@@ -58,6 +58,32 @@ pub struct ZkLoginInputs {
5858 pub address_seed : Bn254FieldElement ,
5959}
6060
61+ impl ZkLoginInputs {
62+ #[ cfg( feature = "serde" ) ]
63+ #[ cfg_attr( doc_cfg, doc( cfg( feature = "serde" ) ) ) ]
64+ pub fn iss ( & self ) -> Result < String , InvalidZkLoginClaimError > {
65+ const ISS : & str = "iss" ;
66+
67+ let iss = self . iss_base64_details . verify_extended_claim ( ISS ) ?;
68+
69+ if iss. len ( ) > 255 {
70+ Err ( InvalidZkLoginClaimError :: new ( "invalid iss: too long" ) )
71+ } else {
72+ Ok ( iss)
73+ }
74+ }
75+
76+ #[ cfg( feature = "serde" ) ]
77+ #[ cfg_attr( doc_cfg, doc( cfg( feature = "serde" ) ) ) ]
78+ pub fn public_identifier ( & self ) -> Result < ZkLoginPublicIdentifier , InvalidZkLoginClaimError > {
79+ let iss = self . iss ( ) ?;
80+ Ok ( ZkLoginPublicIdentifier {
81+ iss,
82+ address_seed : self . address_seed . clone ( ) ,
83+ } )
84+ }
85+ }
86+
6187/// A claim of the iss in a zklogin proof
6288///
6389/// # BCS
@@ -78,6 +104,144 @@ pub struct ZkLoginClaim {
78104 pub index_mod_4 : u8 ,
79105}
80106
107+ #[ derive( Debug ) ]
108+ pub struct InvalidZkLoginClaimError ( String ) ;
109+
110+ #[ cfg( feature = "serde" ) ]
111+ #[ cfg_attr( doc_cfg, doc( cfg( feature = "serde" ) ) ) ]
112+ impl InvalidZkLoginClaimError {
113+ fn new < T : Into < String > > ( err : T ) -> Self {
114+ Self ( err. into ( ) )
115+ }
116+ }
117+
118+ impl std:: fmt:: Display for InvalidZkLoginClaimError {
119+ fn fmt ( & self , f : & mut std:: fmt:: Formatter < ' _ > ) -> std:: fmt:: Result {
120+ write ! ( f, "invalid zklogin claim: {}" , self . 0 )
121+ }
122+ }
123+
124+ impl std:: error:: Error for InvalidZkLoginClaimError { }
125+
126+ #[ cfg( feature = "serde" ) ]
127+ #[ cfg_attr( doc_cfg, doc( cfg( feature = "serde" ) ) ) ]
128+ impl ZkLoginClaim {
129+ fn verify_extended_claim (
130+ & self ,
131+ expected_key : & str ,
132+ ) -> Result < String , InvalidZkLoginClaimError > {
133+ /// Map a base64 string to a bit array by taking each char's index and convert it to binary form with one bit per u8
134+ /// element in the output. Returns InvalidZkLoginClaimError if one of the characters is not in the base64 charset.
135+ fn base64_to_bitarray ( input : & str ) -> Result < Vec < u8 > , InvalidZkLoginClaimError > {
136+ use itertools:: Itertools ;
137+
138+ const BASE64_URL_CHARSET : & str =
139+ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_" ;
140+
141+ input
142+ . chars ( )
143+ . map ( |c| {
144+ BASE64_URL_CHARSET
145+ . find ( c)
146+ . map ( |index| index as u8 )
147+ . map ( |index| ( 0 ..6 ) . rev ( ) . map ( move |i| ( index >> i) & 1 ) )
148+ . ok_or_else ( || {
149+ InvalidZkLoginClaimError :: new ( "base64_to_bitarry invalid input" )
150+ } )
151+ } )
152+ . flatten_ok ( )
153+ . collect ( )
154+ }
155+
156+ /// Convert a bitarray (each bit is represented by a u8) to a byte array by taking each 8 bits as a
157+ /// byte in big-endian format.
