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Diffstat (limited to '')
-rw-r--r-- | twmincrypt/twrsa.c | 199 |
1 files changed, 0 insertions, 199 deletions
diff --git a/twmincrypt/twrsa.c b/twmincrypt/twrsa.c deleted file mode 100644 index 52d6bfbc2..000000000 --- a/twmincrypt/twrsa.c +++ /dev/null @@ -1,199 +0,0 @@ -/* rsa.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 "twrsa.h" -#include "twsha.h" -#include "common.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 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]) { - return 0; - } - } - - /* Check sha digest matches. */ - for (; i < len; ++i) { - if (buf[i] != *sha++) { - return 0; - } - } - - return 1; -} |