Merge pull request #9076 from gilles-peskine-arm/cpp-unbounded-write-3.6
Backport 3.6: ssl_mail_client: Fix unbounded write of sprintf()
diff --git a/programs/ssl/ssl_mail_client.c b/programs/ssl/ssl_mail_client.c
index febb881..e3ed697 100644
--- a/programs/ssl/ssl_mail_client.c
+++ b/programs/ssl/ssl_mail_client.c
@@ -727,7 +727,11 @@
mbedtls_printf(" > Write MAIL FROM to server:");
fflush(stdout);
- len = sprintf((char *) buf, "MAIL FROM:<%s>\r\n", opt.mail_from);
+ len = mbedtls_snprintf((char *) buf, sizeof(buf), "MAIL FROM:<%s>\r\n", opt.mail_from);
+ if (len < 0 || (size_t) len >= sizeof(buf)) {
+ mbedtls_printf(" failed\n ! mbedtls_snprintf encountered error or truncated output\n\n");
+ goto exit;
+ }
ret = write_ssl_and_get_response(&ssl, buf, len);
if (ret < 200 || ret > 299) {
mbedtls_printf(" failed\n ! server responded with %d\n\n", ret);
@@ -739,7 +743,11 @@
mbedtls_printf(" > Write RCPT TO to server:");
fflush(stdout);
- len = sprintf((char *) buf, "RCPT TO:<%s>\r\n", opt.mail_to);
+ len = mbedtls_snprintf((char *) buf, sizeof(buf), "RCPT TO:<%s>\r\n", opt.mail_to);
+ if (len < 0 || (size_t) len >= sizeof(buf)) {
+ mbedtls_printf(" failed\n ! mbedtls_snprintf encountered error or truncated output\n\n");
+ goto exit;
+ }
ret = write_ssl_and_get_response(&ssl, buf, len);
if (ret < 200 || ret > 299) {
mbedtls_printf(" failed\n ! server responded with %d\n\n", ret);
@@ -763,11 +771,16 @@
mbedtls_printf(" > Write content to server:");
fflush(stdout);
- len = sprintf((char *) buf, "From: %s\r\nSubject: Mbed TLS Test mail\r\n\r\n"
- "This is a simple test mail from the "
- "Mbed TLS mail client example.\r\n"
- "\r\n"
- "Enjoy!", opt.mail_from);
+ len = mbedtls_snprintf((char *) buf, sizeof(buf),
+ "From: %s\r\nSubject: Mbed TLS Test mail\r\n\r\n"
+ "This is a simple test mail from the "
+ "Mbed TLS mail client example.\r\n"
+ "\r\n"
+ "Enjoy!", opt.mail_from);
+ if (len < 0 || (size_t) len >= sizeof(buf)) {
+ mbedtls_printf(" failed\n ! mbedtls_snprintf encountered error or truncated output\n\n");
+ goto exit;
+ }
ret = write_ssl_data(&ssl, buf, len);
len = sprintf((char *) buf, "\r\n.\r\n");