9 files changed, 843 insertions, 0 deletions

diff --git a/libmincrypt/Android.mk b/libmincrypt/Android.mk
new file mode 100644
index 000000000..c111f4b1a
--- /dev/null
+++ b/libmincrypt/Android.mk
@@ -0,0 +1,16 @@
+# Copyright 2008 The Android Open Source Project
+#
+LOCAL_PATH := $(call my-dir)
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := libmincrypttwrp
+LOCAL_C_INCLUDES := bootable/recovery/libmincrypt/includes
+LOCAL_SRC_FILES := rsa.c sha.c sha256.c
+include $(BUILD_STATIC_LIBRARY)
+
+include $(CLEAR_VARS)
+
+LOCAL_MODULE := libmincrypttwrp
+LOCAL_SRC_FILES := rsa.c sha.c sha256.c
+include $(BUILD_HOST_STATIC_LIBRARY)
+
diff --git a/libmincrypt/NOTICE b/libmincrypt/NOTICE
new file mode 100644
index 000000000..430d3d62c
--- /dev/null
+++ b/libmincrypt/NOTICE
@@ -0,0 +1,23 @@
+ Copyright 2008, The Android Open Source Project
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+     * Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+     * Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+     * Neither the name of Google Inc. nor the names of its contributors may
+       be used to endorse or promote products derived from this software
+       without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY Google Inc. ``AS IS'' AND ANY EXPRESS OR 
+ IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 
+ EVENT SHALL Google Inc. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 
+ OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
+ WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR 
+ OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/libmincrypt/includes/mincrypt/hash-internal.h b/libmincrypt/includes/mincrypt/hash-internal.h
new file mode 100644
index 000000000..96806f7c6
--- /dev/null
+++ b/libmincrypt/includes/mincrypt/hash-internal.h
@@ -0,0 +1,40 @@
+// Copyright 2007 Google Inc. All Rights Reserved.
+// Author: mschilder@google.com (Marius Schilder)
+
+#ifndef SECURITY_UTIL_LITE_HASH_INTERNAL_H__
+#define SECURITY_UTIL_LITE_HASH_INTERNAL_H__
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif  // __cplusplus
+
+struct HASH_CTX;  // forward decl
+
+typedef struct HASH_VTAB {
+  void (* const init)(struct HASH_CTX*);
+  void (* const update)(struct HASH_CTX*, const void*, int);
+  const uint8_t* (* const final)(struct HASH_CTX*);
+  const uint8_t* (* const hash)(const void*, int, uint8_t*);
+  int size;
+} HASH_VTAB;
+
+typedef struct HASH_CTX {
+  const HASH_VTAB * f;
+  uint64_t count;
+  uint8_t buf[64];
+  uint32_t state[8];  // upto SHA2
+} HASH_CTX;
+
+#define HASH_init(ctx) (ctx)->f->init(ctx)
+#define HASH_update(ctx, data, len) (ctx)->f->update(ctx, data, len)
+#define HASH_final(ctx) (ctx)->f->final(ctx)
+#define HASH_hash(data, len, digest) (ctx)->f->hash(data, len, digest)
+#define HASH_size(ctx) (ctx)->f->size
+
+#ifdef __cplusplus
+}
+#endif  // __cplusplus
+
+#endif  // SECURITY_UTIL_LITE_HASH_INTERNAL_H__
diff --git a/libmincrypt/includes/mincrypt/rsa.h b/libmincrypt/includes/mincrypt/rsa.h
new file mode 100644
index 000000000..cc0e80024
--- /dev/null
+++ b/libmincrypt/includes/mincrypt/rsa.h
@@ -0,0 +1,58 @@
+/* rsa.h
+**
+** Copyright 2008, The Android Open Source Project
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are met:
+**     * Redistributions of source code must retain the above copyright
+**       notice, this list of conditions and the following disclaimer.
+**     * Redistributions in binary form must reproduce the above copyright
+**       notice, this list of conditions and the following disclaimer in the
+**       documentation and/or other materials provided with the distribution.
