v0.3.10-pre.002

crates/ksp-raw-transaction-lib/src/signature.rs

@@ -0,0 +1,67 @@
+// file: crates/ksp-raw-transaction-lib/src/signature.rs
+// version: 1
+
+/// Maximum UTF-8 byte length admitted for one textual Base58 Solana transaction signature.
+pub const MAX_RAW_TRANSACTION_SIGNATURE_TEXT_BYTES: usize = 88;
+/// Minimum UTF-8 byte length admitted for one textual Base58 Solana transaction signature.
+pub const MIN_RAW_TRANSACTION_SIGNATURE_TEXT_BYTES: usize = 64;
+
+/// Parses one bounded Base58 Solana transaction signature to exactly 64 canonical bytes.
+pub fn parse_raw_transaction_signature(value: &str) -> ksp_core_lib::Result<ksp_store_api::RawTransactionSignature> {
+    let text = value.as_bytes();
+    if text.len() < crate::MIN_RAW_TRANSACTION_SIGNATURE_TEXT_BYTES || text.len() > crate::MAX_RAW_TRANSACTION_SIGNATURE_TEXT_BYTES {
+        return std::result::Result::Err(
+            crate::signature_error()
+                .with_context("actual_len", text.len().to_string())
+                .with_context("minimum_len", crate::MIN_RAW_TRANSACTION_SIGNATURE_TEXT_BYTES.to_string())
+                .with_context("maximum_len", crate::MAX_RAW_TRANSACTION_SIGNATURE_TEXT_BYTES.to_string()),
+        );
+    }
+    let mut decoded = [0_u8; 64];
+    let mut leading_zeroes = 0_usize;
+    for byte in text {
+        if *byte != b'1' {
+            break;
+        }
+        leading_zeroes += 1;
+    }
+    for byte in text {
+        let digit = match base58_digit(*byte) {
+            std::option::Option::Some(digit) => digit,
+            std::option::Option::None => return std::result::Result::Err(crate::signature_error()),
+        };
+        let mut carry = u32::from(digit);
+        for output in decoded.iter_mut().rev() {
+            let expanded = (u32::from(*output) * 58) + carry;
+            *output = (expanded & 0xff) as u8;
+            carry = expanded >> 8;
+        }
+        if carry != 0 {
+            return std::result::Result::Err(crate::signature_error());
+        }
+    }
+    let significant_len = match decoded.iter().position(|byte| return *byte != 0) {
+        std::option::Option::Some(index) => decoded.len() - index,
+        std::option::Option::None => 0,
+    };
+    if leading_zeroes + significant_len != decoded.len() {
+        return std::result::Result::Err(crate::signature_error());
+    }
+    return std::result::Result::Ok(ksp_store_api::RawTransactionSignature::new(decoded));
+}
+
+fn base58_digit(byte: u8) -> std::option::Option<u8> {
+    return match byte {
+        b'1'..=b'9' => std::option::Option::Some(byte - b'1'),
+        b'A'..=b'H' => std::option::Option::Some((byte - b'A') + 9),
+        b'J'..=b'N' => std::option::Option::Some((byte - b'J') + 17),
+        b'P'..=b'Z' => std::option::Option::Some((byte - b'P') + 22),
+        b'a'..=b'k' => std::option::Option::Some((byte - b'a') + 33),
+        b'm'..=b'z' => std::option::Option::Some((byte - b'm') + 44),
+        _ => std::option::Option::None,
+    };
+}
+
+#[cfg(test)]
+#[path = "../unit_tests/signature.rs"]
+mod tests;