rsa_oaep.c revision 392aa7cc7d2b122614c5393c3e357da07fd07af3
1656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project/* crypto/rsa/rsa_oaep.c */ 2656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project/* Written by Ulf Moeller. This software is distributed on an "AS IS" 3656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. */ 4656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 5656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project/* EME-OAEP as defined in RFC 2437 (PKCS #1 v2.0) */ 6656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 7656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project/* See Victor Shoup, "OAEP reconsidered," Nov. 2000, 8656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * <URL: http://www.shoup.net/papers/oaep.ps.Z> 9656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * for problems with the security proof for the 10656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * original OAEP scheme, which EME-OAEP is based on. 11656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * 12656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * A new proof can be found in E. Fujisaki, T. Okamoto, 13656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * D. Pointcheval, J. Stern, "RSA-OEAP is Still Alive!", 14656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * Dec. 2000, <URL: http://eprint.iacr.org/2000/061/>. 15656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * The new proof has stronger requirements for the 16656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * underlying permutation: "partial-one-wayness" instead 17656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * of one-wayness. For the RSA function, this is 18656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * an equivalent notion. 19656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project */ 20656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 21656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 22656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#if !defined(OPENSSL_NO_SHA) && !defined(OPENSSL_NO_SHA1) 23656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#include <stdio.h> 24656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#include "cryptlib.h" 25656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#include <openssl/bn.h> 26656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#include <openssl/rsa.h> 27656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#include <openssl/evp.h> 28656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#include <openssl/rand.h> 29656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#include <openssl/sha.h> 30656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 31221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstromstatic int MGF1(unsigned char *mask, long len, 32656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project const unsigned char *seed, long seedlen); 33656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 34656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Projectint RSA_padding_add_PKCS1_OAEP(unsigned char *to, int tlen, 35656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project const unsigned char *from, int flen, 36656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project const unsigned char *param, int plen) 37656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 38656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int i, emlen = tlen - 1; 39656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project unsigned char *db, *seed; 40656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project unsigned char *dbmask, seedmask[SHA_DIGEST_LENGTH]; 41656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 42656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (flen > emlen - 2 * SHA_DIGEST_LENGTH - 1) 43656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 44656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, 45656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE); 46656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return 0; 47656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 48656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 49656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (emlen < 2 * SHA_DIGEST_LENGTH + 1) 50656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 51656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, RSA_R_KEY_SIZE_TOO_SMALL); 52656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return 0; 53656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 54656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 55656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project to[0] = 0; 56656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project seed = to + 1; 57656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project db = to + SHA_DIGEST_LENGTH + 1; 58656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 59392aa7cc7d2b122614c5393c3e357da07fd07af3Brian Carlstrom if (!EVP_Digest((void *)param, plen, db, NULL, EVP_sha1(), NULL)) 60392aa7cc7d2b122614c5393c3e357da07fd07af3Brian Carlstrom return 0; 61656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memset(db + SHA_DIGEST_LENGTH, 0, 62656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project emlen - flen - 2 * SHA_DIGEST_LENGTH - 1); 63656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project db[emlen - flen - SHA_DIGEST_LENGTH - 1] = 0x01; 64656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memcpy(db + emlen - flen - SHA_DIGEST_LENGTH, from, (unsigned int) flen); 65656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (RAND_bytes(seed, SHA_DIGEST_LENGTH) <= 0) 66656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return 0; 67656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifdef PKCS_TESTVECT 68656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memcpy(seed, 69656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project "\xaa\xfd\x12\xf6\x59\xca\xe6\x34\x89\xb4\x79\xe5\x07\x6d\xde\xc2\xf0\x6c\xb5\x8f", 70656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 20); 71656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 72656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 7398d58bb80c64b02a33662f0ea80351d4a1535267Brian Carlstrom dbmask = OPENSSL_malloc(emlen - SHA_DIGEST_LENGTH); 7498d58bb80c64b02a33662f0ea80351d4a1535267Brian Carlstrom if (dbmask == NULL) 7598d58bb80c64b02a33662f0ea80351d4a1535267Brian Carlstrom { 7698d58bb80c64b02a33662f0ea80351d4a1535267Brian Carlstrom RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, ERR_R_MALLOC_FAILURE); 7798d58bb80c64b02a33662f0ea80351d4a1535267Brian Carlstrom return 0; 7898d58bb80c64b02a33662f0ea80351d4a1535267Brian Carlstrom } 7998d58bb80c64b02a33662f0ea80351d4a1535267Brian Carlstrom 80221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom if (MGF1(dbmask, emlen - SHA_DIGEST_LENGTH, seed, SHA_DIGEST_LENGTH) < 0) 81221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom return 0; 82656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project for (i = 0; i < emlen - SHA_DIGEST_LENGTH; i++) 83656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project db[i] ^= dbmask[i]; 84656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 85221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom if (MGF1(seedmask, SHA_DIGEST_LENGTH, db, emlen - SHA_DIGEST_LENGTH) < 0) 86221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom return 0; 87656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project for (i = 0; i < SHA_DIGEST_LENGTH; i++) 88656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project seed[i] ^= seedmask[i]; 89656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 90656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project OPENSSL_free(dbmask); 91656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return 1; 92656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 93656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 94656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Projectint RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen, 95656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project const unsigned char *from, int flen, int num, 96656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project const unsigned char *param, int plen) 97656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 98656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int i, dblen, mlen = -1; 99656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project const unsigned char *maskeddb; 100656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int lzero; 101656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project unsigned char *db = NULL, seed[SHA_DIGEST_LENGTH], phash[SHA_DIGEST_LENGTH]; 102656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project unsigned char *padded_from; 103656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int bad = 0; 104656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 105656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (--num < 2 * SHA_DIGEST_LENGTH + 1) 106656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* 'num' is the length of the modulus, i.e. does not depend on the 107656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * particular ciphertext. */ 108656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project goto decoding_err; 109656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 110656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project lzero = num - flen; 111656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (lzero < 0) 112656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 113656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* signalling this error immediately after detection might allow 114656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * for side-channel attacks (e.g. timing if 'plen' is huge 115656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * -- cf. James H. Manger, "A Chosen Ciphertext Attack on RSA Optimal 116656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * Asymmetric Encryption Padding (OAEP) [...]", CRYPTO 2001), 117656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * so we use a 'bad' flag */ 118656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bad = 1; 119656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project lzero = 0; 120656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project flen = num; /* don't overflow the memcpy to padded_from */ 121656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 122656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 123656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project dblen = num - SHA_DIGEST_LENGTH; 124656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project db = OPENSSL_malloc(dblen + num); 125656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (db == NULL) 126656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 127656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, ERR_R_MALLOC_FAILURE); 128656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return -1; 129656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 130656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 131656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* Always do this zero-padding copy (even when lzero == 0) 132656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * to avoid leaking timing info about the value of lzero. */ 133656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project padded_from = db + dblen; 134656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memset(padded_from, 0, lzero); 135656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memcpy(padded_from + lzero, from, flen); 136656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 137656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project maskeddb = padded_from + SHA_DIGEST_LENGTH; 138656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 139221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom if (MGF1(seed, SHA_DIGEST_LENGTH, maskeddb, dblen)) 140221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom return -1; 141656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project for (i = 0; i < SHA_DIGEST_LENGTH; i++) 142656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project seed[i] ^= padded_from[i]; 143656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 144221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom if (MGF1(db, dblen, seed, SHA_DIGEST_LENGTH)) 145221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom return -1; 146656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project for (i = 0; i < dblen; i++) 147656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project db[i] ^= maskeddb[i]; 148656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 149392aa7cc7d2b122614c5393c3e357da07fd07af3Brian Carlstrom if (!EVP_Digest((void *)param, plen, phash, NULL, EVP_sha1(), NULL)) 150392aa7cc7d2b122614c5393c3e357da07fd07af3Brian Carlstrom return -1; 151656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 152656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (memcmp(db, phash, SHA_DIGEST_LENGTH) != 0 || bad) 153656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project goto decoding_err; 154656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 155656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 156656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project for (i = SHA_DIGEST_LENGTH; i < dblen; i++) 157656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (db[i] != 0x00) 158656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project break; 159656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (i == dblen || db[i] != 0x01) 160656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project goto decoding_err; 161656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 162656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 163656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* everything looks OK */ 164656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 165656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project mlen = dblen - ++i; 166656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (tlen < mlen) 167656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 168656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_DATA_TOO_LARGE); 169656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project mlen = -1; 170656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 171656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 172656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memcpy(to, db + i, mlen); 173656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 174656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 175656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project OPENSSL_free(db); 176656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return mlen; 177656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 178656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Projectdecoding_err: 179656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* to avoid chosen ciphertext attacks, the error message should not reveal 180656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * which kind of decoding error happened */ 181656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_OAEP_DECODING_ERROR); 182656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (db != NULL) OPENSSL_free(db); 183656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return -1; 184656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 185656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 186656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Projectint PKCS1_MGF1(unsigned char *mask, long len, 187656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project const unsigned char *seed, long seedlen, const EVP_MD *dgst) 188656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 189656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project long i, outlen = 0; 190656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project unsigned char cnt[4]; 191656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project EVP_MD_CTX c; 192656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project unsigned char md[EVP_MAX_MD_SIZE]; 193656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int mdlen; 194ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom int rv = -1; 195656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 196656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project EVP_MD_CTX_init(&c); 197221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom mdlen = EVP_MD_size(dgst); 198221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom if (mdlen < 0) 199ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom goto err; 200656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project for (i = 0; outlen < len; i++) 201656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 202656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project cnt[0] = (unsigned char)((i >> 24) & 255); 203656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project cnt[1] = (unsigned char)((i >> 16) & 255); 204656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project cnt[2] = (unsigned char)((i >> 8)) & 255; 205656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project cnt[3] = (unsigned char)(i & 255); 206ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom if (!EVP_DigestInit_ex(&c,dgst, NULL) 207ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom || !EVP_DigestUpdate(&c, seed, seedlen) 208ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom || !EVP_DigestUpdate(&c, cnt, 4)) 209ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom goto err; 210656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (outlen + mdlen <= len) 211656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 212ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom if (!EVP_DigestFinal_ex(&c, mask + outlen, NULL)) 213ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom goto err; 214656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project outlen += mdlen; 215656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 216656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 217656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 218ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom if (!EVP_DigestFinal_ex(&c, md, NULL)) 219ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom goto err; 220656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memcpy(mask + outlen, md, len - outlen); 221656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project outlen = len; 222656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 223656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 224ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom rv = 0; 225ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom err: 226656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project EVP_MD_CTX_cleanup(&c); 227ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom return rv; 228656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 229656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 230221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstromstatic int MGF1(unsigned char *mask, long len, const unsigned char *seed, 231221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom long seedlen) 232656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 233656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return PKCS1_MGF1(mask, len, seed, seedlen, EVP_sha1()); 234656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 235656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 236