lightning · rustyrussell · May 11, 2020 · May 11, 2020 · May 11, 2020 · May 11, 2020
diff --git a/11-payment-encoding.md b/11-payment-encoding.md
@@ -78,8 +78,10 @@ A reader:
     a `multiplier` (see table above):
   	  - MUST fail the payment.
     - if the `multiplier` is present:
-	    - MUST multiply `amount` by the `multiplier` value to derive the
+	  - MUST multiply `amount` by the `multiplier` value to derive the
       amount required for payment.
+      - if multiplier is `p` and the last decimal of `amount` is not 0:
+	    - MUST fail the payment.
 
 ## Rationale
 
@@ -566,6 +568,38 @@ Breakdown:
   * `6c6e626332306d0b25fe64570d0e496dbd9f8b0d000dbb44824f751380da37c6dba89b14f6f92047d63f576e304021a00008101820283038404800081018202830384048000810182028303840480810243500c318a1e0a628b34025e8c9019ab6d09b64c2b3c66a693d0dc63194b02481931000` hex of data for signing (prefix + data after separator up to the start of the signature)
   * `399a8b167029fda8564fd2e99912236b0b8017e7d17e416ae17307812c92cf42` hex of SHA256 of the preimage
 
+> ### Please send 0.00967878534 BTC for a list of items within one week, amount in pico-BTC
+> lnbc9678785340p1pwmna7lpp5gc3xfm08u9qy06djf8dfflhugl6p7lgza6dsjxq454gxhj9t7a0sd8dgfkx7cmtwd68yetpd5s9xar0wfjn5gpc8qhrsdfq24f5ggrxdaezqsnvda3kkum5wfjkzmfqf3jkgem9wgsyuctwdus9xgrcyqcjcgpzgfskx6eqf9hzqnteypzxz7fzypfhg6trddjhygrcyqezcgpzfysywmm5ypxxjemgw3hxjmn8yptk7untd9hxwg3q2d6xjcmtv4ezq7pqxgsxzmnyyqcjqmt0wfjjq6t5v4khxxqyjw5qcqp2rzjq0gxwkzc8w6323m55m4jyxcjwmy7stt9hwkwe2qxmy8zpsgg7jcuwz87fcqqeuqqqyqqqqlgqqqqn3qq9qn07ytgrxxzad9hc4xt3mawjjt8znfv8xzscs7007v9gh9j569lencxa8xeujzkxs0uamak9aln6ez02uunw6rd2ht2sqe4hz8thcdagpleym0j
+
+Breakdown:
+
+* `lnbc`: prefix, Lightning on bitcoin mainnet
+* `9678785340p`: amount (9678785340 pico-bitcoin = 967878534 milli satoshi)
+* `1`: Bech32 separator
+* `pwmna7l`: timestamp (1572468703)
+* `p`: payment hash.
+  * `p5`: `data_length` (`p` = 1, `5` = 20; 1 * 32 + 20 == 52)
+  * `gc3xfm08u9qy06djf8dfflhugl6p7lgza6dsjxq454gxhj9t7a0s`: payment hash 462264ede7e14047e9b249da94fefc47f41f7d02ee9b091815a5506bc8abf75f
+* `d`: short description
+  * `8d`: `data_length` (`8` = 7, `d` = 13; 7 * 32 + 13 == 237)
+  * `gfkx7cmtwd68yetpd5s9xar0wfjn5gpc8qhrsdfq24f5ggrxdaezqsnvda3kkum5wfjkzmfqf3jkgem9wgsyuctwdus9xgrcyqcjcgpzgfskx6eqf9hzqnteypzxz7fzypfhg6trddjhygrcyqezcgpzfysywmm5ypxxjemgw3hxjmn8yptk7untd9hxwg3q2d6xjcmtv4ezq7pqxgsxzmnyyqcjqmt0wfjjq6t5v4khx`: 'Blockstream Store: 88.85 USD for Blockstream Ledger Nano S x 1, \"Back In My Day\" Sticker x 2, \"I Got Lightning Working\" Sticker x 2 and 1 more items'
+* `x`: expiry time
+  * `qy`: `data_length` (`q` = 0, `y` = 2; 0 * 32 + 4 == 4)
+  * `jw5q`: 604800 seconds (`j` = 18, `w` = 14, `5` = 20, `q` = 0; 18 * 32^3 + 14 * 32^2 + 20 * 32 + 0 == 604800)
+* `c`: `min_final_cltv_expiry`
+  * `qp`: `data_length` (`q` = 0, `p` = 1; 0 * 32 + 1 == 1)
+  * `2`: min_final_cltv_expiry = 10
+* `r`: tagged field: route information
+  * `zj`: `data_length` (`z` = 2, `j` = 18; 2 * 32 + 18 == 82)
+  * `q0gxwkzc8w6323m55m4jyxcjwmy7stt9hwkwe2qxmy8zpsgg7jcuwz87fcqqeuqqqyqqqqlgqqqqn3qq9q`:
+    * pubkey: 03d06758583bb5154774a6eb221b1276c9e82d65bbaceca806d90e20c108f4b1c7
+    * short_channel_id: 589390x3312x1
+    * fee_base_msat = 1000
+    * fee_proportional_millionths = 2500
+    * cltv_expiry_delta = 40
+* `n07ytgrxxzad9hc4xt3mawjjt8znfv8xzscs7007v9gh9j569lencxa8xeujzkxs0uamak9aln6ez02uunw6rd2ht2sqe4hz8thcdagp`: signature
+* `leym0j`: Bech32 checksum
+
 > ### Please send $30 for coffee beans to the same peer, which supports features 9, 15 and 99, using secret 0x1111111111111111111111111111111111111111111111111111111111111111
 > lnbc25m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5vdhkven9v5sxyetpdeessp5zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zygs9q5sqqqqqqqqqqqqqqqpqsq67gye39hfg3zd8rgc80k32tvy9xk2xunwm5lzexnvpx6fd77en8qaq424dxgt56cag2dpt359k3ssyhetktkpqh24jqnjyw6uqd08sgptq44qu
 
