Merge branch 'hans/crypto/cuddle_docs'

* hans/crypto/cuddle_docs:
  crypto: User's Guide and Reference Manual for the new api

4 files changed, 557 insertions, 157 deletions

diff --git a/lib/crypto/doc/src/Makefile b/lib/crypto/doc/src/Makefile
index cbcafb7375..8da494dad6 100644
--- a/lib/crypto/doc/src/Makefile
+++ b/lib/crypto/doc/src/Makefile
@@ -39,7 +39,8 @@ XML_REF3_FILES = crypto.xml
 XML_REF6_FILES = crypto_app.xml
 
 XML_PART_FILES = usersguide.xml
-XML_CHAPTER_FILES = notes.xml licenses.xml fips.xml engine_load.xml engine_keys.xml algorithm_details.xml
+XML_CHAPTER_FILES = notes.xml licenses.xml fips.xml engine_load.xml engine_keys.xml \
+	algorithm_details.xml new_api.xml
 
 BOOK_FILES = book.xml
 
diff --git a/lib/crypto/doc/src/crypto.xml b/lib/crypto/doc/src/crypto.xml
index 8a4fad67de..14efc5c6f6 100644
--- a/lib/crypto/doc/src/crypto.xml
+++ b/lib/crypto/doc/src/crypto.xml
@@ -42,7 +42,7 @@
 	      <item>
 		<url href="https://www.nist.gov/publications/sha-3-standard-permutation-based-hash-and-extendable-output-functions?pub_id=919061">
 		  SHA-3 Standard: Permutation-Based Hash and Extendable-Output Functions [FIPS PUB 202]
-		</url>		  
+		</url>		
 	      </item>
             <tag>BLAKE2</tag>
               <item>
@@ -190,70 +190,101 @@
   </description>
 
   <datatypes>
-    <datatype_title>Ciphers</datatype_title>
+    <datatype_title>Ciphers, new API</datatype_title>
     <datatype>
       <name name="cipher"/>
-      <name name="stream_cipher"/>
-      <name name="block_cipher"/>
       <desc>
-	<p>Ciphers known byt the CRYPTO application. Note that this list might be reduced if the
-	underlying libcrypto does not support all of them.</p>
       </desc>
     </datatype>
-
     <datatype>
-      <name name="stream_cipher_iv"/>
-      <name name="stream_cipher_no_iv"/>
+      <name name="cipher_no_iv"/>
       <desc>
-	<p>Stream ciphers for
-	<seealso marker="#stream_init-3">stream_init/3</seealso> and
-	<seealso marker="#stream_init-2">stream_init/2</seealso> .
-	</p>
+      </desc>
+    </datatype>
+    <datatype>
+      <name name="cipher_iv"/>
+      <desc>
+      </desc>
+    </datatype>
+    <datatype>
+      <name name="cipher_aead"/>
+      <desc>
+	<p>Ciphers known by the CRYPTO application when using the
+	<seealso marker="crypto:new_api#the-new-api">new API</seealso>.</p>
+	<p>Note that this list might be reduced if the underlying libcrypto does not support all of them.</p>
       </desc>
     </datatype>
 
+    <datatype_title>Ciphers, old API</datatype_title>
+    <datatype>
+      <name name="block_cipher_with_iv"/>
+      <desc>
+      </desc>
+    </datatype>
+    <datatype>
+      <name name="block_cipher_without_iv"/>
+      <desc>
+      </desc>
+    </datatype>
+    <datatype>
+      <name name="stream_cipher"/>
+      <desc>
+      </desc>
+    </datatype>
+    <datatype>
+      <name name="aead_cipher"/>
+      <desc>
+      </desc>
+    </datatype>
     <datatype>
-      <name name="block_cipher_iv"/>
       <name name="cbc_cipher"/>
+      <desc>
+      </desc>
+    </datatype>
+    <datatype>
       <name name="cfb_cipher"/>
       <desc>
-	<p>Block ciphers with initialization vector for
-	<seealso marker="#block_encrypt-4">block_encrypt/4</seealso> and
-	<seealso marker="#block_decrypt-4">block_decrypt/4</seealso> .
-	</p>
       </desc>
     </datatype>
-
     <datatype>
-      <name name="alias_cfb"/>
-      <name name="alias_cbc"/>
+      <name name="ctr_cipher"/>
       <desc>
-	<p>Names that are replaced by more common names. They may deprecated in futer releases.</p>
-	<p><c>des3_cbc</c> and <c>des_ede3</c> should be replaced by <c>des_ede3_cbc</c></p>
-	<p><c>des_ede3_cbf</c>, <c>des3_cbf</c> and <c>des3_cfb</c> should be replaced by <c>des_ede3_cfb</c>.</p>
-	<p><c>aes_cbc128</c> should be replaced by <c>aes_128_cbc</c>.</p>
-	<p><c>aes_cbc256</c> should be replaced by <c>aes_256_cbc</c>.</p>
       </desc>
     </datatype>
-
     <datatype>
-      <name name="block_cipher_no_iv"/>
       <name name="ecb_cipher"/>
       <desc>
-	<p>Block ciphers without initialization vector for
-	<seealso marker="#block_encrypt-3">block_encrypt/3</seealso> and
-	<seealso marker="#block_decrypt-3">block_decrypt/3</seealso> .
-	</p>
+	<p>Ciphers known by the CRYPTO application when using the
+	<seealso marker="crypto:new_api#the-old-api">old API</seealso>.</p>
+	<p>Note that this list might be reduced if the underlying libcrypto does not support all of them.</p>
       </desc>
     </datatype>
 
