diff options
Diffstat (limited to 'common/b64enc.c')
| -rw-r--r-- | common/b64enc.c | 422 |
1 files changed, 422 insertions, 0 deletions
diff --git a/common/b64enc.c b/common/b64enc.c new file mode 100644 index 0000000..d633048 --- /dev/null +++ b/common/b64enc.c @@ -0,0 +1,422 @@ +/* b64enc.c - Simple Base64 encoder. + * Copyright (C) 2001, 2003, 2004, 2008, 2010, + * 2011 Free Software Foundation, Inc. + * Copyright (C) 2001, 2003, 2004, 2008, 2010, + * 2011 g10 Code GmbH + * + * This file is part of GnuPG. + * + * This file is free software; you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as + * published by the Free Software Foundation; either version 2.1 of + * the License, or (at your option) any later version. + * + * This file is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with this program; if not, see <https://www.gnu.org/licenses/>. + */ + +#include <config.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <assert.h> + +#include "i18n.h" +#include "util.h" + +#define B64ENC_DID_HEADER 1 +#define B64ENC_DID_TRAILER 2 +#define B64ENC_NO_LINEFEEDS 16 +#define B64ENC_USE_PGPCRC 32 + +/* The base-64 character list */ +static unsigned char bintoasc[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "abcdefghijklmnopqrstuvwxyz" + "0123456789+/"; + +/* Stuff required to create the OpenPGP CRC. This crc_table has been + created using this code: + + #include <stdio.h> + #include <stdint.h> + + #define CRCPOLY 0x864CFB + + int + main (void) + { + int i, j; + uint32_t t; + uint32_t crc_table[256]; + + crc_table[0] = 0; + for (i=j=0; j < 128; j++ ) + { + t = crc_table[j]; + if ( (t & 0x00800000) ) + { + t <<= 1; + crc_table[i++] = t ^ CRCPOLY; + crc_table[i++] = t; + } + else + { + t <<= 1; + crc_table[i++] = t; + crc_table[i++] = t ^ CRCPOLY; + } + } + + puts ("static const u32 crc_table[256] = {"); + for (i=j=0; i < 256; i++) + { + printf ("%s 0x%08lx", j? "":" ", (unsigned long)crc_table[i]); + if (i != 255) + { + putchar (','); + if ( ++j > 5) + { + j = 0; + putchar ('\n'); + } + } + } + puts ("\n};"); + return 0; + } +*/ +#define CRCINIT 0xB704CE +static const u32 crc_table[256] = { + 0x00000000, 0x00864cfb, 0x018ad50d, 0x010c99f6, 0x0393e6e1, 0x0315aa1a, + 0x021933ec, 0x029f7f17, 0x07a18139, 0x0727cdc2, 0x062b5434, 0x06ad18cf, + 0x043267d8, 0x04b42b23, 0x05b8b2d5, 0x053efe2e, 0x0fc54e89, 0x0f430272, + 0x0e4f9b84, 0x0ec9d77f, 0x0c56a868, 0x0cd0e493, 0x0ddc7d65, 0x0d5a319e, + 0x0864cfb0, 0x08e2834b, 0x09ee1abd, 0x09685646, 0x0bf72951, 0x0b7165aa, + 0x0a7dfc5c, 0x0afbb0a7, 0x1f0cd1e9, 0x1f8a9d12, 0x1e8604e4, 0x1e00481f, + 0x1c9f3708, 0x1c197bf3, 0x1d15e205, 0x1d93aefe, 0x18ad50d0, 0x182b1c2b, + 0x192785dd, 0x19a1c926, 0x1b3eb631, 0x1bb8faca, 0x1ab4633c, 0x1a322fc7, + 0x10c99f60, 0x104fd39b, 0x11434a6d, 0x11c50696, 0x135a7981, 0x13dc357a, + 0x12d0ac8c, 0x1256e077, 0x17681e59, 0x17ee52a2, 0x16e2cb54, 0x166487af, + 0x14fbf8b8, 0x147db443, 0x15712db5, 