@@ -588,6 +622,63 @@ Breakdown:
 * `67gye39hfg3zd8rgc8032tvy9xk2xunwm5lzexnvpx6fd77en8qaq424dxgt56cag2dpt359k3ssyhetktkpqh24jqnjyw6uqd08sgp`: signature
 * `tq44qu`: Bech32 checksum
 
+> ### Same, but all upper case.
+> LNBC25M1PVJLUEZPP5QQQSYQCYQ5RQWZQFQQQSYQCYQ5RQWZQFQQQSYQCYQ5RQWZQFQYPQDQ5VDHKVEN9V5SXYETPDEESSP5ZYG3ZYG3ZYG3ZYG3ZYG3ZYG3ZYG3ZYG3ZYG3ZYG3ZYG3ZYG3ZYGS9Q5SQQQQQQQQQQQQQQQPQSQ67GYE39HFG3ZD8RGC80K32TVY9XK2XUNWM5LZEXNVPX6FD77EN8QAQ424DXGT56CAG2DPT359K3SSYHETKTKPQH24JQNJYW6UQD08SGPTQ44QU
+
+> ### Same, but including fields which must be ignored.
+> 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
+
+Breakdown:
+
+* `lnbc`: prefix, Lightning on Bitcoin mainnet
+* `25m`: amount (25 milli-bitcoin)
+* `1`: Bech32 separator
+* `pvjluez`: timestamp (1496314658)
+* `p`: payment hash...
+* `d`: short description
+  * `q5`: `data_length` (`q` = 0, `5` = 20; 0 * 32 + 20 == 20)
+  * `vdhkven9v5sxyetpdees`: 'coffee beans'
+* `s`: payment secret
+  * `p5`: `data_length` (`p` = 1, `5` = 20; 1 * 32 + 20 == 52)
+  * `zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zygs`: 0x1111111111111111111111111111111111111111111111111111111111111111
+* `9`: features
+  * `q5`: `data_length` (`q` = 0, `5` = 20; 0 * 32 + 20 == 20)
+  * `sqqqqqqqqqqqqqqqpqsq`: b1000....00001000001000000000
+* `2`: unknown field
+  * `qr`: `data_length` (`q` = 0, `r` = 3; 0 * 32 + 3 == 3)
+  * `qqq`: zeroes
+* `f`: tagged field: fallback address
+  * `pp`: `data_length` (`p` = 1, `p` = 1; 1 * 32 + 1 == 33)
+  * `nqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq`: fallback address type 19 (ignored)
+* `p`: payment hash
+  * `pn`: `data_length` (`p` = 1, `n` = 19; 1 * 32 + 19 == 51) (ignored)
+  * `qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq`
+* `p`: payment hash
+  * `p4`: `data_length` (`p` = 1, `4` = 21; 1 * 32 + 21 == 53) (ignored)
+  * `qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq`
+* `h`: hash of description
+  * `pn`: `data_length` (`p` = 1, `n` = 19; 1 * 32 + 19 == 51) (ignored)
+  * `qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq`
+* `h`: hash of description
+  * `p4`: `data_length` (`p` = 1, `4` = 21; 1 * 32 + 21 == 53) (ignored)
+  * `qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq`
+* `s`: payment secret
+  * `pn`: `data_length` (`p` = 1, `n` = 19; 1 * 32 + 19 == 51) (ignored)
+  * `qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq`
+* `s`: payment secret
+  * `p4`: `data_length` (`p` = 1, `4` = 21; 1 * 32 + 21 == 53) (ignored)
+  * `qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq`
+* `n`: node id
+  * `p5`: `data_length` (`p` = 1, `5` = 20; 1 * 32 + 20 == 52) (ignored)
+  * `qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq`
+* `n`: node id
+  * `pk`: `data_length` (`p` = 1, `k` = 22; 1 * 32 + 22 == 54) (ignored)
+  * `qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq`
+* `2jxxfsnucm4jf4zwtznpaxphce606fvhvje5x7d4gw7n73994hgs7nteqvenq8a4ml8aqtchv5d9pf7l558889hp4yyrqv6a7zpq9fgp`: signature
+* `skqhza`: Bech32 checksum
+
+# Examples of Invalid Invoices
+
 > # Same, but adding invalid unknown feature 100
 > lnbc25m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5vdhkven9v5sxyetpdeessp5zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zyg3zygs9q4psqqqqqqqqqqqqqqqpqsqq40wa3khl49yue3zsgm26jrepqr2eghqlx86rttutve3ugd05em86nsefzh4pfurpd9ek9w2vp95zxqnfe2u7ckudyahsa52q66tgzcp6t2dyk
 