     <datatype>
-      <name name="aead_cipher"/>
+      <name name="retired_cbc_cipher_aliases"/>
+      <desc>
+      </desc>
+    </datatype>
+    <datatype>
+      <name name="retired_cfb_cipher_aliases"/>
       <desc>
-	<p>Ciphers with simultaneous MAC-calculation or MAC-checking.
-	<seealso marker="#block_encrypt-4">block_encrypt/4</seealso> and
-	<seealso marker="#block_decrypt-4">block_decrypt/4</seealso> .
+      </desc>
+    </datatype>
+    <datatype>
+      <name name="retired_ctr_cipher_aliases"/>
+      <desc>
+      </desc>
+    </datatype>
+    <datatype>
+      <name name="retired_ecb_cipher_aliases"/>
+      <desc>
+	<p>Alternative, old names of ciphers known by the CRYPTO application when using the
+	<seealso marker="crypto:new_api#the-old-api">old API</seealso>.
+	See <seealso marker="crypto:new_api#retired-cipher-names">Retired cipher names</seealso> for names to
+	use instead to be prepared for an easy convertion to the
+	<seealso marker="crypto:new_api#the-new-api">new API</seealso>.
 	</p>
+	<p>Note that this list might be reduced if the underlying libcrypto does not support all of them.</p>
       </desc>
     </datatype>
 
@@ -547,6 +578,7 @@
       <name name="stream_state"/>
       <name name="hmac_state"/>
       <name name="hash_state"/>
+      <name name="crypto_state"/>
       <desc>
 	<p>Contexts with an internal state that should not be manipulated but passed between function calls.
 	</p>
@@ -575,117 +607,171 @@
 	<p>This is a more developed variant of the older
 	<seealso marker="#type-run_time_error">run_time_error()</seealso>.
 	</p>
+	<p>The exception is:</p>
+	<pre>
+	  {Tag, {C_FileName,LineNumber}, Description}
+
+	   Tag = badarg | notsup | error
+	   C_FileName = string()
+	   LineNumber = integer()
+	   Description = string()
+	</pre>
+
 	<p>It is like the older type an exception of the <c>error</c> class. In addition they contain
 	a descriptive text in English. That text is targeted to a developer. Examples are "Bad key size"
 	or "Cipher id is not an atom".
 	</p>
-	<p>The exceptions are:</p>
+	<p>The exception tags are:</p>
 	<taglist>
-	  <tag><c>{badarg, Description::string()}</c></tag>
+	  <tag><c>badarg</c></tag>
 	  <item><p>Signifies that one or more arguments are of wrong data type or are otherwise badly formed.</p>
 	  </item>
 
-	  <tag><c>{notsup, Description::string()}</c></tag>
+	  <tag><c>notsup</c></tag>
 	  <item><p>Signifies that the algorithm is known but is not supported by current underlying libcrypto
 	  or explicitly disabled when building that one.</p>
 	  </item>
 
-	  <tag><c>{error, Description::string()}</c></tag>
+	  <tag><c>error</c></tag>
 	  <item><p>An error condition that should not occur, for example a memory allocation failed or
 	  the underlying cryptolib returned an error code, for example "Can't initialize context, step 1".
 	  Thoose text usually needs searching the C-code to be understood.</p>
 	  </item>
 	</taglist>
+	<p>To catch the exception, use for example:</p>
+	<code>
+	  try crypto:crypto_init(Ciph, Key, IV, true)
+	  catch
+	      error:{Tag, {C_FileName,LineNumber}, Description} ->
+	              do_something(......)
+	      .....
+	  end
+	</code>
       </desc>
     </datatype>
 
   </datatypes>
 
   <!--================ FUNCTIONS ================-->
+  <section>
+    <title>New API</title>
+  </section>
+
   <funcs>
     <func>
-      <name name="block_encrypt" arity="3" since="OTP 18.0"/>
-      <fsummary>Encrypt <c>PlainText</c> according to <c>Type</c> block cipher</fsummary>
+      <name name="crypto_init" arity="3" since="OTP 22.0"/>
+      <fsummary>Initializes a series of encryptions or decryptions</fsummary>
       <desc>
-	<p>Encrypt <c>PlainText</c> according to <c>Type</c> block cipher.</p>
-	<p>May raise exception <c>error:notsup</c> in case the chosen <c>Type</c>
-	is not supported by the underlying libcrypto implementation.</p>
-	<p>For keylengths and blocksizes see the
-	<seealso marker="crypto:algorithm_details#ciphers">User's Guide</seealso>.
+	<p>As <seealso marker="#crypto_init/4">crypto_init/4</seealso> but for ciphers without IVs.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="crypto_init" arity="4" since="OTP 22.0"/>
+      <fsummary>Initializes a series of encryptions or decryptions</fsummary>
+      <desc>
+	<p>Part of the <seealso marker="crypto:new_api#the-new-api">new API</seealso>.
+	Initializes a series of encryptions or decryptions.
+	The actual encryption or decryption is done by
+	<seealso marker="crypto#crypto_update/2">crypto_update/2</seealso>.
+	</p>
+	<p>For encryption, set the <c>EncryptFlag</c> to <c>true</c>.
+	</p>
+	<p>See <seealso marker="crypto:new_api#the-new-api">examples in the User's Guide.</seealso>
 	</p>
       </desc>
     </func>
 
     <func>
-      <name name="block_decrypt" arity="3" since="OTP 18.0"/>
-      <fsummary>Decrypt <c>CipherText</c> according to <c>Type</c> block cipher</fsummary>
+      <name name="crypto_init_dyn_iv" arity="3" since="OTP 22.0"/>
+      <fsummary>Initializes a series of encryptions or decryptions where the IV is provided later</fsummary>
       <desc>
-        <p>Decrypt <c>CipherText</c> according to <c>Type</c> block cipher.</p>
-	<p>May raise exception <c>error:notsup</c> in case the chosen <c>Type</c>
-	is not supported by the underlying libcrypto implementation.</p>
-	<p>For keylengths and blocksizes see the
-	<seealso marker="crypto:algorithm_details#ciphers">User's Guide</seealso>.
+	<p>Part of the <seealso marker="crypto:new_api#the-new-api">new API</seealso>.
+	Initializes a series of encryptions or decryptions where the IV is provided later.
+	The actual encryption or decryption is done by
+	<seealso marker="crypto#crypto_update_dyn_iv/3">crypto_update_dyn_iv/3</seealso>.
+	</p>
+	<p>For encryption, set the <c>EncryptFlag</c> to <c>true</c>.
+	</p>
+	<p>See <seealso marker="crypto:new_api#the-new-api">examples in the User's Guide.</seealso>
 	</p>
       </desc>
     </func>
 