+**     * Neither the name of Google Inc. nor the names of its contributors may
+**       be used to endorse or promote products derived from this software
+**       without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED BY Google Inc. ``AS IS'' AND ANY EXPRESS OR
+** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+** EVENT SHALL Google Inc. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+** PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+** OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+** OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+** ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#ifndef _EMBEDDED_RSA_H_
+#define _EMBEDDED_RSA_H_
+
+#include <inttypes.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define RSANUMBYTES 256           /* 2048 bit key length */
+#define RSANUMWORDS (RSANUMBYTES / sizeof(uint32_t))
+
+typedef struct RSAPublicKey {
+    int len;                  /* Length of n[] in number of uint32_t */
+    uint32_t n0inv;           /* -1 / n[0] mod 2^32 */
+    uint32_t n[RSANUMWORDS];  /* modulus as little endian array */
+    uint32_t rr[RSANUMWORDS]; /* R^2 as little endian array */
+    int exponent;             /* 3 or 65537 */
+} RSAPublicKey;
+
+int RSA_verify(const RSAPublicKey *key,
+               const uint8_t* signature,
+               const int len,
+               const uint8_t* hash,
+               const int hash_len);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif
diff --git a/libmincrypt/includes/mincrypt/sha.h b/libmincrypt/includes/mincrypt/sha.h
new file mode 100644
index 000000000..120ddcb4f
--- /dev/null
+++ b/libmincrypt/includes/mincrypt/sha.h
@@ -0,0 +1,30 @@
+// Copyright 2005 Google Inc. All Rights Reserved.
+// Author: mschilder@google.com (Marius Schilder)
+
+#ifndef SECURITY_UTIL_LITE_SHA1_H__
+#define SECURITY_UTIL_LITE_SHA1_H__
+
+#include <stdint.h>
+#include "hash-internal.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+typedef HASH_CTX SHA_CTX;
+
+void SHA_init(SHA_CTX* ctx);
+void SHA_update(SHA_CTX* ctx, const void* data, int len);
+const uint8_t* SHA_final(SHA_CTX* ctx);
+
+// Convenience method. Returns digest address.
+// NOTE: *digest needs to hold SHA_DIGEST_SIZE bytes.
+const uint8_t* SHA_hash(const void* data, int len, uint8_t* digest);
+
+#define SHA_DIGEST_SIZE 20
+
+#ifdef __cplusplus
+}
+#endif // __cplusplus
+
+#endif  // SECURITY_UTIL_LITE_SHA1_H__
diff --git a/libmincrypt/includes/mincrypt/sha256.h b/libmincrypt/includes/mincrypt/sha256.h
new file mode 100644
index 000000000..0f3efb7f0
--- /dev/null
+++ b/libmincrypt/includes/mincrypt/sha256.h
@@ -0,0 +1,29 @@
+// Copyright 2011 Google Inc. All Rights Reserved.
+// Author: mschilder@google.com (Marius Schilder)
+
+#ifndef SECURITY_UTIL_LITE_SHA256_H__
+#define SECURITY_UTIL_LITE_SHA256_H__
+
+#include <stdint.h>
+#include "hash-internal.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif // __cplusplus
+
+typedef HASH_CTX SHA256_CTX;
+
+void SHA256_init(SHA256_CTX* ctx);
+void SHA256_update(SHA256_CTX* ctx, const void* data, int len);
+const uint8_t* SHA256_final(SHA256_CTX* ctx);
+
+// Convenience method. Returns digest address.
+const uint8_t* SHA256_hash(const void* data, int len, uint8_t* digest);
+
+#define SHA256_DIGEST_SIZE 32
+
+#ifdef __cplusplus
+}
+#endif // __cplusplus
+
+#endif  // SECURITY_UTIL_LITE_SHA256_H__
diff --git a/libmincrypt/rsa.c b/libmincrypt/rsa.c
new file mode 100644
index 000000000..9061b3ae3
--- /dev/null
+++ b/libmincrypt/rsa.c
@@ -0,0 +1,308 @@
+/* rsa.c
+**
+** Copyright 2012, The Android Open Source Project
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are met:
+**     * Redistributions of source code must retain the above copyright
+**       notice, this list of conditions and the following disclaimer.
