diff --git a/applypatch/applypatch.c b/applypatch/applypatch.c
index 69f8633..259fa58 100644
--- a/applypatch/applypatch.c
+++ b/applypatch/applypatch.c
@@ -101,7 +101,7 @@
         }
     }
 
-    SHA(file->data, file->size, file->sha1);
+    SHA_hash(file->data, file->size, file->sha1);
     return 0;
 }
 
diff --git a/install.cpp b/install.cpp
index 0f3298f..0cb5cc7 100644
--- a/install.cpp
+++ b/install.cpp
@@ -190,7 +190,7 @@
     ui->Print("Opening update package...\n");
 
     int numKeys;
-    RSAPublicKey* loadedKeys = load_keys(PUBLIC_KEYS_FILE, &numKeys);
+    Certificate* loadedKeys = load_keys(PUBLIC_KEYS_FILE, &numKeys);
     if (loadedKeys == NULL) {
         LOGE("Failed to load keys\n");
         return INSTALL_CORRUPT;
diff --git a/recovery.cpp b/recovery.cpp
index c82844d..b7fb616 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -283,6 +283,19 @@
     }
 }
 
+static void
+copy_logs() {
+    // Copy logs to cache so the system can find out what happened.
+    copy_log_file(TEMPORARY_LOG_FILE, LOG_FILE, true);
+    copy_log_file(TEMPORARY_LOG_FILE, LAST_LOG_FILE, false);
+    copy_log_file(TEMPORARY_INSTALL_FILE, LAST_INSTALL_FILE, false);
+    chmod(LOG_FILE, 0600);
+    chown(LOG_FILE, 1000, 1000);   // system user
+    chmod(LAST_LOG_FILE, 0640);
+    chmod(LAST_INSTALL_FILE, 0644);
+    sync();
+}
+
 // clear the recovery command and prepare to boot a (hopefully working) system,
 // copy our log file to cache as well (for the system to read), and
 // record any intent we were asked to communicate back to the system.
@@ -312,14 +325,7 @@
         check_and_fclose(fp, LOCALE_FILE);
     }
 
-    // Copy logs to cache so the system can find out what happened.
-    copy_log_file(TEMPORARY_LOG_FILE, LOG_FILE, true);
-    copy_log_file(TEMPORARY_LOG_FILE, LAST_LOG_FILE, false);
-    copy_log_file(TEMPORARY_INSTALL_FILE, LAST_INSTALL_FILE, false);
-    chmod(LOG_FILE, 0600);
-    chown(LOG_FILE, 1000, 1000);   // system user
-    chmod(LAST_LOG_FILE, 0640);
-    chmod(LAST_INSTALL_FILE, 0644);
+    copy_logs();
 
     // Reset to normal system boot so recovery won't cycle indefinitely.
     struct bootloader_message boot;
@@ -789,6 +795,7 @@
                     if (status != INSTALL_SUCCESS) {
                         ui->SetBackground(RecoveryUI::ERROR);
                         ui->Print("Installation aborted.\n");
+                        copy_logs();
                     } else if (!ui->IsTextVisible()) {
                         return;  // reboot if logs aren't visible
                     } else {
@@ -866,7 +873,7 @@
 
     load_volume_table();
     ensure_path_mounted(LAST_LOG_FILE);
-    rotate_last_logs(5);
+    rotate_last_logs(10);
     get_args(&argc, &argv);
 
