rsa_oaep.c revision ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3
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 59656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project EVP_Digest((void *)param, plen, db, NULL, EVP_sha1(), NULL); 60656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memset(db + SHA_DIGEST_LENGTH, 0, 61656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project emlen - flen - 2 * SHA_DIGEST_LENGTH - 1); 62656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project db[emlen - flen - SHA_DIGEST_LENGTH - 1] = 0x01; 63656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memcpy(db + emlen - flen - SHA_DIGEST_LENGTH, from, (unsigned int) flen); 64656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (RAND_bytes(seed, SHA_DIGEST_LENGTH) <= 0) 65656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return 0; 66656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#ifdef PKCS_TESTVECT 67656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memcpy(seed, 68656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project "\xaa\xfd\x12\xf6\x59\xca\xe6\x34\x89\xb4\x79\xe5\x07\x6d\xde\xc2\xf0\x6c\xb5\x8f", 69656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 20); 70656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 71656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 7298d58bb80c64b02a33662f0ea80351d4a1535267Brian Carlstrom dbmask = OPENSSL_malloc(emlen - SHA_DIGEST_LENGTH); 7398d58bb80c64b02a33662f0ea80351d4a1535267Brian Carlstrom if (dbmask == NULL) 7498d58bb80c64b02a33662f0ea80351d4a1535267Brian Carlstrom { 7598d58bb80c64b02a33662f0ea80351d4a1535267Brian Carlstrom RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, ERR_R_MALLOC_FAILURE); 7698d58bb80c64b02a33662f0ea80351d4a1535267Brian Carlstrom return 0; 7798d58bb80c64b02a33662f0ea80351d4a1535267Brian Carlstrom } 7898d58bb80c64b02a33662f0ea80351d4a1535267Brian Carlstrom 79221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom if (MGF1(dbmask, emlen - SHA_DIGEST_LENGTH, seed, SHA_DIGEST_LENGTH) < 0) 80221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom return 0; 81656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project for (i = 0; i < emlen - SHA_DIGEST_LENGTH; i++) 82656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project db[i] ^= dbmask[i]; 83656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 84221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom if (MGF1(seedmask, SHA_DIGEST_LENGTH, db, emlen - SHA_DIGEST_LENGTH) < 0) 85221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom return 0; 86656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project for (i = 0; i < SHA_DIGEST_LENGTH; i++) 87656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project seed[i] ^= seedmask[i]; 88656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 89656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project OPENSSL_free(dbmask); 90656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return 1; 91656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 92656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 93656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Projectint RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen, 94656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project const unsigned char *from, int flen, int num, 95656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project const unsigned char *param, int plen) 96656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 97656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int i, dblen, mlen = -1; 98656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project const unsigned char *maskeddb; 99656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int lzero; 100656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project unsigned char *db = NULL, seed[SHA_DIGEST_LENGTH], phash[SHA_DIGEST_LENGTH]; 101656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project unsigned char *padded_from; 102656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int bad = 0; 103656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 104656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (--num < 2 * SHA_DIGEST_LENGTH + 1) 105656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* 'num' is the length of the modulus, i.e. does not depend on the 106656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * particular ciphertext. */ 107656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project goto decoding_err; 108656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 109656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project lzero = num - flen; 110656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (lzero < 0) 111656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 112656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* signalling this error immediately after detection might allow 113656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * for side-channel attacks (e.g. timing if 'plen' is huge 114656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * -- cf. James H. Manger, "A Chosen Ciphertext Attack on RSA Optimal 115656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * Asymmetric Encryption Padding (OAEP) [...]", CRYPTO 2001), 116656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * so we use a 'bad' flag */ 117656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project bad = 1; 118656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project lzero = 0; 119656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project flen = num; /* don't overflow the memcpy to padded_from */ 120656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 121656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 122656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project dblen = num - SHA_DIGEST_LENGTH; 123656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project db = OPENSSL_malloc(dblen + num); 124656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (db == NULL) 125656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 126656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, ERR_R_MALLOC_FAILURE); 127656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return -1; 128656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 129656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 130656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* Always do this zero-padding copy (even when lzero == 0) 131656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * to avoid leaking timing info about the value of lzero. */ 132656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project padded_from = db + dblen; 133656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memset(padded_from, 0, lzero); 134656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memcpy(padded_from + lzero, from, flen); 135656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 136656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project maskeddb = padded_from + SHA_DIGEST_LENGTH; 137656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 138221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom if (MGF1(seed, SHA_DIGEST_LENGTH, maskeddb, dblen)) 139221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom return -1; 140656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project for (i = 0; i < SHA_DIGEST_LENGTH; i++) 141656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project