+**     * Redistributions in binary form must reproduce the above copyright
+**       notice, this list of conditions and the following disclaimer in the
+**       documentation and/or other materials provided with the distribution.
+**     * Neither the name of Google Inc. nor the names of its contributors may
+**       be used to endorse or promote products derived from this software
+**       without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED BY Google Inc. ``AS IS'' AND ANY EXPRESS OR
+** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+** EVENT SHALL Google Inc. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+** PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+** OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+** OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+** ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+#include "mincrypt/rsa.h"
+#include "mincrypt/sha.h"
+#include "mincrypt/sha256.h"
+
+// a[] -= mod
+static void subM(const RSAPublicKey* key,
+                 uint32_t* a) {
+    int64_t A = 0;
+    int i;
+    for (i = 0; i < key->len; ++i) {
+        A += (uint64_t)a[i] - key->n[i];
+        a[i] = (uint32_t)A;
+        A >>= 32;
+    }
+}
+
+// return a[] >= mod
+static int geM(const RSAPublicKey* key,
+               const uint32_t* a) {
+    int i;
+    for (i = key->len; i;) {
+        --i;
+        if (a[i] < key->n[i]) return 0;
+        if (a[i] > key->n[i]) return 1;
+    }
+    return 1;  // equal
+}
+
+// montgomery c[] += a * b[] / R % mod
+static void montMulAdd(const RSAPublicKey* key,
+                       uint32_t* c,
+                       const uint32_t a,
+                       const uint32_t* b) {
+    uint64_t A = (uint64_t)a * b[0] + c[0];
+    uint32_t d0 = (uint32_t)A * key->n0inv;
+    uint64_t B = (uint64_t)d0 * key->n[0] + (uint32_t)A;
+    int i;
+
+    for (i = 1; i < key->len; ++i) {
+        A = (A >> 32) + (uint64_t)a * b[i] + c[i];
+        B = (B >> 32) + (uint64_t)d0 * key->n[i] + (uint32_t)A;
+        c[i - 1] = (uint32_t)B;
+    }
+
+    A = (A >> 32) + (B >> 32);
+
+    c[i - 1] = (uint32_t)A;
+
+    if (A >> 32) {
+        subM(key, c);
+    }
+}
+
+// montgomery c[] = a[] * b[] / R % mod
+static void montMul(const RSAPublicKey* key,
+                    uint32_t* c,
+                    const uint32_t* a,
+                    const uint32_t* b) {
+    int i;
+    for (i = 0; i < key->len; ++i) {
+        c[i] = 0;
+    }
+    for (i = 0; i < key->len; ++i) {
+        montMulAdd(key, c, a[i], b);
+    }
+}
+
+// In-place public exponentiation.
+// Input and output big-endian byte array in inout.
+static void modpow(const RSAPublicKey* key,
+                   uint8_t* inout) {
+    uint32_t a[RSANUMWORDS];
+    uint32_t aR[RSANUMWORDS];
+    uint32_t aaR[RSANUMWORDS];
+    uint32_t* aaa = 0;
+    int i;
+
+    // Convert from big endian byte array to little endian word array.
+    for (i = 0; i < key->len; ++i) {
+        uint32_t tmp =
+            (inout[((key->len - 1 - i) * 4) + 0] << 24) |
+            (inout[((key->len - 1 - i) * 4) + 1] << 16) |
+            (inout[((key->len - 1 - i) * 4) + 2] << 8) |
+            (inout[((key->len - 1 - i) * 4) + 3] << 0);
+        a[i] = tmp;
+    }
+
+    if (key->exponent == 65537) {
+        aaa = aaR;  // Re-use location.
+        montMul(key, aR, a, key->rr);  // aR = a * RR / R mod M
+        for (i = 0; i < 16; i += 2) {
+            montMul(key, aaR, aR, aR);  // aaR = aR * aR / R mod M
+            montMul(key, aR, aaR, aaR);  // aR = aaR * aaR / R mod M
+        }
+        montMul(key, aaa, aR, a);  // aaa = aR * a / R mod M
+    } else if (key->exponent == 3) {
+        aaa = aR;  // Re-use location.