     int previous_runs = 0;
@@ -979,6 +986,7 @@
     }
 
     if (status == INSTALL_ERROR || status == INSTALL_CORRUPT) {
+        copy_logs();
         ui->SetBackground(RecoveryUI::ERROR);
     }
     if (status != INSTALL_SUCCESS || ui->IsTextVisible()) {
diff --git a/testdata/otasigned_f4_sha256.zip b/testdata/otasigned_f4_sha256.zip
new file mode 100644
index 0000000..3af408c
--- /dev/null
+++ b/testdata/otasigned_f4_sha256.zip
Binary files differ
diff --git a/testdata/otasigned_sha256.zip b/testdata/otasigned_sha256.zip
new file mode 100644
index 0000000..0ed4409
--- /dev/null
+++ b/testdata/otasigned_sha256.zip
Binary files differ
diff --git a/testdata/test_f4_sha256.x509.pem b/testdata/test_f4_sha256.x509.pem
new file mode 100644
index 0000000..9d5376b
--- /dev/null
+++ b/testdata/test_f4_sha256.x509.pem
@@ -0,0 +1,25 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----
diff --git a/testdata/testkey.pk8 b/testdata/testkey.pk8
new file mode 100644
index 0000000..586c1bd
--- /dev/null
+++ b/testdata/testkey.pk8
Binary files differ
diff --git a/testdata/testkey.x509.pem b/testdata/testkey.x509.pem
new file mode 100644
index 0000000..e242d83
--- /dev/null
+++ b/testdata/testkey.x509.pem
@@ -0,0 +1,27 @@
+-----BEGIN CERTIFICATE-----
+MIIEqDCCA5CgAwIBAgIJAJNurL4H8gHfMA0GCSqGSIb3DQEBBQUAMIGUMQswCQYD
+VQQGEwJVUzETMBEGA1UECBMKQ2FsaWZvcm5pYTEWMBQGA1UEBxMNTW91bnRhaW4g
+VmlldzEQMA4GA1UEChMHQW5kcm9pZDEQMA4GA1UECxMHQW5kcm9pZDEQMA4GA1UE
+AxMHQW5kcm9pZDEiMCAGCSqGSIb3DQEJARYTYW5kcm9pZEBhbmRyb2lkLmNvbTAe
+Fw0wODAyMjkwMTMzNDZaFw0zNTA3MTcwMTMzNDZaMIGUMQswCQYDVQQGEwJVUzET
+MBEGA1UECBMKQ2FsaWZvcm5pYTEWMBQGA1UEBxMNTW91bnRhaW4gVmlldzEQMA4G
+A1UEChMHQW5kcm9pZDEQMA4GA1UECxMHQW5kcm9pZDEQMA4GA1UEAxMHQW5kcm9p
+ZDEiMCAGCSqGSIb3DQEJARYTYW5kcm9pZEBhbmRyb2lkLmNvbTCCASAwDQYJKoZI
+hvcNAQEBBQADggENADCCAQgCggEBANaTGQTexgskse3HYuDZ2CU+Ps1s6x3i/waM
+qOi8qM1r03hupwqnbOYOuw+ZNVn/2T53qUPn6D1LZLjk/qLT5lbx4meoG7+yMLV4
+wgRDvkxyGLhG9SEVhvA4oU6Jwr44f46+z4/Kw9oe4zDJ6pPQp8PcSvNQIg1QCAcy
+4ICXF+5qBTNZ5qaU7Cyz8oSgpGbIepTYOzEJOmc3Li9kEsBubULxWBjf/gOBzAzU
+RNps3cO4JFgZSAGzJWQTT7/emMkod0jb9WdqVA2BVMi7yge54kdVMxHEa5r3b97s
+zI5p58ii0I54JiCUP5lyfTwE/nKZHZnfm644oLIXf6MdW2r+6R8CAQOjgfwwgfkw
+HQYDVR0OBBYEFEhZAFY9JyxGrhGGBaR0GawJyowRMIHJBgNVHSMEgcEwgb6AFEhZ
+AFY9JyxGrhGGBaR0GawJyowRoYGapIGXMIGUMQswCQYDVQQGEwJVUzETMBEGA1UE
+CBMKQ2FsaWZvcm5pYTEWMBQGA1UEBxMNTW91bnRhaW4gVmlldzEQMA4GA1UEChMH
+QW5kcm9pZDEQMA4GA1UECxMHQW5kcm9pZDEQMA4GA1UEAxMHQW5kcm9pZDEiMCAG
+CSqGSIb3DQEJARYTYW5kcm9pZEBhbmRyb2lkLmNvbYIJAJNurL4H8gHfMAwGA1Ud
+EwQFMAMBAf8wDQYJKoZIhvcNAQEFBQADggEBAHqvlozrUMRBBVEY0NqrrwFbinZa
+J6cVosK0TyIUFf/azgMJWr+kLfcHCHJsIGnlw27drgQAvilFLAhLwn62oX6snb4Y
+LCBOsVMR9FXYJLZW2+TcIkCRLXWG/oiVHQGo/rWuWkJgU134NDEFJCJGjDbiLCpe
++ZTWHdcwauTJ9pUbo8EvHRkU3cYfGmLaLfgn9gP+pWA7LFQNvXwBnDa6sppCccEX
+31I828XzgXpJ4O+mDL1/dBd+ek8ZPUP0IgdyZm5MTYPhvVqGCHzzTy3sIeJFymwr
+sBbmg2OAUNLEMO6nwmocSdN2ClirfxqCzJOLSDE4QyS9BAH6EhY6UFcOaE0=
+-----END CERTIFICATE-----
diff --git a/testdata/testkey_sha256.x509.pem b/testdata/testkey_sha256.x509.pem
new file mode 100644
index 0000000..002ce89
--- /dev/null
+++ b/testdata/testkey_sha256.x509.pem
@@ -0,0 +1,27 @@
+-----BEGIN CERTIFICATE-----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=
+-----END CERTIFICATE-----
diff --git a/updater/install.c b/updater/install.c
index 1905423..1fc4fd3 100644
--- a/updater/install.c
+++ b/updater/install.c
@@ -1057,7 +1057,7 @@
         return StringValue(strdup(""));
     }
     uint8_t digest[SHA_DIGEST_SIZE];
-    SHA(args[0]->data, args[0]->size, digest);
+    SHA_hash(args[0]->data, args[0]->size, digest);
     FreeValue(args[0]);
 
