/*------------------------------------------------------------------------- * * encode.c * Various data encoding/decoding things. * * Copyright (c) 2001 PostgreSQL Global Development Group * * * IDENTIFICATION * $Header: /cvsroot/pgsql/src/backend/utils/adt/encode.c,v 1.1 2001/07/12 14:05:31 momjian Exp $ * *------------------------------------------------------------------------- */ #include "postgres.h" #include #include "utils/builtins.h" struct pg_encoding { unsigned (*encode_len) (unsigned dlen); unsigned (*decode_len) (unsigned dlen); unsigned (*encode) (const uint8 *data, unsigned dlen, uint8 *res); unsigned (*decode) (const uint8 *data, unsigned dlen, uint8 *res); }; static struct pg_encoding * pg_find_encoding(const char *name); /* * SQL functions. */ Datum binary_encode(PG_FUNCTION_ARGS) { bytea *data = PG_GETARG_BYTEA_P(0); Datum name = PG_GETARG_DATUM(1); text *result; char *namebuf; int namelen, datalen, resultlen, res; struct pg_encoding *enc; datalen = VARSIZE(data) - VARHDRSZ; namelen = VARSIZE(name) - VARHDRSZ; namebuf = (char *)DirectFunctionCall1(textout, name); enc = pg_find_encoding(namebuf); if (enc == NULL) elog(ERROR, "No such encoding"); resultlen = enc->encode_len(datalen); result = palloc(VARHDRSZ + resultlen); res = enc->encode(VARDATA(data), datalen, VARDATA(result)); if (res > resultlen) elog(ERROR, "Overflow - encode estimate too small"); VARATT_SIZEP(result) = VARHDRSZ + res; PG_RETURN_TEXT_P(result); } Datum binary_decode(PG_FUNCTION_ARGS) { text *data = PG_GETARG_TEXT_P(0); Datum name = PG_GETARG_DATUM(1); bytea *result; char *namebuf; int namelen, datalen, resultlen, res; struct pg_encoding *enc; datalen = VARSIZE(data) - VARHDRSZ; namelen = VARSIZE(name) - VARHDRSZ; namebuf = (char *)DirectFunctionCall1(textout, name); enc = pg_find_encoding(namebuf); if (enc == NULL) elog(ERROR, "No such encoding"); resultlen = enc->decode_len(datalen); result = palloc(VARHDRSZ + resultlen); res = enc->decode(VARDATA(data), datalen, VARDATA(result)); if (res > resultlen) elog(ERROR, "Overflow - decode estimate too small"); VARATT_SIZEP(result) = VARHDRSZ + res; PG_RETURN_BYTEA_P(result); } /* * HEX */ static const char *hextbl = "0123456789abcdef"; static const int8 hexlookup[128] = { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, }; static unsigned hex_encode(const uint8 * src, unsigned len, uint8 * dst) { const uint8 *end = src + len; while (src < end) { *dst++ = hextbl[(*src >> 4) & 0xF]; *dst++ = hextbl[*src & 0xF]; src++; } return len * 2; } static uint8 get_hex(unsigned c) { int res = -1; if (c > 0 && c < 127) res = hexlookup[c]; if (res < 0) elog(ERROR, "Bad hex code: '%c'", c); return (uint8)res; } static unsigned hex_decode(const uint8 * src, unsigned len, uint8 * dst) { const uint8 *s, *srcend; uint8 v1, v2, *p = dst; srcend = src + len; s = src; p = dst; while (s < srcend) { if (*s == ' ' || *s == '\n' || *s == '\t' || *s == '\r') { s++; continue; } v1 = get_hex(*s++) << 4; if (s >= srcend) elog(ERROR, "hex_decode: invalid data"); v2 = get_hex(*s++); *p++ = v1 | v2; } return p - dst; } static unsigned hex_enc_len(unsigned srclen) { return srclen << 1; } static unsigned hex_dec_len(unsigned srclen) { return srclen >> 1; } /* * BASE64 */ static const unsigned char _base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; static const int8 b64lookup[128] = { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1, }; static unsigned b64_encode(const uint8 * src, unsigned len, uint8 * dst) { uint8 *p, *lend = dst + 76; const uint8 *s, *end = src + len; int pos = 2; uint32 buf = 0; s = src; p = dst; while (s < end) { buf |= *s << (pos << 3); pos--; s++; /* write it out */ if (pos < 0) { *p++ = _base64[(buf >> 18) & 0x3f]; *p++ = _base64[(buf >> 12) & 0x3f]; *p++ = _base64[(buf >> 6) & 0x3f]; *p++ = _base64[buf & 0x3f]; pos = 2; buf = 0; } if (p >= lend) { *p++ = '\n'; lend = p + 76; } } if (pos != 2) { *p++ = _base64[(buf >> 18) & 0x3f]; *p++ = _base64[(buf >> 12) & 0x3f]; *p++ = (pos == 0) ? _base64[(buf >> 6) & 0x3f] : '='; *p++ = '='; } return p - dst; } static unsigned b64_decode(const uint8 * src, unsigned len, uint8 * dst) { const char *srcend = src + len, *s = src; uint8 *p = dst; unsigned c; int b = 0; uint32 buf = 0; int pos = 0, end = 0; while (s < srcend) { c = *s++; if (c == ' ' || c == '\t' || c == '\n' || c == '\r') continue; if (c == '=') { /* end sequence */ if (!end) { if (pos == 2) end = 1; else if (pos == 3) end = 2; else elog(ERROR, "base64: unexpected '='"); } b = 0; } else { b = -1; if (c > 0 && c < 127) b = b64lookup[c]; if (b < 0) elog(ERROR, "base64: Invalid symbol"); } /* add it to buffer */ buf = (buf << 6) + b; pos++; if (pos == 4) { *p++ = (buf >> 16) & 255; if (end == 0 || end > 1) *p++ = (buf >> 8) & 255; if (end == 0 || end > 2) *p++ = buf & 255; buf = 0; pos = 0; } } if (pos != 0) elog(ERROR, "base64: invalid end sequence"); return p - dst; } static unsigned b64_enc_len(unsigned srclen) { /* 3 bytes will be converted to 4, linefeed after 76 chars */ return (srclen + 2) * 4 / 3 + srclen / (76 * 3 / 4); } static unsigned b64_dec_len(unsigned srclen) { return (srclen * 3) >> 2; } /* * Common */ static struct { const char *name; struct pg_encoding enc; } enclist[] = { {"hex", { hex_enc_len, hex_dec_len, hex_encode, hex_decode }}, {"base64", { b64_enc_len, b64_dec_len, b64_encode, b64_decode }}, {NULL, { NULL, NULL, NULL, NULL } } }; static struct pg_encoding * pg_find_encoding(const char *name) { int i; for (i = 0; enclist[i].name; i++) if (!strcasecmp(enclist[i].name, name)) return &enclist[i].enc; return NULL; }