PIP-0027: E-PASA updates for Pay To Key

PIP/PIP-0027.md

@@ -119,7 +119,15 @@ Layer-1 account checkum must be the following number:
 
 These strings are used to denote an account names and conform to the following rules.
 - By definition, they must **not** start with a digit. 
-- String length must between 3..64 inclusive.
+
+### Account Name validation
+
+Account names in PascalCoin must be 3..64 characters in length. This validation rule is applied at the processing-tier level and not enforced by the EPASA grammar where a Pascal64 string is unbounded in size.
+
+### New Account validation
+
+EPASA is used to encode addresses for new accounts. An E-PASA of the form
+"@[1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2]" is used to denote a "Pay to Key" style transaction where payments are sent to a "new account" containing the key encoded in the payload.
 
 #### Extended Checksum
 
@@ -323,6 +331,8 @@ The below cases are only example E-PASA without valid checksums.
     <th>Description</th>
 </thead>
 <tbody>
+    <tr><td>@[1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2]</td><td>Pay To Key style transaction with Base58 encoded public key <b>without</b> checksum protection</td></tr>    
+    <tr><td>@[1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2]:a054</td><td>Pay To Key style transaction with Base58 encoded public key <b>with</b> checksum protection</td></tr>        
     <tr><td>77-44[1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2]</td><td>Account 77-44 with unencrypted (public) Base58 payload (bitcoin address) <b>without</b> checksum protection</td></tr>
     <tr><td>77-44[1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2]:10cb</td><td>Checksum protected</td></tr>
     <tr><td>77-44(1BvBMSEYstWetqTFn5Au4m4GFg7xJaNVN2):7ba2</td><td>ECIES encrypted using <b>recipients</b> public key</td></tr>
@@ -378,7 +388,7 @@ For Layer-2 applications the ability for a receiver to auto-decode the E-PASA vi
 
 The following regex parses an e-pasa:
 ```
-((?<AccountNumber>(0|[1-9]\d+))(?:(?<ChecksumDelim>-)(?<Checksum>\d{2}))?|(?<AccountName>(a|b|c|d|e|f|g|h|i|j|k|l|m|n|o|p|q|r|s|t|u|v|w|x|y|z|!|@|#|\$|%|\^|&|\*|\\\(|\\\)|-|\+|\\\{|\\\}|\\\[|\\]|_|\\:|\\"|`|\||\\<|\\>|,|\.|\?|/|~)(a|b|c|d|e|f|g|h|i|j|k|l|m|n|o|p|q|r|s|t|u|v|w|x|y|z|0|1|2|3|4|5|6|7|8|9|!|@|#|\$|%|\^|&|\*|\\\(|\\\)|-|\+|\\\{|\\\}|\\\[|\\]|_|\\:|\\"|`|\||\\<|\\>|,|\.|\?|/|~){2,63}))(?:(?<PayloadStartChar>[\[\(<\{])(?<PayloadContent>"( |!|\\"|#|\$|%|&|'|\\\(|\\\)|\*|\+|,|-|\.|/|0|1|2|3|4|5|6|7|8|9|\\:|;|\\<|=|\\>|\?|@|A|B|C|D|E|F|G|H|I|J|K|L|M|N|O|P|Q|R|S|T|U|V|W|X|Y|Z|\\\[|\\\\|\\]|\^|_|`|a|b|c|d|e|f|g|h|i|j|k|l|m|n|o|p|q|r|s|t|u|v|w|x|y|z|\\\{|\||\\\}|~)+"|0x(?:[0-9a-f]{2})+|[123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz]+)?(?:(?<PayloadPasswordDelim>:){1}(?<PayloadPassword>( |!|\\"|#|\$|%|&|'|\\\(|\\\)|\*|\+|,|-|\.|/|0|1|2|3|4|5|6|7|8|9|\\:|;|\\<|=|\\>|\?|@|A|B|C|D|E|F|G|H|I|J|K|L|M|N|O|P|Q|R|S|T|U|V|W|X|Y|Z|\\\[|\\\\|\\]|\^|_|`|a|b|c|d|e|f|g|h|i|j|k|l|m|n|o|p|q|r|s|t|u|v|w|x|y|z|\\\{|\||\\\}|~)+)?)?(?<PayloadEndChar>[]\)>\}]))?(?:(?<ExtendedChecksumDelim>:)(?<ExtendedChecksum>[0-9a-f]{2}[0-9a-f]{2}))?
+((?<AccountNumber>(0|[1-9]\d+))(?:(?<ChecksumDelim>-)(?<Checksum>\d{2}))?|(?<AccountName>(a|b|c|d|e|f|g|h|i|j|k|l|m|n|o|p|q|r|s|t|u|v|w|x|y|z|!|@|#|\$|%|\^|&|\*|\\\(|\\\)|-|\+|\\\{|\\\}|\\\[|\\]|_|\\:|\\"|`|\||\\<|\\>|,|\.|\?|/|~)(a|b|c|d|e|f|g|h|i|j|k|l|m|n|o|p|q|r|s|t|u|v|w|x|y|z|0|1|2|3|4|5|6|7|8|9|!|@|#|\$|%|\^|&|\*|\\\(|\\\)|-|\+|\\\{|\\\}|\\\[|\\]|_|\\:|\\"|`|\||\\<|\\>|,|\.|\?|/|~)*))(?:(?<PayloadStartChar>[\[\(<\{])(?<PayloadContent>"( |!|\\"|#|\$|%|&|'|\\\(|\\\)|\*|\+|,|-|\.|/|0|1|2|3|4|5|6|7|8|9|\\:|;|\\<|=|\\>|\?|@|A|B|C|D|E|F|G|H|I|J|K|L|M|N|O|P|Q|R|S|T|U|V|W|X|Y|Z|\\\[|\\\\|\\]|\^|_|`|a|b|c|d|e|f|g|h|i|j|k|l|m|n|o|p|q|r|s|t|u|v|w|x|y|z|\\\{|\||\\\}|~)+"|0x(?:[0-9a-f]{2})+|[123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz]+)?(?:(?<PayloadPasswordDelim>:){1}(?<PayloadPassword>( |!|\\"|#|\$|%|&|'|\\\(|\\\)|\*|\+|,|-|\.|/|0|1|2|3|4|5|6|7|8|9|\\:|;|\\<|=|\\>|\?|@|A|B|C|D|E|F|G|H|I|J|K|L|M|N|O|P|Q|R|S|T|U|V|W|X|Y|Z|\\\[|\\\\|\\]|\^|_|`|a|b|c|d|e|f|g|h|i|j|k|l|m|n|o|p|q|r|s|t|u|v|w|x|y|z|\\\{|\||\\\}|~)+)?)?(?<PayloadEndChar>[]\)>\}]))?(?:(?<ExtendedChecksumDelim>:)(?<ExtendedChecksum>[0-9a-f]{2}[0-9a-f]{2}))?
 ```
 
 After matching with the above regex, the named groups need to be extracted and validated as the below snippet shows