     if (argc == 1) {
diff --git a/verifier.cpp b/verifier.cpp
index 5f4c981..782a838 100644
--- a/verifier.cpp
+++ b/verifier.cpp
@@ -20,6 +20,7 @@
 
 #include "mincrypt/rsa.h"
 #include "mincrypt/sha.h"
+#include "mincrypt/sha256.h"
 
 #include <string.h>
 #include <stdio.h>
@@ -34,7 +35,7 @@
 // Return VERIFY_SUCCESS, VERIFY_FAILURE (if any error is encountered
 // or no key matches the signature).
 
-int verify_file(const char* path, const RSAPublicKey *pKeys, unsigned int numKeys) {
+int verify_file(const char* path, const Certificate* pKeys, unsigned int numKeys) {
     ui->SetProgress(0.0);
 
     FILE* f = fopen(path, "rb");
@@ -68,6 +69,7 @@
     }
 
     if (footer[2] != 0xff || footer[3] != 0xff) {
+        LOGE("footer is wrong\n");
         fclose(f);
         return VERIFY_FAILURE;
     }
@@ -139,8 +141,19 @@
 
 #define BUFFER_SIZE 4096
 
-    SHA_CTX ctx;
-    SHA_init(&ctx);
+    bool need_sha1 = false;
+    bool need_sha256 = false;
+    for (i = 0; i < numKeys; ++i) {
+        switch (pKeys[i].hash_len) {
+            case SHA_DIGEST_SIZE: need_sha1 = true; break;
+            case SHA256_DIGEST_SIZE: need_sha256 = true; break;
+        }
+    }
+
+    SHA_CTX sha1_ctx;
+    SHA256_CTX sha256_ctx;
+    SHA_init(&sha1_ctx);
+    SHA256_init(&sha256_ctx);
     unsigned char* buffer = (unsigned char*)malloc(BUFFER_SIZE);
     if (buffer == NULL) {
         LOGE("failed to alloc memory for sha1 buffer\n");
@@ -159,7 +172,8 @@
             fclose(f);
             return VERIFY_FAILURE;
         }
-        SHA_update(&ctx, buffer, size);
+        if (need_sha1) SHA_update(&sha1_ctx, buffer, size);
+        if (need_sha256) SHA256_update(&sha256_ctx, buffer, size);
         so_far += size;
         double f = so_far / (double)signed_len;
         if (f > frac + 0.02 || size == so_far) {
@@ -170,12 +184,21 @@
     fclose(f);
     free(buffer);
 
