Merge TP1A.220120.003

Change-Id: Ie5eba313ee102e452f5f96942ed2f3a7bb4e8f01

9 files changed, 372 insertions, 11 deletions

diff --git a/identity/aidl/default/libeic/EicCommon.h b/identity/aidl/default/libeic/EicCommon.h
index 476276ebcf..2a08a35f65 100644
--- a/identity/aidl/default/libeic/EicCommon.h
+++ b/identity/aidl/default/libeic/EicCommon.h
@@ -21,6 +21,9 @@
 #ifndef ANDROID_HARDWARE_IDENTITY_EIC_COMMON_H
 #define ANDROID_HARDWARE_IDENTITY_EIC_COMMON_H
 
+// KeyMint auth-challenges are 64-bit numbers and 0 typically means unset.
+#define EIC_KM_AUTH_CHALLENGE_UNSET 0
+
 // Feature version 202009:
 //
 //         CredentialKeys = [
diff --git a/identity/aidl/default/libeic/EicOps.h b/identity/aidl/default/libeic/EicOps.h
index d4fcf0e1bb..aa26e6202a 100644
--- a/identity/aidl/default/libeic/EicOps.h
+++ b/identity/aidl/default/libeic/EicOps.h
@@ -141,6 +141,10 @@ void* eicMemCpy(void* dest, const void* src, size_t n);
 // String length, see strlen(3).
 size_t eicStrLen(const char* s);
 
+// Locate a substring, see memmem(3)
+void* eicMemMem(const uint8_t* haystack, size_t haystackLen, const uint8_t* needle,
+                size_t needleLen);
+
 // Memory compare, see CRYPTO_memcmp(3SSL)
 //
 // It takes an amount of time dependent on len, but independent of the contents of the
@@ -151,6 +155,12 @@ int eicCryptoMemCmp(const void* s1, const void* s2, size_t n);
 // Random number generation.
 bool eicOpsRandom(uint8_t* buf, size_t numBytes);
 
+// Creates a new non-zero identifier in |id|.
+//
+// Is guaranteed to be non-zero and different than what is already in |id|.
+//
+bool eicNextId(uint32_t* id);
+
 // If |testCredential| is true, returns the 128-bit AES Hardware-Bound Key (16 bytes).
 //
 // Otherwise returns all zeroes (16 bytes).
@@ -295,6 +305,8 @@ bool eicOpsValidateAuthToken(uint64_t challenge, uint64_t secureUserId, uint64_t
                              int verificationTokenSecurityLevel,
                              const uint8_t* verificationTokenMac, size_t verificationTokenMacSize);
 
+// Also see eicOpsLookupActiveSessionFromId() defined in EicSession.h
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/identity/aidl/default/libeic/EicPresentation.c b/identity/aidl/default/libeic/EicPresentation.c
index 0d03ae9620..104a559697 100644
--- a/identity/aidl/default/libeic/EicPresentation.c
+++ b/identity/aidl/default/libeic/EicPresentation.c
@@ -16,11 +16,17 @@
 
 #include "EicPresentation.h"
 #include "EicCommon.h"
+#include "EicSession.h"
 
 #include <inttypes.h>
 
-bool eicPresentationInit(EicPresentation* ctx, bool testCredential, const char* docType,
-                         size_t docTypeLength, const uint8_t* encryptedCredentialKeys,
+// Global used for assigning ids for presentation objects.
+//
+static uint32_t gPresentationLastIdAssigned = 0;
+
+bool eicPresentationInit(EicPresentation* ctx, uint32_t sessionId, bool testCredential,
+                         const char* docType, size_t docTypeLength,
+                         const uint8_t* encryptedCredentialKeys,
                          size_t encryptedCredentialKeysSize) {
     uint8_t credentialKeys[EIC_CREDENTIAL_KEYS_CBOR_SIZE_FEATURE_VERSION_202101];
     bool expectPopSha256 = false;
@@ -39,6 +45,13 @@ bool eicPresentationInit(EicPresentation* ctx, bool testCredential, const char*
     }
 
