Fix documentation of BIO_FLAGS_BASE64_NO_NL

Commit 8bfb7506d2 updated
`BIO_f_base64(3)` to improve the documentation of the
`BIO_FLAGS_BASE64_NO_NL` flag.  In particular, the updated text
states that when this flag is used, all newlines in the input are
ignored.  This is incorrect, as the following program proves:

```c

unsigned char *in_buf =
    "IlRoZSBxdWljayBicm93biBmb3gganVt\ncHMgb3ZlciBhIGxhenkgZG9nLiI=\n";

int main(int argc, char **argv) {
    BIO *b64 = BIO_new(BIO_f_base64());
    if (b64 == NULL) return 1;
    BIO_set_flags(b64, BIO_get_flags(b64) | BIO_FLAGS_BASE64_NO_NL);
    int in_len = strlen(in_buf);
    BIO *in = BIO_new_mem_buf(in_buf, in_len);
    if (in == NULL) return 2;
    in = BIO_push(b64, in);
    unsigned char *out_buf = calloc(in_len, sizeof(unsigned char));
    if (out_buf == NULL) return 3;
    size_t out_len;
    int r = BIO_read_ex(in, out_buf, in_len, &out_len);
    printf("rv = %d\n", r);
    printf("decoded = %s\n", out_buf);
    return 0;
}
```

Update the text of `BIO_f_base64(3)` to clarify that when the flag
is set, the data must be all on one line (with or without a trailing
newline character).

Signed-off-by: Fraser Tweedale <ftweedal@redhat.com>

Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/18568)
This commit is contained in:
Fraser Tweedale 2022-06-15 10:50:57 +10:00 committed by Tomas Mraz
parent 909d590fe7
commit 0edcbacca9

View File

@ -38,9 +38,8 @@ to flush the final block through the BIO.
The flag BIO_FLAGS_BASE64_NO_NL can be set with BIO_set_flags().
For writing, it causes all data to be written on one line without
newline at the end.
For reading, it forces the decoder to process the data regardless
of newlines. All newlines are ignored and the input does not need
to contain any newline at all.
For reading, it expects the data to be all on one line (with or
without a trailing newline).
=head1 NOTES