-    const uint8_t* sha1 = SHA_final(&ctx);
+    const uint8_t* sha1 = SHA_final(&sha1_ctx);
+    const uint8_t* sha256 = SHA256_final(&sha256_ctx);
+
     for (i = 0; i < numKeys; ++i) {
+        const uint8_t* hash;
+        switch (pKeys[i].hash_len) {
+            case SHA_DIGEST_SIZE: hash = sha1; break;
+            case SHA256_DIGEST_SIZE: hash = sha256; break;
+            default: continue;
+        }
+
         // The 6 bytes is the "(signature_start) $ff $ff (comment_size)" that
         // the signing tool appends after the signature itself.
-        if (RSA_verify(pKeys+i, eocd + eocd_size - 6 - RSANUMBYTES,
-                       RSANUMBYTES, sha1)) {
+        if (RSA_verify(pKeys[i].public_key, eocd + eocd_size - 6 - RSANUMBYTES,
+                       RSANUMBYTES, hash, pKeys[i].hash_len)) {
             LOGI("whole-file signature verified against key %d\n", i);
             free(eocd);
             return VERIFY_SUCCESS;
@@ -207,10 +230,19 @@
 // The file may contain multiple keys in this format, separated by
 // commas.  The last key must not be followed by a comma.
 //
+// A Certificate is a pair of an RSAPublicKey and a particular hash
+// (we support SHA-1 and SHA-256; we store the hash length to signify
+// which is being used).  The hash used is implied by the version number.
+//
+//       1: 2048-bit RSA key with e=3 and SHA-1 hash
+//       2: 2048-bit RSA key with e=65537 and SHA-1 hash
+//       3: 2048-bit RSA key with e=3 and SHA-256 hash
+//       4: 2048-bit RSA key with e=65537 and SHA-256 hash
+//
 // Returns NULL if the file failed to parse, or if it contain zero keys.
-RSAPublicKey*
+Certificate*
 load_keys(const char* filename, int* numKeys) {
-    RSAPublicKey* out = NULL;
+    Certificate* out = NULL;
     *numKeys = 0;
 
     FILE* f = fopen(filename, "r");
@@ -224,24 +256,38 @@
         bool done = false;
         while (!done) {
             ++*numKeys;
-            out = (RSAPublicKey*)realloc(out, *numKeys * sizeof(RSAPublicKey));
-            RSAPublicKey* key = out + (*numKeys - 1);
+            out = (Certificate*)realloc(out, *numKeys * sizeof(Certificate));
+            Certificate* cert = out + (*numKeys - 1);
+            cert->public_key = (RSAPublicKey*)malloc(sizeof(RSAPublicKey));
 
             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;
+                cert->public_key->exponent = 3;
+                cert->hash_len = SHA_DIGEST_SIZE;
             } else if (start_char == 'v') {
                 int version;
                 if (fscanf(f, "%d {", &version) != 1) goto exit;
-                if (version == 2) {
-                    key->exponent = 65537;
-                } else {
-                    goto exit;
+                switch (version) {
+                    case 2:
+                        cert->public_key->exponent = 65537;
+                        cert->hash_len = SHA_DIGEST_SIZE;
+                        break;
+                    case 3:
+                        cert->public_key->exponent = 3;
+                        cert->hash_len = SHA256_DIGEST_SIZE;
+                        break;
+                    case 4:
+                        cert->public_key->exponent = 65537;
+                        cert->hash_len = SHA256_DIGEST_SIZE;
+                        break;
+                    default:
+                        goto exit;
                 }
             }
 
+            RSAPublicKey* key = cert->public_key;
             if (fscanf(f, " %i , 0x%x , { %u",
                        &(key->len), &(key->n0inv), &(key->n[0])) != 3) {
                 goto exit;
@@ -274,7 +320,7 @@
                 goto exit;
             }
 
-            LOGI("read key e=%d\n", key->exponent);
+            LOGI("read key e=%d hash=%d\n", key->exponent, cert->hash_len);
         }
     }
 
diff --git a/verifier.h b/verifier.h
index e9ef3b7..6ce1b44 100644
--- a/verifier.h
+++ b/verifier.h
@@ -19,12 +19,17 @@
 
 #include "mincrypt/rsa.h"
 