+        montMul(key, aR, a, key->rr);  /* aR = a * RR / R mod M   */
+        montMul(key, aaR, aR, aR);     /* aaR = aR * aR / R mod M */
+        montMul(key, aaa, aaR, a);     /* aaa = aaR * a / R mod M */
+    }
+
+    // Make sure aaa < mod; aaa is at most 1x mod too large.
+    if (geM(key, aaa)) {
+        subM(key, aaa);
+    }
+
+    // Convert to bigendian byte array
+    for (i = key->len - 1; i >= 0; --i) {
+        uint32_t tmp = aaa[i];
+        *inout++ = tmp >> 24;
+        *inout++ = tmp >> 16;
+        *inout++ = tmp >> 8;
+        *inout++ = tmp >> 0;
+    }
+}
+
+// Expected PKCS1.5 signature padding bytes, for a keytool RSA signature.
+// Has the 0-length optional parameter encoded in the ASN1 (as opposed to the
+// other flavor which omits the optional parameter entirely). This code does not
+// accept signatures without the optional parameter.
+
+/*
+static const uint8_t sha_padding[RSANUMBYTES] = {
+    0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0x00, 0x30, 0x21, 0x30,
+    0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a,
+    0x05, 0x00, 0x04, 0x14,
+
+    // 20 bytes of hash go here.
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+};
+*/
+
+// SHA-1 of PKCS1.5 signature sha_padding for 2048 bit, as above.
+// At the location of the bytes of the hash all 00 are hashed.
+static const uint8_t kExpectedPadShaRsa2048[SHA_DIGEST_SIZE] = {
+    0xdc, 0xbd, 0xbe, 0x42, 0xd5, 0xf5, 0xa7, 0x2e,
+    0x6e, 0xfc, 0xf5, 0x5d, 0xaf, 0x9d, 0xea, 0x68,
+    0x7c, 0xfb, 0xf1, 0x67
+};
+
+/*
+static const uint8_t sha256_padding[RSANUMBYTES] = {
+    0x00, 0x01, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+    0xff, 0xff, 0xff, 0xff, 0x00, 0x30, 0x31, 0x30,
+    0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65,
+    0x03, 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20,
+
+    // 32 bytes of hash go here.
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+    0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
+};
+*/
+
+// SHA-256 of PKCS1.5 signature sha256_padding for 2048 bit, as above.
+// At the location of the bytes of the hash all 00 are hashed.
+static const uint8_t kExpectedPadSha256Rsa2048[SHA256_DIGEST_SIZE] = {
+    0xab, 0x28, 0x8d, 0x8a, 0xd7, 0xd9, 0x59, 0x92,
+    0xba, 0xcc, 0xf8, 0x67, 0x20, 0xe1, 0x15, 0x2e,
+    0x39, 0x8d, 0x80, 0x36, 0xd6, 0x6f, 0xf0, 0xfd,
+    0x90, 0xe8, 0x7d, 0x8b, 0xe1, 0x7c, 0x87, 0x59,
+};
+
+// Verify a 2048-bit RSA PKCS1.5 signature against an expected hash.
+// Both e=3 and e=65537 are supported.  hash_len may be
+// SHA_DIGEST_SIZE (== 20) to indicate a SHA-1 hash, or
+// SHA256_DIGEST_SIZE (== 32) to indicate a SHA-256 hash.  No other
+// values are supported.
+//
+// Returns 1 on successful verification, 0 on failure.
+int RSA_verify(const RSAPublicKey *key,
+               const uint8_t *signature,
+               const int len,
+               const uint8_t *hash,
+               const int hash_len) {
+    uint8_t buf[RSANUMBYTES];
+    int i;
+    const uint8_t* padding_hash;
+
+    if (key->len != RSANUMWORDS) {
+        return 0;  // Wrong key passed in.
+    }
+
+    if (len != sizeof(buf)) {
+        return 0;  // Wrong input length.
+    }
+
+    if (hash_len != SHA_DIGEST_SIZE &&
+        hash_len != SHA256_DIGEST_SIZE) {
+        return 0;  // Unsupported hash.