     <func>
-      <name since="OTP R16B01">block_encrypt(Type, Key, Ivec, PlainText) -> CipherText | Error</name>
-      <name since="OTP R16B01">block_encrypt(AeadType, Key, Ivec, {AAD, PlainText}) -> {CipherText, CipherTag} | Error</name>
-      <name since="OTP R16B01">block_encrypt(aes_gcm | aes_ccm, Key, Ivec, {AAD, PlainText, TagLength}) -> {CipherText, CipherTag} | Error </name>
-      <fsummary>Encrypt <c>PlainText</c> according to <c>Type</c> block cipher</fsummary>
-      <type>
-	<v>Type = <seealso marker="#type-block_cipher_iv">block_cipher_iv()</seealso></v>
-	<v>AeadType = <seealso marker="#type-aead_cipher">aead_cipher()</seealso></v>
-	<v>Key = <seealso marker="#type-key">key()</seealso> | <seealso marker="#type-des3_key">des3_key()</seealso></v>
-        <v>PlainText = iodata()</v>
-        <v>AAD = IVec = CipherText = CipherTag = binary()</v>
-        <v>TagLength = 1..16</v>
-	<v>Error = <seealso marker="#type-run_time_error">run_time_error()</seealso></v>
-      </type>
+      <name name="crypto_update" arity="2" since="OTP 22.0"/>
+      <fsummary>Do an actual crypto operation on a part of the full text</fsummary>
       <desc>
-        <p>Encrypt <c>PlainText</c> according to <c>Type</c> block cipher.
-	<c>IVec</c> is an arbitrary initializing vector.</p>
-	<p>In AEAD (Authenticated Encryption with Associated Data) mode, encrypt
-	<c>PlainText</c>according to <c>Type</c> block cipher and calculate
-	<c>CipherTag</c> that also authenticates the <c>AAD</c> (Associated Authenticated Data).</p>
-	<p>May raise exception <c>error:notsup</c> in case the chosen <c>Type</c>
-	is not supported by the underlying libcrypto implementation.</p>
-	<p>For keylengths, iv-sizes and blocksizes see the
-	<seealso marker="crypto:algorithm_details#ciphers">User's Guide</seealso>.
+	<p>Part of the <seealso marker="crypto:new_api#the-new-api">new API</seealso>.
+	Do an actual crypto operation on a part of the full text.
+	The <c>State</c> should be created with
+	<seealso marker="crypto#crypto_init/3">crypto_init/3</seealso>
+	or
+	<seealso marker="crypto#crypto_init/4">crypto_init/4</seealso>.
+	</p>
+	<p>See <seealso marker="crypto:new_api#the-new-api">examples in the User's Guide.</seealso>
 	</p>
       </desc>
     </func>
 
     <func>
-      <name since="OTP R16B01">block_decrypt(Type, Key, Ivec, CipherText) -> PlainText | Error</name>
-      <name since="OTP R16B01">block_decrypt(AeadType, Key, Ivec, {AAD, CipherText, CipherTag}) -> PlainText | Error</name>
-      <fsummary>Decrypt <c>CipherText</c> according to <c>Type</c> block cipher</fsummary>
-      <type>
-	<v>Type = <seealso marker="#type-block_cipher_iv">block_cipher_iv()</seealso></v>
-	<v>AeadType = <seealso marker="#type-aead_cipher">aead_cipher()</seealso></v>
-	<v>Key = <seealso marker="#type-key">key()</seealso> | <seealso marker="#type-des3_key">des3_key()</seealso></v>
-        <v>PlainText = iodata()</v>
-        <v>AAD = IVec = CipherText = CipherTag = binary()</v>
-	<v>Error = BadTag | <seealso marker="#type-run_time_error">run_time_error()</seealso></v>
-	<v>BadTag = error</v>
-      </type>
+      <name name="crypto_update_dyn_iv" arity="3" since="OTP 22.0"/>
+      <fsummary>Do an actual crypto operation on a part of the full text and the IV is supplied for each part</fsummary>
       <desc>
-        <p>Decrypt <c>CipherText</c> according to <c>Type</c> block cipher.
-	<c>IVec</c> is an arbitrary initializing vector.</p>
-        <p>In AEAD (Authenticated Encryption with Associated Data) mode, decrypt
-	<c>CipherText</c>according to <c>Type</c> block cipher and check the authenticity
-	the <c>PlainText</c> and <c>AAD</c> (Associated Authenticated Data) using the
-	<c>CipherTag</c>. May return <c>error</c> if the decryption or validation fail's</p>
-	<p>May raise exception <c>error:notsup</c> in case the chosen <c>Type</c>
-	is not supported by the underlying libcrypto implementation.</p>
-	<p>For keylengths, iv-sizes and blocksizes see the
-	<seealso marker="crypto:algorithm_details#ciphers">User's Guide</seealso>.
+	<p>Part of the <seealso marker="crypto:new_api#the-new-api">new API</seealso>.
+	Do an actual crypto operation on a part of the full text and the IV is supplied for each part.
+	The <c>State</c> should be created with
+	<seealso marker="crypto#crypto_init_dyn_iv/3">crypto_init_dyn_iv/3</seealso>.
+	</p>
+	<p>See <seealso marker="crypto:new_api#the-new-api">examples in the User's Guide.</seealso>
 	</p>
       </desc>
     </func>
 
