commit d6f5b272f0db1765f432e1182f671e28e405cf9c
parent 93ca03d675cbd7c12a08c07c61f528478fea42dd
Author: William Casarin <jb55@jb55.com>
Date: Sat, 12 Mar 2022 20:38:57 -0800
bech32: add decoding functions
We'll need this for lnurl and maybe local decoding of invoices
eventually
Signed-off-by: William Casarin <jb55@jb55.com>
Diffstat:
| M | Makefile | | | 2 | +- |
| A | bech32.c | | | 211 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
| A | bech32.h | | | 134 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
3 files changed, 346 insertions(+), 1 deletion(-)
diff --git a/Makefile b/Makefile
@@ -12,7 +12,7 @@ IOS_SDK=$(XCODEDIR)/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk
HEADERS=config.h deps/secp256k1/include/secp256k1.h deps/libsodium/src/libsodium/include/sodium/crypto_aead_chacha20poly1305.h
ARS=libsecp256k1.a libsodium.a
WASM_ARS=target/wasm/libsecp256k1.a target/wasm/libsodium.a target/wasm/lnsocket.a
-OBJS=sha256.o hkdf.o hmac.o sha512.o lnsocket.o error.o handshake.o crypto.o bigsize.o commando.o
+OBJS=sha256.o hkdf.o hmac.o sha512.o lnsocket.o error.o handshake.o crypto.o bigsize.o commando.o bech32.o
ARM64_OBJS=$(OBJS:.o=-arm64.o)
X86_64_OBJS=$(OBJS:.o=-x86_64.o)
WASM_OBJS=$(OBJS:.o=-wasm.o) lnsocket_wasm-wasm.o
diff --git a/bech32.c b/bech32.c
@@ -0,0 +1,211 @@
+/* Stolen from https://github.com/sipa/bech32/blob/master/ref/c/segwit_addr.c,
+ * with only the two ' > 90' checks hoisted, and more internals exposed */
+
+/* Copyright (c) 2017, 2021 Pieter Wuille
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "config.h"
+#include <assert.h>
+#include <string.h>
+#include "bech32.h"
+
+static uint32_t bech32_polymod_step(uint32_t pre) {
+ uint8_t b = pre >> 25;
+ return ((pre & 0x1FFFFFF) << 5) ^
+ (-((b >> 0) & 1) & 0x3b6a57b2UL) ^
+ (-((b >> 1) & 1) & 0x26508e6dUL) ^
+ (-((b >> 2) & 1) & 0x1ea119faUL) ^
+ (-((b >> 3) & 1) & 0x3d4233ddUL) ^
+ (-((b >> 4) & 1) & 0x2a1462b3UL);
+}
+
+static uint32_t bech32_final_constant(bech32_encoding enc) {
+ if (enc == BECH32_ENCODING_BECH32) return 1;
+ if (enc == BECH32_ENCODING_BECH32M) return 0x2bc830a3;
+ assert(0);
+}
+
+const char bech32_charset[] = "qpzry9x8gf2tvdw0s3jn54khce6mua7l";
+
+const int8_t bech32_charset_rev[128] = {
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ 15, -1, 10, 17, 21, 20, 26, 30, 7, 5, -1, -1, -1, -1, -1, -1,
+ -1, 29, -1, 24, 13, 25, 9, 8, 23, -1, 18, 22, 31, 27, 19, -1,
+ 1, 0, 3, 16, 11, 28, 12, 14, 6, 4, 2, -1, -1, -1, -1, -1,
+ -1, 29, -1, 24, 13, 25, 9, 8, 23, -1, 18, 22, 31, 27, 19, -1,
+ 1, 0, 3, 16, 11, 28, 12, 14, 6, 4, 2, -1, -1, -1, -1, -1
+};
+
+int bech32_encode(char *output, const char *hrp, const uint8_t *data, size_t data_len, size_t max_input_len, bech32_encoding enc) {
+ uint32_t chk = 1;
+ size_t i = 0;
+ while (hrp[i] != 0) {
+ int ch = hrp[i];
+ if (ch < 33 || ch > 126) {
+ return 0;
+ }
+
+ if (ch >= 'A' && ch <= 'Z') return 0;
+ chk = bech32_polymod_step(chk) ^ (ch >> 5);
+ ++i;
+ }
+ if (i + 7 + data_len > max_input_len) return 0;
+ chk = bech32_polymod_step(chk);
+ while (*hrp != 0) {
+ chk = bech32_polymod_step(chk) ^ (*hrp & 0x1f);
+ *(output++) = *(hrp++);
+ }
+ *(output++) = '1';
+ for (i = 0; i < data_len; ++i) {
+ if (*data >> 5) return 0;
+ chk = bech32_polymod_step(chk) ^ (*data);
+ *(output++) = bech32_charset[*(data++)];
+ }
+ for (i = 0; i < 6; ++i) {
+ chk = bech32_polymod_step(chk);
+ }
+ chk ^= bech32_final_constant(enc);
+ for (i = 0; i < 6; ++i) {
+ *(output++) = bech32_charset[(chk >> ((5 - i) * 5)) & 0x1f];
+ }
+ *output = 0;
+ return 1;
+}
+
+bech32_encoding bech32_decode(char* hrp, uint8_t *data, size_t *data_len, const char *input, size_t max_input_len) {
+ uint32_t chk = 1;
+ size_t i;
+ size_t input_len = strlen(input);
+ size_t hrp_len;
+ int have_lower = 0, have_upper = 0;
+ if (input_len < 8 || input_len > max_input_len) {
+ return BECH32_ENCODING_NONE;
+ }
+ *data_len = 0;