+    }
+
+    if (key->exponent != 3 && key->exponent != 65537) {
+        return 0;  // Unsupported exponent.
+    }
+
+    for (i = 0; i < len; ++i) {  // Copy input to local workspace.
+        buf[i] = signature[i];
+    }
+
+    modpow(key, buf);  // In-place exponentiation.
+
+    // Xor sha portion, so it all becomes 00 iff equal.
+    for (i = len - hash_len; i < len; ++i) {
+        buf[i] ^= *hash++;
+    }
+
+    // Hash resulting buf, in-place.
+    switch (hash_len) {
+        case SHA_DIGEST_SIZE:
+            padding_hash = kExpectedPadShaRsa2048;
+            SHA_hash(buf, len, buf);
+            break;
+        case SHA256_DIGEST_SIZE:
+            padding_hash = kExpectedPadSha256Rsa2048;
+            SHA256_hash(buf, len, buf);
+            break;
+        default:
+            return 0;
+    }
+
+    // Compare against expected hash value.
+    for (i = 0; i < hash_len; ++i) {
+        if (buf[i] != padding_hash[i]) {
+            return 0;
+        }
+    }
+
+    return 1;  // All checked out OK.
+}
diff --git a/libmincrypt/sha.c b/libmincrypt/sha.c
new file mode 100644
index 000000000..5bef32e42
--- /dev/null
+++ b/libmincrypt/sha.c
@@ -0,0 +1,155 @@
+/* sha.c
+**
+** Copyright 2013, The Android Open Source Project
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are met:
+**     * Redistributions of source code must retain the above copyright
+**       notice, this list of conditions and the following disclaimer.
+**     * Redistributions in binary form must reproduce the above copyright
+**       notice, this list of conditions and the following disclaimer in the
+**       documentation and/or other materials provided with the distribution.
+**     * Neither the name of Google Inc. nor the names of its contributors may
+**       be used to endorse or promote products derived from this software
+**       without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED BY Google Inc. ``AS IS'' AND ANY EXPRESS OR
+** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+** EVENT SHALL Google Inc. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+** PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+** OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+** OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+** ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+// Optimized for minimal code size.
+
+#include "mincrypt/sha.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+
+#define rol(bits, value) (((value) << (bits)) | ((value) >> (32 - (bits))))
+
+static void SHA1_Transform(SHA_CTX* ctx) {
+    uint32_t W[80];
+    uint32_t A, B, C, D, E;
+    uint8_t* p = ctx->buf;
+    int t;
+
+    for(t = 0; t < 16; ++t) {
+        uint32_t tmp =  *p++ << 24;
+        tmp |= *p++ << 16;
+        tmp |= *p++ << 8;
+        tmp |= *p++;
+        W[t] = tmp;
+    }
+
+    for(; t < 80; t++) {
+        W[t] = rol(1,W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16]);
+    }
+
+    A = ctx->state[0];
+    B = ctx->state[1];
+    C = ctx->state[2];
+    D = ctx->state[3];
+    E = ctx->state[4];
+
+    for(t = 0; t < 80; t++) {
+        uint32_t tmp = rol(5,A) + E + W[t];
+
+        if (t < 20)
+            tmp += (D^(B&(C^D))) + 0x5A827999;
+        else if ( t < 40)
+            tmp += (B^C^D) + 0x6ED9EBA1;
+        else if ( t < 60)