+typedef struct Certificate {
+    int hash_len;  // SHA_DIGEST_SIZE (SHA-1) or SHA256_DIGEST_SIZE (SHA-256)
+    RSAPublicKey* public_key;
+} Certificate;
+
 /* Look in the file for a signature footer, and verify that it
  * matches one of the given keys.  Return one of the constants below.
  */
-int verify_file(const char* path, const RSAPublicKey *pKeys, unsigned int numKeys);
+int verify_file(const char* path, const Certificate *pKeys, unsigned int numKeys);
 
-RSAPublicKey* load_keys(const char* filename, int* numKeys);
+Certificate* load_keys(const char* filename, int* numKeys);
 
 #define VERIFY_SUCCESS        0
 #define VERIFY_FAILURE        1
diff --git a/verifier_test.cpp b/verifier_test.cpp
index 2ef52a0..1063cba 100644
--- a/verifier_test.cpp
+++ b/verifier_test.cpp
@@ -21,80 +21,82 @@
 #include "common.h"
 #include "verifier.h"
 #include "ui.h"
+#include "mincrypt/sha.h"
+#include "mincrypt/sha256.h"
 
 // This is build/target/product/security/testkey.x509.pem after being
 // dumped out by dumpkey.jar.
 RSAPublicKey test_key =
     { 64, 0xc926ad21,
-      { 1795090719, 2141396315, 950055447, -1713398866,
-        -26044131, 1920809988, 546586521, -795969498,
-        1776797858, -554906482, 1805317999, 1429410244,
-        129622599, 1422441418, 1783893377, 1222374759,
-        -1731647369, 323993566, 28517732, 609753416,
-        1826472888, 215237850, -33324596, -245884705,
-        -1066504894, 774857746, 154822455, -1797768399,
-        -1536767878, -1275951968, -1500189652, 87251430,
-        -1760039318, 120774784, 571297800, -599067824,
-        -1815042109, -483341846, -893134306, -1900097649,
-        -1027721089, 950095497, 555058928, 414729973,
-        1136544882, -1250377212, 465547824, -236820568,
-        -1563171242, 1689838846, -404210357, 1048029507,
-        895090649, 247140249, 178744550, -747082073,
-        -1129788053, 109881576, -350362881, 1044303212,
-        -522594267, -1309816990, -557446364, -695002876},
-      { -857949815, -510492167, -1494742324, -1208744608,
-        251333580, 2131931323, 512774938, 325948880,
-        -1637480859, 2102694287, -474399070, 792812816,
-        1026422502, 2053275343, -1494078096, -1181380486,
-        165549746, -21447327, -229719404, 1902789247,
-        772932719, -353118870, -642223187, 216871947,
-        -1130566647, 1942378755, -298201445, 1055777370,
-        964047799, 629391717, -2062222979, -384408304,
