support e=65537 for libmincrypt, DumpPublicKey
The output produced by DumpPublicKey now has a version tag on each
line (ie, each key). The existing keys are retroactively dubbed
"version 1", and we add a version 2 for 2048-bit e=65537 keys.
Change-Id: I204ec615c8f2346670220a1aeb99269e4abd5f81
diff --git a/Android.mk b/Android.mk
index b09a941..f58eab9 100644
--- a/Android.mk
+++ b/Android.mk
@@ -4,13 +4,13 @@
include $(CLEAR_VARS)
LOCAL_MODULE := libmincrypt
-LOCAL_SRC_FILES := rsa.c sha.c
+LOCAL_SRC_FILES := rsa.c rsa_e_3.c rsa_e_f4.c sha.c
include $(BUILD_STATIC_LIBRARY)
include $(CLEAR_VARS)
LOCAL_MODULE := libmincrypt
-LOCAL_SRC_FILES := rsa.c sha.c
+LOCAL_SRC_FILES := rsa.c rsa_e_3.c rsa_e_f4.c sha.c
include $(BUILD_HOST_STATIC_LIBRARY)
diff --git a/include/mincrypt/rsa.h b/include/mincrypt/rsa.h
index 7d7d571..d7429fc 100644
--- a/include/mincrypt/rsa.h
+++ b/include/mincrypt/rsa.h
@@ -13,14 +13,14 @@
** 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
+** 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
+** 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
+** 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.
*/
@@ -42,6 +42,7 @@
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,
diff --git a/rsa.c b/rsa.c
index d7124fb..b4ee6af 100644
--- a/rsa.c
+++ b/rsa.c
@@ -1,6 +1,6 @@
/* rsa.c
**
-** Copyright 2008, The Android Open Source Project
+** 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:
@@ -13,186 +13,42 @@
** 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
+** 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
+** 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
+** 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"
-/* 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;
- }
-}
+int RSA_e_f4_verify(const RSAPublicKey* key,
+ const uint8_t* signature,
+ const int len,
+ const uint8_t* sha);
-/* 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 */
-}
+int RSA_e_3_verify(const RSAPublicKey *key,
+ const uint8_t *signature,
+ const int len,
+ const uint8_t *sha);
-/* 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 modpow3(const RSAPublicKey *key,
- uint8_t* inout) {
- uint32_t a[RSANUMWORDS];
- uint32_t aR[RSANUMWORDS];
- uint32_t aaR[RSANUMWORDS];
- uint32_t *aaa = aR; /* Re-use location. */
- 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;
- }
-
- 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 padding[RSANUMBYTES - SHA_DIGEST_SIZE] = {
- 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
-};
-
-/* Verify a 2048 bit RSA PKCS1.5 signature against an expected SHA-1 hash.
-** Returns 0 on failure, 1 on success.
-*/
int RSA_verify(const RSAPublicKey *key,
const uint8_t *signature,
const int len,
const uint8_t *sha) {
- uint8_t buf[RSANUMBYTES];
- int i;
-
- if (key->len != RSANUMWORDS) {
- return 0; /* Wrong key passed in. */
- }
-
- if (len != sizeof(buf)) {
- return 0; /* Wrong input length. */
- }
-
- for (i = 0; i < len; ++i) {
- buf[i] = signature[i];
- }
-
- modpow3(key, buf);
-
- /* Check pkcs1.5 padding bytes. */
- for (i = 0; i < (int) sizeof(padding); ++i) {
- if (buf[i] != padding[i]) {
+ switch (key->exponent) {
+ case 3:
+ return RSA_e_3_verify(key, signature, len, sha);
+ break;
+ case 65537:
+ return RSA_e_f4_verify(key, signature, len, sha);
+ break;
+ default:
return 0;
- }
}
-
- /* Check sha digest matches. */
- for (; i < len; ++i) {
- if (buf[i] != *sha++) {
- return 0;
- }
- }
-
- return 1;
}
diff --git a/rsa_e_3.c b/rsa_e_3.c
new file mode 100644
index 0000000..c8c02c4
--- /dev/null
+++ b/rsa_e_3.c
@@ -0,0 +1,202 @@
+/* rsa_e_3.c
+**
+** 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.
+*/
+
+#include "mincrypt/rsa.h"
+#include "mincrypt/sha.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 modpow3(const RSAPublicKey *key,
+ uint8_t* inout) {
+ uint32_t a[RSANUMWORDS];
+ uint32_t aR[RSANUMWORDS];
+ uint32_t aaR[RSANUMWORDS];
+ uint32_t *aaa = aR; /* Re-use location. */
+ 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;
+ }
+
+ 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 padding[RSANUMBYTES - SHA_DIGEST_SIZE] = {
+ 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
+};
+
+/* Verify a 2048 bit RSA e=3 PKCS1.5 signature against an expected SHA-1 hash.
+** Returns 0 on failure, 1 on success.
