Doxygen code comment cleanups and new blog post. No code changes. (0.41.5)

src/vm/openssl/md5.c

@@ -7,14 +7,27 @@
  * https://opensource.org/license/apache-2-0
  */
 
- /**
-  * @file md5.c
-  * @brief VM opcode snippet: compute MD5 hash (OP_MD5). Included by vm.c.
-  */
-
 /**
- * OpenSSL MD5 builtin
+ * @file md5.c
+ * @brief Implements OP_OPENSSL_MD5 to compute an MD5 hash in hexadecimal.
+ *
+ * Behavior:
+ * - Pops one value from the VM stack and converts it to a byte sequence by
+ *   obtaining its string representation using value_to_string_alloc().
+ * - Computes the MD5 digest of the resulting bytes via fun_openssl_md5_hex()
+ *   and pushes the lowercase hexadecimal string back onto the stack.
+ * - On allocation or hashing failure, pushes an empty string ("").
+ *
+ * Notes:
+ * - Non-string inputs are accepted; they are stringified first.
+ * - This snippet is included by vm.c and executed when OP_OPENSSL_MD5 is
+ *   dispatched.
+ *
+ * Errors:
+ * - This opcode does not terminate the VM. Failures result in an empty
+ *   string being pushed.
  */
+
 case OP_OPENSSL_MD5: {
   Value vdata = pop_value(vm);
   char *s = value_to_string_alloc(&vdata);

src/vm/openssl/ripemd160.c

@@ -7,9 +7,25 @@
  * https://opensource.org/license/apache-2-0
  */
 
-/*
- * OpenSSL RIPEMD-160 builtin
+/**
+ * @file ripemd160.c
+ * @brief Implements OP_OPENSSL_RIPEMD160 to compute a RIPEMD-160 hash in hex.
+ *
+ * Behavior:
+ * - Pops one value from the VM stack and converts it to bytes by first
+ *   producing its string representation with value_to_string_alloc().
+ * - Computes the RIPEMD-160 digest via fun_openssl_ripemd160_hex() and
+ *   pushes the lowercase hexadecimal string.
+ * - On allocation or hashing failure, pushes an empty string ("").
+ *
+ * Notes:
+ * - Accepts any value type; non-strings are stringified first.
+ * - Included by vm.c and executed for OP_OPENSSL_RIPEMD160.
+ *
+ * Errors:
+ * - Does not abort the VM; failures result in an empty string.
  */
+
 case OP_OPENSSL_RIPEMD160: {
   Value vdata = pop_value(vm);
   char *s = value_to_string_alloc(&vdata);

src/vm/openssl/sha256.c

@@ -8,8 +8,24 @@
  */
 
 /**
- * OpenSSL SHA-256 builtin
+ * @file sha256.c
+ * @brief Implements OP_OPENSSL_SHA256 to compute a SHA-256 hash in hex.
+ *
+ * Behavior:
+ * - Pops one value from the VM stack and converts it to bytes by first
+ *   producing its string form with value_to_string_alloc().
+ * - Computes the SHA-256 digest via fun_openssl_sha256_hex() and pushes the
+ *   lowercase hexadecimal string.
+ * - On allocation or hashing failure, pushes an empty string ("").
+ *
+ * Notes:
+ * - Non-string inputs are allowed; values are stringified first.
+ * - Snippet is included by vm.c and executed for OP_OPENSSL_SHA256.
+ *
+ * Errors:
+ * - No hard VM error is raised; failures push an empty string.
  */
+
 case OP_OPENSSL_SHA256: {
   Value vdata = pop_value(vm);
   char *s = value_to_string_alloc(&vdata);

src/vm/openssl/sha512.c

@@ -8,8 +8,24 @@
  */
 
 /**
- * OpenSSL SHA-512 builtin
+ * @file sha512.c
+ * @brief Implements OP_OPENSSL_SHA512 to compute a SHA-512 hash in hex.
+ *
+ * Behavior:
+ * - Pops one value from the VM stack and converts it to bytes by first
+ *   turning it into a string with value_to_string_alloc().
+ * - Computes the SHA-512 digest via fun_openssl_sha512_hex() and pushes the
+ *   lowercase hexadecimal string back on the stack.
+ * - On allocation or hashing failure, pushes an empty string ("").
+ *
+ * Notes:
+ * - Non-string inputs are accepted and stringified first.
+ * - This file is included by vm.c and handles OP_OPENSSL_SHA512.
+ *
+ * Errors:
+ * - Does not abort the VM; failures return an empty string.
  */
+
 case OP_OPENSSL_SHA512: {
   Value vdata = pop_value(vm);
   char *s = value_to_string_alloc(&vdata);