-        191868569, -1536083459, -612150544, -1297252564,
-        -1592438046, -724266841, -518093464, -370899750,
-        -739277751, -1536141862, 1323144535, 61311905,
-        1997411085, 376844204, 213777604, -217643712,
-        9135381, 1625809335, -1490225159, -1342673351,
-        1117190829, -57654514, 1825108855, -1281819325,
-        1111251351, -1726129724, 1684324211, -1773988491,
-        367251975, 810756730, -1941182952, 1175080310 },
+      { 0x6afee91fu, 0x7fa31d5bu, 0x38a0b217u, 0x99df9baeu,
+        0xfe72991du, 0x727d3c04u, 0x20943f99u, 0xd08e7826u,
+        0x69e7c8a2u, 0xdeeccc8eu, 0x6b9af76fu, 0x553311c4u,
+        0x07b9e247u, 0x54c8bbcau, 0x6a540d81u, 0x48dbf567u,
+        0x98c92877u, 0x134fbfdeu, 0x01b32564u, 0x24581948u,
+        0x6cddc3b8u, 0x0cd444dau, 0xfe0381ccu, 0xf15818dfu,
+        0xc06e6d42u, 0x2e2f6412u, 0x093a6737u, 0x94d83b31u,
+        0xa466c87au, 0xb3f284a0u, 0xa694ec2cu, 0x053359e6u,
+        0x9717ee6au, 0x0732e080u, 0x220d5008u, 0xdc4af350u,
+        0x93d0a7c3u, 0xe330c9eau, 0xcac3da1eu, 0x8ebecf8fu,
+        0xc2be387fu, 0x38a14e89u, 0x211586f0u, 0x18b846f5u,
+        0x43be4c72u, 0xb578c204u, 0x1bbfb230u, 0xf1e267a8u,
+        0xa2d3e656u, 0x64b8e4feu, 0xe7e83d4bu, 0x3e77a943u,
+        0x3559ffd9u, 0x0ebb0f99u, 0x0aa76ce6u, 0xd3786ea7u,
+        0xbca8cd6bu, 0x068ca8e8u, 0xeb1de2ffu, 0x3e3ecd6cu,
+        0xe0d9d825u, 0xb1edc762u, 0xdec60b24u, 0xd6931904u},
+      { 0xccdcb989u, 0xe19281f9u, 0xa6e80accu, 0xb7f40560u,
+        0x0efb0bccu, 0x7f12b0bbu, 0x1e90531au, 0x136d95d0u,
+        0x9e660665u, 0x7d54918fu, 0xe3b93ea2u, 0x2f415d10u,
+        0x3d2df6e6u, 0x7a627ecfu, 0xa6f22d70u, 0xb995907au,
+        0x09de16b2u, 0xfeb8bd61u, 0xf24ec294u, 0x716a427fu,
+        0x2e12046fu, 0xeaf3d56au, 0xd9b873adu, 0x0ced340bu,
+        0xbc9cec09u, 0x73c65903u, 0xee39ce9bu, 0x3eede25au,
+        0x397633b7u, 0x2583c165u, 0x8514f97du, 0xe9166510u,
+        0x0b6fae99u, 0xa47139fdu, 0xdb8352f0u, 0xb2ad7f2cu,
+        0xa11552e2u, 0xd4d490a7u, 0xe11e8568u, 0xe9e484dau,
+        0xd3ef8449u, 0xa47055dau, 0x4edd9557u, 0x03a78ba1u,
+        0x770e130du, 0x16762facu, 0x0cbdfcc4u, 0xf3070540u,
+        0x008b6515u, 0x60e7e1b7u, 0xa72cf7f9u, 0xaff86e39u,
+        0x4296faadu, 0xfc90430eu, 0x6cc8f377u, 0xb398fd43u,
+        0x423c5997u, 0x991d59c4u, 0x6464bf73u, 0x96431575u,
+        0x15e3d207u, 0x30532a7au, 0x8c4be618u, 0x460a4d76u },
       3
     };
 
