From e707fdbbdee0e001b89db3eab21600b14c56a1d4 Mon Sep 17 00:00:00 2001
From: Rene Meusel <rene.meusel@rohde-schwarz.com>
Date: Fri, 22 Dec 2023 16:30:58 +0100
Subject: [PATCH] std::span for BigInt constructors

---
 src/lib/math/bigint/bigint.cpp | 11 ++++++-----
 src/lib/math/bigint/bigint.h   | 13 ++++++++++---
 2 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/src/lib/math/bigint/bigint.cpp b/src/lib/math/bigint/bigint.cpp
index 3ab1e3d49fd..6817d9736b4 100644
--- a/src/lib/math/bigint/bigint.cpp
+++ b/src/lib/math/bigint/bigint.cpp
@@ -79,7 +79,8 @@ BigInt::BigInt(std::string_view str) {
       base = Hexadecimal;
    }
 
-   *this = decode(cast_char_ptr_to_uint8(str.data()) + markers, str.length() - markers, base);
+   std::span<const uint8_t> strdata(cast_char_ptr_to_uint8(str.data()), str.length());
+   *this = decode(strdata.subspan(markers), base);
 
    if(negative) {
       set_sign(Negative);
@@ -88,15 +89,15 @@ BigInt::BigInt(std::string_view str) {
    }
 }
 
-BigInt::BigInt(const uint8_t input[], size_t length) {
-   binary_decode(input, length);
+BigInt::BigInt(std::span<const uint8_t> input) {
+   binary_decode(input);
 }
 
 /*
 * Construct a BigInt from an encoded BigInt
 */
-BigInt::BigInt(const uint8_t input[], size_t length, Base base) {
-   *this = decode(input, length, base);
+BigInt::BigInt(std::span<const uint8_t> input, Base base) {
+   *this = decode(input.data(), input.size(), base);
 }
 
 //static
diff --git a/src/lib/math/bigint/bigint.h b/src/lib/math/bigint/bigint.h
index 83ace2e27ff..68e194beec6 100644
--- a/src/lib/math/bigint/bigint.h
+++ b/src/lib/math/bigint/bigint.h
@@ -94,13 +94,13 @@ class BOTAN_PUBLIC_API(2, 0) BigInt final {
        * @param buf the byte array holding the value
        * @param length size of buf
        */
-      BigInt(const uint8_t buf[], size_t length);
+      BigInt(const uint8_t buf[], size_t length) : BigInt(std::span{buf, length}) {}
 
       /**
        * Create a BigInt from an integer in a byte array
        * @param vec the byte vector holding the value
        */
-      explicit BigInt(std::span<const uint8_t> vec) : BigInt(vec.data(), vec.size()) {}
+      explicit BigInt(std::span<const uint8_t> vec);
 
       /**
        * Create a BigInt from an integer in a byte array
@@ -108,7 +108,14 @@ class BOTAN_PUBLIC_API(2, 0) BigInt final {
        * @param length size of buf
        * @param base is the number base of the integer in buf
        */
-      BigInt(const uint8_t buf[], size_t length, Base base);
+      BigInt(const uint8_t buf[], size_t length, Base base) : BigInt(std::span{buf, length}, base) {}
+
+      /**
+       * Create a BigInt from an integer in a byte array
+       * @param buf the byte array holding the value
+       * @param base is the number base of the integer in buf
+       */
+      BigInt(std::span<const uint8_t> buf, Base base);
 
       /**
        * Create a BigInt from an integer in a byte array