     eicMemSet(ctx, '\0', sizeof(EicPresentation));
+    ctx->sessionId = sessionId;
+
+    if (!eicNextId(&gPresentationLastIdAssigned)) {
+        eicDebug("Error getting id for object");
+        return false;
+    }
+    ctx->id = gPresentationLastIdAssigned;
 
     if (!eicOpsDecryptAes128Gcm(eicOpsGetHardwareBoundKey(testCredential), encryptedCredentialKeys,
                                 encryptedCredentialKeysSize,
@@ -86,6 +99,23 @@ bool eicPresentationInit(EicPresentation* ctx, bool testCredential, const char*
     if (expectPopSha256) {
         eicMemCpy(ctx->proofOfProvisioningSha256, credentialKeys + 54, EIC_SHA256_DIGEST_SIZE);
     }
+
+    eicDebug("Initialized presentation with id %" PRIu32, ctx->id);
+    return true;
+}
+
+bool eicPresentationShutdown(EicPresentation* ctx) {
+    if (ctx->id == 0) {
+        eicDebug("Trying to shut down presentation with id 0");
+        return false;
+    }
+    eicDebug("Shut down presentation with id %" PRIu32, ctx->id);
+    eicMemSet(ctx, '\0', sizeof(EicPresentation));
+    return true;
+}
+
+bool eicPresentationGetId(EicPresentation* ctx, uint32_t* outId) {
+    *outId = ctx->id;
     return true;
 }
 
@@ -174,7 +204,7 @@ bool eicPresentationCreateAuthChallenge(EicPresentation* ctx, uint64_t* authChal
             eicDebug("Failed generating random challenge");
             return false;
         }
-    } while (ctx->authChallenge == 0);
+    } while (ctx->authChallenge == EIC_KM_AUTH_CHALLENGE_UNSET);
     eicDebug("Created auth challenge %" PRIu64, ctx->authChallenge);
     *authChallenge = ctx->authChallenge;
     return true;
@@ -190,6 +220,24 @@ bool eicPresentationValidateRequestMessage(EicPresentation* ctx, const uint8_t*
                                            int coseSignAlg,
                                            const uint8_t* readerSignatureOfToBeSigned,
                                            size_t readerSignatureOfToBeSignedSize) {
+    if (ctx->sessionId != 0) {
+        EicSession* session = eicSessionGetForId(ctx->sessionId);
+        if (session == NULL) {
+            eicDebug("Error looking up session for sessionId %" PRIu32, ctx->sessionId);
+            return false;
+        }
+        EicSha256Ctx sha256;
+        uint8_t sessionTranscriptSha256[EIC_SHA256_DIGEST_SIZE];
+        eicOpsSha256Init(&sha256);
+        eicOpsSha256Update(&sha256, sessionTranscript, sessionTranscriptSize);
+        eicOpsSha256Final(&sha256, sessionTranscriptSha256);
+        if (eicCryptoMemCmp(sessionTranscriptSha256, session->sessionTranscriptSha256,
+                            EIC_SHA256_DIGEST_SIZE) != 0) {
+            eicDebug("SessionTranscript mismatch");
+            return false;
+        }
+    }
+
     if (ctx->readerPublicKeySize == 0) {
         eicDebug("No public key for reader");
         return false;
@@ -330,6 +378,20 @@ bool eicPresentationPushReaderCert(EicPresentation* ctx, const uint8_t* certX509
     return true;
 }
 