 RSAPublicKey test_f4_key =
     { 64, 0xc9bd1f21,
-      { 293133087u, 3210546773u, 865313125u, 250921607u,
-        3158780490u, 943703457u, 1242806226u, 2986289859u,
-        2942743769u, 2457906415u, 2719374299u, 1783459420u,
-        149579627u, 3081531591u, 3440738617u, 2788543742u,
-        2758457512u, 1146764939u, 3699497403u, 2446203424u,
-        1744968926u, 1159130537u, 2370028300u, 3978231572u,
-        3392699980u, 1487782451u, 1180150567u, 2841334302u,
-        3753960204u, 961373345u, 3333628321u, 748825784u,
-        2978557276u, 1566596926u, 1613056060u, 2600292737u,
-        1847226629u, 50398611u, 1890374404u, 2878700735u,
-        2286201787u, 1401186359u, 619285059u, 731930817u,
-        2340993166u, 1156490245u, 2992241729u, 151498140u,
-        318782170u, 3480838990u, 2100383433u, 4223552555u,
-        3628927011u, 4247846280u, 1759029513u, 4215632601u,
-        2719154626u, 3490334597u, 1751299340u, 3487864726u,
-        3668753795u, 4217506054u, 3748782284u, 3150295088u },
-      { 1772626313u, 445326068u, 3477676155u, 1758201194u,
-        2986784722u, 491035581u, 3922936562u, 702212696u,
-        2979856666u, 3324974564u, 2488428922u, 3056318590u,
-        1626954946u, 664714029u, 398585816u, 3964097931u,
-        3356701905u, 2298377729u, 2040082097u, 3025491477u,
-        539143308u, 3348777868u, 2995302452u, 3602465520u,
-        212480763u, 2691021393u, 1307177300u, 704008044u,
-        2031136606u, 1054106474u, 3838318865u, 2441343869u,
-        1477566916u, 700949900u, 2534790355u, 3353533667u,
-        336163563u, 4106790558u, 2701448228u, 1571536379u,
-        1103842411u, 3623110423u, 1635278839u, 1577828979u,
-        910322800u, 715583630u, 138128831u, 1017877531u,
-        2289162787u, 447994798u, 1897243165u, 4121561445u,
-        4150719842u, 2131821093u, 2262395396u, 3305771534u,
-        980753571u, 3256525190u, 3128121808u, 1072869975u,
-        3507939515u, 4229109952u, 118381341u, 2209831334u },
+      { 0x1178db1fu, 0xbf5d0e55u, 0x3393a165u, 0x0ef4c287u,
+        0xbc472a4au, 0x383fc5a1u, 0x4a13b7d2u, 0xb1ff2ac3u,
+        0xaf66b4d9u, 0x9280acefu, 0xa2165bdbu, 0x6a4d6e5cu,
+        0x08ea676bu, 0xb7ac70c7u, 0xcd158139u, 0xa635ccfeu,
+        0xa46ab8a8u, 0x445a3e8bu, 0xdc81d9bbu, 0x91ce1a20u,
+        0x68021cdeu, 0x4516eda9u, 0x8d43c30cu, 0xed1eff14u,
+        0xca387e4cu, 0x58adc233u, 0x4657ab27u, 0xa95b521eu,
+        0xdfc0e30cu, 0x394d64a1u, 0xc6b321a1u, 0x2ca22cb8u,
+        0xb1892d5cu, 0x5d605f3eu, 0x6025483cu, 0x9afd5181u,
+        0x6e1a7105u, 0x03010593u, 0x70acd304u, 0xab957cbfu,
+        0x8844abbbu, 0x53846837u, 0x24e98a43u, 0x2ba060c1u,
+        0x8b88b88eu, 0x44eea405u, 0xb259fc41u, 0x0907ad9cu,
+        0x13003adau, 0xcf79634eu, 0x7d314ec9u, 0xfbbe4c2bu,
+        0xd84d0823u, 0xfd30fd88u, 0x68d8a909u, 0xfb4572d9u,
+        0xa21301c2u, 0xd00a4785u, 0x6862b50cu, 0xcfe49796u,
+        0xdaacbd83u, 0xfb620906u, 0xdf71e0ccu, 0xbbc5b030u },
+      { 0x69a82189u, 0x1a8b22f4u, 0xcf49207bu, 0x68cc056au,
+        0xb206b7d2u, 0x1d449bbdu, 0xe9d342f2u, 0x29daea58u,
+        0xb19d011au, 0xc62f15e4u, 0x9452697au, 0xb62bb87eu,
+        0x60f95cc2u, 0x279ebb2du, 0x17c1efd8u, 0xec47558bu,
+        0xc81334d1u, 0x88fe7601u, 0x79992eb1u, 0xb4555615u,
+        0x2022ac8cu, 0xc79a4b8cu, 0xb288b034u, 0xd6b942f0u,
+        0x0caa32fbu, 0xa065ba51u, 0x4de9f154u, 0x29f64f6cu,
+        0x7910af5eu, 0x3ed4636au, 0xe4c81911u, 0x9183f37du,
+        0x5811e1c4u, 0x29c7a58cu, 0x9715d4d3u, 0xc7e2dce3u,
+        0x140972ebu, 0xf4c8a69eu, 0xa104d424u, 0x5dabbdfbu,
+        0x41cb4c6bu, 0xd7f44717u, 0x61785ff7u, 0x5e0bc273u,
+        0x36426c70u, 0x2aa6f08eu, 0x083badbfu, 0x3cab941bu,
+        0x8871da23u, 0x1ab3dbaeu, 0x7115a21du, 0xf5aa0965u,
+        0xf766f562u, 0x7f110225u, 0x86d96a04u, 0xc50a120eu,
+        0x3a751ca3u, 0xc21aa186u, 0xba7359d0u, 0x3ff2b257u,
+        0xd116e8bbu, 0xfc1318c0u, 0x070e5b1du, 0x83b759a6u },
       65537
     };
 