-     <func>
+    <func>
+      <name name="crypto_one_time" arity="4" since="OTP 22.0"/>
+      <fsummary>Do a complete encrypt or decrypt of the full text</fsummary>
+      <desc>
+	<p>As <seealso marker="#crypto_one_time/5">crypto_one_time/5</seealso> but for ciphers without IVs.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="crypto_one_time" arity="5" since="OTP 22.0"/>
+      <fsummary>Do a complete encrypt or decrypt of the full text</fsummary>
+      <desc>
+	<p>Part of the <seealso marker="crypto:new_api#the-new-api">new API</seealso>.
+	Do a complete encrypt or decrypt of the full text.
+	</p>
+	<p>For encryption, set the <c>EncryptFlag</c> to <c>true</c>.
+	</p>
+	<p>See <seealso marker="crypto:new_api#the-new-api">examples in the User's Guide.</seealso>
+	</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="crypto_aead" arity="6" since="OTP 22.0"/>
+      <name name="crypto_aead" arity="7" since="OTP 22.0"/>
+      <fsummary>Do a complete encrypt or decrypt with an AEAD cipher of the full text</fsummary>
+      <desc>
+	<p>Part of the <seealso marker="crypto:new_api#the-new-api">new API</seealso>.
+	Do a complete encrypt or decrypt with an AEAD cipher of the full text.
+	</p>
+	<p>For encryption, set the <c>EncryptFlag</c> to <c>true</c>.
+	</p>
+	<p>See <seealso marker="crypto:new_api#the-new-api">examples in the User's Guide.</seealso>
+	</p>
+      </desc>
+    </func>
+  </funcs>
+
+  <section>
+    <title>API kept from previous versions</title>
+  </section>
+
+  <funcs>
+    <func>
       <name name="bytes_to_integer" arity="1" since="OTP R16B01"/>
       <fsummary>Convert binary representation, of an integer, to an Erlang integer.</fsummary>
       <desc>
@@ -928,7 +1014,7 @@
 	cipher algorithm in question.
 	</p>
         <note>
-	  <p>The ciphers <c>aes_cbc</c>, <c>aes_cfb8</c>, <c>aes_cfb128</c>, <c>aes_ctr</c>, 
+	  <p>The ciphers <c>aes_cbc</c>, <c>aes_cfb8</c>, <c>aes_cfb128</c>, <c>aes_ctr</c>,
 	  <c>aes_ecb</c>, <c>aes_gcm</c> and <c>aes_ccm</c>
 	  has no keylength in the <c>Type</c> as opposed to for example <c>aes_128_ctr</c>. They adapt to the length of
 	  the key provided in the encrypt and decrypt function. Therefor it is impossible to return a valid keylength
@@ -1094,7 +1180,7 @@
 	  <seealso marker="#rand_seed_s-0">rand_seed_s/0</seealso>.
 	</p>
 	<p>
-	  When using the state object from this function the 
+	  When using the state object from this function the
 	  <seealso marker="stdlib:rand">rand</seealso> functions using it
 	  may raise exception <c>error:low_entropy</c> in case the random generator
 	  failed due to lack of secure "randomness".
@@ -1120,7 +1206,7 @@ _FloatValue = rand:uniform().     % [0.0; 1.0[</pre>
 	  <seealso marker="stdlib:rand#seed_s-1">rand:seed_s/1</seealso>.
 	</p>
 	<p>
-	  When using the state object from this function the 
+	  When using the state object from this function the
 	  <seealso marker="stdlib:rand">rand</seealso> functions using it
 	  may raise exception <c>error:low_entropy</c> in case the random generator
 	  failed due to lack of secure "randomness".
@@ -1129,7 +1215,7 @@ _FloatValue = rand:uniform().     % [0.0; 1.0[</pre>
 	  <p>
 	    The state returned from this function cannot be used
 	    to get a reproducable random sequence as from
-	    the other 
+	    the other
 	    <seealso marker="stdlib:rand">rand</seealso>
 	    functions,
 	    since reproducability does not match cryptographically safe.
@@ -1160,7 +1246,7 @@ _FloatValue = rand:uniform().     % [0.0; 1.0[</pre>
 	  <seealso marker="#rand_seed_alg_s-1">rand_seed_alg_s/1</seealso>.
 	</p>
 	<p>
-	  When using the state object from this function the 
+	  When using the state object from this function the
 	  <seealso marker="stdlib:rand">rand</seealso> functions using it
 	  may raise exception <c>error:low_entropy</c> in case the random generator
 	  failed due to lack of secure "randomness".
@@ -1227,7 +1313,7 @@ FloatValue = rand:uniform().     % again
 	  of 56 bits that makes calculations fast on 64 bit machines.
 	</p>
 	<p>
-	  When using the state object from this function the 
+	  When using the state object from this function the
 	  <seealso marker="stdlib:rand">rand</seealso> functions using it
 	  may raise exception <c>error:low_entropy</c> in case the random generator
 	  failed due to lack of secure "randomness".
@@ -1248,7 +1334,7 @@ FloatValue = rand:uniform().     % again
 	  <p>
 	    The state returned from this function cannot be used
 	    to get a reproducable random sequence as from
-	    the other 
+	    the other
 	    <seealso marker="stdlib:rand">rand</seealso>
 	    functions,
 	    since reproducability does not match cryptographically safe.
@@ -1331,56 +1417,6 @@ FloatValue = rand:uniform().     % again
       </desc>
     </func>
 