@@ -610,37 +701,26 @@ Breakdown:
 * `40wa3khl49yue3zsgm26jrepqr2eghqlx86rttutve3ugd05em86nsefzh4pfurpd9ek9w2vp95zxqnfe2u7ckudyahsa52q66tgzcp`: signature
 * `6t2dyk`: Bech32 checksum
 
-> ### Please send 0.00967878534 BTC for a list of items within one week, amount in pico-BTC
-> 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
+> ### Bech32 checksum is invalid.
+> lnbc2500u1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdpquwpc4curk03c9wlrswe78q4eyqc7d8d0xqzpuyk0sg5g70me25alkluzd2x62aysf2pyy8edtjeevuv4p2d5p76r4zkmneet7uvyakky2zr4cusd45tftc9c5fh0nnqpnl2jfll544esqchsrnt
 
-Breakdown:
+> ### Malformed bech32 string (no 1)
+> pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdpquwpc4curk03c9wlrswe78q4eyqc7d8d0xqzpuyk0sg5g70me25alkluzd2x62aysf2pyy8edtjeevuv4p2d5p76r4zkmneet7uvyakky2zr4cusd45tftc9c5fh0nnqpnl2jfll544esqchsrny
 
-* `lnbc`: prefix, Lightning on bitcoin mainnet
-* `9678785340p`: amount (9678785340 pico-bitcoin = 967878534 milli satoshi)
-* `1`: Bech32 separator
-* `pwmna7l`: timestamp (1572468703)
-* `p`: payment hash.
-  * `p5`: `data_length` (`p` = 1, `5` = 20; 1 * 32 + 20 == 52)
-  * `gc3xfm08u9qy06djf8dfflhugl6p7lgza6dsjxq454gxhj9t7a0s`: payment hash 462264ede7e14047e9b249da94fefc47f41f7d02ee9b091815a5506bc8abf75f
-* `d`: short description
-  * `8d`: `data_length` (`8` = 7, `d` = 13; 7 * 32 + 13 == 237)
-  * `gfkx7cmtwd68yetpd5s9xar0wfjn5gpc8qhrsdfq24f5ggrxdaezqsnvda3kkum5wfjkzmfqf3jkgem9wgsyuctwdus9xgrcyqcjcgpzgfskx6eqf9hzqnteypzxz7fzypfhg6trddjhygrcyqezcgpzfysywmm5ypxxjemgw3hxjmn8yptk7untd9hxwg3q2d6xjcmtv4ezq7pqxgsxzmnyyqcjqmt0wfjjq6t5v4khx`: 'Blockstream Store: 88.85 USD for Blockstream Ledger Nano S x 1, \"Back In My Day\" Sticker x 2, \"I Got Lightning Working\" Sticker x 2 and 1 more items'
-* `x`: expiry time
-  * `qy`: `data_length` (`q` = 0, `y` = 2; 0 * 32 + 4 == 4)
-  * `jw5q`: 604800 seconds (`j` = 18, `w` = 14, `5` = 20, `q` = 0; 18 * 32^3 + 14 * 32^2 + 20 * 32 + 0 == 604800)
-* `c`: `min_final_cltv_expiry`
-  * `qp`: `data_length` (`q` = 0, `p` = 1; 0 * 32 + 1 == 1)
-  * `2`: min_final_cltv_expiry = 10
-* `r`: tagged field: route information
-  * `zj`: `data_length` (`z` = 2, `j` = 18; 2 * 32 + 18 == 82)
-  * `q0gxwkzc8w6323m55m4jyxcjwmy7stt9hwkwe2qxmy8zpsgg7jcuwz87fcqqeuqqqyqqqqlgqqqqn3qq9q`:
-    * pubkey: 03d06758583bb5154774a6eb221b1276c9e82d65bbaceca806d90e20c108f4b1c7
-    * short_channel_id: 589390x3312x1
-    * fee_base_msat = 1000
-    * fee_proportional_millionths = 2500
-    * cltv_expiry_delta = 40
-* `n07ytgrxxzad9hc4xt3mawjjt8znfv8xzscs7007v9gh9j569lencxa8xeujzkxs0uamak9aln6ez02uunw6rd2ht2sqe4hz8thcdagp`: signature
