C API: Internationalizing Domain Names in Applications (IDNA) More...

#include "unicode/utypes.h"
#include <stdbool.h>
#include "unicode/parseerr.h"
#include "unicode/localpointer.h"

Data Structures
struct	UIDNAInfo
	Output container for IDNA processing errors. More...

Namespaces
namespace	icu
	File coll.h.

Macros
#define	UIDNA_INFO_INITIALIZER
	Static initializer for a UIDNAInfo struct.

Typedefs
typedef struct UIDNA	UIDNA
	C typedef for struct UIDNA.

typedef struct UIDNAInfo	UIDNAInfo
	Output container for IDNA processing errors.

Enumerations
enum	{ UIDNA_DEFAULT =0x30 , UIDNA_ALLOW_UNASSIGNED =1 , UIDNA_USE_STD3_RULES =2 , UIDNA_CHECK_BIDI =4 , UIDNA_CHECK_CONTEXTJ =8 , UIDNA_NONTRANSITIONAL_TO_ASCII =0x10 , UIDNA_NONTRANSITIONAL_TO_UNICODE =0x20 , UIDNA_CHECK_CONTEXTO =0x40 }

enum	{ UIDNA_ERROR_EMPTY_LABEL =1 , UIDNA_ERROR_LABEL_TOO_LONG =2 , UIDNA_ERROR_DOMAIN_NAME_TOO_LONG =4 , UIDNA_ERROR_LEADING_HYPHEN =8 , UIDNA_ERROR_TRAILING_HYPHEN =0x10 , UIDNA_ERROR_HYPHEN_3_4 =0x20 , UIDNA_ERROR_LEADING_COMBINING_MARK =0x40 , UIDNA_ERROR_DISALLOWED =0x80 , UIDNA_ERROR_PUNYCODE =0x100 , UIDNA_ERROR_LABEL_HAS_DOT =0x200 , UIDNA_ERROR_INVALID_ACE_LABEL =0x400 , UIDNA_ERROR_BIDI =0x800 , UIDNA_ERROR_CONTEXTJ =0x1000 , UIDNA_ERROR_CONTEXTO_PUNCTUATION =0x2000 , UIDNA_ERROR_CONTEXTO_DIGITS =0x4000 }

Functions
U_CAPI UIDNA *	uidna_openUTS46 (uint32_t options, UErrorCode *pErrorCode)
	Returns a UIDNA instance which implements UTS #46.

U_CAPI void	uidna_close (UIDNA *idna)
	Closes a UIDNA instance.

U_CAPI int32_t	uidna_labelToASCII (const UIDNA idna, const UChar label, int32_t length, UChar dest, int32_t capacity, UIDNAInfo pInfo, UErrorCode *pErrorCode)
	Converts a single domain name label into its ASCII form for DNS lookup.

U_CAPI int32_t	uidna_labelToUnicode (const UIDNA idna, const UChar label, int32_t length, UChar dest, int32_t capacity, UIDNAInfo pInfo, UErrorCode *pErrorCode)
	Converts a single domain name label into its Unicode form for human-readable display.

U_CAPI int32_t	uidna_nameToASCII (const UIDNA idna, const UChar name, int32_t length, UChar dest, int32_t capacity, UIDNAInfo pInfo, UErrorCode *pErrorCode)
	Converts a whole domain name into its ASCII form for DNS lookup.

U_CAPI int32_t	uidna_nameToUnicode (const UIDNA idna, const UChar name, int32_t length, UChar dest, int32_t capacity, UIDNAInfo pInfo, UErrorCode *pErrorCode)
	Converts a whole domain name into its Unicode form for human-readable display.

U_CAPI int32_t	uidna_labelToASCII_UTF8 (const UIDNA idna, const char label, int32_t length, char dest, int32_t capacity, UIDNAInfo pInfo, UErrorCode *pErrorCode)
	Converts a single domain name label into its ASCII form for DNS lookup.

U_CAPI int32_t	uidna_labelToUnicodeUTF8 (const UIDNA idna, const char label, int32_t length, char dest, int32_t capacity, UIDNAInfo pInfo, UErrorCode *pErrorCode)
	Converts a single domain name label into its Unicode form for human-readable display.

U_CAPI int32_t	uidna_nameToASCII_UTF8 (const UIDNA idna, const char name, int32_t length, char dest, int32_t capacity, UIDNAInfo pInfo, UErrorCode *pErrorCode)
	Converts a whole domain name into its ASCII form for DNS lookup.