0x15f7614e, 0x3e19a3d2, 0x3e9fef29, + 0x3f9376df, 0x3f153a24, 0x3d8a4533, 0x3d0c09c8, 0x3c00903e, 0x3c86dcc5, + 0x39b822eb, 0x393e6e10, 0x3832f7e6, 0x38b4bb1d, 0x3a2bc40a, 0x3aad88f1, + 0x3ba11107, 0x3b275dfc, 0x31dced5b, 0x315aa1a0, 0x30563856, 0x30d074ad, + 0x324f0bba, 0x32c94741, 0x33c5deb7, 0x3343924c, 0x367d6c62, 0x36fb2099, + 0x37f7b96f, 0x3771f594, 0x35ee8a83, 0x3568c678, 0x34645f8e, 0x34e21375, + 0x2115723b, 0x21933ec0, 0x209fa736, 0x2019ebcd, 0x228694da, 0x2200d821, + 0x230c41d7, 0x238a0d2c, 0x26b4f302, 0x2632bff9, 0x273e260f, 0x27b86af4, + 0x252715e3, 0x25a15918, 0x24adc0ee, 0x242b8c15, 0x2ed03cb2, 0x2e567049, + 0x2f5ae9bf, 0x2fdca544, 0x2d43da53, 0x2dc596a8, 0x2cc90f5e, 0x2c4f43a5, + 0x2971bd8b, 0x29f7f170, 0x28fb6886, 0x287d247d, 0x2ae25b6a, 0x2a641791, + 0x2b688e67, 0x2beec29c, 0x7c3347a4, 0x7cb50b5f, 0x7db992a9, 0x7d3fde52, + 0x7fa0a145, 0x7f26edbe, 0x7e2a7448, 0x7eac38b3, 0x7b92c69d, 0x7b148a66, + 0x7a181390, 0x7a9e5f6b, 0x7801207c, 0x78876c87, 0x798bf571, 0x790db98a, + 0x73f6092d, 0x737045d6, 0x727cdc20, 0x72fa90db, 0x7065efcc, 0x70e3a337, + 0x71ef3ac1, 0x7169763a, 0x74578814, 0x74d1c4ef, 0x75dd5d19, 0x755b11e2, + 0x77c46ef5, 0x7742220e, 0x764ebbf8, 0x76c8f703, 0x633f964d, 0x63b9dab6, + 0x62b54340, 0x62330fbb, 0x60ac70ac, 0x602a3c57, 0x6126a5a1, 0x61a0e95a, + 0x649e1774, 0x64185b8f, 0x6514c279, 0x65928e82, 0x670df195, 0x678bbd6e, + 0x66872498, 0x66016863, 0x6cfad8c4, 0x6c7c943f, 0x6d700dc9, 0x6df64132, + 0x6f693e25, 0x6fef72de, 0x6ee3eb28, 0x6e65a7d3, 0x6b5b59fd, 0x6bdd1506, + 0x6ad18cf0, 0x6a57c00b, 0x68c8bf1c, 0x684ef3e7, 0x69426a11, 0x69c426ea, + 0x422ae476, 0x42aca88d, 0x43a0317b, 0x43267d80, 0x41b90297, 0x413f4e6c, + 0x4033d79a, 0x40b59b61, 0x458b654f, 0x450d29b4, 0x4401b042, 0x4487fcb9, + 0x461883ae, 0x469ecf55, 0x479256a3, 0x47141a58, 0x4defaaff, 0x4d69e604, + 0x4c657ff2, 0x4ce33309, 0x4e7c4c1e, 0x4efa00e5, 0x4ff69913, 0x4f70d5e8, + 0x4a4e2bc6, 0x4ac8673d, 0x4bc4fecb, 0x4b42b230, 0x49ddcd27, 0x495b81dc, + 0x4857182a, 0x48d154d1, 0x5d26359f, 0x5da07964, 0x5cace092, 0x5c2aac69, + 0x5eb5d37e, 0x5e339f85, 0x5f3f0673, 0x5fb94a88, 0x5a87b4a6, 0x5a01f85d, + 0x5b0d61ab, 0x5b8b2d50, 0x59145247, 0x59921ebc, 0x589e874a, 0x5818cbb1, + 0x52e37b16, 0x526537ed, 0x5369ae1b, 0x53efe2e0, 0x51709df7, 0x51f6d10c, + 0x50fa48fa, 0x507c0401, 0x5542fa2f, 0x55c4b6d4, 0x54c82f22, 0x544e63d9, + 0x56d11cce, 0x56575035, 0x575bc9c3, 0x57dd8538 +}; + + +static gpg_error_t +enc_start (struct b64state *state, FILE *fp, estream_t stream, + const char *title) +{ + memset (state, 0, sizeof *state); + state->fp = fp; + state->stream = stream; + state->lasterr = 0; + if (title && !