diff --git a/Package.swift b/Package.swift
index 96e6c67..bfbe632 100644
--- a/Package.swift
+++ b/Package.swift
@@ -37,7 +37,7 @@ let package = Package(
             path: "xcode",
             exclude: [ "OLMKit/Info.plist" ],
             sources: [ "OLMKit" ],
-            publicHeadersPath: "OLMKit",
+            publicHeadersPath: "PublicHeaders",
             cSettings: [
                 .headerSearchPath("."),
                 .unsafeFlags([
diff --git a/xcode/PublicHeaders/OLMKit/OLMAccount.h b/xcode/PublicHeaders/OLMKit/OLMAccount.h
new file mode 100644
index 0000000..c8d65cd
--- /dev/null
+++ b/xcode/PublicHeaders/OLMKit/OLMAccount.h
@@ -0,0 +1,51 @@
+/*
+ Copyright 2016 Chris Ballinger
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+#import "OLMSerializable.h"
+
+@class OLMSession;
+
+@interface OLMAccount : NSObject <OLMSerializable, NSSecureCoding>
+
+/** Creates new account */
+- (instancetype) initNewAccount;
+
+/** public identity keys. base64 encoded in "curve25519" and "ed25519" keys */
+- (NSDictionary*) identityKeys;
+
+/** signs message with ed25519 key for account */
+- (NSString*) signMessage:(NSData*)messageData;
+
+/** Public parts of the unpublished one time keys for the account */
+- (NSDictionary*) oneTimeKeys;
+
+- (BOOL) removeOneTimeKeysForSession:(OLMSession*)session;
+
+/** Marks the current set of one time keys as being published. */
+- (void) markOneTimeKeysAsPublished;
+
+/** The largest number of one time keys this account can store. */
+- (NSUInteger) maxOneTimeKeys;
+
+/** Generates a number of new one time keys. If the total number of keys stored
+ * by this account exceeds -maxOneTimeKeys then the old keys are
+ * discarded. */
+- (void) generateOneTimeKeys:(NSUInteger)numberOfKeys;
+
+@end
diff --git a/xcode/PublicHeaders/OLMKit/OLMInboundGroupSession.h b/xcode/PublicHeaders/OLMKit/OLMInboundGroupSession.h
new file mode 100644
index 0000000..c0d2c59
--- /dev/null
+++ b/xcode/PublicHeaders/OLMKit/OLMInboundGroupSession.h
@@ -0,0 +1,38 @@
+/*
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+#import "OLMSerializable.h"
+
+@interface OLMInboundGroupSession : NSObject <OLMSerializable, NSSecureCoding>
+
+- (instancetype)initInboundGroupSessionWithSessionKey:(NSString*)sessionKey error:(NSError**)error;
+
+- (instancetype)initInboundGroupSessionWithImportedSession:(NSString*)sessionKey error:(NSError**)error;
+
+- (NSString*)sessionIdentifier;
+
+/** base64 ciphertext -> UTF-8 plaintext */
+- (NSString*)decryptMessage:(NSString*)message messageIndex:(NSUInteger*)messageIndex error:(NSError**)error;
+
+- (NSUInteger)firstKnownIndex;
+
+- (BOOL)isVerified;
+
+- (NSString*)exportSessionAtMessageIndex:(NSUInteger)messageIndex error:(NSError**)error;
+
+@end
diff --git a/xcode/PublicHeaders/OLMKit/OLMKit.h b/xcode/PublicHeaders/OLMKit/OLMKit.h
new file mode 100644
index 0000000..54496a0
--- /dev/null
+++ b/xcode/PublicHeaders/OLMKit/OLMKit.h
@@ -0,0 +1,39 @@
+/*
+ Copyright 2016 Chris Ballinger
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+// In this header, you should import all the public headers of your framework using statements like #import <OLMKit/PublicHeader.h>
+
+#import <OLMKit/OLMAccount.h>
+#import <OLMKit/OLMSession.h>
+#import <OLMKit/OLMMessage.h>
+#import <OLMKit/OLMUtility.h>
+#import <OLMKit/OLMInboundGroupSession.h>
+#import <OLMKit/OLMOutboundGroupSession.h>
+#import <OLMKit/OLMPkEncryption.h>
+#import <OLMKit/OLMPkDecryption.h>
+#import <OLMKit/OLMPkSigning.h>
+#import <OLMKit/OLMSAS.h>
+
+@interface OLMKit : NSObject
+
+//! Project version string for OLMKit, the same as libolm.
