1 files changed, 220 insertions, 0 deletions

diff --git a/src/lib/libcrypto/rsa/rsa_oaep.c b/src/lib/libcrypto/rsa/rsa_oaep.c
new file mode 100644
index 0000000000..4d30c9d2d3
--- /dev/null
+++ b/src/lib/libcrypto/rsa/rsa_oaep.c
@@ -0,0 +1,220 @@
+/* crypto/rsa/rsa_oaep.c */
+/* Written by Ulf Moeller. This software is distributed on an "AS IS"
+   basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. */
+
+/* EME-OAEP as defined in RFC 2437 (PKCS #1 v2.0) */
+
+/* See Victor Shoup, "OAEP reconsidered," Nov. 2000,
+ * <URL: http://www.shoup.net/papers/oaep.ps.Z>
+ * for problems with the security proof for the
+ * original OAEP scheme, which EME-OAEP is based on.
+ * 
+ * A new proof can be found in E. Fujisaki, T. Okamoto,
+ * D. Pointcheval, J. Stern, "RSA-OEAP is Still Alive!",
+ * Dec. 2000, <URL: http://eprint.iacr.org/2000/061/>.
+ * The new proof has stronger requirements for the
+ * underlying permutation: "partial-one-wayness" instead
+ * of one-wayness.  For the RSA function, this is
+ * an equivalent notion.
+ */
+
+
+#if !defined(OPENSSL_NO_SHA) && !defined(OPENSSL_NO_SHA1)
+#include <stdio.h>
+#include "cryptlib.h"
+#include <openssl/bn.h>
+#include <openssl/rsa.h>
+#include <openssl/evp.h>
+#include <openssl/rand.h>
+#include <openssl/sha.h>
+
+int MGF1(unsigned char *mask, long len,
+        const unsigned char *seed, long seedlen);
+
+int RSA_padding_add_PKCS1_OAEP(unsigned char *to, int tlen,
+        const unsigned char *from, int flen,
+        const unsigned char *param, int plen)
+        {
+        int i, emlen = tlen - 1;
+        unsigned char *db, *seed;
+        unsigned char *dbmask, seedmask[SHA_DIGEST_LENGTH];
+
+        if (flen > emlen - 2 * SHA_DIGEST_LENGTH - 1)
+                {
+                RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP,
+                   RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE);
+                return 0;
+                }
+
+        if (emlen < 2 * SHA_DIGEST_LENGTH + 1)
+                {
+                RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, RSA_R_KEY_SIZE_TOO_SMALL);
+                return 0;
+                }
+
+        dbmask = OPENSSL_malloc(emlen - SHA_DIGEST_LENGTH);
+        if (dbmask == NULL)
+                {
+                RSAerr(RSA_F_RSA_PADDING_ADD_PKCS1_OAEP, ERR_R_MALLOC_FAILURE);
+                return 0;
+                }
+
+        to[0] = 0;
+        seed = to + 1;
+        db = to + SHA_DIGEST_LENGTH + 1;
+
+        EVP_Digest((void *)param, plen, db, NULL, EVP_sha1(), NULL);
+        memset(db + SHA_DIGEST_LENGTH, 0,
+                emlen - flen - 2 * SHA_DIGEST_LENGTH - 1);
+        db[emlen - flen - SHA_DIGEST_LENGTH - 1] = 0x01;
+        memcpy(db + emlen - flen - SHA_DIGEST_LENGTH, from, (unsigned int) flen);
+        if (RAND_bytes(seed, SHA_DIGEST_LENGTH) <= 0)
+                return 0;
+#ifdef PKCS_TESTVECT
+        memcpy(seed,
+           "\xaa\xfd\x12\xf6\x59\xca\xe6\x34\x89\xb4\x79\xe5\x07\x6d\xde\xc2\xf0\x6c\xb5\x8f",
+           20);
+#endif
+
+        MGF1(dbmask, emlen - SHA_DIGEST_LENGTH, seed, SHA_DIGEST_LENGTH);
+        for (i = 0; i < emlen - SHA_DIGEST_LENGTH; i++)
+                db[i] ^= dbmask[i];
+
+        MGF1(seedmask, SHA_DIGEST_LENGTH, db, emlen - SHA_DIGEST_LENGTH);
+        for (i = 0; i < SHA_DIGEST_LENGTH; i++)
+                seed[i] ^= seedmask[i];
+
+        OPENSSL_free(dbmask);
+        return 1;
+        }
+
+int RSA_padding_check_PKCS1_OAEP(unsigned char *to, int tlen,
+        const unsigned char *from, int flen, int num,
+        const unsigned char *param, int plen)
+        {
+        int i, dblen, mlen = -1;
+        const unsigned char *maskeddb;
+        int lzero;
+        unsigned char *db = NULL, seed[SHA_DIGEST_LENGTH], phash[SHA_DIGEST_LENGTH];
+        unsigned char *padded_from;
+        int bad = 0;
+
+        if (--num < 2 * SHA_DIGEST_LENGTH + 1)
+                /* 'num' is the length of the modulus, i.e. does not depend on the
+                 * particular ciphertext. */
+                goto decoding_err;
+
+        lzero = num - flen;
+        if (lzero < 0)
+                {
+                /* signalling this error immediately after detection might allow