+            tmp += ((B&C)|(D&(B|C))) + 0x8F1BBCDC;
+        else
+            tmp += (B^C^D) + 0xCA62C1D6;
+
+        E = D;
+        D = C;
+        C = rol(30,B);
+        B = A;
+        A = tmp;
+    }
+
+    ctx->state[0] += A;
+    ctx->state[1] += B;
+    ctx->state[2] += C;
+    ctx->state[3] += D;
+    ctx->state[4] += E;
+}
+
+static const HASH_VTAB SHA_VTAB = {
+    SHA_init,
+    SHA_update,
+    SHA_final,
+    SHA_hash,
+    SHA_DIGEST_SIZE
+};
+
+void SHA_init(SHA_CTX* ctx) {
+    ctx->f = &SHA_VTAB;
+    ctx->state[0] = 0x67452301;
+    ctx->state[1] = 0xEFCDAB89;
+    ctx->state[2] = 0x98BADCFE;
+    ctx->state[3] = 0x10325476;
+    ctx->state[4] = 0xC3D2E1F0;
+    ctx->count = 0;
+}
+
+
+void SHA_update(SHA_CTX* ctx, const void* data, int len) {
+    int i = (int) (ctx->count & 63);
+    const uint8_t* p = (const uint8_t*)data;
+
+    ctx->count += len;
+
+    while (len--) {
+        ctx->buf[i++] = *p++;
+        if (i == 64) {
+            SHA1_Transform(ctx);
+            i = 0;
+        }
+    }
+}
+
+
+const uint8_t* SHA_final(SHA_CTX* ctx) {
+    uint8_t *p = ctx->buf;
+    uint64_t cnt = ctx->count * 8;
+    int i;
+
+    SHA_update(ctx, (uint8_t*)"\x80", 1);
+    while ((ctx->count & 63) != 56) {
+        SHA_update(ctx, (uint8_t*)"\0", 1);
+    }
+    for (i = 0; i < 8; ++i) {
+        uint8_t tmp = (uint8_t) (cnt >> ((7 - i) * 8));
+        SHA_update(ctx, &tmp, 1);
+    }
+
+    for (i = 0; i < 5; i++) {
+        uint32_t tmp = ctx->state[i];
+        *p++ = tmp >> 24;
+        *p++ = tmp >> 16;
+        *p++ = tmp >> 8;
+        *p++ = tmp >> 0;
+    }
+
+    return ctx->buf;
+}
+
+/* Convenience function */
+const uint8_t* SHA_hash(const void* data, int len, uint8_t* digest) {
+    SHA_CTX ctx;
+    SHA_init(&ctx);
+    SHA_update(&ctx, data, len);
+    memcpy(digest, SHA_final(&ctx), SHA_DIGEST_SIZE);
+    return digest;
+}
diff --git a/libmincrypt/sha256.c b/libmincrypt/sha256.c
new file mode 100644
index 000000000..eb6e308e8
--- /dev/null
+++ b/libmincrypt/sha256.c
@@ -0,0 +1,184 @@
+/* sha256.c
+**
+** Copyright 2013, The Android Open Source Project
+**
+** Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are met:
+**     * Redistributions of source code must retain the above copyright
+**       notice, this list of conditions and the following disclaimer.
+**     * Redistributions in binary form must reproduce the above copyright
+**       notice, this list of conditions and the following disclaimer in the
+**       documentation and/or other materials provided with the distribution.
+**     * Neither the name of Google Inc. nor the names of its contributors may
+**       be used to endorse or promote products derived from this software
+**       without specific prior written permission.
+**
+** THIS SOFTWARE IS PROVIDED BY Google Inc. ``AS IS'' AND ANY EXPRESS OR
+** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+** MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
+** EVENT SHALL Google Inc. BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+** PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+** OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+** WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+** OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+** ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+// Optimized for minimal code size.