158+ fn bitarray_to_bytearray ( bits : & [ u8 ] ) -> Result < Vec < u8 > , InvalidZkLoginClaimError > {
159+ if bits. len ( ) % 8 != 0 {
160+ return Err ( InvalidZkLoginClaimError :: new (
161+ "bitarray_to_bytearray invalid input" ,
162+ ) ) ;
163+ }
164+ Ok ( bits
165+ . chunks ( 8 )
166+ . map ( |chunk| {
167+ let mut byte = 0u8 ;
168+ for ( i, bit) in chunk. iter ( ) . rev ( ) . enumerate ( ) {
169+ byte |= bit << i;
170+ }
171+ byte
172+ } )
173+ . collect ( ) )
174+ }
175+
176+ /// Parse the base64 string, add paddings based on offset, and convert to a bytearray.
177+ fn decode_base64_url (
178+ s : & str ,
179+ index_mod_4 : & u8 ,
180+ ) -> Result < String , InvalidZkLoginClaimError > {
181+ if s. len ( ) < 2 {
182+ return Err ( InvalidZkLoginClaimError :: new (
183+ "Base64 string smaller than 2" ,
184+ ) ) ;
185+ }
186+ let mut bits = base64_to_bitarray ( s) ?;
187+ match index_mod_4 {
188+ 0 => { }
189+ 1 => {
190+ bits. drain ( ..2 ) ;
191+ }
192+ 2 => {
193+ bits. drain ( ..4 ) ;
194+ }
195+ _ => {
196+ return Err ( InvalidZkLoginClaimError :: new ( "Invalid first_char_offset" ) ) ;
197+ }
198+ }
199+
200+ let last_char_offset = ( index_mod_4 + s. len ( ) as u8 - 1 ) % 4 ;
201+ match last_char_offset {
202+ 3 => { }
203+ 2 => {
204+ bits. drain ( bits. len ( ) - 2 ..) ;
205+ }
206+ 1 => {
207+ bits. drain ( bits. len ( ) - 4 ..) ;
208+ }
209+ _ => {
210+ return Err ( InvalidZkLoginClaimError :: new ( "Invalid last_char_offset" ) ) ;
211+ }
212+ }
213+
214+ if bits. len ( ) % 8 != 0 {
215+ return Err ( InvalidZkLoginClaimError :: new ( "Invalid bits length" ) ) ;
216+ }
217+
218+ Ok ( std:: str:: from_utf8 ( & bitarray_to_bytearray ( & bits) ?)
219+ . map_err ( |_| InvalidZkLoginClaimError :: new ( "Invalid UTF8 string" ) ) ?
220+ . to_owned ( ) )
221+ }
222+
223+ let extended_claim = decode_base64_url ( & self . value , & self . index_mod_4 ) ?;
224+
225+ // Last character of each extracted_claim must be '}' or ','
226+ if !( extended_claim. ends_with ( '}' ) || extended_claim. ends_with ( ',' ) ) {
227+ return Err ( InvalidZkLoginClaimError :: new ( "Invalid extended claim" ) ) ;
228+ }
229+
230+ let json_str = format ! ( "{{{}}}" , & extended_claim[ ..extended_claim. len( ) - 1 ] ) ;
231+
232+ serde_json:: from_str :: < serde_json:: Value > ( & json_str)
233+ . map_err ( |e| InvalidZkLoginClaimError :: new ( e. to_string ( ) ) ) ?
234+ . as_object_mut ( )
235+ . and_then ( |o| o. get_mut ( expected_key) )
236+ . map ( serde_json:: Value :: take)
237+ . and_then ( |v| match v {
238+ serde_json:: Value :: String ( s) => Some ( s) ,
239+ _ => None ,
240+ } )
241+ . ok_or_else ( || InvalidZkLoginClaimError :: new ( "invalid extended claim" ) )
242+ }
243+ }
244+
81245/// A zklogin groth16 proof
82246///
83247/// # BCS
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