-    <func>
-      <name name="stream_init" arity="2" since="OTP R16B01"/>
-      <fsummary></fsummary>
-      <desc>
-        <p>Initializes the state for use in RC4 stream encryption
-        <seealso marker="#stream_encrypt-2">stream_encrypt</seealso> and
-        <seealso marker="#stream_decrypt-2">stream_decrypt</seealso></p>
-	<p>For keylengths see the
-	<seealso marker="crypto:algorithm_details#stream-ciphers">User's Guide</seealso>.
-	</p>
-      </desc>
-    </func>
-
-   <func>
-      <name name="stream_init" arity="3" since="OTP R16B01"/>
-      <fsummary></fsummary>
-      <desc>
-        <p>Initializes the state for use in streaming AES encryption using Counter mode (CTR).
-        <c>Key</c> is the AES key and must be either 128, 192, or 256 bits long. <c>IVec</c> is
-        an arbitrary initializing vector of 128 bits (16 bytes). This state is for use with
-        <seealso marker="#stream_encrypt-2">stream_encrypt</seealso> and
-        <seealso marker="#stream_decrypt-2">stream_decrypt</seealso>.</p>
-	<p>For keylengths and iv-sizes see the
-	<seealso marker="crypto:algorithm_details#stream-ciphers">User's Guide</seealso>.
-	</p>
-      </desc>
-    </func>
-
-    <func>
-      <name name="stream_encrypt" arity="2" since="OTP R16B01"/>
-      <fsummary></fsummary>
-      <desc>
-	<p>Encrypts <c>PlainText</c> according to the stream cipher <c>Type</c> specified in stream_init/3.
-	<c>Text</c> can be any number of bytes. The initial <c>State</c> is created using
-        <seealso marker="#stream_init-2">stream_init</seealso>.
-	<c>NewState</c> must be passed into the next call to <c>stream_encrypt</c>.</p>
-      </desc>
-    </func>
-
-    <func>
-      <name name="stream_decrypt" arity="2" since="OTP R16B01"/>
-      <fsummary></fsummary>
-      <desc>
-	<p>Decrypts <c>CipherText</c> according to the stream cipher <c>Type</c> specified in stream_init/3.
-	<c>PlainText</c> can be any number of bytes. The initial <c>State</c> is created using
-        <seealso marker="#stream_init-2">stream_init</seealso>.
-	<c>NewState</c> must be passed into the next call to <c>stream_decrypt</c>.</p>
-      </desc>
-    </func>
-
    <func>
       <name name="supports" arity="0" since="OTP R16B01"/>
       <fsummary>Provide a list of available crypto algorithms.</fsummary>
@@ -1440,6 +1476,12 @@ FloatValue = rand:uniform().     % again
       </desc>
     </func>
 
+  </funcs>
+    <section>
+      <title>Engine API</title>
+    </section>
+
+  <funcs>
     <!-- Engine functions -->
     <func>
       <name name="privkey_to_pubkey" arity="2" since="OTP 20.2"/>
@@ -1752,5 +1794,152 @@ FloatValue = rand:uniform().     % again
 