+
+#include "mincrypt/sha256.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <stdint.h>
+
+#define ror(value, bits) (((value) >> (bits)) | ((value) << (32 - (bits))))
+#define shr(value, bits) ((value) >> (bits))
+
+static const uint32_t K[64] = {
+    0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
+    0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
+    0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
+    0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
+    0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
+    0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+    0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
+    0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
+    0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
+    0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
+    0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
+    0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+    0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
+    0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
+    0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
+    0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2 };
+
+static void SHA256_Transform(SHA256_CTX* ctx) {
+    uint32_t W[64];
+    uint32_t A, B, C, D, E, F, G, H;
+    uint8_t* p = ctx->buf;
+    int t;
+
+    for(t = 0; t < 16; ++t) {
+        uint32_t tmp =  *p++ << 24;
+        tmp |= *p++ << 16;
+        tmp |= *p++ << 8;
+        tmp |= *p++;
+        W[t] = tmp;
+    }
+
+    for(; t < 64; t++) {
+        uint32_t s0 = ror(W[t-15], 7) ^ ror(W[t-15], 18) ^ shr(W[t-15], 3);
+        uint32_t s1 = ror(W[t-2], 17) ^ ror(W[t-2], 19) ^ shr(W[t-2], 10);
+        W[t] = W[t-16] + s0 + W[t-7] + s1;
+    }
+
+    A = ctx->state[0];
+    B = ctx->state[1];
+    C = ctx->state[2];
+    D = ctx->state[3];
+    E = ctx->state[4];
+    F = ctx->state[5];
+    G = ctx->state[6];
+    H = ctx->state[7];
+
+    for(t = 0; t < 64; t++) {
+        uint32_t s0 = ror(A, 2) ^ ror(A, 13) ^ ror(A, 22);
+        uint32_t maj = (A & B) ^ (A & C) ^ (B & C);
+        uint32_t t2 = s0 + maj;
+        uint32_t s1 = ror(E, 6) ^ ror(E, 11) ^ ror(E, 25);
+        uint32_t ch = (E & F) ^ ((~E) & G);
+        uint32_t t1 = H + s1 + ch + K[t] + W[t];
+
+        H = G;
+        G = F;
+        F = E;
+        E = D + t1;
+        D = C;
+        C = B;
+        B = A;
+        A = t1 + t2;
+    }
+
+    ctx->state[0] += A;
+    ctx->state[1] += B;
+    ctx->state[2] += C;
+    ctx->state[3] += D;
+    ctx->state[4] += E;
+    ctx->state[5] += F;
+    ctx->state[6] += G;
+    ctx->state[7] += H;
+}
+
+static const HASH_VTAB SHA256_VTAB = {
+    SHA256_init,
+    SHA256_update,
+    SHA256_final,
+    SHA256_hash,
+    SHA256_DIGEST_SIZE
+};
+
+void SHA256_init(SHA256_CTX* ctx) {
+    ctx->f = &SHA256_VTAB;
+    ctx->state[0] = 0x6a09e667;
+    ctx->state[1] = 0xbb67ae85;
+    ctx->state[2] = 0x3c6ef372;
+    ctx->state[3] = 0xa54ff53a;
+    ctx->state[4] = 0x510e527f;
+    ctx->state[5] = 0x9b05688c;
+    ctx->state[6] = 0x1f83d9ab;
+    ctx->state[7] = 0x5be0cd19;
+    ctx->count = 0;
+}
+
+
+void SHA256_update(SHA256_CTX* ctx, const void* data, int len) {
+    int i = (int) (ctx->count & 63);
+    const uint8_t* p = (const uint8_t*)data;
+
+    ctx->count += len;
+
+    while (len--) {
+        ctx->buf[i++] = *p++;
+        if (i == 64) {
+            SHA256_Transform(ctx);
+            i = 0;
+        }
+    }
+}
+
+
+const uint8_t* SHA256_final(SHA256_CTX* ctx) {
+    uint8_t *p = ctx->buf;
+    uint64_t cnt = ctx->count * 8;
+    int i;
+
+    SHA256_update(ctx, (uint8_t*)"\x80", 1);
+    while ((ctx->count & 63) != 56) {
+        SHA256_update(ctx, (uint8_t*)"\0", 1);
+    }
+    for (i = 0; i < 8; ++i) {
+        uint8_t tmp = (uint8_t) (cnt >> ((7 - i) * 8));
+        SHA256_update(ctx, &tmp, 1);
+    }
+
+    for (i = 0; i < 8; i++) {
+        uint32_t tmp = ctx->state[i];
+        *p++ = tmp >> 24;
+        *p++ = tmp >> 16;
+        *p++ = tmp >> 8;
+        *p++ = tmp >> 0;
+    }
+
+    return ctx->buf;
+}
+
+/* Convenience function */
+const uint8_t* SHA256_hash(const void* data, int len, uint8_t* digest) {
+    SHA256_CTX ctx;
+    SHA256_init(&ctx);
+    SHA256_update(&ctx, data, len);
+    memcpy(digest, SHA256_final(&ctx), SHA256_DIGEST_SIZE);
+    return digest;
+}