diff --git a/src/util/address.rs b/src/util/address.rs index 93c18c84..abfddba2 100644 --- a/src/util/address.rs +++ b/src/util/address.rs @@ -33,7 +33,7 @@ //! let address = Address::p2pkh(&public_key, Network::Bitcoin); //! ``` -use std::fmt::{self, Display, Formatter}; +use std::fmt; use std::str::FromStr; use std::error; @@ -349,10 +349,27 @@ impl Address { pub fn script_pubkey(&self) -> script::Script { self.payload.script_pubkey() } + + /// Creates a URI string *bitcoin:address* optimized to be encoded in QR codes. + /// + /// If the address is bech32, both the schema and the address become uppercase. + /// If the address is base58, the schema is lowercase and the address is left mixed case. + /// + /// Quoting BIP 173 "inside QR codes uppercase SHOULD be used, as those permit the use of + /// alphanumeric mode, which is 45% more compact than the normal byte mode." + pub fn to_qr_uri(&self) -> String { + let schema = match self.payload { + Payload::WitnessProgram { .. } => "BITCOIN", + _ => "bitcoin", + }; + format!("{}:{:#}", schema, self) + } } -impl Display for Address { - fn fmt(&self, fmt: &mut Formatter) -> fmt::Result { +// Alternate formatting `{:#}` is used to return uppercase version of bech32 addresses which should +// be used in QR codes, see [Address::to_qr_uri] +impl fmt::Display for Address { + fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result { match self.payload { Payload::PubkeyHash(ref hash) => { let mut prefixed = [0; 21]; @@ -378,10 +395,17 @@ impl Display for Address { } => { let hrp = match self.network { Network::Bitcoin => "bc", - Network::Testnet | Network::Signet => "tb", + Network::Testnet | Network::Signet => "tb", Network::Regtest => "bcrt", }; - let mut bech32_writer = bech32::Bech32Writer::new(hrp, fmt)?; + let mut upper_writer; + let writer = if fmt.alternate() { + upper_writer = UpperWriter(fmt); + &mut upper_writer as &mut dyn fmt::Write + } else { + fmt as &mut dyn fmt::Write + }; + let mut bech32_writer = bech32::Bech32Writer::new(hrp, writer)?; bech32::WriteBase32::write_u5(&mut bech32_writer, ver)?; bech32::ToBase32::write_base32(&prog, &mut bech32_writer) } @@ -389,6 +413,17 @@ impl Display for Address { } } +struct UpperWriter(W); + +impl fmt::Write for UpperWriter { + fn write_str(&mut self, s: &str) -> fmt::Result { + for c in s.chars() { + self.0.write_char(c.to_ascii_uppercase())?; + } + Ok(()) + } +} + /// Extract the bech32 prefix. /// Returns the same slice when no prefix is found. fn find_bech32_prefix(bech32: &str) -> &str { @@ -740,4 +775,18 @@ mod tests { hex_script!("001454d26dddb59c7073c6a197946ea1841951fa7a74") ); } + + #[test] + fn test_qr_string() { + for el in ["132F25rTsvBdp9JzLLBHP5mvGY66i1xdiM", "33iFwdLuRpW1uK1RTRqsoi8rR4NpDzk66k"].iter() { + let addr = Address::from_str(el).unwrap(); + assert_eq!(addr.to_qr_uri(), format!("bitcoin:{}", el)); + } + + for el in ["bcrt1q2nfxmhd4n3c8834pj72xagvyr9gl57n5r94fsl", "bc1qwqdg6squsna38e46795at95yu9atm8azzmyvckulcc7kytlcckxswvvzej"].iter() { + let addr = Address::from_str(el).unwrap(); + assert_eq!(addr.to_qr_uri(), format!("BITCOIN:{}", el.to_ascii_uppercase()) ); + } + } + }