support version 2 (2048-bit e=65537) keys in recovery

Change-Id: I9849c69777d513bb12926c8c622d1c12d2da568a

1 files changed, 25 insertions, 1 deletions

diff --git a/install.cpp b/install.cpp
index 4d73aa9..819650e 100644
--- a/install.cpp
+++ b/install.cpp
@@ -180,6 +180,12 @@ try_update_binary(const char *path, ZipArchive *zip, int* wipe_cache) {
 //
 //  "{64,0xc926ad21,{1795090719,...,-695002876},{-857949815,...,1175080310}}"
 //
+// For key versions newer than the original 2048-bit e=3 keys
+// supported by Android, the string is preceded by a version
+// identifier, eg:
+//
+//  "v2 {64,0xc926ad21,{1795090719,...,-695002876},{-857949815,...,1175080310}}"
+//
 // (Note that the braces and commas in this example are actual
 // characters the parser expects to find in the file; the ellipses
 // indicate more numbers omitted from this example.)
@@ -206,7 +212,23 @@ load_keys(const char* filename, int* numKeys) {
             ++*numKeys;
             out = (RSAPublicKey*)realloc(out, *numKeys * sizeof(RSAPublicKey));
             RSAPublicKey* key = out + (*numKeys - 1);
-            if (fscanf(f, " { %i , 0x%x , { %u",
+
+            char start_char;
+            if (fscanf(f, " %c", &start_char) != 1) goto exit;
+            if (start_char == '{') {
+                // a version 1 key has no version specifier.
+                key->exponent = 3;
+            } else if (start_char == 'v') {
+                int version;
+                if (fscanf(f, "%d {", &version) != 1) goto exit;
+                if (version == 2) {
+                    key->exponent = 65537;
+                } else {
+                    goto exit;
+                }
+            }
+
+            if (fscanf(f, " %i , 0x%x , { %u",
                        &(key->len), &(key->n0inv), &(key->n[0])) != 3) {
                 goto exit;
             }
@@ -237,6 +259,8 @@ load_keys(const char* filename, int* numKeys) {
                 LOGE("unexpected character between keys\n");
                 goto exit;
             }
+
+            LOGI("read key e=%d\n", key->exponent);
         }
     }