From 39db24ab7c54f1d34795676f8c043fd1146573ac Mon Sep 17 00:00:00 2001
From: Switck <69336248+switck@users.noreply.github.com>
Date: Wed, 3 Feb 2021 11:54:48 -0500
Subject: [PATCH 1/2] ref/c: segwit_decode_addr_details: capture details and
 return

---
 ref/c/segwit_addr.c | 31 +++++++++++++++++++++++++++----
 ref/c/segwit_addr.h | 35 +++++++++++++++++++++++++++++------
 2 files changed, 56 insertions(+), 10 deletions(-)

diff --git a/ref/c/segwit_addr.c b/ref/c/segwit_addr.c
index a1164e7..bf50cfc 100644
--- a/ref/c/segwit_addr.c
+++ b/ref/c/segwit_addr.c
@@ -189,21 +189,44 @@ int segwit_addr_encode(char *output, const char *hrp, int witver, const uint8_t
     return bech32_encode(output, hrp, data, datalen, enc);
 }
 
-int segwit_addr_decode(int* witver, uint8_t* witdata, size_t* witdata_len, const char* hrp, const char* addr) {
+int segwit_addr_decode_detailed(int* witver, uint8_t* witdata, size_t* witdata_len,
+                char *hrp_out, bech32_encoding* enc_out, 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);
     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 (!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];
+
+    if(hrp_out) {
+        strncpy(hrp_out, hrp_actual, 20);
+    }
+    if(enc_out) *enc_out = enc;
+
+    return 1;
+}
+
+int segwit_addr_decode(int* witver, uint8_t* witdata, size_t* witdata_len, const char* hrp, const char* addr) {
+
+    char hrp_actual[84];
+    bech32_encoding enc;
+
+    int ok = segwit_addr_decode_detailed(witver, witdata, witdata_len, hrp_actual, &enc, addr);
+    if (!ok) return 0;
+
+    if (strncmp(hrp, hrp_actual, 84) != 0) return 0;
+    if ((*witver) == 0 && enc != BECH32_ENCODING_BECH32) return 0;
+    if ((*witver) > 0 && enc != BECH32_ENCODING_BECH32M) return 0;
+
     return 1;
 }
diff --git a/ref/c/segwit_addr.h b/ref/c/segwit_addr.h
index 511970a..1d768b9 100644
--- a/ref/c/segwit_addr.h
+++ b/ref/c/segwit_addr.h
@@ -24,6 +24,13 @@
 
 #include <stdint.h>
 
+/** Supported encodings. */
+typedef enum {
+    BECH32_ENCODING_NONE,
+    BECH32_ENCODING_BECH32,
+    BECH32_ENCODING_BECH32M
+} bech32_encoding;
+
 
 /** Encode a SegWit address
  *
@@ -65,12 +72,28 @@ int segwit_addr_decode(
     const char* addr
 );
 
-/** Supported encodings. */
-typedef enum {
-    BECH32_ENCODING_NONE,
-    BECH32_ENCODING_BECH32,
-    BECH32_ENCODING_BECH32M
-} bech32_encoding;
+
+/** Decode a SegWit address, capturing details.
+ *
+ *  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_out:  Pointer to char[10] to hold observed HRP value, or NULL if not wanted.
+ *       encoding: Pointer to return observed bech32 encoding (or NULL, unused)
+ *       addr:     Pointer to the null-terminated address.
+ *  Returns 1 if successful.
+ */
+int segwit_addr_decode_detailed(
+    int* ver,
+    uint8_t* prog,
+    size_t* prog_len,
+    char *hrp_out,
+    bech32_encoding* encoding,
+    const char* addr
+);
 
 /** Encode a Bech32 or Bech32m string
  *

From 10d38fbba12da9f93c54c7fd44376152e1c06d85 Mon Sep 17 00:00:00 2001
From: Switck <69336248+switck@users.noreply.github.com>
Date: Fri, 5 Feb 2021 08:44:02 -0500
Subject: [PATCH 2/2] Restore encoding vs. version checks

---
 ref/c/segwit_addr.c | 13 ++++++-------
 ref/c/segwit_addr.h |  6 ++----
 2 files changed, 8 insertions(+), 11 deletions(-)

diff --git a/ref/c/segwit_addr.c b/ref/c/segwit_addr.c
index bf50cfc..390b3da 100644
--- a/ref/c/segwit_addr.c
+++ b/ref/c/segwit_addr.c
@@ -190,7 +190,7 @@ int segwit_addr_encode(char *output, const char *hrp, int witver, const uint8_t
 }
 
 int segwit_addr_decode_detailed(int* witver, uint8_t* witdata, size_t* witdata_len,
-                char *hrp_out, bech32_encoding* enc_out, const char* addr)
+                char *hrp_out, const char* addr)
 {
     uint8_t data[84];
     char hrp_actual[84];
@@ -202,16 +202,18 @@ int segwit_addr_decode_detailed(int* witver, uint8_t* witdata, size_t* witdata_l
     if (data[0] > 16) return 0;
 
     *witdata_len = 0;
+    *witver = data[0];
+
     if (!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];
+    if (data[0] == 0 && enc != BECH32_ENCODING_BECH32) return 0;
+    if (data[0] > 0 && enc != BECH32_ENCODING_BECH32M) return 0;
 
     if(hrp_out) {
         strncpy(hrp_out, hrp_actual, 20);
     }
-    if(enc_out) *enc_out = enc;
 
     return 1;
 }
@@ -219,14 +221,11 @@ int segwit_addr_decode_detailed(int* witver, uint8_t* witdata, size_t* witdata_l
 int segwit_addr_decode(int* witver, uint8_t* witdata, size_t* witdata_len, const char* hrp, const char* addr) {
 
     char hrp_actual[84];
-    bech32_encoding enc;
 
-    int ok = segwit_addr_decode_detailed(witver, witdata, witdata_len, hrp_actual, &enc, addr);
+    int ok = segwit_addr_decode_detailed(witver, witdata, witdata_len, hrp_actual, addr);
     if (!ok) return 0;
 
     if (strncmp(hrp, hrp_actual, 84) != 0) return 0;
-    if ((*witver) == 0 && enc != BECH32_ENCODING_BECH32) return 0;
-    if ((*witver) > 0 && enc != BECH32_ENCODING_BECH32M) return 0;
 
     return 1;
 }
diff --git a/ref/c/segwit_addr.h b/ref/c/segwit_addr.h
index 1d768b9..096870f 100644
--- a/ref/c/segwit_addr.h
+++ b/ref/c/segwit_addr.h
@@ -73,7 +73,7 @@ int segwit_addr_decode(
 );
 
 
-/** Decode a SegWit address, capturing details.
+/** Decode a SegWit address, capturing HRP.
  *
  *  Out: ver:      Pointer to an int that will be updated to contain the witness
  *                 program version (between 0 and 16 inclusive).
@@ -81,8 +81,7 @@ int segwit_addr_decode(
  *                 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_out:  Pointer to char[10] to hold observed HRP value, or NULL if not wanted.
- *       encoding: Pointer to return observed bech32 encoding (or NULL, unused)
+ *       hrp_out:  Pointer to char[20] to hold observed HRP value, or NULL if not wanted.
  *       addr:     Pointer to the null-terminated address.
  *  Returns 1 if successful.
  */
@@ -91,7 +90,6 @@ int segwit_addr_decode_detailed(
     uint8_t* prog,
     size_t* prog_len,
     char *hrp_out,
-    bech32_encoding* encoding,
     const char* addr
 );