+ while (*data_len < input_len && input[(input_len - 1) - *data_len] != '1') {
+ ++(*data_len);
+ }
+ hrp_len = input_len - (1 + *data_len);
+ if (1 + *data_len >= input_len || *data_len < 6) {
+ return BECH32_ENCODING_NONE;
+ }
+ *(data_len) -= 6;
+ for (i = 0; i < hrp_len; ++i) {
+ int ch = input[i];
+ if (ch < 33 || ch > 126) {
+ return BECH32_ENCODING_NONE;
+ }
+ if (ch >= 'a' && ch <= 'z') {
+ have_lower = 1;
+ } else if (ch >= 'A' && ch <= 'Z') {
+ have_upper = 1;
+ ch = (ch - 'A') + 'a';
+ }
+ hrp[i] = ch;
+ chk = bech32_polymod_step(chk) ^ (ch >> 5);
+ }
+ hrp[i] = 0;
+ chk = bech32_polymod_step(chk);
+ for (i = 0; i < hrp_len; ++i) {
+ chk = bech32_polymod_step(chk) ^ (input[i] & 0x1f);
+ }
+ ++i;
+ while (i < input_len) {
+ int v = (input[i] & 0x80) ? -1 : bech32_charset_rev[(int)input[i]];
+ if (input[i] >= 'a' && input[i] <= 'z') have_lower = 1;
+ if (input[i] >= 'A' && input[i] <= 'Z') have_upper = 1;
+ if (v == -1) {
+ return BECH32_ENCODING_NONE;
+ }
+ chk = bech32_polymod_step(chk) ^ v;
+ if (i + 6 < input_len) {
+ data[i - (1 + hrp_len)] = v;
+ }
+ ++i;
+ }
+ if (have_lower && have_upper) {
+ return BECH32_ENCODING_NONE;
+ }
+ if (chk == bech32_final_constant(BECH32_ENCODING_BECH32)) {
+ return BECH32_ENCODING_BECH32;
+ } else if (chk == bech32_final_constant(BECH32_ENCODING_BECH32M)) {
+ return BECH32_ENCODING_BECH32M;
+ } else {
+ return BECH32_ENCODING_NONE;
+ }
+}
+
+int bech32_convert_bits(uint8_t* out, size_t* outlen, int outbits, const uint8_t* in, size_t inlen, int inbits, int pad) {
+ uint32_t val = 0;
+ int bits = 0;
+ uint32_t maxv = (((uint32_t)1) << outbits) - 1;
+ while (inlen--) {
+ val = (val << inbits) | *(in++);
+ bits += inbits;
+ while (bits >= outbits) {
+ bits -= outbits;
+ out[(*outlen)++] = (val >> bits) & maxv;
+ }
+ }
+ if (pad) {
+ if (bits) {
+ out[(*outlen)++] = (val << (outbits - bits)) & maxv;
+ }
+ } else if (((val << (outbits - bits)) & maxv) || bits >= inbits) {
+ return 0;
+ }
+ return 1;
+}
+
+int segwit_addr_encode(char *output, const char *hrp, int witver, const uint8_t *witprog, size_t witprog_len) {
+ uint8_t data[65];
+ size_t datalen = 0;
+ bech32_encoding enc = BECH32_ENCODING_BECH32;
+ if (witver > 16) return 0;
+ if (witver == 0 && witprog_len != 20 && witprog_len != 32) return 0;
+ if (witprog_len < 2 || witprog_len > 40) return 0;
+ if (witver > 0) enc = BECH32_ENCODING_BECH32M;
+ data[0] = witver;
+ bech32_convert_bits(data + 1, &datalen, 5, witprog, witprog_len, 8, 1);
+ ++datalen;
+ return bech32_encode(output, hrp, data, datalen, 90, enc);
+}
+
+int segwit_addr_decode(int* witver, uint8_t* witdata, size_t* witdata_len, const char* hrp, const char* addr) {
+ uint8_t data[84];
+ char hrp_actual[84];
+ size_t data_len;
+ bech32_encoding enc = bech32_decode(hrp_actual, data, &data_len, addr, 90);
+ if (enc == BECH32_ENCODING_NONE) return 0;
+ if (data_len == 0 || data_len > 65) return 0;
+ if (strncmp(hrp, hrp_actual, 84) != 0) return 0;
+ if (data[0] > 16) return 0;
+ if (data[0] == 0 && enc != BECH32_ENCODING_BECH32) return 0;
+ if (data[0] > 0 && enc != BECH32_ENCODING_BECH32M) return 0;
+ *witdata_len = 0;
+ if (!bech32_convert_bits(witdata, witdata_len, 8, data + 1, data_len - 1, 5, 0)) return 0;
+ if (*witdata_len < 2 || *witdata_len > 40) return 0;
+ if (data[0] == 0 && *witdata_len != 20 && *witdata_len != 32) return 0;
+ *witver = data[0];
+ return 1;
+}
diff --git a/bech32.h b/bech32.h
@@ -0,0 +1,134 @@
+/* Stolen from https://github.com/sipa/bech32/blob/master/ref/c/segwit_addr.h,
+ * with only the two ' > 90' checks hoisted */
+
+/* Copyright (c) 2017, 2021 Pieter Wuille
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef LIGHTNING_COMMON_BECH32_H
+#define LIGHTNING_COMMON_BECH32_H
+#include "config.h"
+
+#include <stdint.h>
+#include <stdlib.h>
+
+/** Encode a SegWit address
+ *
+ * Out: output: Pointer to a buffer of size 73 + strlen(hrp) that will be
+ * updated to contain the null-terminated address.