@@ -136,30 +138,37 @@
 
 int main(int argc, char **argv) {
     if (argc < 2 || argc > 4) {
-        fprintf(stderr, "Usage: %s [-f4 | -file <keys>] <package>\n", argv[0]);
+        fprintf(stderr, "Usage: %s [-sha256] [-f4 | -file <keys>] <package>\n", argv[0]);
         return 2;
     }
 
-    RSAPublicKey* key = &test_key;
+    Certificate default_cert;
+    Certificate* cert = &default_cert;
+    cert->public_key = &test_key;
+    cert->hash_len = SHA_DIGEST_SIZE;
     int num_keys = 1;
     ++argv;
+    if (strcmp(argv[0], "-sha256") == 0) {
+        ++argv;
+        cert->hash_len = SHA256_DIGEST_SIZE;
+    }
     if (strcmp(argv[0], "-f4") == 0) {
         ++argv;
-        key = &test_f4_key;
+        cert->public_key = &test_f4_key;
     } else if (strcmp(argv[0], "-file") == 0) {
         ++argv;
-        key = load_keys(argv[0], &num_keys);
+        cert = load_keys(argv[0], &num_keys);
         ++argv;
     }
 
     ui = new FakeUI();
 
-    int result = verify_file(*argv, key, num_keys);
+    int result = verify_file(*argv, cert, num_keys);
     if (result == VERIFY_SUCCESS) {
-        printf("SUCCESS\n");
+        printf("VERIFIED\n");
         return 0;
     } else if (result == VERIFY_FAILURE) {
-        printf("FAILURE\n");
+        printf("NOT VERIFIED\n");
         return 1;
     } else {
         printf("bad return value\n");
diff --git a/verifier_test.sh b/verifier_test.sh
index 378b0e5..65f77f4 100755
--- a/verifier_test.sh
+++ b/verifier_test.sh
@@ -64,33 +64,39 @@
 expect_succeed() {
   testname "$1 (should succeed)"
   $ADB push $DATA_DIR/$1 $WORK_DIR/package.zip
-  run_command $WORK_DIR/verifier_test $WORK_DIR/package.zip || fail
+  shift
+  run_command $WORK_DIR/verifier_test "$@" $WORK_DIR/package.zip || fail
 }
 
 expect_fail() {
   testname "$1 (should fail)"
   $ADB push $DATA_DIR/$1 $WORK_DIR/package.zip
-  run_command $WORK_DIR/verifier_test $WORK_DIR/package.zip && fail
+  shift
+  run_command $WORK_DIR/verifier_test "$@" $WORK_DIR/package.zip && fail
 }
 
-expect_succeed_f4() {
-  testname "$1 (should succeed)"
-  $ADB push $DATA_DIR/$1 $WORK_DIR/package.zip
-  run_command $WORK_DIR/verifier_test -f4 $WORK_DIR/package.zip || fail
-}
-
-expect_fail_f4() {
-  testname "$1 (should fail)"
-  $ADB push $DATA_DIR/$1 $WORK_DIR/package.zip
-  run_command $WORK_DIR/verifier_test -f4 $WORK_DIR/package.zip && fail
-}
-
+# not signed at all
 expect_fail unsigned.zip
+# signed in the pre-donut way
 expect_fail jarsigned.zip
+
+# success cases
 expect_succeed otasigned.zip
-expect_fail_f4 otasigned.zip
-expect_succeed_f4 otasigned_f4.zip
+expect_succeed otasigned_f4.zip -f4
+expect_succeed otasigned_sha256.zip -sha256
+expect_succeed otasigned_f4_sha256.zip -sha256 -f4
+
+# verified against different key
+expect_fail otasigned.zip -f4
 expect_fail otasigned_f4.zip
+
+# verified against right key but wrong hash algorithm
+expect_fail otasigned.zip -sha256
+expect_fail otasigned_f4.zip -sha256 -f4
+expect_fail otasigned_sha256.zip
+expect_fail otasigned_f4_sha256.zip -f4
+
+# various other cases
 expect_fail random.zip
 expect_fail fake-eocd.zip
 expect_fail alter-metadata.zip