seed[i] ^= padded_from[i]; 142656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 143221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom if (MGF1(db, dblen, seed, SHA_DIGEST_LENGTH)) 144221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom return -1; 145656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project for (i = 0; i < dblen; i++) 146656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project db[i] ^= maskeddb[i]; 147656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 148656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project EVP_Digest((void *)param, plen, phash, NULL, EVP_sha1(), NULL); 149656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 150656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (memcmp(db, phash, SHA_DIGEST_LENGTH) != 0 || bad) 151656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project goto decoding_err; 152656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 153656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 154656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project for (i = SHA_DIGEST_LENGTH; i < dblen; i++) 155656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (db[i] != 0x00) 156656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project break; 157656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (i == dblen || db[i] != 0x01) 158656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project goto decoding_err; 159656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 160656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 161656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* everything looks OK */ 162656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 163656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project mlen = dblen - ++i; 164656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (tlen < mlen) 165656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 166656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_DATA_TOO_LARGE); 167656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project mlen = -1; 168656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 169656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 170656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memcpy(to, db + i, mlen); 171656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 172656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 173656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project OPENSSL_free(db); 174656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return mlen; 175656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 176656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Projectdecoding_err: 177656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project /* to avoid chosen ciphertext attacks, the error message should not reveal 178656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project * which kind of decoding error happened */ 179656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_OAEP_DECODING_ERROR); 180656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (db != NULL) OPENSSL_free(db); 181656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return -1; 182656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 183656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 184656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Projectint PKCS1_MGF1(unsigned char *mask, long len, 185656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project const unsigned char *seed, long seedlen, const EVP_MD *dgst) 186656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 187656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project long i, outlen = 0; 188656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project unsigned char cnt[4]; 189656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project EVP_MD_CTX c; 190656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project unsigned char md[EVP_MAX_MD_SIZE]; 191656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project int mdlen; 192ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom int rv = -1; 193656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 194656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project EVP_MD_CTX_init(&c); 195221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom mdlen = EVP_MD_size(dgst); 196221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom if (mdlen < 0) 197ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom goto err; 198656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project for (i = 0; outlen < len; i++) 199656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 200656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project cnt[0] = (unsigned char)((i >> 24) & 255); 201656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project cnt[1] = (unsigned char)((i >> 16) & 255); 202656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project cnt[2] = (unsigned char)((i >> 8)) & 255; 203656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project cnt[3] = (unsigned char)(i & 255); 204ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom if (!EVP_DigestInit_ex(&c,dgst, NULL) 205ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom || !EVP_DigestUpdate(&c, seed, seedlen) 206ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom || !EVP_DigestUpdate(&c, cnt, 4)) 207ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom goto err; 208656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project if (outlen + mdlen <= len) 209656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 210ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom if (!EVP_DigestFinal_ex(&c, mask + outlen, NULL)) 211ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom goto err; 212656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project outlen += mdlen; 213656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 214656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project else 215656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 216ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom if (!EVP_DigestFinal_ex(&c, md, NULL)) 217ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom goto err; 218656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project memcpy(mask + outlen, md, len - outlen); 219656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project outlen = len; 220656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 221656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 222ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom rv = 0; 223ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom err: 224656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project EVP_MD_CTX_cleanup(&c); 225ee7afb3c942c4eefef6ed06201eafaf8ec58e2e3Brian Carlstrom return rv; 226656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 227656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project 228221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstromstatic int MGF1(unsigned char *mask, long len, const unsigned char *seed, 229221304ee937bc0910948a8be1320cb8cc4eb6d36Brian Carlstrom long seedlen) 230656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project { 231656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project return PKCS1_MGF1(mask, len, seed, seedlen, EVP_sha1()); 232656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project } 233656d9c7f52f88b3a3daccafa7655dec086c4756eThe Android Open Source Project#endif 234