6d6 100644
--- a/modules/mbedtls/debug.c
+++ b/modules/mbedtls/debug.c
@@ -13,6 +13,7 @@ LOG_MODULE_REGISTER(mbedtls, CONFIG_MBEDTLS_LOG_LEVEL);
 void zephyr_mbedtls_debug(void *ctx, int level, const char *file, int line, const char *str)
 {
 	const char *p, *basename = file;
+	int str_len;
 
 	ARG_UNUSED(ctx);
 
@@ -29,19 +30,28 @@ void zephyr_mbedtls_debug(void *ctx, int level, const char *file, int line, cons
 		}
 	}
 
+	str_len = strlen(str);
+
+	if (IS_ENABLED(CONFIG_MBEDTLS_DEBUG_STRIP_NEWLINE)) {
+		/* Remove newline only when it exists */
+		if (str_len > 0 && str[str_len - 1] == '\n') {
+			str_len--;
+		}
+	}
+
 	switch (level) {
 	case 0:
 	case 1:
-		LOG_ERR("%s:%04d: %s", basename, line, str);
+		LOG_ERR("%s:%04d: %.*s", basename, line, str_len, str);
 		break;
 	case 2:
-		LOG_WRN("%s:%04d: %s", basename, line, str);
+		LOG_WRN("%s:%04d: %.*s", basename, line, str_len, str);
 		break;
 	case 3:
-		LOG_INF("%s:%04d: %s", basename, line, str);
+		LOG_INF("%s:%04d: %.*s", basename, line, str_len, str);
 		break;
 	default:
-		LOG_DBG("%s:%04d: %s", basename, line, str);
+		LOG_DBG("%s:%04d: %.*s", basename, line, str_len, str);
 		break;
 	}
 }