*title) + state->flags |= B64ENC_NO_LINEFEEDS; + else if (title) + { + if (!strncmp (title, "PGP ", 4)) + { + state->flags |= B64ENC_USE_PGPCRC; + state->crc = CRCINIT; + } + state->title = xtrystrdup (title); + if (!state->title) + state->lasterr = gpg_error_from_syserror (); + } + return state->lasterr; +} + + +/* Prepare for base-64 writing to the stream FP. If TITLE is not NULL + and not an empty string, this string will be used as the title for + the armor lines, with TITLE being an empty string, we don't write + the header lines and furthermore even don't write any linefeeds. + If TITLE starts with "PGP " the OpenPGP CRC checksum will be + written as well. With TITLE being NULL, we merely don't write + header but make sure that lines are not too long. Note, that we + don't write any output unless at least one byte get written using + b64enc_write. */ +gpg_error_t +b64enc_start (struct b64state *state, FILE *fp, const char *title) +{ + return enc_start (state, fp, NULL, title); +} + +/* Same as b64enc_start but takes an estream. */ +gpg_error_t +b64enc_start_es (struct b64state *state, estream_t fp, const char *title) +{ + return enc_start (state, NULL, fp, title); +} + + +static int +my_fputs (const char *string, struct b64state *state) +{ + if (state->stream) + return es_fputs (string, state->stream); + else + return fputs (string, state->fp); +} + + +/* Write NBYTES from BUFFER to the Base 64 stream identified by + STATE. With BUFFER and NBYTES being 0, merely do a fflush on the + stream. */ +gpg_error_t +b64enc_write (struct b64state *state, const void *buffer, size_t nbytes) +{ + unsigned char radbuf[4]; + int idx, quad_count; + const unsigned char *p; + + if (state->lasterr) + return state->lasterr; + + if (!nbytes) + { + if (buffer) + if (state->stream? es_fflush (state->stream) : fflush (state->fp)) + goto write_error; + return 0; + } + + if (!(state->flags & B64ENC_DID_HEADER)) + { + if (state->title) + { + if ( my_fputs ("-----BEGIN ", state) == EOF + || my_fputs (state->title, state) == EOF + || my_fputs ("-----\n", state) == EOF) + goto write_error; + if ( (state->flags & B64ENC_USE_PGPCRC) + && my_fputs ("\n", state) == EOF) + goto write_error; + } + + state->flags |= B64ENC_DID_HEADER; + } + + idx = state->idx; + quad_count = state->quad_count; + assert (idx < 4); + memcpy (radbuf, state->radbuf, idx); + + if ( (state->flags & B64ENC_USE_PGPCRC) ) + { + size_t n; + u32 crc = state->crc; + + for (p=buffer, n=nbytes; n; p++, n-- ) + crc = ((u32)crc << 8) ^ crc_table[((crc >> 16)&0xff) ^ *p]; + state->crc = (crc & 0x00ffffff); + } + + for (p=buffer; nbytes; p++, nbytes--) + { + radbuf[idx++] = *p; + if (idx > 2) + { + char tmp[4]; + + tmp[0] = bintoasc[(*radbuf >> 2) & 077]; + tmp[1] = bintoasc[(((*radbuf<<4)&060)|((radbuf[1] >> 4)&017))&077]; + tmp[2] = bintoasc[(((radbuf[1]<<2)&074)|((radbuf[2]>>6)&03))&077]; + tmp[3] = bintoasc[radbuf[2]&077]; + if (state->stream) + { + for (idx=0; idx < 4; idx++) + es_putc (tmp[idx], state->stream); + idx = 0; + if (es_ferror (state->stream)) + goto write_error; + } + else + { + for (idx=0; idx < 4; idx++) + putc (tmp[idx], state->fp); + idx = 0; + if (ferror (state->fp)) + goto write_error; + } + if (++quad_count >= (64/4)) + { + quad_count = 0; + if (!