Implement signature check.

Currently, we just have debug keys, and always fail verification on
user builds. Production keys will be added later.

This CL also includes some helper scripts:
- Used to generate debug keys, for the record
- To sign data using the debug keys
- To verify base64 encoded data, used for debugging

Test: atest CtsSignedConfigHostTestCases
Note: The test also relies on some other changes going in too; it has
been verified with all relevant change in place, but will not pass at
HEAD quite yet.

Bug: 110509075
Change-Id: I8bd420c44a0a523cbefb21f90c49550c25beb0a6

5 files changed, 32 insertions, 0 deletions

diff --git a/tools/signedconfig/debug_key.pem b/tools/signedconfig/debug_key.pem
new file mode 100644
index 000000000000..0af577bf81e1
--- /dev/null
+++ b/tools/signedconfig/debug_key.pem
@@ -0,0 +1,5 @@
+-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEIEfgtO+KPOoqJqTnqkDDKkAcOzyvtovsUO/ShLE6y4XRoAoGCCqGSM49
+AwEHoUQDQgAEaAn2XVifsLTHg616nTsOMVmlhBoECGbTEBTKKvdd2hO60pj1pnU8
+SMkhYfaNxZuKgw9LNvOwlFwStboIYeZ3lQ==
+-----END EC PRIVATE KEY-----
diff --git a/tools/signedconfig/debug_public.pem b/tools/signedconfig/debug_public.pem
new file mode 100644
index 000000000000..f61f81322b94
--- /dev/null
+++ b/tools/signedconfig/debug_public.pem
@@ -0,0 +1,4 @@
+-----BEGIN PUBLIC KEY-----
+MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEaAn2XVifsLTHg616nTsOMVmlhBoE
+CGbTEBTKKvdd2hO60pj1pnU8SMkhYfaNxZuKgw9LNvOwlFwStboIYeZ3lQ==
+-----END PUBLIC KEY-----
diff --git a/tools/signedconfig/debug_sign.sh b/tools/signedconfig/debug_sign.sh
new file mode 100755
index 000000000000..28e54289f8f8
--- /dev/null
+++ b/tools/signedconfig/debug_sign.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+# Script to sign data with the debug keys. Outputs base64 for embedding into
+# APK metadata.
+
+openssl dgst -sha256 -sign $(dirname $0)/debug_key.pem  $1 | base64 -w 0
+echo
diff --git a/tools/signedconfig/gen_priv_key.sh b/tools/signedconfig/gen_priv_key.sh
new file mode 100755
index 000000000000..834c86bc8c12
--- /dev/null
+++ b/tools/signedconfig/gen_priv_key.sh
@@ -0,0 +1,7 @@
+#!/bin/bash
+
+# This script acts as a record of how the debug key was generated. There should
+# be no need to run it again.
+
+openssl ecparam -name prime256v1 -genkey -noout -out debug_key.pem
+openssl ec -in debug_key.pem -pubout -out debug_public.pem
diff --git a/tools/signedconfig/verify_b64.sh b/tools/signedconfig/verify_b64.sh
new file mode 100755
index 000000000000..8e1f58ce7b45
--- /dev/null
+++ b/tools/signedconfig/verify_b64.sh
@@ -0,0 +1,10 @@
+#!/bin/bash
+
+# Script to verify signatures, with both signature & data given in b64
+# Args:
+# 1. data (base64 encoded)
+# 2. signature (base64 encoded)
+# The arg values can be taken from the debug log for SignedConfigService when verbose logging is
+# enabled.
+
+openssl dgst -sha256 -verify $(dirname $0)/debug_public.pem -signature <(echo $2 | base64 -d) <(echo $1 | base64 -d)