diff options
Diffstat (limited to 'g10/armor.c')
| -rw-r--r-- | g10/armor.c | 224 |
1 files changed, 222 insertions, 2 deletions
diff --git a/g10/armor.c b/g10/armor.c index e84fb3709..8ffa5e6ea 100644 --- a/g10/armor.c +++ b/g10/armor.c @@ -151,8 +151,9 @@ initialize(void) } /**************** - * Check whether this is an armored file or not - * See also parse-packet.c for details on this code + * Check whether this is an armored file or not See also + * parse-packet.c for details on this code For unknown historic + * reasons we use a string here but only the first byte will be used. * Returns: True if it seems to be armored */ static int @@ -195,6 +196,7 @@ use_armor_filter( IOBUF a ) byte buf[1]; int n; + /* fixme: there might be a problem with iobuf_peek */ n = iobuf_peek(a, buf, 1 ); if( n == -1 ) return 0; /* EOF, doesn't matter whether armored or not */ @@ -1093,3 +1095,221 @@ make_radix64_string( const byte *data, size_t len ) return buffer; } + +/*********************************************** + * For the pipemode command we can't use the armor filter for various + * reasons, so we use this new unarmor_pump stuff to remove the armor + */ + +enum unarmor_state_e { + STA_init = 0, + STA_bypass, + STA_wait_newline, + STA_wait_dash, + STA_first_dash, + STA_compare_header, + STA_found_header_wait_newline, + STA_skip_header_lines, + STA_skip_header_lines_non_ws, + STA_read_data, + STA_wait_crc, + STA_read_crc, + STA_ready +}; + +struct unarmor_pump_s { + enum unarmor_state_e state; + byte val; + int checkcrc; + int pos; /* counts from 0..3 */ + u32 crc; + u32 mycrc; /* the one store in the data */ +}; + + + +UnarmorPump +unarmor_pump_new (void) +{ + UnarmorPump x; + + if( !is_initialized ) + initialize(); + x = m_alloc_clear (sizeof *x); + return x; +} + +void +unarmor_pump_release (UnarmorPump x) +{ + m_free (x); +} + +/* + * Get the next character from the ascii armor taken from the IOBUF + * created earlier by unarmor_pump_new(). + * Return: c = Character + * 256 = ignore this value + * -1 = End of current armor + * -2 = Premature EOF (not used) + * -3 = Invalid armor + */ +int +unarmor_pump (UnarmorPump x, int c) +{ + int rval = 256; /* default is to ignore the return value */ + + switch (x->state) { + case STA_init: + { + byte tmp[1]; + tmp[0] = c; + if ( is_armored (tmp) ) + x->state = c == '-'? STA_first_dash : STA_wait_newline; + else { + x->state = STA_bypass; + return c; + } + } + break; + case STA_bypass: + return c; /* return here to avoid crc calculation */ + case STA_wait_newline: + if (c == '\n') + x->state = STA_wait_dash; + break; + case STA_wait_dash: + x->state = c == '-'? STA_first_dash : STA_wait_newline; + break; + case STA_first_dash: /* just need for initalization */ + x->pos = 0; + x->state = STA_compare_header; + case STA_compare_header: + if ( "-----BEGIN PGP SIGNATURE-----"[++x->pos] == c ) { + if ( x->pos == 28 ) + x->state = STA_found_header_wait_newline; + } + else + x->state = c == '\n'? STA_wait_dash : STA_wait_newline; + break; + case STA_found_header_wait_newline: + /* to make CR,LF issues easier we simply allow for white space + behind the 5 dashes */ + if ( c == '\n' ) + x->state = STA_skip_header_lines; + else if ( c != '\r' && c != ' ' && c != '\t' ) + x->state = STA_wait_dash; /* garbage after the header line */ + break; + case STA_skip_header_lines: + /* i.e. wait for one empty line */ + if ( c == '\n' ) { + x->state = STA_read_data; + x->crc = CRCINIT; + x->val = 0; + x->pos = 0; + } + else if ( c != '\r' && c != ' ' && c != '\t' ) + x->state = STA_skip_header_lines_non_ws; + break; + case STA_skip_header_lines_non_ws: + /* like above but we already encountered non white space */ + if ( c == '\n' ) + x->state = STA_skip_header_lines; + break; + case STA_read_data: + /* fixme: we don't check for the trailing dash lines but rely + * on the armor stop characters */ + if( c == '\n' || c == ' ' || c == '\r' || c == '\t' ) + break; /* skip all kind of white space */ + + if( c == '=' ) { /* pad character: stop */ + if( x->pos == 1 ) /* in this case val has some value */ + rval = x->val; + x->state = STA_wait_crc; + break; + } + + { + int c2; + if( (c = asctobin[(c2=c)]) == 255 ) { + log_error(_("invalid radix64 character %02x skipped\n"), c2); + break; + } + } + + switch(x->pos) { + case 0: + x->val = c << 2; + break; + case 1: + x->val |= (c>>4)&3; + rval = x->val; + x->val = (c<<4)&0xf0; + break; + case 2: + x->val |= (c>>2)&15; + rval = x->val; + x->val = (c<<6)&0xc0; + break; + case 3: + x->val |= c&0x3f; + rval = x->val; + break; + } + x->pos = (x->pos+1) % 4; + break; + case STA_wait_crc: + if( c == '\n' || c == ' ' || c == '\r' || c == '\t' || c == '=' ) + break; /* skip ws and pad characters */ + /* assume that we are at the next line */ + x->state = STA_read_crc; + x->pos = 0; + x->mycrc = 0; + case STA_read_crc: + if( (c = asctobin[c]) == 255 ) { + rval = -1; /* ready */ + if( x->crc != x->mycrc ) { + log_info (_("CRC error; %06lx - %06lx\n"), + (ulong)x->crc, (ulong)x->mycrc); + if ( invalid_crc() ) + rval = -3; + } + x->state = STA_ready; /* not sure whether this is correct */ + break; + } + + switch(x->pos) { + case 0: + x->val = c << 2; + break; + case 1: + x->val |= (c>>4)&3; + x->mycrc |= x->val << 16; + x->val = (c<<4)&0xf0; + break; + case 2: + x->val |= (c>>2)&15; + x->mycrc |= x->val << 8; + x->val = (c<<6)&0xc0; + break; + case 3: + x->val |= c&0x3f; + x->mycrc |= x->val; + break; + } + x->pos = (x->pos+1) % 4; + break; + case STA_ready: + rval = -1; + break; + } + + if ( !(rval & ~255) ) { /* compute the CRC */ + x->crc = (x->crc << 8) ^ crc_table[((x->crc >> 16)&0xff) ^ rval]; + x->crc &= 0x00ffffff; + } + + return rval; +} + + |