  </funcs>
 
+<section>
+  <title>Old API</title>
+</section>
+
+ <funcs>
+    <func>
+      <name name="block_encrypt" arity="3" since="OTP 18.0"/>
+      <fsummary>Encrypt <c>PlainText</c> according to <c>Type</c> block cipher</fsummary>
+      <desc>
+	<dont><p>Don't use this function for new programs! Use <seealso marker="crypto:new_api">the-new-api</seealso>.</p></dont>
+	<p>Encrypt <c>PlainText</c> according to <c>Type</c> block cipher.</p>
+	<p>May raise exception <c>error:notsup</c> in case the chosen <c>Type</c>
+	is not supported by the underlying libcrypto implementation.</p>
+	<p>For keylengths and blocksizes see the
+	<seealso marker="crypto:algorithm_details#ciphers">User's Guide</seealso>.
+	</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="block_decrypt" arity="3" since="OTP 18.0"/>
+      <fsummary>Decrypt <c>CipherText</c> according to <c>Type</c> block cipher</fsummary>
+      <desc>
+	<dont><p>Don't use this function for new programs! Use <seealso marker="crypto:new_api">the new api</seealso>.</p></dont>
+        <p>Decrypt <c>CipherText</c> according to <c>Type</c> block cipher.</p>
+	<p>May raise exception <c>error:notsup</c> in case the chosen <c>Type</c>
+	is not supported by the underlying libcrypto implementation.</p>
+	<p>For keylengths and blocksizes see the
+	<seealso marker="crypto:algorithm_details#ciphers">User's Guide</seealso>.
+	</p>
+      </desc>
+    </func>
+
+    <func>
+      <name since="OTP R16B01">block_encrypt(Type, Key, Ivec, PlainText) -> CipherText | Error</name>
+      <name since="OTP R16B01">block_encrypt(AeadType, Key, Ivec, {AAD, PlainText}) -> {CipherText, CipherTag} | Error</name>
+      <name since="OTP R16B01">block_encrypt(aes_gcm | aes_ccm, Key, Ivec, {AAD, PlainText, TagLength}) -> {CipherText, CipherTag} | Error </name>
+      <fsummary>Encrypt <c>PlainText</c> according to <c>Type</c> block cipher</fsummary>
+      <type>
+	<v>Type = <seealso marker="#type-block_cipher_with_iv">block_cipher_with_iv()</seealso></v>
+	<v>AeadType = <seealso marker="#type-aead_cipher">aead_cipher()</seealso></v>
+	<v>Key = <seealso marker="#type-key">key()</seealso> | <seealso marker="#type-des3_key">des3_key()</seealso></v>
+        <v>PlainText = iodata()</v>
+        <v>AAD = IVec = CipherText = CipherTag = binary()</v>
+        <v>TagLength = 1..16</v>
+	<v>Error = <seealso marker="#type-run_time_error">run_time_error()</seealso></v>
+      </type>
+      <desc>
+	<dont><p>Don't use this function for new programs! Use <seealso marker="crypto:new_api">the new api</seealso>.</p></dont>
+        <p>Encrypt <c>PlainText</c> according to <c>Type</c> block cipher.
+	<c>IVec</c> is an arbitrary initializing vector.</p>
+	<p>In AEAD (Authenticated Encryption with Associated Data) mode, encrypt
+	<c>PlainText</c>according to <c>Type</c> block cipher and calculate
+	<c>CipherTag</c> that also authenticates the <c>AAD</c> (Associated Authenticated Data).</p>
+	<p>May raise exception <c>error:notsup</c> in case the chosen <c>Type</c>
+	is not supported by the underlying libcrypto implementation.</p>
+	<p>For keylengths, iv-sizes and blocksizes see the
+	<seealso marker="crypto:algorithm_details#ciphers">User's Guide</seealso>.
+	</p>
+      </desc>
+    </func>
+
+    <func>
+      <name since="OTP R16B01">block_decrypt(Type, Key, Ivec, CipherText) -> PlainText | Error</name>
+      <name since="OTP R16B01">block_decrypt(AeadType, Key, Ivec, {AAD, CipherText, CipherTag}) -> PlainText | Error</name>
+      <fsummary>Decrypt <c>CipherText</c> according to <c>Type</c> block cipher</fsummary>
+      <type>
+	<v>Type = <seealso marker="#type-block_cipher_with_iv">block_cipher_with_iv()</seealso></v>
+	<v>AeadType = <seealso marker="#type-aead_cipher">aead_cipher()</seealso></v>
+	<v>Key = <seealso marker="#type-key">key()</seealso> | <seealso marker="#type-des3_key">des3_key()</seealso></v>
+        <v>PlainText = iodata()</v>
+        <v>AAD = IVec = CipherText = CipherTag = binary()</v>
+	<v>Error = BadTag | <seealso marker="#type-run_time_error">run_time_error()</seealso></v>
+	<v>BadTag = error</v>
+      </type>
+      <desc>
+	<dont><p>Don't use this function for new programs! Use <seealso marker="crypto:new_api">the new api</seealso>.</p></dont>
+        <p>Decrypt <c>CipherText</c> according to <c>Type</c> block cipher.
+	<c>IVec</c> is an arbitrary initializing vector.</p>
+        <p>In AEAD (Authenticated Encryption with Associated Data) mode, decrypt
+	<c>CipherText</c>according to <c>Type</c> block cipher and check the authenticity
+	the <c>PlainText</c> and <c>AAD</c> (Associated Authenticated Data) using the
+	<c>CipherTag</c>. May return <c>error</c> if the decryption or validation fail's</p>
+	<p>May raise exception <c>error:notsup</c> in case the chosen <c>Type</c>
+	is not supported by the underlying libcrypto implementation.</p>
+	<p>For keylengths, iv-sizes and blocksizes see the
+	<seealso marker="crypto:algorithm_details#ciphers">User's Guide</seealso>.
+	</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="stream_init" arity="2" since="OTP R16B01"/>
+      <fsummary></fsummary>
+      <desc>
+	<dont><p>Don't use this function for new programs! Use <seealso marker="crypto:new_api">the new api</seealso>.</p></dont>
+        <p>Initializes the state for use in RC4 stream encryption
+        <seealso marker="#stream_encrypt-2">stream_encrypt</seealso> and
+        <seealso marker="#stream_decrypt-2">stream_decrypt</seealso></p>
+	<p>For keylengths see the
+	<seealso marker="crypto:algorithm_details#stream-ciphers">User's Guide</seealso>.
+	</p>
+      </desc>
+    </func>
+
+   <func>
+      <name name="stream_init" arity="3" since="OTP R16B01"/>
+      <fsummary></fsummary>
+      <desc>
+	<dont><p>Don't use this function for new programs! Use <seealso marker="crypto:new_api">the new api</seealso>.</p></dont>
+        <p>Initializes the state for use in streaming AES encryption using Counter mode (CTR).
+        <c>Key</c> is the AES key and must be either 128, 192, or 256 bits long. <c>IVec</c> is
+        an arbitrary initializing vector of 128 bits (16 bytes). This state is for use with
+        <seealso marker="#stream_encrypt-2">stream_encrypt</seealso> and
+        <seealso marker="#stream_decrypt-2">stream_decrypt</seealso>.</p>
+	<p>For keylengths and iv-sizes see the
+	<seealso marker="crypto:algorithm_details#stream-ciphers">User's Guide</seealso>.
+	</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="stream_encrypt" arity="2" since="OTP R16B01"/>
+      <fsummary></fsummary>
+      <desc>
+	<dont><p>Don't use this function for new programs! Use <seealso marker="crypto:new_api">the new api</seealso>.</p></dont>
+	<p>Encrypts <c>PlainText</c> according to the stream cipher <c>Type</c> specified in stream_init/3.
+	<c>Text</c> can be any number of bytes. The initial <c>State</c> is created using
+        <seealso marker="#stream_init-2">stream_init</seealso>.
+	<c>NewState</c> must be passed into the next call to <c>stream_encrypt</c>.</p>
+      </desc>
+    </func>
+
+    <func>
+      <name name="stream_decrypt" arity="2" since="OTP R16B01"/>
+      <fsummary></fsummary>
+      <desc>
+	<dont><p>Don't use this function for new programs! Use <seealso marker="crypto:new_api">the new api</seealso>.</p></dont>
+	<p>Decrypts <c>CipherText</c> according to the stream cipher <c>Type</c> specified in stream_init/3.
+	<c>PlainText</c> can be any number of bytes. The initial <c>State</c> is created using
+        <seealso marker="#stream_init-2">stream_init</seealso>.
+	<c>NewState</c> must be passed into the next call to <c>stream_decrypt</c>.</p>
+      </desc>
+    </func>
+
+  </funcs>
+
 