U_CAPI int32_t	uidna_nameToUnicodeUTF8 (const UIDNA idna, const char name, int32_t length, char dest, int32_t capacity, UIDNAInfo pInfo, UErrorCode *pErrorCode)
	Converts a whole domain name into its Unicode form for human-readable display.

int32_t	uidna_toASCII (const UChar src, int32_t srcLength, UChar dest, int32_t destCapacity, int32_t options, UParseError parseError, UErrorCode status)
	IDNA2003: This function implements the ToASCII operation as defined in the IDNA RFC.

int32_t	uidna_toUnicode (const UChar src, int32_t srcLength, UChar dest, int32_t destCapacity, int32_t options, UParseError parseError, UErrorCode status)
	IDNA2003: This function implements the ToUnicode operation as defined in the IDNA RFC.

int32_t	uidna_IDNToASCII (const UChar src, int32_t srcLength, UChar dest, int32_t destCapacity, int32_t options, UParseError parseError, UErrorCode status)
	IDNA2003: Convenience function that implements the IDNToASCII operation as defined in the IDNA RFC.

int32_t	uidna_IDNToUnicode (const UChar src, int32_t srcLength, UChar dest, int32_t destCapacity, int32_t options, UParseError parseError, UErrorCode status)
	IDNA2003: Convenience function that implements the IDNToUnicode operation as defined in the IDNA RFC.

int32_t	uidna_compare (const UChar s1, int32_t length1, const UChar s2, int32_t length2, int32_t options, UErrorCode *status)
	IDNA2003: Compare two IDN strings for equivalence.

Detailed Description

C API: Internationalizing Domain Names in Applications (IDNA)

IDNA2008 is implemented according to UTS #46, see the IDNA C++ class in idna.h.

The C API functions which do take a UIDNA * service object pointer implement UTS #46 and IDNA2008.

IDNA2003 is obsolete. The C API functions which do not take a service object pointer implement IDNA2003. They are all deprecated.

Definition in file uidna.h.

Macro Definition Documentation

◆ UIDNA_INFO_INITIALIZER

#define UIDNA_INFO_INITIALIZER

Value:

    { \
    (int16_t)sizeof(UIDNAInfo), \
    false, false, \
    0, 0, 0 }

Static initializer for a UIDNAInfo struct.

Stable:: ICU 4.6

Definition at line 227 of file uidna.h.

Typedef Documentation

◆ UIDNA

typedef struct UIDNA UIDNA

C typedef for struct UIDNA.

Stable:: ICU 4.6

Definition at line 142 of file uidna.h.

◆ UIDNAInfo

typedef struct UIDNAInfo UIDNAInfo

Output container for IDNA processing errors.

Initialize with UIDNA_INFO_INITIALIZER:

UIDNAInfo info = UIDNA_INFO_INITIALIZER;
int32_t length = uidna_nameToASCII(..., &info, &errorCode);
if(U_SUCCESS(errorCode) && info.errors!=0) { ... }