+static bool getChallenge(EicPresentation* ctx, uint64_t* outAuthChallenge) {
+    // Use authChallenge from session if applicable.
+    *outAuthChallenge = ctx->authChallenge;
+    if (ctx->sessionId != 0) {
+        EicSession* session = eicSessionGetForId(ctx->sessionId);
+        if (session == NULL) {
+            eicDebug("Error looking up session for sessionId %" PRIu32, ctx->sessionId);
+            return false;
+        }
+        *outAuthChallenge = session->authChallenge;
+    }
+    return true;
+}
+
 bool eicPresentationSetAuthToken(EicPresentation* ctx, uint64_t challenge, uint64_t secureUserId,
                                  uint64_t authenticatorId, int hardwareAuthenticatorType,
                                  uint64_t timeStamp, const uint8_t* mac, size_t macSize,
@@ -338,14 +400,19 @@ bool eicPresentationSetAuthToken(EicPresentation* ctx, uint64_t challenge, uint6
                                  int verificationTokenSecurityLevel,
                                  const uint8_t* verificationTokenMac,
                                  size_t verificationTokenMacSize) {
+    uint64_t authChallenge;
+    if (!getChallenge(ctx, &authChallenge)) {
+        return false;
+    }
+
     // It doesn't make sense to accept any tokens if eicPresentationCreateAuthChallenge()
     // was never called.
-    if (ctx->authChallenge == 0) {
-        eicDebug("Trying validate tokens when no auth-challenge was previously generated");
+    if (authChallenge == EIC_KM_AUTH_CHALLENGE_UNSET) {
+        eicDebug("Trying to validate tokens when no auth-challenge was previously generated");
         return false;
     }
     // At least the verification-token must have the same challenge as what was generated.
-    if (verificationTokenChallenge != ctx->authChallenge) {
+    if (verificationTokenChallenge != authChallenge) {
         eicDebug("Challenge in verification token does not match the challenge "
                  "previously generated");
         return false;
@@ -354,6 +421,7 @@ bool eicPresentationSetAuthToken(EicPresentation* ctx, uint64_t challenge, uint6
                 challenge, secureUserId, authenticatorId, hardwareAuthenticatorType, timeStamp, mac,
                 macSize, verificationTokenChallenge, verificationTokenTimestamp,
                 verificationTokenSecurityLevel, verificationTokenMac, verificationTokenMacSize)) {
+        eicDebug("Error validating authToken");
         return false;
     }
     ctx->authTokenChallenge = challenge;
@@ -377,11 +445,16 @@ static bool checkUserAuth(EicPresentation* ctx, bool userAuthenticationRequired,
     // Only ACP with auth-on-every-presentation - those with timeout == 0 - need the
     // challenge to match...
     if (timeoutMillis == 0) {
-        if (ctx->authTokenChallenge != ctx->authChallenge) {
+        uint64_t authChallenge;
+        if (!getChallenge(ctx, &authChallenge)) {
+            return false;
+        }
+
+        if (ctx->authTokenChallenge != authChallenge) {
             eicDebug("Challenge in authToken (%" PRIu64
                      ") doesn't match the challenge "
                      "that was created (%" PRIu64 ") for this session",
-                     ctx->authTokenChallenge, ctx->authChallenge);
+                     ctx->authTokenChallenge, authChallenge);
             return false;
         }
     }
@@ -490,6 +563,25 @@ bool eicPresentationCalcMacKey(EicPresentation* ctx, const uint8_t* sessionTrans
                                const uint8_t signingKeyBlob[60], const char* docType,
                                size_t docTypeLength, unsigned int numNamespacesWithValues,
                                size_t expectedDeviceNamespacesSize) {
+    if (ctx->sessionId != 0) {
+        EicSession* session = eicSessionGetForId(ctx->sessionId);
+        if (session == NULL) {
+            eicDebug("Error looking up session for sessionId %" PRIu32, ctx->sessionId);
+            return false;
+        }
+        EicSha256Ctx sha256;
+        uint8_t sessionTranscriptSha256[EIC_SHA256_DIGEST_SIZE];
+        eicOpsSha256Init(&sha256);
+        eicOpsSha256Update(&sha256, sessionTranscript, sessionTranscriptSize);
+        eicOpsSha256Final(&sha256, sessionTranscriptSha256);
+        if (eicCryptoMemCmp(sessionTranscriptSha256, session->sessionTranscriptSha256,
+                            EIC_SHA256_DIGEST_SIZE) != 0) {
+            eicDebug("SessionTranscript mismatch");
+            return false;
+        }
+        readerEphemeralPublicKey = session->readerEphemeralPublicKey;
+    }
+
     uint8_t signingKeyPriv[EIC_P256_PRIV_KEY_SIZE];
     if (!eicOpsDecryptAes128Gcm(ctx->storageKey, signingKeyBlob, 60, (const uint8_t*)docType,
                                 docTypeLength, signingKeyPriv)) {
diff --git a/identity/aidl/default/libeic/EicPresentation.h b/identity/aidl/default/libeic/EicPresentation.h
index 6f7f432960..a031890e58 100644
--- a/identity/aidl/default/libeic/EicPresentation.h
+++ b/identity/aidl/default/libeic/EicPresentation.h
@@ -30,7 +30,13 @@ extern "C" {
 // The maximum size we support for public keys in reader certificates.
 #define EIC_PRESENTATION_MAX_READER_PUBLIC_KEY_SIZE 65
 