+*/
+int RSA_e_3_verify(const RSAPublicKey *key,
+ const uint8_t *signature,
+ const int len,
+ const uint8_t *sha) {
+ uint8_t buf[RSANUMBYTES];
+ int i;
+
+ if (key->len != RSANUMWORDS) {
+ return 0; /* Wrong key passed in. */
+ }
+
+ if (len != sizeof(buf)) {
+ return 0; /* Wrong input length. */
+ }
+
+ if (key->exponent != 3) {
+ return 0; // Wrong exponent.
+ }
+
+ for (i = 0; i < len; ++i) {
+ buf[i] = signature[i];
+ }
+
+ modpow3(key, buf);
+
+ /* Check pkcs1.5 padding bytes. */
+ for (i = 0; i < (int) sizeof(padding); ++i) {
+ if (buf[i] != padding[i]) {
+ return 0;
+ }
+ }
+
+ /* Check sha digest matches. */
+ for (; i < len; ++i) {
+ if (buf[i] != *sha++) {
+ return 0;
+ }
+ }
+
+ return 1;
+}
diff --git a/rsa_e_f4.c b/rsa_e_f4.c
new file mode 100644
index 0000000..6701bcc
--- /dev/null
+++ b/rsa_e_f4.c
@@ -0,0 +1,196 @@
+/* rsa_e_f4.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"
+
+// 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 modpowF4(const RSAPublicKey* key,
+ uint8_t* inout) {
+ uint32_t a[RSANUMWORDS];
+ uint32_t aR[RSANUMWORDS];
+ uint32_t aaR[RSANUMWORDS];
+ uint32_t* aaa = aaR; // Re-use location.
+ 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;
+ }
+
+ 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
+
+ // 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 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,0x05,0x00,0x04,0x14,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+};
+*/
+
+// SHA-1 of PKCS1.5 signature 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
+};
+
+// Verify a 2048 bit RSA e=65537 PKCS1.5 signature against an expected
+// SHA-1 hash. Returns 0 on failure, 1 on success.
+int RSA_e_f4_verify(const RSAPublicKey* key,
+ const uint8_t* signature,
+ const int len,
+ const uint8_t* sha) {
+ uint8_t buf[RSANUMBYTES];
+ int i;
+
+ if (key->len != RSANUMWORDS) {
+ return 0; // Wrong key passed in.
+ }
+
+ if (len != sizeof(buf)) {
+ return 0; // Wrong input length.
+ }
+
+ if (key->exponent != 65537) {
+ return 0; // Wrong exponent.
+ }
+
+ for (i = 0; i < len; ++i) { // Copy input to local workspace.
+ buf[i] = signature[i];
+ }
+
+ modpowF4(key, buf); // In-place exponentiation.
+
+ // Xor sha portion, so it all becomes 00 iff equal.
+ for (i = len - SHA_DIGEST_SIZE; i < len; ++i) {
+ buf[i] ^= *sha++;
+ }
+
+ // Hash resulting buf, in-place.
+ SHA(buf, len, buf);
+
+ // Compare against expected hash value.
+ for (i = 0; i < SHA_DIGEST_SIZE; ++i) {
+ if (buf[i] != kExpectedPadShaRsa2048[i]) {
+ return 0;
+ }
+ }
+
+ return 1; // All checked out OK.
+}
diff --git a/tools/DumpPublicKey.java b/tools/DumpPublicKey.java
index d2935e0..b83a757 100644
--- a/tools/DumpPublicKey.java
+++ b/tools/DumpPublicKey.java
@@ -34,27 +34,42 @@
class DumpPublicKey {
/**
* @param key to perform sanity checks on
+ * @return version number of key. Supported versions are:
+ * 1: 2048-bit key with e=3
+ * 2: 2048-bit key with e=65537
* @throws Exception if the key has the wrong size or public exponent
+
*/
- static void check(RSAPublicKey key) throws Exception {
+ static int check(RSAPublicKey key) throws Exception {
BigInteger pubexp = key.getPublicExponent();
BigInteger modulus = key.getModulus();
+ int version;
- if (!pubexp.equals(BigInteger.valueOf(3)))
- throw new Exception("Public exponent should be 3 but is " +
- pubexp.toString(10) + ".");
+ if (pubexp.equals(BigInteger.valueOf(3))) {
+ version = 1;
+ } else if (pubexp.equals(BigInteger.valueOf(65537))) {
+ version = 2;
+ } else {
+ throw new Exception("Public exponent should be 3 or 65537 but is " +
+ pubexp.toString(10) + ".");
+ }
- if (modulus.bitLength() != 2048)
+ if (modulus.bitLength() != 2048) {
throw new Exception("Modulus should be 2048 bits long but is " +
modulus.bitLength() + " bits.");
+ }
+
+ return version;
}
/**
* @param key to output
- * @return a C initializer representing this public key.
+ * @return a String representing this public key. If the key is a
+ * version 1 key, the string will be a C initializer; this is
+ * not true for newer key versions.
*/
static String print(RSAPublicKey key) throws Exception {
- check(key);
+ int version = check(key);
BigInteger N = key.getModulus();
@@ -62,6 +77,12 @@
int nwords = N.bitLength() / 32; // # of 32 bit integers in modulus
+ if (version > 1) {
+ result.append("v");
+ result.append(Integer.toString(version));
+ result.append(" ");
+ }
+
result.append("{");
result.append(nwords);