 </erlref>
diff --git a/lib/crypto/doc/src/new_api.xml b/lib/crypto/doc/src/new_api.xml
new file mode 100644
index 0000000000..66eeefb692
--- /dev/null
+++ b/lib/crypto/doc/src/new_api.xml
@@ -0,0 +1,209 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<!DOCTYPE chapter SYSTEM "chapter.dtd">
+
+<chapter>
+  <header>
+    <copyright>
+      <year>2014</year><year>2019</year>
+      <holder>Ericsson AB. All Rights Reserved.</holder>
+    </copyright>
+    <legalnotice>
+      The contents of this file are subject to the Erlang Public License,
+      Version 1.1, (the "License"); you may not use this file except in
+      compliance with the License. You should have received a copy of the
+      Erlang Public License along with this software. If not, it can be
+      retrieved online at http://www.erlang.org/.
+
+      Software distributed under the License is distributed on an "AS IS"
+      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
+      the License for the specific language governing rights and limitations
+      under the License.
+
+    </legalnotice>
+
+    <title>New and Old API</title>
+    <prepared>Hans Nilsson</prepared>
+    <docno></docno>
+    <date>2019-08-22</date>
+    <rev>A</rev>
+    <file>new_api.xml</file>
+  </header>
+  <p>
+    This chapter describes the new api to encryption and decryption.
+  </p>
+
+  <section>
+    <title>Background</title>
+    <p>The CRYPTO app has evolved during its lifetime. Since also the OpenSSL cryptolib has changed the
+    API several times, there are parts of the CRYPTO app that uses a very old one internally and
+    other parts that uses the latest one. The internal definitions of e.g cipher names was a bit hard
+    to maintain.
+    </p>
+    <p>It turned out that using the old api in the new way (more about that later), and still keep it
+    backwards compatible was not possible. Specially as more precision in the error messages was wanted
+    it could not be combined with the old standard.
+    </p>
+    <p>Therefore the old api (see next section) is kept for now but internally implemented with new primitives.
+    </p>
+  </section>
+
+  <section>
+    <title>The old API</title>
+    <p>The old functions - not recommended for new programs - are:</p>
+    <list>
+      <item><seealso marker="crypto#block_encrypt-3">block_encrypt/3</seealso></item>
+      <item><seealso marker="crypto#block_encrypt-4">block_encrypt/4</seealso></item>
+      <item><seealso marker="crypto#block_decrypt-3">block_decrypt/3</seealso></item>
+      <item><seealso marker="crypto#block_decrypt-4">block_decrypt/4</seealso></item>
+      <item><seealso marker="crypto#stream_init-2">stream_init/2</seealso></item>
+      <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>
+    </list>
+    <p>They are not deprecated for now, but may be in a future.
+    </p>
+  </section>
+
+  <section>
+    <title>The new API</title>
+    <p>The new functions for encrypting or decrypting one single text in one binary are:
+    </p>
+    <list>
+      <item><seealso marker="crypto#crypto_one_time/4">crypto_one_time/4</seealso></item>
+      <item><seealso marker="crypto#crypto_one_time/5">crypto_one_time/5</seealso></item>
+      <item><seealso marker="crypto#crypto_aead/6">crypto_aead/6</seealso></item>
+      <item><seealso marker="crypto#crypto_aead/7">crypto_aead/7</seealso></item>
+    </list>
+    <p>The <c>crypto_aead</c> functions are for the ciphers of mode <c>ccm</c> or
+    <c>gcm</c>, and for the cipher <c>chacha20-poly1305</c>.
+    </p>
+    <p>For repeated encryption or decryption of a text divided in parts, where the parts are handled
+    one by one but in sequence, the functions are:
+    </p>
+    <list>
+      <item><seealso marker="crypto#crypto_init/4">crypto_init/4</seealso></item>
+      <item><seealso marker="crypto#crypto_init/3">crypto_init/3</seealso></item>
+      <item><seealso marker="crypto#crypto_update/2">crypto_update/2</seealso></item>
+    </list>
+    <p>The <c>crypto_init</c> initialies a cipher operation and one or more calls of
+    <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
+    same cipher and same key is used, but a new initialization vector (nounce) should be applied
+    for each part, the functions are:
+    </p>
+    <list>
+      <item><seealso marker="crypto#crypto_init_dyn_iv/3">crypto_init_dyn_iv/3</seealso></item>
+      <item><seealso marker="crypto#crypto_update_dyn_iv/3">crypto_update_dyn_iv/3</seealso></item>
+    </list>
+    <p>An example of where those functions are needed, is when handling the TLS protocol.</p>
+
+    <section>
+      <title>Examples of crypto_init/4 and crypto_update/2</title>
+      <p>Encrypting two blocks:</p>
+      <code type="erl">
+	1> crypto:start().
+	ok
+	2> Key = &lt;&lt;1:128>>,
+	2> IV = &lt;&lt;0:128>>,
+	2> StateEnc = crypto:crypto_init(aes_128_ctr, Key, IV, true). % encrypt -> true
+	#Ref&lt;0.3768901617.1128660993.124047>
+	3> crypto:crypto_update(StateEnc, &lt;&lt;"First bytes">>).
+	&lt;&lt;67,44,216,166,25,130,203,5,66,6,162>>
+	4> crypto:crypto_update(StateEnc, &lt;&lt;"Second bytes">>).