+// Constant used to convey that no session is associated with a presentation.
+#define EIC_PRESENTATION_ID_UNSET 0
+
 typedef struct {
+    // A non-zero number unique for this EicPresentation instance
+    uint32_t id;
+
     int featureLevel;
 
     uint8_t storageKey[EIC_AES_128_KEY_SIZE];
@@ -38,6 +44,10 @@ typedef struct {
 
     uint8_t ephemeralPrivateKey[EIC_P256_PRIV_KEY_SIZE];
 
+    // If non-zero (not EIC_PRESENTATION_ID_UNSET), the id of the EicSession object this
+    // presentation object is associated with.
+    uint32_t sessionId;
+
     // The challenge generated with eicPresentationCreateAuthChallenge()
     uint64_t authChallenge;
 
@@ -93,10 +103,18 @@ typedef struct {
     EicCbor cbor;
 } EicPresentation;
 
-bool eicPresentationInit(EicPresentation* ctx, bool testCredential, const char* docType,
-                         size_t docTypeLength, const uint8_t* encryptedCredentialKeys,
+// If sessionId is zero (EIC_PRESENTATION_ID_UNSET), the presentation object is not associated
+// with a session object. Otherwise it's the id of the session object.
+//
+bool eicPresentationInit(EicPresentation* ctx, uint32_t sessionId, bool testCredential,
+                         const char* docType, size_t docTypeLength,
+                         const uint8_t* encryptedCredentialKeys,
                          size_t encryptedCredentialKeysSize);
 
+bool eicPresentationShutdown(EicPresentation* ctx);
+
+bool eicPresentationGetId(EicPresentation* ctx, uint32_t* outId);
+
 bool eicPresentationGenerateSigningKeyPair(EicPresentation* ctx, const char* docType,
                                            size_t docTypeLength, time_t now,
                                            uint8_t* publicKeyCert, size_t* publicKeyCertSize,
diff --git a/identity/aidl/default/libeic/EicProvisioning.c b/identity/aidl/default/libeic/EicProvisioning.c
index c9df4fd74f..a241b71b50 100644
--- a/identity/aidl/default/libeic/EicProvisioning.c
+++ b/identity/aidl/default/libeic/EicProvisioning.c
@@ -17,8 +17,21 @@
 #include "EicProvisioning.h"
 #include "EicCommon.h"
 
