[mynewt-core] 03/04: base64: Fail on incomplete input

[ccollins]

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ccollins pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/mynewt-core.git

commit fa773361fd420e6437e387a13f6ac58151e02bed
Author: Christopher Collins <ccoll...@apache.org>
AuthorDate: Sat Jun 13 10:47:08 2020 -0700

    base64: Fail on incomplete input
    
    The code was relying on strchr to detect a misplaced null terminator.
    However, from `man strchr`:
    
        The terminating null byte is considered part of the string, so that
        if c is specified as '\0', these functions return a pointer to the
        terminator.
    
    The fix is to check for a null character separately.
---
 encoding/base64/src/base64.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/encoding/base64/src/base64.c b/encoding/base64/src/base64.c
index 30fb079..d36d4f0 100644
--- a/encoding/base64/src/base64.c
+++ b/encoding/base64/src/base64.c
@@ -231,6 +231,10 @@ base64_decoder_go(struct base64_decoder *dec)
         /* Detect invalid input. */
         for (i = 0; i < read_len; i++) {
             sval = dec->src[src_off + i];
+            if (sval == '\0') {
+                /* Incomplete input. */
+                return -1;
+            }
             if (sval != '=' && strchr(base64_chars, sval) == NULL) {
                 /* Invalid base64 character. */
                 return -1;