++ (NSString*)versionString;
+
+@end
diff --git a/xcode/PublicHeaders/OLMKit/OLMMessage.h b/xcode/PublicHeaders/OLMKit/OLMMessage.h
new file mode 100644
index 0000000..b6e8c8f
--- /dev/null
+++ b/xcode/PublicHeaders/OLMKit/OLMMessage.h
@@ -0,0 +1,38 @@
+/*
+ Copyright 2016 Chris Ballinger
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+/*
+ from olm.hh
+ static const size_t OLM_MESSAGE_TYPE_PRE_KEY = 0;
+ static const size_t OLM_MESSAGE_TYPE_MESSAGE = 1;
+ */
+typedef NS_ENUM(NSInteger, OLMMessageType) {
+    OLMMessageTypePreKey = 0,
+    OLMMessageTypeMessage = 1
+};
+
+@interface OLMMessage : NSObject
+
+@property (nonatomic, copy, readonly, nonnull) NSString *ciphertext;
+@property (readonly) OLMMessageType type;
+
+- (nullable instancetype) initWithCiphertext:(nonnull NSString*)ciphertext type:(OLMMessageType)type;
+
+@end
diff --git a/xcode/PublicHeaders/OLMKit/OLMOutboundGroupSession.h b/xcode/PublicHeaders/OLMKit/OLMOutboundGroupSession.h
new file mode 100644
index 0000000..c979b61
--- /dev/null
+++ b/xcode/PublicHeaders/OLMKit/OLMOutboundGroupSession.h
@@ -0,0 +1,32 @@
+/*
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+#import "OLMSerializable.h"
+
+@interface OLMOutboundGroupSession : NSObject <OLMSerializable, NSSecureCoding>
+
+- (instancetype) initOutboundGroupSession;
+
+- (NSString*)sessionIdentifier;
+- (NSUInteger)messageIndex;
+- (NSString*)sessionKey;
+
+/** UTF-8 plaintext -> base64 ciphertext */
+- (NSString*)encryptMessage:(NSString*)message error:(NSError**)error;
+
+@end
diff --git a/xcode/PublicHeaders/OLMKit/OLMPkDecryption.h b/xcode/PublicHeaders/OLMKit/OLMPkDecryption.h
new file mode 100644
index 0000000..823dc78
--- /dev/null
+++ b/xcode/PublicHeaders/OLMKit/OLMPkDecryption.h
@@ -0,0 +1,71 @@
+/*
+ Copyright 2018 New Vector Ltd
+ 
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+#import "OLMSerializable.h"
+#import "OLMPkMessage.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface OLMPkDecryption : NSObject <OLMSerializable, NSSecureCoding>
+
+/**
+ Initialise the key from the private part of a key as returned by `privateKey`.
+
+ Note that the pubkey is a base64 encoded string, but the private key is
+ an unencoded byte array.
+
+ @param privateKey the private key part.
+ @param error the error if any.
+ @return the associated public key.
+ */
+- (NSString *)setPrivateKey:(NSData*)privateKey error:(NSError* _Nullable *)error;
+
+/**
+ Generate a new key to use for decrypting messages.
+
+ @param error the error if any.
+ @return the public part of the generated key.
+ */
+- (NSString *)generateKey:(NSError* _Nullable *)error;
+
+/**
+ Get the private key.
+
+ @return the private key;
+ */
+- (NSData *)privateKey;
+
+/**
+ Decrypt a ciphertext.
+
+ @param message the cipher message to decrypt.
+ @param error the error if any.
+ @return the decrypted message.
+ */
+- (NSString *)decryptMessage:(OLMPkMessage*)message error:(NSError* _Nullable *)error;
+
+/**
+ Private key length.
+
+ @return the length in bytes.
+ */
++ (NSUInteger)privateKeyLength;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/xcode/PublicHeaders/OLMKit/OLMPkEncryption.h b/xcode/PublicHeaders/OLMKit/OLMPkEncryption.h
new file mode 100644
index 0000000..6ae767c
--- /dev/null
+++ b/xcode/PublicHeaders/OLMKit/OLMPkEncryption.h
@@ -0,0 +1,42 @@
+/*
+ Copyright 2018 New Vector Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+#import "OLMPkMessage.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface OLMPkEncryption : NSObject
+
+/**
+ Set the recipient's public key for encrypting to.