+#include <inttypes.h>
+
+// Global used for assigning ids for provisioning objects.
+//
+static uint32_t gProvisioningLastIdAssigned = 0;
+
 bool eicProvisioningInit(EicProvisioning* ctx, bool testCredential) {
     eicMemSet(ctx, '\0', sizeof(EicProvisioning));
+
+    if (!eicNextId(&gProvisioningLastIdAssigned)) {
+        eicDebug("Error getting id for object");
+        return false;
+    }
+    ctx->id = gProvisioningLastIdAssigned;
+
     ctx->testCredential = testCredential;
     if (!eicOpsRandom(ctx->storageKey, EIC_AES_128_KEY_SIZE)) {
         return false;
@@ -47,6 +60,13 @@ bool eicProvisioningInitForUpdate(EicProvisioning* ctx, bool testCredential, con
     }
 
     eicMemSet(ctx, '\0', sizeof(EicProvisioning));
+
+    if (!eicNextId(&gProvisioningLastIdAssigned)) {
+        eicDebug("Error getting id for object");
+        return false;
+    }
+    ctx->id = gProvisioningLastIdAssigned;
+
     ctx->testCredential = testCredential;
 
     if (!eicOpsDecryptAes128Gcm(eicOpsGetHardwareBoundKey(testCredential), encryptedCredentialKeys,
@@ -96,6 +116,21 @@ bool eicProvisioningInitForUpdate(EicProvisioning* ctx, bool testCredential, con
     return true;
 }
 
+bool eicProvisioningShutdown(EicProvisioning* ctx) {
+    if (ctx->id == 0) {
+        eicDebug("Trying to shut down provsioning with id 0");
+        return false;
+    }
+    eicDebug("Shut down provsioning with id %" PRIu32, ctx->id);
+    eicMemSet(ctx, '\0', sizeof(EicProvisioning));
+    return true;
+}
+
+bool eicProvisioningGetId(EicProvisioning* ctx, uint32_t* outId) {
+    *outId = ctx->id;
+    return true;
+}
+
 bool eicProvisioningCreateCredentialKey(EicProvisioning* ctx, const uint8_t* challenge,
                                         size_t challengeSize, const uint8_t* applicationId,
                                         size_t applicationIdSize, uint8_t* publicKeyCert,
diff --git a/identity/aidl/default/libeic/EicProvisioning.h b/identity/aidl/default/libeic/EicProvisioning.h
index 92f1e4a2a0..d94f8f18c2 100644
--- a/identity/aidl/default/libeic/EicProvisioning.h
+++ b/identity/aidl/default/libeic/EicProvisioning.h
@@ -31,6 +31,9 @@ extern "C" {
 #define EIC_MAX_NUM_ACCESS_CONTROL_PROFILE_IDS 32
 
 typedef struct {
+    // A non-zero number unique for this EicProvisioning instance
+    uint32_t id;
+
     // Set by eicCreateCredentialKey() OR eicProvisioningInitForUpdate()
     uint8_t credentialPrivateKey[EIC_P256_PRIV_KEY_SIZE];
 
@@ -68,6 +71,10 @@ bool eicProvisioningInitForUpdate(EicProvisioning* ctx, bool testCredential, con
                                   size_t docTypeLength, const uint8_t* encryptedCredentialKeys,
                                   size_t encryptedCredentialKeysSize);
 