Stable:: ICU 4.6

Enumeration Type Documentation

◆ anonymous enum

anonymous enum

Enumerator
UIDNA_DEFAULT	Default options value: UTS #46 nontransitional processing. For use in static worker and factory methods. Since ICU 76, this is the same as UIDNA_NONTRANSITIONAL_TO_ASCII \| UIDNA_NONTRANSITIONAL_TO_UNICODE, corresponding to Unicode 15.1 UTS #46 deprecating transitional processing. (These options are ignored by the IDNA2003 implementation.) Before ICU 76, this constant did not set any of the options. Stable: ICU 2.6
UIDNA_ALLOW_UNASSIGNED	Option to allow unassigned code points in domain names and labels. For use in static worker and factory methods. This option is ignored by the UTS46 implementation. (UTS #46 disallows unassigned code points.) Deprecated: ICU 55 Use UTS #46 instead via uidna_openUTS46() or class IDNA.
UIDNA_USE_STD3_RULES	Option to check whether the input conforms to the STD3 ASCII rules, for example the restriction of labels to LDH characters (ASCII Letters, Digits and Hyphen-Minus). For use in static worker and factory methods. Stable: ICU 2.6
UIDNA_CHECK_BIDI	IDNA option to check for whether the input conforms to the BiDi rules. For use in static worker and factory methods. This option is ignored by the IDNA2003 implementation. (IDNA2003 always performs a BiDi check.) Stable: ICU 4.6
UIDNA_CHECK_CONTEXTJ	IDNA option to check for whether the input conforms to the CONTEXTJ rules. For use in static worker and factory methods. This option is ignored by the IDNA2003 implementation. (The CONTEXTJ check is new in IDNA2008.) Stable: ICU 4.6
UIDNA_NONTRANSITIONAL_TO_ASCII	IDNA option for nontransitional processing in ToASCII(). For use in static worker and factory methods. By default, ToASCII() uses transitional processing. Unicode 15.1 UTS #46 deprecated transitional processing. This option is ignored by the IDNA2003 implementation. (This is only relevant for compatibility of newer IDNA implementations with IDNA2003.) Stable: ICU 4.6 See also UIDNA_DEFAULT
UIDNA_NONTRANSITIONAL_TO_UNICODE	IDNA option for nontransitional processing in ToUnicode(). For use in static worker and factory methods. By default, ToUnicode() uses transitional processing. Unicode 15.1 UTS #46 deprecated transitional processing. This option is ignored by the IDNA2003 implementation. (This is only relevant for compatibility of newer IDNA implementations with IDNA2003.) Stable: ICU 4.6 See also UIDNA_DEFAULT
UIDNA_CHECK_CONTEXTO	IDNA option to check for whether the input conforms to the CONTEXTO rules. For use in static worker and factory methods. This option is ignored by the IDNA2003 implementation. (The CONTEXTO check is new in IDNA2008.) This is for use by registries for IDNA2008 conformance. UTS #46 does not require the CONTEXTO check. Stable: ICU 49

Definition at line 50 of file uidna.h.

◆ anonymous enum

anonymous enum

Enumerator
UIDNA_ERROR_EMPTY_LABEL	A non-final domain name label (or the whole domain name) is empty. Stable: ICU 4.6
UIDNA_ERROR_LABEL_TOO_LONG	A domain name label is longer than 63 bytes. (See STD13/RFC1034 3.1. Name space specifications and terminology.) This is only checked in ToASCII operations, and only if the output label is all-ASCII. Stable: ICU 4.6
UIDNA_ERROR_DOMAIN_NAME_TOO_LONG	A domain name is longer than 255 bytes in its storage form. (See STD13/RFC1034 3.1. Name space specifications and terminology.) This is only checked in ToASCII operations, and only if the output domain name is all-ASCII. Stable: ICU 4.6
UIDNA_ERROR_LEADING_HYPHEN	A label starts with a hyphen-minus ('-'). Stable: ICU 4.6
UIDNA_ERROR_TRAILING_HYPHEN	A label ends with a hyphen-minus ('-'). Stable: ICU 4.6
UIDNA_ERROR_HYPHEN_3_4	A label contains hyphen-minus ('-') in the third and fourth positions. Stable: ICU 4.6
UIDNA_ERROR_LEADING_COMBINING_MARK	A label starts with a combining mark. Stable: ICU 4.6
UIDNA_ERROR_DISALLOWED	A label or domain name contains disallowed characters. Stable: ICU 4.6
UIDNA_ERROR_PUNYCODE	A label starts with "xn--" but does not contain valid Punycode. That is, an xn– label failed Punycode decoding. Stable: ICU 4.6
UIDNA_ERROR_LABEL_HAS_DOT	A label contains a dot=full stop. This can occur in an input string for a single-label function. Stable: ICU 4.6
UIDNA_ERROR_INVALID_ACE_LABEL	An ACE label does not contain a valid label string. The label was successfully ACE (Punycode) decoded but the resulting string had severe validation errors. For example, it might contain characters that are not allowed in ACE labels, or it might not be normalized. Stable: ICU 4.6
UIDNA_ERROR_BIDI	A label does not meet the IDNA BiDi requirements (for right-to-left characters). Stable: ICU 4.6
UIDNA_ERROR_CONTEXTJ	A label does not meet the IDNA CONTEXTJ requirements. Stable: ICU 4.6
UIDNA_ERROR_CONTEXTO_PUNCTUATION	A label does not meet the IDNA CONTEXTO requirements for punctuation characters. Some punctuation characters "Would otherwise have been DISALLOWED" but are allowed in certain contexts. (RFC 5892) Stable: ICU 49
UIDNA_ERROR_CONTEXTO_DIGITS	A label does not meet the IDNA CONTEXTO requirements for digits. Arabic-Indic Digits (U+066x) must not be mixed with Extended Arabic-Indic Digits (U+06Fx). Stable: ICU 49

Definition at line 443 of file uidna.h.