(state->flags & B64ENC_NO_LINEFEEDS) + && my_fputs ("\n", state) == EOF) + goto write_error; + } + } + } + memcpy (state->radbuf, radbuf, idx); + state->idx = idx; + state->quad_count = quad_count; + return 0; + + write_error: + state->lasterr = gpg_error_from_syserror (); + if (state->title) + { + xfree (state->title); + state->title = NULL; + } + return state->lasterr; +} + + +gpg_error_t +b64enc_finish (struct b64state *state) +{ + gpg_error_t err = 0; + unsigned char radbuf[4]; + int idx, quad_count; + char tmp[4]; + + if (state->lasterr) + return state->lasterr; + + if (!(state->flags & B64ENC_DID_HEADER)) + goto cleanup; + + /* Flush the base64 encoding */ + idx = state->idx; + quad_count = state->quad_count; + assert (idx < 4); + memcpy (radbuf, state->radbuf, idx); + + if (idx) + { + tmp[0] = bintoasc[(*radbuf>>2)&077]; + if (idx == 1) + { + tmp[1] = bintoasc[((*radbuf << 4) & 060) & 077]; + tmp[2] = '='; + tmp[3] = '='; + } + else + { + tmp[1] = bintoasc[(((*radbuf<<4)&060)|((radbuf[1]>>4)&017))&077]; + tmp[2] = bintoasc[((radbuf[1] << 2) & 074) & 077]; + tmp[3] = '='; + } + if (state->stream) + { + for (idx=0; idx < 4; idx++) + es_putc (tmp[idx], state->stream); + if (es_ferror (state->stream)) + goto write_error; + } + else + { + for (idx=0; idx < 4; idx++) + putc (tmp[idx], state->fp); + if (ferror (state->fp)) + goto write_error; + } + + if (++quad_count >= (64/4)) + { + quad_count = 0; + if (!(state->flags & B64ENC_NO_LINEFEEDS) + && my_fputs ("\n", state) == EOF) + goto write_error; + } + } + + /* Finish the last line and write the trailer. */ + if (quad_count + && !(state->flags & B64ENC_NO_LINEFEEDS) + && my_fputs ("\n", state) == EOF) + goto write_error; + + if ( (state->flags & B64ENC_USE_PGPCRC) ) + { + /* Write the CRC. */ + my_fputs ("=", state); + radbuf[0] = state->crc >>16; + radbuf[1] = state->crc >> 8; + radbuf[2] = state->crc; + tmp[0] = bintoasc[(*radbuf>>2)&077]; + tmp[1] = bintoasc[(((*radbuf<<4)&060)|((radbuf[1]>>4)&017))&077]; + tmp[2] = bintoasc[(((radbuf[1]<<2)&074)|((radbuf[2]>>6)&03))&077]; + tmp[3] = bintoasc[radbuf[2]&077]; + if (state->stream) + { + for (idx=0; idx < 4; idx++) + es_putc (tmp[idx], state->stream); + if (es_ferror (state->stream)) + goto write_error; + } + else + { + for (idx=0; idx < 4; idx++) + putc (tmp[idx], state->fp); + if (ferror (state->fp)) + goto write_error; + } + if (!(state->flags & B64ENC_NO_LINEFEEDS) + && my_fputs ("\n", state) == EOF) + goto write_error; + } + + if (state->title) + { + if ( my_fputs ("-----END ", state) == EOF + || my_fputs (state->title, state) == EOF + || my_fputs ("-----\n", state) == EOF) + goto write_error; + } + + goto cleanup; + + write_error: + err = gpg_error_from_syserror (); + + cleanup: + if (state->title) + { + xfree (state->title); + state->title = NULL; + } + state->fp = NULL; + state->stream = NULL; + state->lasterr = err; + return err; +} |