+bool eicProvisioningShutdown(EicProvisioning* ctx);
+
+bool eicProvisioningGetId(EicProvisioning* ctx, uint32_t* outId);
+
 bool eicProvisioningCreateCredentialKey(EicProvisioning* ctx, const uint8_t* challenge,
                                         size_t challengeSize, const uint8_t* applicationId,
                                         size_t applicationIdSize, uint8_t* publicKeyCert,
diff --git a/identity/aidl/default/libeic/EicSession.c b/identity/aidl/default/libeic/EicSession.c
new file mode 100644
index 0000000000..d0c7a0d77e
--- /dev/null
+++ b/identity/aidl/default/libeic/EicSession.c
@@ -0,0 +1,120 @@
+/*
+ * Copyright 2020, The Android Open Source Project
+ *
+ * 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.
+ */
+
+#include <inttypes.h>
+
+#include "EicCommon.h"
+#include "EicSession.h"
+
+// Global used for assigning ids for session objects.
+//
+static uint32_t gSessionLastIdAssigned = 0;
+
+// The current session object or NULL if never initialized or if it has been shut down.
+//
+static EicSession* gSessionCurrent = NULL;
+
+EicSession* eicSessionGetForId(uint32_t sessionId) {
+    if (gSessionCurrent != NULL && gSessionCurrent->id == sessionId) {
+        return gSessionCurrent;
+    }
+    return NULL;
+}
+
+bool eicSessionInit(EicSession* ctx) {
+    eicMemSet(ctx, '\0', sizeof(EicSession));
+
+    if (!eicNextId(&gSessionLastIdAssigned)) {
+        eicDebug("Error getting id for object");
+        return false;
+    }
+    ctx->id = gSessionLastIdAssigned;
+
+    do {
+        if (!eicOpsRandom((uint8_t*)&(ctx->authChallenge), sizeof(ctx->authChallenge))) {
+            eicDebug("Failed generating random challenge");
+            return false;
+        }
+    } while (ctx->authChallenge == EIC_KM_AUTH_CHALLENGE_UNSET);
+
+    if (!eicOpsCreateEcKey(ctx->ephemeralPrivateKey, ctx->ephemeralPublicKey)) {
+        eicDebug("Error creating ephemeral key-pair");
+        return false;
+    }
+
+    gSessionCurrent = ctx;
+    eicDebug("Initialized session with id %" PRIu32, ctx->id);
+    return true;
+}
+
+bool eicSessionShutdown(EicSession* ctx) {
+    if (ctx->id == 0) {
+        eicDebug("Trying to shut down session with id 0");
+        return false;
+    }
+    eicDebug("Shut down session with id %" PRIu32, ctx->id);
+    eicMemSet(ctx, '\0', sizeof(EicSession));
+    gSessionCurrent = NULL;
+    return true;
+}
+
+bool eicSessionGetId(EicSession* ctx, uint32_t* outId) {
+    *outId = ctx->id;
+    return true;
+}
+
+bool eicSessionGetAuthChallenge(EicSession* ctx, uint64_t* outAuthChallenge) {
+    *outAuthChallenge = ctx->authChallenge;
+    return true;
+}
+
+bool eicSessionGetEphemeralKeyPair(EicSession* ctx,
+                                   uint8_t ephemeralPrivateKey[EIC_P256_PRIV_KEY_SIZE]) {
+    eicMemCpy(ephemeralPrivateKey, ctx->ephemeralPrivateKey, EIC_P256_PRIV_KEY_SIZE);
+    return true;
+}
+
+bool eicSessionSetReaderEphemeralPublicKey(
+        EicSession* ctx, const uint8_t readerEphemeralPublicKey[EIC_P256_PUB_KEY_SIZE]) {
+    eicMemCpy(ctx->readerEphemeralPublicKey, readerEphemeralPublicKey, EIC_P256_PUB_KEY_SIZE);
+    return true;
+}
+
+bool eicSessionSetSessionTranscript(EicSession* ctx, const uint8_t* sessionTranscript,
+                                    size_t sessionTranscriptSize) {
+    // Only accept the SessionTranscript if X and Y from the ephemeral key
+    // we created is somewhere in SessionTranscript...