+                 * for side-channel attacks (e.g. timing if 'plen' is huge
+                 * -- cf. James H. Manger, "A Chosen Ciphertext Attack on RSA Optimal
+                 * Asymmetric Encryption Padding (OAEP) [...]", CRYPTO 2001),
+                 * so we use a 'bad' flag */
+                bad = 1;
+                lzero = 0;
+                flen = num; /* don't overflow the memcpy to padded_from */
+                }
+
+        dblen = num - SHA_DIGEST_LENGTH;
+        db = OPENSSL_malloc(dblen + num);
+        if (db == NULL)
+                {
+                RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, ERR_R_MALLOC_FAILURE);
+                return -1;
+                }
+
+        /* Always do this zero-padding copy (even when lzero == 0)
+         * to avoid leaking timing info about the value of lzero. */
+        padded_from = db + dblen;
+        memset(padded_from, 0, lzero);
+        memcpy(padded_from + lzero, from, flen);
+
+        maskeddb = padded_from + SHA_DIGEST_LENGTH;
+
+        MGF1(seed, SHA_DIGEST_LENGTH, maskeddb, dblen);
+        for (i = 0; i < SHA_DIGEST_LENGTH; i++)
+                seed[i] ^= padded_from[i];
+  
+        MGF1(db, dblen, seed, SHA_DIGEST_LENGTH);
+        for (i = 0; i < dblen; i++)
+                db[i] ^= maskeddb[i];
+
+        EVP_Digest((void *)param, plen, phash, NULL, EVP_sha1(), NULL);
+
+        if (memcmp(db, phash, SHA_DIGEST_LENGTH) != 0 || bad)
+                goto decoding_err;
+        else
+                {
+                for (i = SHA_DIGEST_LENGTH; i < dblen; i++)
+                        if (db[i] != 0x00)
+                                break;
+                if (i == dblen || db[i] != 0x01)
+                        goto decoding_err;
+                else
+                        {
+                        /* everything looks OK */
+
+                        mlen = dblen - ++i;
+                        if (tlen < mlen)
+                                {
+                                RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_DATA_TOO_LARGE);
+                                mlen = -1;
+                                }
+                        else
+                                memcpy(to, db + i, mlen);
+                        }
+                }
+        OPENSSL_free(db);
+        return mlen;
+
+decoding_err:
+        /* to avoid chosen ciphertext attacks, the error message should not reveal
+         * which kind of decoding error happened */
+        RSAerr(RSA_F_RSA_PADDING_CHECK_PKCS1_OAEP, RSA_R_OAEP_DECODING_ERROR);
+        if (db != NULL) OPENSSL_free(db);
+        return -1;
+        }
+
+int PKCS1_MGF1(unsigned char *mask, long len,
+        const unsigned char *seed, long seedlen, const EVP_MD *dgst)
+        {
+        long i, outlen = 0;
+        unsigned char cnt[4];
+        EVP_MD_CTX c;
+        unsigned char md[EVP_MAX_MD_SIZE];
+        int mdlen;
+
+        EVP_MD_CTX_init(&c);
+        mdlen = M_EVP_MD_size(dgst);
+        for (i = 0; outlen < len; i++)
+                {
+                cnt[0] = (unsigned char)((i >> 24) & 255);
+                cnt[1] = (unsigned char)((i >> 16) & 255);
+                cnt[2] = (unsigned char)((i >> 8)) & 255;
+                cnt[3] = (unsigned char)(i & 255);
+                EVP_DigestInit_ex(&c,dgst, NULL);
+                EVP_DigestUpdate(&c, seed, seedlen);
+                EVP_DigestUpdate(&c, cnt, 4);
+                if (outlen + mdlen <= len)
+                        {
+                        EVP_DigestFinal_ex(&c, mask + outlen, NULL);
+                        outlen += mdlen;
+                        }
+                else
+                        {
+                        EVP_DigestFinal_ex(&c, md, NULL);
+                        memcpy(mask + outlen, md, len - outlen);
+                        outlen = len;
+                        }
+                }
+        EVP_MD_CTX_cleanup(&c);
+        return 0;
+        }
+
+int MGF1(unsigned char *mask, long len, const unsigned char *seed, long seedlen)
+        {
+        return PKCS1_MGF1(mask, len, seed, seedlen, EVP_sha1());
+        }
+#endif