-* `leym0j`: Bech32 checksum
+> ### Malformed bech32 string (mixed case)
+> LNBC2500u1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdpquwpc4curk03c9wlrswe78q4eyqc7d8d0xqzpuyk0sg5g70me25alkluzd2x62aysf2pyy8edtjeevuv4p2d5p76r4zkmneet7uvyakky2zr4cusd45tftc9c5fh0nnqpnl2jfll544esqchsrny
+
+> ### Signature is not recoverable.
+> lnbc2500u1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5xysxxatsyp3k7enxv4jsxqzpuaxtrnwngzn3kdzw5hydlzf03qdgm2hdq27cqv3agm2awhz5se903vruatfhq77w3ls4evs3ch9zw97j25emudupq63nyw24cg27h2rspk28uwq
+
+> ### String is too short.
+> lnbc1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdpl2pkx2ctnv5sxxmmwwd5kgetjypeh2ursdae8g6na6hlh
+
+> ### Invalid multiplier
+> lnbc2500x1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5xysxxatsyp3k7enxv4jsxqzpujr6jxr9gq9pv6g46y7d20jfkegkg4gljz2ea2a3m9lmvvr95tq2s0kvu70u3axgelz3kyvtp2ywwt0y8hkx2869zq5dll9nelr83zzqqpgl2zg
+
+> ### Invalid sub-millisatoshi precision.
+> lnbc2500000001p1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5xysxxatsyp3k7enxv4jsxqzpu7hqtk93pkf7sw55rdv4k9z2vj050rxdr6za9ekfs3nlt5lr89jqpdmxsmlj9urqumg0h9wzpqecw7th56tdms40p2ny9q4ddvjsedzcplva53s
 
 # Authors
 

diff --git a/tools/spellcheck.sh b/tools/spellcheck.sh
@@ -60,16 +60,17 @@ do
 	# Short hex strings, eg '0x2bb038521914 12'
 	# long hex strings
 	# long base58 strings
-	WORDS=$(sed -e 's/\]([-#a-zA-Z0-9_.]*)//g' \
+	WORDS=$(sed -e 's/ [lL][nN]\([bB][cC]\|[tT][bB]\)[0-9munpxMUNP]*1[qpzry9x8gf2tvdw0s3jn54khce6mua7lQPZRY9X8GF2TVDW0S3JN54KHCE6MUA7L]\+//g' \
+            -e 's/\]([-#a-zA-Z0-9_.]*)//g' \
 	    -e '/^```/,/^```/d' \
 	    -e 's/`[a-zA-Z0-9_]*`//g' \
 	    -e 's/\* \[`[_a-z0-9*]\+`://g' \
 	    -e 's/0x[a-fA-F0-9 ]\+//g' \
 	    -e 's/[a-fA-F0-9]\{20,\}//g' \
 	    -e 's/^    .*_htlcs//g' \
-	    -e 's/ ln\(bc\|tb\)[0-9munp]*1[qpzry9x8gf2tvdw0s3jn54khce6mua7l]\+//g' \
 	    -e 's/ \(bc\|tb\)1[qpzry9x8gf2tvdw0s3jn54khce6mua7l]\+//g' \
-	    -e 's/[123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz]\{20,\}//g' < $f | aspell -l en_US --home-dir ${homedir} list)
+	    -e 's/pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdpquwpc4curk03c9wlrswe78q4eyqc7d8d0xqzpuyk0sg5g70me25alkluzd2x62aysf2pyy8edtjeevuv4p2d5p76r4zkmneet7uvyakky2zr4cusd45tftc9c5fh0nnqpnl2jfll544esqchsrny//' \
+	    -e 's/[123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz]\{20,\}//g' < $f | tee /tmp/`basename $f`.aspell | aspell -l en_US --home-dir ${homedir} list)
 	if [ -n "$WORDS" ]; then
 	    echo Misspelled words in $f: $WORDS >&2
 	    exit 1