+    //
+    if (eicMemMem(sessionTranscript, sessionTranscriptSize, ctx->ephemeralPublicKey,
+                  EIC_P256_PUB_KEY_SIZE / 2) == NULL) {
+        eicDebug("Error finding X from ephemeralPublicKey in sessionTranscript");
+        return false;
+    }
+    if (eicMemMem(sessionTranscript, sessionTranscriptSize,
+                  ctx->ephemeralPublicKey + EIC_P256_PUB_KEY_SIZE / 2,
+                  EIC_P256_PUB_KEY_SIZE / 2) == NULL) {
+        eicDebug("Error finding Y from ephemeralPublicKey in sessionTranscript");
+        return false;
+    }
+
+    // To save space we only store the SHA-256 of SessionTranscript
+    //
+    EicSha256Ctx shaCtx;
+    eicOpsSha256Init(&shaCtx);
+    eicOpsSha256Update(&shaCtx, sessionTranscript, sessionTranscriptSize);
+    eicOpsSha256Final(&shaCtx, ctx->sessionTranscriptSha256);
+    return true;
+}
diff --git a/identity/aidl/default/libeic/EicSession.h b/identity/aidl/default/libeic/EicSession.h
new file mode 100644
index 0000000000..0303dae1c3
--- /dev/null
+++ b/identity/aidl/default/libeic/EicSession.h
@@ -0,0 +1,73 @@
+/*
+ * Copyright 2021, The Android Open Source Project
+ *
+ * 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.
+ */
+
+#if !defined(EIC_INSIDE_LIBEIC_H) && !defined(EIC_COMPILATION)
+#error "Never include this file directly, include libeic.h instead."
+#endif
+
+#ifndef ANDROID_HARDWARE_IDENTITY_EIC_SESSION_H
+#define ANDROID_HARDWARE_IDENTITY_EIC_SESSION_H
+
+#include "EicOps.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+    // A non-zero number unique for this EicSession instance
+    uint32_t id;
+
+    // The challenge generated at construction time by eicSessionInit().
+    uint64_t authChallenge;
+
+    uint8_t ephemeralPrivateKey[EIC_P256_PRIV_KEY_SIZE];
+    uint8_t ephemeralPublicKey[EIC_P256_PUB_KEY_SIZE];
+
+    uint8_t readerEphemeralPublicKey[EIC_P256_PUB_KEY_SIZE];
+
+    uint8_t sessionTranscriptSha256[EIC_SHA256_DIGEST_SIZE];
+
+} EicSession;
+
+bool eicSessionInit(EicSession* ctx);
+
+bool eicSessionShutdown(EicSession* ctx);
+
+bool eicSessionGetId(EicSession* ctx, uint32_t* outId);
+
+bool eicSessionGetAuthChallenge(EicSession* ctx, uint64_t* outAuthChallenge);
+
+bool eicSessionGetEphemeralKeyPair(EicSession* ctx,
+                                   uint8_t ephemeralPrivateKey[EIC_P256_PRIV_KEY_SIZE]);
+
+bool eicSessionSetReaderEphemeralPublicKey(
+        EicSession* ctx, const uint8_t readerEphemeralPublicKey[EIC_P256_PUB_KEY_SIZE]);
+
+bool eicSessionSetSessionTranscript(EicSession* ctx, const uint8_t* sessionTranscript,
+                                    size_t sessionTranscriptSize);
+
+// Looks up an active session with the given id.
+//
+// Returns NULL if no active session with the given id is found.
+//
+EicSession* eicSessionGetForId(uint32_t sessionId);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // ANDROID_HARDWARE_IDENTITY_EIC_PRESENTATION_H
diff --git a/identity/aidl/default/libeic/libeic.h b/identity/aidl/default/libeic/libeic.h
index 20c889660f..d89fc9a0e3 100644
--- a/identity/aidl/default/libeic/libeic.h
+++ b/identity/aidl/default/libeic/libeic.h
@@ -27,10 +27,11 @@ extern "C" {
  */
 #define EIC_INSIDE_LIBEIC_H
 #include "EicCbor.h"
+#include "EicCommon.h"
 #include "EicOps.h"
 #include "EicPresentation.h"
 #include "EicProvisioning.h"
-#include "EicCommon.h"
+#include "EicSession.h"
 #undef EIC_INSIDE_LIBEIC_H
 
 #ifdef __cplusplus