Function Documentation

◆ uidna_close()

U_CAPI void uidna_close ( UIDNA * idna )

Closes a UIDNA instance.

Parameters

idna	UIDNA instance to be closed

Stable:: ICU 4.6

◆ uidna_compare()

int32_t uidna_compare	(	const UChar *	s1,
		int32_t	length1,
		const UChar *	s2,
		int32_t	length2,
		int32_t	options,
		UErrorCode *	status
	)

IDNA2003: Compare two IDN strings for equivalence.

This function splits the domain names into labels and compares them. According to IDN RFC, whenever two labels are compared, they are considered equal if and only if their ASCII forms (obtained by applying toASCII) match using an case-insensitive ASCII comparison. Two domain names are considered a match if and only if all labels match regardless of whether label separators match.

Parameters

s1	First source string.
length1	Length of first source string, or -1 if NUL-terminated.
s2	Second source string.
length2	Length of second source string, or -1 if NUL-terminated.
options	A bit set of options:

UIDNA_DEFAULT Use default options, i.e., do not process unassigned code points and do not use STD3 ASCII rules If unassigned code points are found the operation fails with U_UNASSIGNED_CODE_POINT_FOUND error code.
UIDNA_ALLOW_UNASSIGNED Unassigned values can be converted to ASCII for query operations If this option is set, the unassigned code points are in the input are treated as normal Unicode code points.
UIDNA_USE_STD3_RULES Use STD3 ASCII rules for host name syntax restrictions If this option is set and the input does not satisfy STD3 rules,
the operation will fail with U_IDNA_STD3_ASCII_RULES_ERROR

Parameters

status ICU error code in/out parameter. Must fulfill U_SUCCESS before the function call.

Returns: <0 or 0 or >0 as usual for string comparisons

Deprecated:: ICU 55 Use UTS #46 instead via uidna_openUTS46() or class IDNA.

◆ uidna_IDNToASCII()

int32_t uidna_IDNToASCII	(	const UChar *	src,
		int32_t	srcLength,
		UChar *	dest,
		int32_t	destCapacity,
		int32_t	options,
		UParseError *	parseError,
		UErrorCode *	status
	)

IDNA2003: Convenience function that implements the IDNToASCII operation as defined in the IDNA RFC.

This operation is done on complete domain names, e.g: "www.example.com". It is important to note that this operation can fail. If it fails, then the input domain name cannot be used as an Internationalized Domain Name and the application should have methods defined to deal with the failure.

Note: IDNA RFC specifies that a conformant application should divide a domain name into separate labels, decide whether to apply allowUnassigned and useSTD3ASCIIRules on each, and then convert. This function does not offer that level of granularity. The options once
set will apply to all labels in the domain name

Parameters

src	Input UChar array containing IDN in Unicode.
srcLength	Number of UChars in src, or -1 if NUL-terminated.
dest	Output UChar array with ASCII (ACE encoded) IDN.
destCapacity	Size of dest.
options	A bit set of options:

UIDNA_DEFAULT Use default options, i.e., do not process unassigned code points and do not use STD3 ASCII rules If unassigned code points are found the operation fails with U_UNASSIGNED_CODE_POINT_FOUND error code.
UIDNA_ALLOW_UNASSIGNED Unassigned values can be converted to ASCII for query operations If this option is set, the unassigned code points are in the input are treated as normal Unicode code points.
UIDNA_USE_STD3_RULES Use STD3 ASCII rules for host name syntax restrictions If this option is set and the input does not satisfy STD3 rules,
the operation will fail with U_IDNA_STD3_ASCII_RULES_ERROR

Parameters

parseError	Pointer to UParseError struct to receive information on position of error if an error is encountered. Can be NULL.
status	ICU in/out error code parameter. U_INVALID_CHAR_FOUND if src contains unmatched single surrogates. U_INDEX_OUTOFBOUNDS_ERROR if src contains too many code points. U_BUFFER_OVERFLOW_ERROR if destCapacity is not enough

Returns: The length of the result string, if successful - or in case of a buffer overflow, in which case it will be greater than destCapacity.

Deprecated:: ICU 55 Use UTS #46 instead via uidna_openUTS46() or class IDNA.

