From 938e788fb404e9e270975d36db5e27d7e136ef09 Mon Sep 17 00:00:00 2001
From: Hans Nilsson <hans@erlang.org>
Date: Tue, 30 Apr 2019 16:47:42 +0200
Subject: crypto: Document supports/1

---
 lib/crypto/doc/src/crypto.xml  | 40 ++++++++++++++++++++++++++++------------
 lib/crypto/doc/src/new_api.xml | 10 +++++++++-
 lib/crypto/src/crypto.erl      | 21 +++++++++++++++++++++
 3 files changed, 58 insertions(+), 13 deletions(-)

diff --git a/lib/crypto/doc/src/crypto.xml b/lib/crypto/doc/src/crypto.xml
index 641738247e..751cf9d1fc 100644
--- a/lib/crypto/doc/src/crypto.xml
+++ b/lib/crypto/doc/src/crypto.xml
@@ -772,6 +772,19 @@
 	</p>
       </desc>
     </func>
+
+    <func>
+      <name name="supports" arity="1" since="OTP 22.0"/>
+      <fsummary>Provide a list of available crypto algorithms.</fsummary>
+      <desc>
+        <p> Can be used to determine which crypto algorithms that are supported
+	by the underlying libcrypto library</p>
+	<p>See <seealso marker="#hash_info-1">hash_info/1</seealso> and <seealso marker="#cipher_info-1">cipher_info/1</seealso>
+	for information about the hash and cipher algorithms.
+	</p>
+      </desc>
+    </func>
+
   </funcs>
 
   <section>
@@ -1425,18 +1438,6 @@ FloatValue = rand:uniform().     % again
       </desc>
     </func>
 
-   <func>
-      <name name="supports" arity="0" since="OTP R16B01"/>
-      <fsummary>Provide a list of available crypto algorithms.</fsummary>
-      <desc>
-        <p> Can be used to determine which crypto algorithms that are supported
-	by the underlying libcrypto library</p>
-	<p>See <seealso marker="#hash_info-1">hash_info/1</seealso> and <seealso marker="#cipher_info-1">cipher_info/1</seealso>
-	for information about the hash and cipher algorithms.
-	</p>
-      </desc>
-    </func>
-
     <func>
       <name name="ec_curves" arity="0" since="OTP 17.0"/>
       <fsummary>Provide a list of available named elliptic curves.</fsummary>
@@ -1947,6 +1948,21 @@ FloatValue = rand:uniform().     % again
       </desc>
     </func>
 
+   <func>
+      <name name="supports" arity="0" since="OTP R16B01"/>
+      <fsummary>Provide a list of available crypto algorithms.</fsummary>
+      <desc>
+	<dont><p>Don't use this function for new programs! Use
+	<seealso marker="crypto#supports-1">supports/1</seealso> in
+	<seealso marker="crypto:new_api">the new api</seealso>.</p></dont>
+        <p> Can be used to determine which crypto algorithms that are supported
+	by the underlying libcrypto library</p>
+	<p>See <seealso marker="#hash_info-1">hash_info/1</seealso> and <seealso marker="#cipher_info-1">cipher_info/1</seealso>
+	for information about the hash and cipher algorithms.
+	</p>
+      </desc>
+    </func>
+
   </funcs>
 
 
diff --git a/lib/crypto/doc/src/new_api.xml b/lib/crypto/doc/src/new_api.xml
index 79096b55e8..58ace97554 100644
--- a/lib/crypto/doc/src/new_api.xml
+++ b/lib/crypto/doc/src/new_api.xml
@@ -59,6 +59,7 @@
       <item><seealso marker="crypto#stream_init-2">stream_init/3</seealso></item>
       <item><seealso marker="crypto#stream_encrypt-2">stream_encrypt/2</seealso></item>
       <item><seealso marker="crypto#stream_decrypt-2">stream_decrypt/2</seealso></item>
+      <item><seealso marker="crypto#supports-0">suppports/0</seealso></item>
     </list>
     <p>They are not deprecated for now, but may be in a future.
     </p>
@@ -94,7 +95,7 @@
     <c>crypto_update</c> does the acual encryption or decryption. Note that AEAD ciphers
     can't be handled this way due to their nature.
     </p>
-    <p>Finally, for repeated encryption or decryption of a text divided in parts where the
+    <p>For repeated encryption or decryption of a text divided in parts where the
     same cipher and same key is used, but a new initialization vector (nounce) should be applied
     for each part, the functions are:
     </p>
@@ -103,6 +104,13 @@
       <item><seealso marker="crypto#crypto_dyn_iv_update/3">crypto_dyn_iv_update/3</seealso></item>
     </list>
     <p>An example of where those functions are needed, is when handling the TLS protocol.</p>
+    <p>For information about available algorithms, use:
+    </p>
+    <list>
+      <item><seealso marker="crypto#supports-1">supports/1</seealso></item>
+      <item><seealso marker="crypto#hash_info-1">hash_info/1</seealso></item>
+      <item><seealso marker="crypto#cipher_info-1">cipher_info/1</seealso></item>
+    </list>
 
     <section>
       <title>Examples of crypto_init/4 and crypto_update/2</title>
diff --git a/lib/crypto/src/crypto.erl b/lib/crypto/src/crypto.erl
index 98378412d4..8ffdde2b90 100644
--- a/lib/crypto/src/crypto.erl
+++ b/lib/crypto/src/crypto.erl
@@ -509,6 +509,27 @@ supports() ->
       {rsa_opts, rsa_opts_algorithms()}
      ].
 
+
+-spec supports(Type) -> Support
+                        when Type :: hashs
+			           | ciphers
+                                   | public_keys
+                                   | macs
+                                   | curves
+                                   | rsa_opts,
+			     Support :: Hashs
+                                      | Ciphers
+                                      | PKs
+                                      | Macs
+                                      | Curves
+                                      | RSAopts,
+                             Hashs :: [sha1() | sha2() | sha3() | blake2() | ripemd160 | compatibility_only_hash()],
+                             Ciphers :: [cipher()],
+                             PKs :: [rsa | dss | ecdsa | dh | ecdh | ec_gf2m],
+                             Macs :: [hmac | cmac | poly1305],
+                             Curves :: [ec_named_curve() | edwards_curve_dh() | edwards_curve_ed()],
+                             RSAopts :: [rsa_sign_verify_opt() | rsa_opt()] .
+
 supports(hashs)       -> hash_algorithms();
 supports(public_keys) -> pubkey_algorithms();
 supports(ciphers)     -> cipher_algorithms();
-- 
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