diff options
Diffstat (limited to 'coreutils')
| -rw-r--r-- | coreutils/uudecode.c | 53 |
1 files changed, 26 insertions, 27 deletions
diff --git a/coreutils/uudecode.c b/coreutils/uudecode.c index 207fb0b..0da9b09 100644 --- a/coreutils/uudecode.c +++ b/coreutils/uudecode.c @@ -77,18 +77,21 @@ static void read_stduu(FILE *src_stream, FILE *dst_stream) static void read_base64(FILE *src_stream, FILE *dst_stream) { - int term_count = 1; + int term_count = 0; while (1) { unsigned char translated[4]; int count = 0; + /* Process one group of 4 chars */ while (count < 4) { char *table_ptr; int ch; /* Get next _valid_ character. - * global vector bb_uuenc_tbl_base64[] contains this string: + * bb_uuenc_tbl_base64[] contains this string: + * 0 1 2 3 4 5 6 + * 012345678901234567890123456789012345678901234567890123456789012345 * "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=\n" */ do { @@ -103,42 +106,38 @@ static void read_base64(FILE *src_stream, FILE *dst_stream) bb_error_msg_and_die("short file"); } table_ptr = strchr(bb_uuenc_tbl_base64, ch); - } while (table_ptr == NULL); + } while (!table_ptr); /* Convert encoded character to decimal */ ch = table_ptr - bb_uuenc_tbl_base64; - if (*table_ptr == '=') { - if (term_count == 0) { - translated[count] = '\0'; - break; - } - term_count++; - } else if (*table_ptr == '\n') { - /* Check for terminating line */ - if (term_count == 5) { - return; - } - term_count = 1; - continue; - } else { - translated[count] = ch; - count++; + if (ch == 65 /* '\n' */) { + /* Terminating "====" line? */ + if (term_count == 4) + return; /* yes */ term_count = 0; + continue; + } + /* ch is 64 is char was '=', otherwise 0..63 */ + translated[count] = ch & 63; /* 64 -> 0 */ + if (ch == 64) { + term_count++; + break; } + count++; } - /* Merge 6 bit chars to 8 bit */ - if (count > 1) { + /* Merge 6 bit chars to 8 bit. + * count can be < 4 when we decode the tail: + * "eQ==" -> "y", not "y NUL NUL" + */ + if (count > 1) fputc(translated[0] << 2 | translated[1] >> 4, dst_stream); - } - if (count > 2) { + if (count > 2) fputc(translated[1] << 4 | translated[2] >> 2, dst_stream); - } - if (count > 3) { + if (count > 3) fputc(translated[2] << 6 | translated[3], dst_stream); - } - } + } /* while (1) */ } #if ENABLE_UUDECODE |