◆ uidna_IDNToUnicode()

int32_t uidna_IDNToUnicode	(	const UChar *	src,
		int32_t	srcLength,
		UChar *	dest,
		int32_t	destCapacity,
		int32_t	options,
		UParseError *	parseError,
		UErrorCode *	status
	)

IDNA2003: Convenience function that implements the IDNToUnicode operation as defined in the IDNA RFC.

This operation is done on complete domain names, e.g: "www.example.com".

Note: IDNA RFC specifies that a conformant application should divide a domain name into separate labels, decide whether to apply allowUnassigned and useSTD3ASCIIRules on each, and then convert. This function does not offer that level of granularity. The options once
set will apply to all labels in the domain name

Parameters

src	Input UChar array containing IDN in ASCII (ACE encoded) form.
srcLength	Number of UChars in src, or -1 if NUL-terminated.
dest	Output UChar array containing Unicode equivalent of source IDN.
destCapacity	Size of dest.
options	A bit set of options:

UIDNA_DEFAULT Use default options, i.e., do not process unassigned code points and do not use STD3 ASCII rules If unassigned code points are found the operation fails with U_UNASSIGNED_CODE_POINT_FOUND error code.
UIDNA_ALLOW_UNASSIGNED Unassigned values can be converted to ASCII for query operations If this option is set, the unassigned code points are in the input are treated as normal Unicode code points.
UIDNA_USE_STD3_RULES Use STD3 ASCII rules for host name syntax restrictions If this option is set and the input does not satisfy STD3 rules,
the operation will fail with U_IDNA_STD3_ASCII_RULES_ERROR

Parameters

parseError	Pointer to UParseError struct to receive information on position of error if an error is encountered. Can be NULL.
status	ICU in/out error code parameter. U_INVALID_CHAR_FOUND if src contains unmatched single surrogates. U_INDEX_OUTOFBOUNDS_ERROR if src contains too many code points. U_BUFFER_OVERFLOW_ERROR if destCapacity is not enough

Returns: The length of the result string, if successful - or in case of a buffer overflow, in which case it will be greater than destCapacity.

Deprecated:: ICU 55 Use UTS #46 instead via uidna_openUTS46() or class IDNA.

◆ uidna_labelToASCII()

U_CAPI int32_t uidna_labelToASCII	(	const UIDNA *	idna,
		const UChar *	label,
		int32_t	length,
		UChar *	dest,
		int32_t	capacity,
		UIDNAInfo *	pInfo,
		UErrorCode *	pErrorCode
	)

Converts a single domain name label into its ASCII form for DNS lookup.

If any processing step fails, then pInfo->errors will be non-zero and the result might not be an ASCII string. The label might be modified according to the types of errors. Labels with severe errors will be left in (or turned into) their Unicode form.

The UErrorCode indicates an error only in exceptional cases, such as a U_MEMORY_ALLOCATION_ERROR.

Parameters

idna	UIDNA instance
label	Input domain name label
length	Label length, or -1 if NUL-terminated
dest	Destination string buffer
capacity	Destination buffer capacity
pInfo	Output container of IDNA processing details.
pErrorCode	Standard ICU error code. Its input value must pass the U_SUCCESS() test, or else the function returns immediately. Check for U_FAILURE() on output or use with function chaining. (See User Guide for details.)

Returns: destination string length

Stable:: ICU 4.6

◆ uidna_labelToASCII_UTF8()

U_CAPI int32_t uidna_labelToASCII_UTF8	(	const UIDNA *	idna,
		const char *	label,
		int32_t	length,
		char *	dest,
		int32_t	capacity,
		UIDNAInfo *	pInfo,
		UErrorCode *	pErrorCode
	)

Converts a single domain name label into its ASCII form for DNS lookup.

UTF-8 version of uidna_labelToASCII(), same behavior.

Parameters

idna	UIDNA instance
label	Input domain name label
length	Label length, or -1 if NUL-terminated
dest	Destination string buffer
capacity	Destination buffer capacity
pInfo	Output container of IDNA processing details.
pErrorCode	Standard ICU error code. Its input value must pass the U_SUCCESS() test, or else the function returns immediately. Check for U_FAILURE() on output or use with function chaining. (See User Guide for details.)