+
+ @param recipientKey the recipient's public key.
+ */
+- (void)setRecipientKey:(NSString*)recipientKey;
+
+/**
+ Encrypt a plaintext for the recipient.
+
+ @param message the message to encrypt.
+ @param error the error if any.
+ @return the encrypted message.
+ */
+- (OLMPkMessage *)encryptMessage:(NSString*)message error:(NSError* _Nullable *)error;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/xcode/PublicHeaders/OLMKit/OLMPkMessage.h b/xcode/PublicHeaders/OLMKit/OLMPkMessage.h
new file mode 100644
index 0000000..1559fca
--- /dev/null
+++ b/xcode/PublicHeaders/OLMKit/OLMPkMessage.h
@@ -0,0 +1,31 @@
+/*
+ Copyright 2018 New Vector Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface OLMPkMessage : NSObject
+
+@property (nonatomic, copy, readonly) NSString *ciphertext;
+@property (nonatomic, copy, readonly,) NSString *mac;
+@property (nonatomic, copy, readonly) NSString *ephemeralKey;
+
+- (instancetype) initWithCiphertext:(NSString*)ciphertext mac:(NSString*)mac ephemeralKey:(NSString*)ephemeralKey;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/xcode/PublicHeaders/OLMKit/OLMPkSigning.h b/xcode/PublicHeaders/OLMKit/OLMPkSigning.h
new file mode 100644
index 0000000..09724e1
--- /dev/null
+++ b/xcode/PublicHeaders/OLMKit/OLMPkSigning.h
@@ -0,0 +1,49 @@
+/*
+ Copyright 2019 New Vector Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface OLMPkSigning : NSObject
+
+/**
+ Initialise the signing object with a public/private keypair from a seed.
+
+ @param seed the seed.
+ @param error the error if any.
+ @return the public key
+ */
+- (NSString *)doInitWithSeed:(NSData*)seed error:(NSError* _Nullable *)error;
+
+/**
+ Sign a message.
+
+ @param message the message to sign.
+ @param error the error if any.
+ @return the signature.
+ */
+- (NSString *)sign:(NSString*)message error:(NSError* _Nullable *)error;
+
+/**
+ Generate a seed.
+
+ @return the generated seed.
+ */
++ (NSData *)generateSeed;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/xcode/PublicHeaders/OLMKit/OLMSAS.h b/xcode/PublicHeaders/OLMKit/OLMSAS.h
new file mode 100644
index 0000000..3785b03
--- /dev/null
+++ b/xcode/PublicHeaders/OLMKit/OLMSAS.h
@@ -0,0 +1,70 @@
+/*
+ Copyright 2019 New Vector Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ Short Authentication String verification utility class.
+ */
+@interface OLMSAS : NSObject
+
+/**
+ Get the public key of the SAS object.
+ */
+- (NSString * _Nullable)publicKey;
+
+/**
+ Set the public key of other user.
+
+ @param theirPublicKey the other user's public key.
+ @return error the error if any.
+ */
+- (NSError* _Nullable)setTheirPublicKey:(NSString*)theirPublicKey;
+
+/**
+ Generate bytes to use for the short authentication string.
+
+ @param info extra information to mix in when generating the bytes, as per the Matrix spec.
+ @param length the size of the output buffer. For hex-based SAS as in the Matrix spec, this will be 5.
+ @return generated bytes
+ */
+- (NSData *)generateBytes:(NSString*)info length:(NSUInteger)length;
+
+/**
+ Generate a message authentication code (MAC) based on the shared secret.
+
+ @param input the message to produce the authentication code for.
+ @param info extra information to mix in when generating the MAC, as per the Matrix spec.
+ @param error the error if any.
+ @return the MAC.
+ */
+- (NSString *)calculateMac:(NSString*)input info:(NSString*)info error:(NSError* _Nullable *)error;
+
+/**
+ Generate a message authentication code (MAC) based on the shared secret.
+ For compatibility with an old version of olm.js.
+
+ @param input the message to produce the authentication code for.
+ @param info extra information to mix in when generating the MAC, as per the Matrix spec.
+ @param error the error if any.
+ @return the MAC.