+	&lt;&lt;16,79,94,115,234,197,94,253,16,144,151,41>>
+	5>
+	5> StateDec = crypto:crypto_init(aes_128_ctr, Key, IV, false). % decrypt -> false
+	#Ref&lt;0.3768901617.1128660994.124255>
+	6> crypto:crypto_update(StateDec, &lt;&lt;67,44,216,166,25,130,203>>).
+	&lt;&lt;"First b">>
+	7> crypto:crypto_update(StateDec, &lt;&lt;5,66,6,162,16,79,94,115,234,197,
+                                                                     94,253,16,144,151>>).
+	&lt;&lt;"ytesSecond byte">>
+	8> crypto:crypto_update(StateDec, &lt;&lt;41>>).
+	&lt;&lt;"s">>
+	9>
+      </code>
+      <p>Note that the data that the <c>StateEnc</c> and <c>StateDec</c> references are destructivly
+      updated by the calls to <seealso marker="crypto#crypto_update/2">crypto_update/2</seealso>.
+      This is to gain time in the calls of the nifs interfacing the cryptolib. In a loop where the
+      state is saved in the loop's state, it also saves one update of the loop state per crypto operation.
+      </p>
+      <p>For example, a simple server receiving text parts to encrypt and send the result back to the
+      one who sent them (the <c>Requester</c>):
+      </p>
+      <code type="erl">
+	encode(Crypto, Key, IV) ->
+	crypto_loop(crypto:crypto_init(Crypto, Key, IV, true)).
+
+	crypto_loop(State) ->
+	    receive
+                {Text, Requester} ->
+                    Requester ! crypto:crypto_update(State, Text),
+	            loop(State)
+	    end.
+      </code>
+      <p>Note that the <c>State</c> is not updated. Such updates could be costly if the loop state
+      is a tuple or record with many elements.
+      </p>
+    </section>
+
+    <section>
+      <title>Example of crypto_one_time/5</title>
+      <p>The same eample as in the
+      <seealso marker="#examples-of-crypto_init-4-and-crypto_update-2">previous section</seealso>,
+      but now with one call to <c>crypto_one_time/5</c>:
+      </p>
+      <code>
+	2> Key = &lt;&lt;1:128>>,
+	2> IV = &lt;&lt;0:128>>,
+	2> Txt = [&lt;&lt;"First bytes">>,&lt;&lt;"Second bytes">>],
+	2> crypto:crypto_one_time(aes_128_ctr, Key, IV, Txt, true).
+	&lt;&lt;67,44,216,166,25,130,203,5,66,6,162,16,79,94,115,234,
+	197,94,253,16,144,151,41>>
+	3>
+      </code>
+      <p>The <c>[&lt;&lt;"First bytes">>,&lt;&lt;"Second bytes">>]</c> could of course have been one
+      single binary: <c>&lt;&lt;"First bytesSecond bytes">></c>.
+      </p>
+    </section>
+  </section>
+
+  <section>
+    <title>Retired cipher names</title>
+    <p>This table lists the retired cipher names in the first column and suggests names to replace them with
+    in the second column.
+    </p>
+    <p>The new names follows the OpenSSL libcrypto names. The format is ALGORITM_KEYSIZE_MODE.
+    </p>
+    <p>Examples of algorithms are aes, chacha20 and des.  The keysize is the number of bits
+    and examples of the mode are cbc, ctr and gcm. The mode may be followed by a number depending
+    on the mode. An example is the ccm mode which has a variant called ccm8 where the so called tag
+    has a length of eight bits.
+    </p>
+    <p>The old names had by time lost any common naming which the new names now introduces. The new names include
+    the key length which improves the error checking in the lower levels of the crypto application.
+    </p>
+
+    <table>
+      <row><cell><strong>Instead of:</strong></cell> <cell><strong>Use:</strong> </cell></row>
+
+      <row><cell><c>aes_cbc128</c>   </cell> <cell> <c>aes_128_cbc</c> </cell></row>
+      <row><cell><c>aes_cbc256</c>   </cell> <cell> <c>aes_256_cbc</c> </cell></row>
+      <row><cell><c>aes_cbc</c>      </cell> <cell> <c>aes_128_cbc, aes_192_cbc, aes_256_cbc</c></cell></row>
+      <row><cell><c>aes_ccm</c>      </cell> <cell> <c>aes_128_ccm, aes_192_ccm, aes_256_ccm</c></cell></row>
+      <row><cell><c>aes_cfb128</c>   </cell> <cell> <c>aes_128_cfb128, aes_192_cfb128, aes_256_cfb128</c></cell></row>
+      <row><cell><c>aes_cfb8</c>     </cell> <cell> <c>aes_128_cfb8, aes_192_cfb8, aes_256_cfb8</c></cell></row>
+      <row><cell><c>aes_ctr</c>      </cell> <cell> <c>aes_128_ctr, aes_192_ctr, aes_256_ctr</c></cell></row>
+      <row><cell><c>aes_gcm</c>      </cell> <cell> <c>aes_128_gcm, aes_192_gcm, aes_256_gcm</c></cell></row>
+      <row><cell><c>des3_cbc</c>     </cell> <cell> <c>des_ede3_cbc</c></cell></row>
+      <row><cell><c>des3_cbf</c>     </cell> <cell> <c>des_ede3_cfb</c></cell></row>
+      <row><cell><c>des3_cfb</c>     </cell> <cell> <c>des_ede3_cfb</c></cell></row>
+      <row><cell><c>des_ede3</c>     </cell> <cell> <c>des_ede3_cbc</c></cell></row>
+      <row><cell><c>des_ede3_cbf</c> </cell> <cell> <c>des_ede3_cfb</c></cell></row>
+      <tcaption></tcaption>
+    </table>
+  </section>
+
+</chapter>
diff --git a/lib/crypto/doc/src/usersguide.xml b/lib/crypto/doc/src/usersguide.xml
index 2dfc966609..134f900d4c 100644
--- a/lib/crypto/doc/src/usersguide.xml
+++ b/lib/crypto/doc/src/usersguide.xml
@@ -51,4 +51,5 @@
   <xi:include href="engine_load.xml"/>
   <xi:include href="engine_keys.xml"/>
   <xi:include href="algorithm_details.xml"/>
+  <xi:include href="new_api.xml"/>
 </part>