Returns: destination string length

Stable:: ICU 4.6

◆ uidna_labelToUnicode()

U_CAPI int32_t uidna_labelToUnicode	(	const UIDNA *	idna,
		const UChar *	label,
		int32_t	length,
		UChar *	dest,
		int32_t	capacity,
		UIDNAInfo *	pInfo,
		UErrorCode *	pErrorCode
	)

Converts a single domain name label into its Unicode form for human-readable display.

If any processing step fails, then pInfo->errors will be non-zero. The label might be modified according to the types of errors.

The UErrorCode indicates an error only in exceptional cases, such as a U_MEMORY_ALLOCATION_ERROR.

Parameters

idna	UIDNA instance
label	Input domain name label
length	Label length, or -1 if NUL-terminated
dest	Destination string buffer
capacity	Destination buffer capacity
pInfo	Output container of IDNA processing details.
pErrorCode	Standard ICU error code. Its input value must pass the U_SUCCESS() test, or else the function returns immediately. Check for U_FAILURE() on output or use with function chaining. (See User Guide for details.)

Returns: destination string length

Stable:: ICU 4.6

◆ uidna_labelToUnicodeUTF8()

U_CAPI int32_t uidna_labelToUnicodeUTF8	(	const UIDNA *	idna,
		const char *	label,
		int32_t	length,
		char *	dest,
		int32_t	capacity,
		UIDNAInfo *	pInfo,
		UErrorCode *	pErrorCode
	)

Converts a single domain name label into its Unicode form for human-readable display.

UTF-8 version of uidna_labelToUnicode(), same behavior.

Parameters

idna	UIDNA instance
label	Input domain name label
length	Label length, or -1 if NUL-terminated
dest	Destination string buffer
capacity	Destination buffer capacity
pInfo	Output container of IDNA processing details.
pErrorCode	Standard ICU error code. Its input value must pass the U_SUCCESS() test, or else the function returns immediately. Check for U_FAILURE() on output or use with function chaining. (See User Guide for details.)

Returns: destination string length

Stable:: ICU 4.6

◆ uidna_nameToASCII()

U_CAPI int32_t uidna_nameToASCII	(	const UIDNA *	idna,
		const UChar *	name,
		int32_t	length,
		UChar *	dest,
		int32_t	capacity,
		UIDNAInfo *	pInfo,
		UErrorCode *	pErrorCode
	)

Converts a whole domain name into its ASCII form for DNS lookup.

If any processing step fails, then pInfo->errors will be non-zero and the result might not be an ASCII string. The domain name might be modified according to the types of errors. Labels with severe errors will be left in (or turned into) their Unicode form.

The UErrorCode indicates an error only in exceptional cases, such as a U_MEMORY_ALLOCATION_ERROR.

Parameters

idna	UIDNA instance
name	Input domain name
length	Domain name length, or -1 if NUL-terminated
dest	Destination string buffer
capacity	Destination buffer capacity
pInfo	Output container of IDNA processing details.
pErrorCode	Standard ICU error code. Its input value must pass the U_SUCCESS() test, or else the function returns immediately. Check for U_FAILURE() on output or use with function chaining. (See User Guide for details.)

Returns: destination string length

Stable:: ICU 4.6

◆ uidna_nameToASCII_UTF8()

U_CAPI int32_t uidna_nameToASCII_UTF8	(	const UIDNA *	idna,
		const char *	name,
		int32_t	length,
		char *	dest,
		int32_t	capacity,
		UIDNAInfo *	pInfo,
		UErrorCode *	pErrorCode
	)

Converts a whole domain name into its ASCII form for DNS lookup.

UTF-8 version of uidna_nameToASCII(), same behavior.

Parameters

idna	UIDNA instance
name	Input domain name
length	Domain name length, or -1 if NUL-terminated
dest	Destination string buffer
capacity	Destination buffer capacity
pInfo	Output container of IDNA processing details.
pErrorCode	Standard ICU error code. Its input value must pass the U_SUCCESS() test, or else the function returns immediately. Check for U_FAILURE() on output or use with function chaining. (See User Guide for details.)

Returns: destination string length

Stable:: ICU 4.6

◆ uidna_nameToUnicode()

U_CAPI int32_t uidna_nameToUnicode	(	const UIDNA *	idna,
		const UChar *	name,
		int32_t	length,
		UChar *	dest,
		int32_t	capacity,
		UIDNAInfo *	pInfo,
		UErrorCode *	pErrorCode
	)

Converts a whole domain name into its Unicode form for human-readable display.

If any processing step fails, then pInfo->errors will be non-zero. The domain name might be modified according to the types of errors.

