diff options
Diffstat (limited to 'xs_encdec.h')
| -rw-r--r-- | xs_encdec.h | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/xs_encdec.h b/xs_encdec.h new file mode 100644 index 0000000..e336218 --- /dev/null +++ b/xs_encdec.h @@ -0,0 +1,180 @@ +/* copyright (c) 2022 grunfink - MIT license */ + +#ifndef _XS_ENCDEC_H + +#define _XS_ENCDEC_H + +d_char *xs_hex_enc(const char *data, int size); +d_char *xs_hex_dec(const char *hex); +d_char *xs_base64_enc(const char *data, int sz); +d_char *xs_base64_dec(const char *data, int *size); +d_char *xs_utf8_enc(d_char *str, unsigned int cpoint); + + +#ifdef XS_IMPLEMENTATION + +d_char *xs_hex_enc(const char *data, int size) +/* returns an hexdump of data */ +{ + d_char *s; + char *p; + int n; + + p = s = calloc(size * 2 + 1, 1); + + for (n = 0; n < size; n++) { + sprintf(p, "%02x", (unsigned char)data[n]); + p += 2; + } + + return s; +} + + +d_char *xs_hex_dec(const char *hex) +/* decodes an hexdump into data */ +{ + int sz = strlen(hex); + d_char *s; + char *p; + int n; + + p = s = calloc(sz / 2, 1); + + for (n = 0; n < sz; n += 2) { + int i; + if (sscanf(&hex[n], "%02x", &i) == 0) { + /* decoding error */ + free(s); + s = NULL; + } + else + *p = i; + + p++; + } + + return s; +} + + +d_char *xs_base64_enc(const char *data, int sz) +/* encodes data to base64 */ +{ + d_char *s; + unsigned char *p; + int n; + static char *b64_tbl = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "abcdefghijklmnopqrstuvwxyz" + "0123456789+/"; + + s = xs_str_new(NULL); + p = (unsigned char *)data; + + for (n = 0; n < sz; n += 3) { + int l = sz - n; + + if (l == 1) { + s = xs_append_m(s, &b64_tbl[(p[n] >> 2) & 0x3f], 1); + s = xs_append_m(s, &b64_tbl[(p[n] << 4) & 0x3f], 1); + s = xs_append_m(s, "==", 2); + } + else + if (l == 2) { + s = xs_append_m(s, &b64_tbl[(p[n] >> 2) & 0x3f], 1); + s = xs_append_m(s, &b64_tbl[(p[n] << 4 | p[n + 1] >> 4) & 0x3f], 1); + s = xs_append_m(s, &b64_tbl[(p[n + 1] << 2) & 0x3f], 1); + s = xs_append_m(s, "=", 1); + } + else { + s = xs_append_m(s, &b64_tbl[(p[n] >> 2) & 0x3f], 1); + s = xs_append_m(s, &b64_tbl[(p[n] << 4 | p[n + 1] >> 4) & 0x3f], 1); + s = xs_append_m(s, &b64_tbl[(p[n + 1] << 2 | p[n + 2] >> 6) & 0x3f], 1); + s = xs_append_m(s, &b64_tbl[(p[n + 2]) & 0x3f], 1); + } + } + + return s; +} + + +d_char *xs_base64_dec(const char *data, int *size) +/* decodes data from base64 */ +{ + d_char *s = NULL; + int sz = 0; + char *p; + static char *b64_tbl = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" + "abcdefghijklmnopqrstuvwxyz" + "0123456789+/="; + + p = (char *)data; + + for (p = (char *)data; *p; p += 4) { + int cs[4]; + int n; + unsigned char tmp[3]; + + for (n = 0; n < 4; n++) { + char *ss = strchr(b64_tbl, p[n]); + + if (ss == NULL) { + /* not a base64 char */ + free(s); + return NULL; + } + + cs[n] = ss - b64_tbl; + } + + n = 0; + + /* first byte */ + tmp[n++] = cs[0] << 2 | ((cs[1] >> 4) & 0x0f); + + /* second byte */ + if (cs[2] != 64) + tmp[n++] = cs[1] << 4 | ((cs[2] >> 2) & 0x3f); + + /* third byte */ + if (cs[3] != 64) + tmp[n++] = cs[2] << 6 | (cs[3] & 0x3f); + + /* must be done manually because data can be pure binary */ + s = realloc(s, sz + n); + memcpy(s + sz, tmp, n); + sz += n; + } + + *size = sz; + + return s; +} + + +d_char *xs_utf8_enc(d_char *str, unsigned int cpoint) +/* encodes an Unicode codepoint to utf8 */ +{ + unsigned char tmp[4]; + int n = 0; + + if (cpoint < 0x80) + tmp[n++] = cpoint & 0xff; + else + if (cpoint < 0x800) { + tmp[n++] = 0xc0 | (cpoint >> 6); + tmp[n++] = 0x80 | (cpoint & 0x3f); + } + else + if (cpoint < 0x10000) { + tmp[n++] = 0xe0 | (cpoint >> 12); + tmp[n++] = 0x80 | ((cpoint >> 6) & 0x3f); + tmp[n++] = 0x80 | (cpoint & 0x3f); + } + + return xs_append_m(str, (char *)tmp, n); +} + +#endif /* XS_IMPLEMENTATION */ + +#endif /* _XS_ENCDEC_H */ |