From a9c4772bc66057d78d346b9a7e8b45b220c5b812 Mon Sep 17 00:00:00 2001 From: "Suraj N. Kurapati" Date: Thu, 17 Aug 2017 23:00:10 -0700 Subject: [PATCH 1/2] base64dec: skip non-printable characters like \r\n Non-printable characters, such as line breaks, in a base64 encoded string violate the "string length must be a multiple of four" rule. This patch pads the result buffer by one extra unit of four bytes, and skips over non-printable characters found in the input string. --- st.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/st.c b/st.c index ae93ade..7c7ddff 100644 --- a/st.c +++ b/st.c @@ -386,6 +386,13 @@ static const char base64_digits[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; +char +base64dec_getc(const char **src) +{ + while (**src && !isprint(**src)) (*src)++; + return *((*src)++); +} + char * base64dec(const char *src) { @@ -393,13 +400,13 @@ base64dec(const char *src) char *result, *dst; if (in_len % 4) - return NULL; + in_len += 4 - (in_len % 4); result = dst = xmalloc(in_len / 4 * 3 + 1); while (*src) { - int a = base64_digits[(unsigned char) *src++]; - int b = base64_digits[(unsigned char) *src++]; - int c = base64_digits[(unsigned char) *src++]; - int d = base64_digits[(unsigned char) *src++]; + int a = base64_digits[(unsigned char) base64dec_getc(&src)]; + int b = base64_digits[(unsigned char) base64dec_getc(&src)]; + int c = base64_digits[(unsigned char) base64dec_getc(&src)]; + int d = base64_digits[(unsigned char) base64dec_getc(&src)]; *dst++ = (a << 2) | ((b & 0x30) >> 4); if (c == -1) -- 2.14.1