The UErrorCode indicates an error only in exceptional cases, such as a U_MEMORY_ALLOCATION_ERROR.

Parameters

idna	UIDNA instance
name	Input domain name
length	Domain name length, or -1 if NUL-terminated
dest	Destination string buffer
capacity	Destination buffer capacity
pInfo	Output container of IDNA processing details.
pErrorCode	Standard ICU error code. Its input value must pass the U_SUCCESS() test, or else the function returns immediately. Check for U_FAILURE() on output or use with function chaining. (See User Guide for details.)

Returns: destination string length

Stable:: ICU 4.6

◆ uidna_nameToUnicodeUTF8()

U_CAPI int32_t uidna_nameToUnicodeUTF8	(	const UIDNA *	idna,
		const char *	name,
		int32_t	length,
		char *	dest,
		int32_t	capacity,
		UIDNAInfo *	pInfo,
		UErrorCode *	pErrorCode
	)

Converts a whole domain name into its Unicode form for human-readable display.

UTF-8 version of uidna_nameToUnicode(), same behavior.

Parameters

idna	UIDNA instance
name	Input domain name
length	Domain name length, or -1 if NUL-terminated
dest	Destination string buffer
capacity	Destination buffer capacity
pInfo	Output container of IDNA processing details.
pErrorCode	Standard ICU error code. Its input value must pass the U_SUCCESS() test, or else the function returns immediately. Check for U_FAILURE() on output or use with function chaining. (See User Guide for details.)

Returns: destination string length

Stable:: ICU 4.6

◆ uidna_openUTS46()

U_CAPI UIDNA * uidna_openUTS46	(	uint32_t	options,
		UErrorCode *	pErrorCode
	)

Returns a UIDNA instance which implements UTS #46.

Returns an unmodifiable instance, owned by the caller. Cache it for multiple operations, and uidna_close() it when done. The instance is thread-safe, that is, it can be used concurrently.

For details about the UTS #46 implementation see the IDNA C++ class in idna.h.

Parameters

options	Bit set to modify the processing and error checking. These should include UIDNA_DEFAULT, or UIDNA_NONTRANSITIONAL_TO_ASCII \| UIDNA_NONTRANSITIONAL_TO_UNICODE. See option bit set values in uidna.h.
pErrorCode	Standard ICU error code. Its input value must pass the U_SUCCESS() test, or else the function returns immediately. Check for U_FAILURE() on output or use with function chaining. (See User Guide for details.)

Returns: the UTS #46 UIDNA instance, if successful

Stable:: ICU 4.6

◆ uidna_toASCII()

int32_t uidna_toASCII	(	const UChar *	src,
		int32_t	srcLength,
		UChar *	dest,
		int32_t	destCapacity,
		int32_t	options,
		UParseError *	parseError,
		UErrorCode *	status
	)

IDNA2003: This function implements the ToASCII operation as defined in the IDNA RFC.

This operation is done on single labels before sending it to something that expects ASCII names. A label is an individual part of a domain name. Labels are usually separated by dots; e.g. "www.example.com" is composed of 3 labels "www","example", and "com".

IDNA2003 API Overview:

The uidna_ API implements the IDNA protocol as defined in the IDNA RFC (http://www.ietf.org/rfc/rfc3490.txt). The RFC defines 2 operations: ToASCII and ToUnicode. Domain name labels containing non-ASCII code points are processed by the ToASCII operation before passing it to resolver libraries. Domain names that are obtained from resolver libraries are processed by the ToUnicode operation before displaying the domain name to the user. IDNA requires that implementations process input strings with Nameprep (http://www.ietf.org/rfc/rfc3491.txt), which is a profile of Stringprep (http://www.ietf.org/rfc/rfc3454.txt), and then with Punycode (http://www.ietf.org/rfc/rfc3492.txt). Implementations of IDNA MUST fully implement Nameprep and Punycode; neither Nameprep nor Punycode are optional. The input and output of ToASCII and ToUnicode operations are Unicode and are designed to be chainable, i.e., applying ToASCII or ToUnicode operations multiple times to an input string will yield the same result as applying the operation once. ToUnicode(ToUnicode(ToUnicode...(ToUnicode(string)))) == ToUnicode(string) ToASCII(ToASCII(ToASCII...(ToASCII(string))) == ToASCII(string).

