From 0408b8d499658c847b826e14976f0809658cdbc9 Mon Sep 17 00:00:00 2001
From: Evan Burkey <evan@burkey.co>
Date: Fri, 29 Mar 2024 07:18:01 -0700
Subject: [PATCH] add hex_to_str

---
 docs/crypto.md     | 9 +++++++++
 include/lfcrypto.h | 2 ++
 src/crypto.c       | 9 +++++++++
 tests/tests.c      | 8 ++++++++
 4 files changed, 28 insertions(+)

diff --git a/docs/crypto.md b/docs/crypto.md
index 33714eb..624d27f 100644
--- a/docs/crypto.md
+++ b/docs/crypto.md
@@ -56,4 +56,13 @@ for (size_t i = 0; i < 4; ++i) {
     assert(s[i] == h[i]);
 }
 free(s);
+```
+
+### hex_to_str
+
+Converts an array of `unsigned char` into a string based on the ASCII values of each byte. User is
+responsible for freeing the returned string.
+
+```c
+const char *hex_to_str(const unsigned char *hex, size_t sz);
 ```
\ No newline at end of file
diff --git a/include/lfcrypto.h b/include/lfcrypto.h
index 0771811..7ba54ec 100644
--- a/include/lfcrypto.h
+++ b/include/lfcrypto.h
@@ -5,7 +5,9 @@
 
 const char *b64_encode(const unsigned char *s, size_t sz);
 unsigned char *b64_decode(const char *s, size_t sz, size_t *decode_sz);
+
 const char *hex_encode(const unsigned char *hex, size_t sz);
 unsigned char *hex_decode(const char *orig, size_t *sz);
+const char *hex_to_str(const unsigned char *hex, size_t sz);
 
 #endif // LIBFLINT_CRYPTO_H
diff --git a/src/crypto.c b/src/crypto.c
index 0286f8c..7c332bf 100644
--- a/src/crypto.c
+++ b/src/crypto.c
@@ -243,3 +243,12 @@ const char *hex_encode(const unsigned char *hex, size_t sz) {
 
     return s;
 }
+
+const char *hex_to_str(const unsigned char *hex, size_t sz) {
+    char *s = malloc(sizeof(char) * (sz + 1));
+    for (size_t i = 0; i < sz; ++i) {
+        s[i] = (char)hex[i];
+    }
+    s[sz] = '\0';
+    return s;
+}
\ No newline at end of file
diff --git a/tests/tests.c b/tests/tests.c
index 5193efa..bcbca01 100644
--- a/tests/tests.c
+++ b/tests/tests.c
@@ -349,6 +349,14 @@ void test_crypto() {
     s = hex_encode(h, 4);
     assert(strcmp(s, "DEADBEEF") == 0);
     free(s);
+
+    // "Sup?"
+    unsigned char hexsup[4] = {
+            0x53, 0x75, 0x70, 0x3F
+    };
+    s = hex_to_str(hexsup, 4);
+    assert(strcmp(s, "Sup?") == 0);
+    free(s);
 }
 
 #if defined(__APPLE__) || defined(__MACH__)