+ */
+- (NSString *)calculateMacLongKdf:(NSString*)input info:(NSString*)info error:(NSError* _Nullable *)error;
+
+@end
+
+NS_ASSUME_NONNULL_END
diff --git a/xcode/PublicHeaders/OLMKit/OLMSerializable.h b/xcode/PublicHeaders/OLMKit/OLMSerializable.h
new file mode 100644
index 0000000..e929903
--- /dev/null
+++ b/xcode/PublicHeaders/OLMKit/OLMSerializable.h
@@ -0,0 +1,29 @@
+/*
+ Copyright 2016 Chris Ballinger
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+@protocol OLMSerializable <NSObject>
+
+/** Initializes from encrypted serialized data. Will throw error if invalid key or invalid base64. */
+- (instancetype) initWithSerializedData:(NSString*)serializedData key:(NSData*)key error:(NSError**)error;
+
+/** Serializes and encrypts object data, outputs base64 blob */
+- (NSString*) serializeDataWithKey:(NSData*)key error:(NSError**)error;
+
+@end
diff --git a/xcode/PublicHeaders/OLMKit/OLMSession.h b/xcode/PublicHeaders/OLMKit/OLMSession.h
new file mode 100644
index 0000000..0446f98
--- /dev/null
+++ b/xcode/PublicHeaders/OLMKit/OLMSession.h
@@ -0,0 +1,44 @@
+/*
+ Copyright 2016 Chris Ballinger
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+#import "OLMSerializable.h"
+#import "OLMAccount.h"
+#import "OLMMessage.h"
+
+@interface OLMSession : NSObject <OLMSerializable, NSSecureCoding>
+
+- (instancetype) initOutboundSessionWithAccount:(OLMAccount*)account theirIdentityKey:(NSString*)theirIdentityKey theirOneTimeKey:(NSString*)theirOneTimeKey error:(NSError**)error;
+
+- (instancetype) initInboundSessionWithAccount:(OLMAccount*)account oneTimeKeyMessage:(NSString*)oneTimeKeyMessage error:(NSError**)error;
+
+- (instancetype) initInboundSessionWithAccount:(OLMAccount*)account theirIdentityKey:(NSString*)theirIdentityKey oneTimeKeyMessage:(NSString*)oneTimeKeyMessage error:(NSError**)error;
+
+- (NSString*) sessionIdentifier;
+
+- (BOOL) matchesInboundSession:(NSString*)oneTimeKeyMessage;
+
+- (BOOL) matchesInboundSessionFrom:(NSString*)theirIdentityKey oneTimeKeyMessage:(NSString *)oneTimeKeyMessage;
+
+/** UTF-8 plaintext -> base64 ciphertext */
+- (OLMMessage*) encryptMessage:(NSString*)message error:(NSError**)error;
+
+/** base64 ciphertext -> UTF-8 plaintext */
+- (NSString*) decryptMessage:(OLMMessage*)message error:(NSError**)error;
+
+@end
diff --git a/xcode/PublicHeaders/OLMKit/OLMUtility.h b/xcode/PublicHeaders/OLMKit/OLMUtility.h
new file mode 100644
index 0000000..3041da9
--- /dev/null
+++ b/xcode/PublicHeaders/OLMKit/OLMUtility.h
@@ -0,0 +1,49 @@
+/*
+ Copyright 2016 Chris Ballinger
+ Copyright 2016 OpenMarket Ltd
+ Copyright 2016 Vector Creations Ltd
+
+ Licensed under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License.
+ You may obtain a copy of the License at
+
+ http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software
+ distributed under the License is distributed on an "AS IS" BASIS,
+ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+FOUNDATION_EXPORT NSString *const OLMErrorDomain;
+
+@interface OLMUtility : NSObject
+
+/**
+ Calculate the SHA-256 hash of the input and encodes it as base64.
+ 
+ @param message the message to hash.
+ @return the base64-encoded hash value.
+ */
+- (NSString*)sha256:(NSData*)message;
+
+/**
+ Verify an ed25519 signature.
+
+ @param signature the base64-encoded signature to be checked.
+ @param key the ed25519 key.
+ @param message the message which was signed.
+ @param error if there is a problem with the verification.
+ If the key was too small then the message will be "OLM.INVALID_BASE64".
+ If the signature was invalid then the message will be "OLM.BAD_MESSAGE_MAC".
+
+ @return YES if valid.
+ */
+- (BOOL)verifyEd25519Signature:(NSString*)signature key:(NSString*)key message:(NSData*)message error:(NSError**)error;
+
++ (NSMutableData*) randomBytesOfLength:(NSUInteger)length;
+
+@end