Parameters

src	Input UChar array containing label in Unicode.
srcLength	Number of UChars in src, or -1 if NUL-terminated.
dest	Output UChar array with ASCII (ACE encoded) label.
destCapacity	Size of dest.
options	A bit set of options:

UIDNA_DEFAULT Use default options, i.e., do not process unassigned code points and do not use STD3 ASCII rules If unassigned code points are found the operation fails with U_UNASSIGNED_ERROR error code.
UIDNA_ALLOW_UNASSIGNED Unassigned values can be converted to ASCII for query operations If this option is set, the unassigned code points are in the input are treated as normal Unicode code points.
UIDNA_USE_STD3_RULES Use STD3 ASCII rules for host name syntax restrictions If this option is set and the input does not satisfy STD3 rules,
the operation will fail with U_IDNA_STD3_ASCII_RULES_ERROR

Parameters

parseError	Pointer to UParseError struct to receive information on position of error if an error is encountered. Can be NULL.
status	ICU in/out error code parameter. U_INVALID_CHAR_FOUND if src contains unmatched single surrogates. U_INDEX_OUTOFBOUNDS_ERROR if src contains too many code points. U_BUFFER_OVERFLOW_ERROR if destCapacity is not enough

Returns: The length of the result string, if successful - or in case of a buffer overflow, in which case it will be greater than destCapacity.

Deprecated:: ICU 55 Use UTS #46 instead via uidna_openUTS46() or class IDNA.

◆ uidna_toUnicode()

int32_t uidna_toUnicode	(	const UChar *	src,
		int32_t	srcLength,
		UChar *	dest,
		int32_t	destCapacity,
		int32_t	options,
		UParseError *	parseError,
		UErrorCode *	status
	)

IDNA2003: This function implements the ToUnicode operation as defined in the IDNA RFC.

This operation is done on single labels before sending it to something that expects Unicode names. A label is an individual part of a domain name. Labels are usually separated by dots; for e.g. "www.example.com" is composed of 3 labels "www","example", and "com".

Parameters

src	Input UChar array containing ASCII (ACE encoded) label.
srcLength	Number of UChars in src, or -1 if NUL-terminated.
dest	Output Converted UChar array containing Unicode equivalent of label.
destCapacity	Size of dest.
options	A bit set of options:

UIDNA_DEFAULT Use default options, i.e., do not process unassigned code points and do not use STD3 ASCII rules If unassigned code points are found the operation fails with U_UNASSIGNED_ERROR error code.
UIDNA_ALLOW_UNASSIGNED Unassigned values can be converted to ASCII for query operations If this option is set, the unassigned code points are in the input are treated as normal Unicode code points. Note: This option is required on toUnicode operation because the RFC mandates verification of decoded ACE input by applying toASCII and comparing its output with source
UIDNA_USE_STD3_RULES Use STD3 ASCII rules for host name syntax restrictions If this option is set and the input does not satisfy STD3 rules,
the operation will fail with U_IDNA_STD3_ASCII_RULES_ERROR

Parameters

parseError	Pointer to UParseError struct to receive information on position of error if an error is encountered. Can be NULL.
status	ICU in/out error code parameter. U_INVALID_CHAR_FOUND if src contains unmatched single surrogates. U_INDEX_OUTOFBOUNDS_ERROR if src contains too many code points. U_BUFFER_OVERFLOW_ERROR if destCapacity is not enough

Returns: The length of the result string, if successful - or in case of a buffer overflow, in which case it will be greater than destCapacity.

Deprecated:: ICU 55 Use UTS #46 instead via uidna_openUTS46() or class IDNA.

Data Structures

Namespaces

Macros

Typedefs

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ UIDNA_INFO_INITIALIZER

Typedef Documentation

◆ UIDNA

◆ UIDNAInfo

Enumeration Type Documentation

◆ anonymous enum

◆ anonymous enum

Function Documentation

◆ uidna_close()

◆ uidna_compare()

◆ uidna_IDNToASCII()

◆ uidna_IDNToUnicode()

◆ uidna_labelToASCII()

◆ uidna_labelToASCII_UTF8()

◆ uidna_labelToUnicode()

◆ uidna_labelToUnicodeUTF8()

◆ uidna_nameToASCII()

◆ uidna_nameToASCII_UTF8()

◆ uidna_nameToUnicode()

◆ uidna_nameToUnicodeUTF8()

◆ uidna_openUTS46()

◆ uidna_toASCII()

◆ uidna_toUnicode()