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Diffstat (limited to 'src/utf8.c')
| -rw-r--r-- | src/utf8.c | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/src/utf8.c b/src/utf8.c new file mode 100644 index 0000000..bc7adb8 --- /dev/null +++ b/src/utf8.c @@ -0,0 +1,278 @@ +/************************************************* +* Exim - an Internet mail transport agent * +*************************************************/ + +/* Copyright (c) The Exim Maintainers 2022 */ +/* Copyright (c) Jeremy Harris 2015 - 2018 */ +/* See the file NOTICE for conditions of use and distribution. */ + + +#include "exim.h" + +#ifdef SUPPORT_I18N + +#ifdef SUPPORT_I18N_2008 +# include <idn2.h> +#else +# include <idna.h> +#endif + +#include <punycode.h> +#include <stringprep.h> + +static uschar * +string_localpart_alabel_to_utf8_(const uschar * alabel, uschar ** err); + +/**************************************************/ + +BOOL +string_is_utf8(const uschar * s) +{ +uschar c; +if (s) while ((c = *s++)) if (c & 0x80) return TRUE; +return FALSE; +} + +static BOOL +string_is_alabel(const uschar * s) +{ +return s[0] == 'x' && s[1] == 'n' && s[2] == '-' && s[3] == '-'; +} + +/**************************************************/ +/* Domain conversions. +The *err string pointer should be null before the call + +Return NULL for error, with optional errstr pointer filled in +*/ + +uschar * +string_domain_utf8_to_alabel(const uschar * utf8, uschar ** err) +{ +uschar * s1, * s; +int rc; + +#ifdef SUPPORT_I18N_2008 +/* Avoid lowercasing plain-ascii domains */ +if (!string_is_utf8(utf8)) + return string_copy(utf8); + +/* Only lowercase is accepted by the library call. A pity since we lose +any mixed-case annotation. This does not really matter for a domain. */ + { + uschar c; + for (s1 = s = US utf8; (c = *s1); s1++) if (!(c & 0x80) && isupper(c)) + { + s = string_copy(utf8); + for (s1 = s + (s1 - utf8); (c = *s1); s1++) if (!(c & 0x80) && isupper(c)) + *s1 = tolower(c); + break; + } + } +if ((rc = idn2_lookup_u8((const uint8_t *) s, &s1, IDN2_NFC_INPUT)) != IDN2_OK) + { + if (err) *err = US idn2_strerror(rc); + return NULL; + } +#else +s = US stringprep_utf8_nfkc_normalize(CCS utf8, -1); +if ( (rc = idna_to_ascii_8z(CCS s, CSS &s1, IDNA_ALLOW_UNASSIGNED)) + != IDNA_SUCCESS) + { + free(s); + if (err) *err = US idna_strerror(rc); + return NULL; + } +free(s); +#endif +s = string_copy(s1); +free(s1); +return s; +} + + + +uschar * +string_domain_alabel_to_utf8(const uschar * alabel, uschar ** err) +{ +#ifdef SUPPORT_I18N_2008 +const uschar * label; +int sep = '.'; +gstring * g = NULL; + +while (label = string_nextinlist(&alabel, &sep, NULL, 0)) + if ( string_is_alabel(label) + && !(label = string_localpart_alabel_to_utf8_(label, err)) + ) + return NULL; + else + g = string_append_listele(g, '.', label); +return string_from_gstring(g); + +#else + +uschar * s1, * s; +int rc; + +if ( (rc = idna_to_unicode_8z8z(CCS alabel, CSS &s1, IDNA_USE_STD3_ASCII_RULES)) + != IDNA_SUCCESS) + { + if (err) *err = US idna_strerror(rc); + return NULL; + } +s = string_copy(s1); +free(s1); +return s; +#endif +} + +/**************************************************/ +/* localpart conversions */ +/* the *err string pointer should be null before the call */ + + +uschar * +string_localpart_utf8_to_alabel(const uschar * utf8, uschar ** err) +{ +size_t ucs4_len = 0; +punycode_uint * p; +size_t p_len; +uschar * res; +int rc; + +if (!string_is_utf8(utf8)) return string_copy(utf8); + +p = (punycode_uint *) stringprep_utf8_to_ucs4(CCS utf8, -1, &ucs4_len); +if (!p || !ucs4_len) + { + if (err) *err = US"l_u2a: bad UTF-8 input"; + return NULL; + } +p_len = ucs4_len*4; /* this multiplier is pure guesswork */ +res = store_get(p_len+5, utf8); + +res[0] = 'x'; res[1] = 'n'; res[2] = res[3] = '-'; + +if ((rc = punycode_encode(ucs4_len, p, NULL, &p_len, CS res+4)) != PUNYCODE_SUCCESS) + { + DEBUG(D_expand) debug_printf("l_u2a: bad '%s'\n", punycode_strerror(rc)); + free(p); + if (err) *err = US punycode_strerror(rc); + return NULL; + } +p_len += 4; +free(p); +res[p_len] = '\0'; +return res; +} + + +static uschar * +string_localpart_alabel_to_utf8_(const uschar * alabel, uschar ** err) +{ +size_t p_len; +punycode_uint * p; +int rc; +uschar * s, * res; + +DEBUG(D_expand) debug_printf("l_a2u: '%s'\n", alabel); +alabel += 4; +p_len = Ustrlen(alabel); +p = store_get((p_len+1) * sizeof(*p), alabel); + +if ((rc = punycode_decode(p_len, CCS alabel, &p_len, p, NULL)) != PUNYCODE_SUCCESS) + { + if (err) *err = US punycode_strerror(rc); + return NULL; + } + +s = US stringprep_ucs4_to_utf8(p, p_len, NULL, &p_len); +res = string_copyn(s, p_len); +free(s); +return res; +} + + +uschar * +string_localpart_alabel_to_utf8(const uschar * alabel, uschar ** err) +{ +if (string_is_alabel(alabel)) + return string_localpart_alabel_to_utf8_(alabel, err); + +if (err) *err = US"bad alabel prefix"; +return NULL; +} + + +/**************************************************/ +/* Whole address conversion. +The *err string pointer should be null before the call. + +Return NULL on error, with (optional) errstring pointer filled in +*/ + +uschar * +string_address_utf8_to_alabel(const uschar * utf8, uschar ** err) +{ +uschar * l, * d; + +if (!*utf8) return string_copy(utf8); + +DEBUG(D_expand) debug_printf("addr from utf8 <%s>", utf8); + +for (const uschar * s = utf8; *s; s++) + if (*s == '@') + { + l = string_copyn(utf8, s - utf8); + if ( !(l = string_localpart_utf8_to_alabel(l, err)) + || !(d = string_domain_utf8_to_alabel(++s, err)) + ) + return NULL; + l = string_sprintf("%s@%s", l, d); + DEBUG(D_expand) debug_printf(" -> <%s>\n", l); + return l; + } + +l = string_localpart_utf8_to_alabel(utf8, err); +DEBUG(D_expand) debug_printf(" -> <%s>\n", l); +return l; +} + + + +/************************************************* +* Report the library versions. * +*************************************************/ + +/* See a description in tls-openssl.c for an explanation of why this exists. + +Arguments: string to append to +Returns: string +*/ + +gstring * +utf8_version_report(gstring * g) +{ +#ifdef SUPPORT_I18N_2008 +g = string_fmt_append(g, "Library version: IDN2: Compile: %s\n" + " Runtime: %s\n", + IDN2_VERSION, + idn2_check_version(NULL)); +g = string_fmt_append(g, "Library version: Stringprep: Compile: %s\n" + " Runtime: %s\n", + STRINGPREP_VERSION, + stringprep_check_version(NULL)); +#else +g = string_fmt_append(g, "Library version: IDN: Compile: %s\n" + " Runtime: %s\n", + STRINGPREP_VERSION, + stringprep_check_version(NULL)); +#endif +return g; +} + +#endif /* whole file */ + +/* vi: aw ai sw=2 +*/ +/* End of utf8.c */ |