+ * In: hrp: Pointer to the null-terminated human readable part to use
+ * (chain/network specific).
+ * ver: Version of the witness program (between 0 and 16 inclusive).
+ * prog: Data bytes for the witness program (between 2 and 40 bytes).
+ * prog_len: Number of data bytes in prog.
+ * Returns 1 if successful.
+ */
+int segwit_addr_encode(
+ char *output,
+ const char *hrp,
+ int ver,
+ const uint8_t *prog,
+ size_t prog_len
+);
+
+/** Decode a SegWit address
+ *
+ * Out: ver: Pointer to an int that will be updated to contain the witness
+ * program version (between 0 and 16 inclusive).
+ * prog: Pointer to a buffer of size 40 that will be updated to
+ * contain the witness program bytes.
+ * prog_len: Pointer to a size_t that will be updated to contain the length
+ * of bytes in prog.
+ * hrp: Pointer to the null-terminated human readable part that is
+ * expected (chain/network specific).
+ * addr: Pointer to the null-terminated address.
+ * Returns 1 if successful.
+ */
+int segwit_addr_decode(
+ int* ver,
+ uint8_t* prog,
+ size_t* prog_len,
+ const char* hrp,
+ const char* addr
+);
+
+/** Supported encodings. */
+typedef enum {
+ BECH32_ENCODING_NONE,
+ BECH32_ENCODING_BECH32,
+ BECH32_ENCODING_BECH32M
+} bech32_encoding;
+
+/** Encode a Bech32 or Bech32m string
+ *
+ * Out: output: Pointer to a buffer of size strlen(hrp) + data_len + 8 that
+ * will be updated to contain the null-terminated Bech32 string.
+ * In: hrp : Pointer to the null-terminated human readable part.
+ * data : Pointer to an array of 5-bit values.
+ * data_len: Length of the data array.
+ * max_input_len: Maximum valid length of input (90 for segwit usage).
+ * enc: Which encoding to use (BECH32_ENCODING_BECH32{,M}).
+ * Returns 1 if successful.
+ */
+int bech32_encode(
+ char *output,
+ const char *hrp,
+ const uint8_t *data,
+ size_t data_len,
+ size_t max_input_len,
+ bech32_encoding enc
+);
+
+/** Decode a Bech32 or Bech32m string
+ *
+ * Out: hrp: Pointer to a buffer of size strlen(input) - 6. Will be
+ * updated to contain the null-terminated human readable part.
+ * data: Pointer to a buffer of size strlen(input) - 8 that will
+ * hold the encoded 5-bit data values.
+ * data_len: Pointer to a size_t that will be updated to be the number
+ * of entries in data.
+ * In: input: Pointer to a null-terminated Bech32 string.
+ * max_input_len: Maximum valid length of input (90 for segwit usage).
+ * Returns BECH32_ENCODING_BECH32{,M} to indicate decoding was successful
+ * with the specified encoding standard. BECH32_ENCODING_NONE is returned if
+ * decoding failed.
+ */
+bech32_encoding bech32_decode(
+ char *hrp,
+ uint8_t *data,
+ size_t *data_len,
+ const char *input,
+ size_t max_input_len
+);
+
+/* Helper from bech32: translates inbits-bit bytes to outbits-bit bytes.
+ * @outlen is incremented as bytes are added.
+ * @pad is true if we're to pad, otherwise truncate last byte if necessary
+ */
+int bech32_convert_bits(uint8_t* out, size_t* outlen, int outbits,
+ const uint8_t* in, size_t inlen, int inbits,
+ int pad);
+
+/* The charset, and reverse mapping */
+extern const char bech32_charset[32];
+extern const int8_t bech32_charset_rev[128];
+
+#endif /* LIGHTNING_COMMON_BECH32_H */
+
