/* $OpenBSD: cryptosoft.c,v 1.9 2000/06/06 06:49:47 deraadt Exp $ */ /* * The author of this code is Angelos D. Keromytis (angelos@cis.upenn.edu) * * This code was written by Angelos D. Keromytis in Athens, Greece, in * February 2000. Network Security Technologies Inc. (NSTI) kindly * supported the development of this code. * * Copyright (c) 2000 Angelos D. Keromytis * * Permission to use, copy, and modify this software without fee * is hereby granted, provided that this entire notice is included in * all source code copies of any software which is or includes a copy or * modification of this software. * * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR * PURPOSE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include u_int8_t hmac_ipad_buffer[64] = { 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36, 0x36 }; u_int8_t hmac_opad_buffer[64] = { 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C, 0x5C }; struct swcr_data **swcr_sessions = NULL; u_int32_t swcr_sesnum = 0; int32_t swcr_id = -1; /* * Apply a symmetric encryption/decryption algorithm. */ int swcr_encdec(struct cryptodesc *crd, struct swcr_data *sw, caddr_t buf, int outtype) { unsigned char iv[EALG_MAX_BLOCK_LEN], blk[EALG_MAX_BLOCK_LEN], *idat; unsigned char *ivp, piv[EALG_MAX_BLOCK_LEN]; struct enc_xform *exf; int i, k, j, blks; struct mbuf *m; exf = sw->sw_exf; blks = exf->blocksize; /* Check for non-padded data */ if (crd->crd_len % blks) return EINVAL; if (outtype == CRYPTO_BUF_CONTIG) { if (crd->crd_flags & CRD_F_ENCRYPT) { /* IV explicitly provided ? */ if (crd->crd_flags & CRD_F_IV_EXPLICIT) bcopy(crd->crd_iv, sw->sw_iv, blks); if (!(crd->crd_flags & CRD_F_IV_PRESENT)) bcopy(sw->sw_iv, buf + crd->crd_inject, blks); for (i = crd->crd_skip; i < crd->crd_skip + crd->crd_len; i += blks) { /* XOR with the IV/previous block, as appropriate. */ if (i == crd->crd_skip) for (k = 0; k < blks; k++) buf[i + k] ^= sw->sw_iv[k]; else for (k = 0; k < blks; k++) buf[i + k] ^= buf[i + k - blks]; exf->encrypt(sw->sw_kschedule, buf + i); } /* Keep the last block */ bcopy(buf + crd->crd_len - blks, sw->sw_iv, blks); } else /* Decrypt */ { /* IV explicitly provided ? */ if (crd->crd_flags & CRD_F_IV_EXPLICIT) bcopy(crd->crd_iv, sw->sw_iv, blks); else /* IV preceeds data */ bcopy(buf + crd->crd_inject, sw->sw_iv, blks); /* * Start at the end, so we don't need to keep the encrypted * block as the IV for the next block. */ for (i = crd->crd_skip + crd->crd_len - blks; i >= crd->crd_skip; i -= blks) { exf->decrypt(sw->sw_kschedule, buf + i); /* XOR with the IV/previous block, as appropriate */ if (i == crd->crd_skip) for (k = 0; k < blks; k++) buf[i + k] ^= sw->sw_iv[k]; else for (k = 0; k < blks; k++) buf[i + k] ^= buf[i + k - blks]; } } return 0; /* Done with contiguous buffer encryption/decryption */ } else /* mbuf */ { m = (struct mbuf *) buf; /* Initialize the IV */ if (crd->crd_flags & CRD_F_ENCRYPT) { /* IV explicitly provided ? */ if (crd->crd_flags & CRD_F_IV_EXPLICIT) bcopy(crd->crd_iv, iv, blks); else bcopy(sw->sw_iv, iv, blks); /* Use IV from context */ /* Do we need to write the IV */ if (!(crd->crd_flags & CRD_F_IV_PRESENT)) m_copyback(m, crd->crd_inject, blks, iv); } else /* Decryption */ { /* IV explicitly provided ? */ if (crd->crd_flags & CRD_F_IV_EXPLICIT) bcopy(crd->crd_iv, iv, blks); else m_copydata(m, crd->crd_inject, blks, iv); /* Get IV off mbuf */ } ivp = iv; /* Find beginning of data */ m = m_getptr(m, crd->crd_skip, &k); if (m == NULL) return EINVAL; i = crd->crd_len; while (i > 0) { /* * If there's insufficient data at the end of an mbuf, we have * to do some copying. */ if ((m->m_len < k + blks) && (m->m_len != k)) { m_copydata(m, k, blks, blk); /* Actual encryption/decryption */ if (crd->crd_flags & CRD_F_ENCRYPT) { /* XOR with previous block */ for (j = 0; j < blks; j++) blk[j] ^= ivp[j]; exf->encrypt(sw->sw_kschedule, blk); /* Keep encrypted block for XOR'ing with next block */ bcopy(blk, iv, blks); ivp = iv; } else /* decrypt */ { /* Keep encrypted block for XOR'ing with next block */ if (ivp == iv) bcopy(blk, piv, blks); else bcopy(blk, iv, blks); exf->decrypt(sw->sw_kschedule, blk); /* XOR with previous block */ for (j = 0; j < blks; j++) blk[j] ^= ivp[j]; if (ivp == iv) bcopy(piv, iv, blks); else ivp = iv; } /* Copy back decrypted block */ m_copyback(m, k, blks, blk); /* Advance pointer */ m = m_getptr(m, k + blks, &k); if (m == NULL) return EINVAL; i -= blks; /* Could be done... */ if (i == 0) break; } /* Skip possibly empty mbufs */ if (k == m->m_len) { for (m = m->m_next; m && m->m_len == 0; m = m->m_next) ; k = 0; } /* Sanity check */ if (m == NULL) return EINVAL; /* * Warning: idat may point to garbage here, but we only use it * in the while() loop, only if there are indeed enough data. */ idat = mtod(m, unsigned char *) + k; while ((m->m_len >= k + blks) && (i > 0)) { if (crd->crd_flags & CRD_F_ENCRYPT) { /* XOR with previous block/IV */ for (j = 0; j < blks; j++) idat[j] ^= ivp[j]; exf->encrypt(sw->sw_kschedule, idat); ivp = idat; } else /* decrypt */ { /* * Keep encrypted block to be used in next block's * processing. */ if (ivp == iv) bcopy(idat, piv, blks); else bcopy(idat, iv, blks); exf->decrypt(sw->sw_kschedule, idat); /* XOR with previous block/IV */ for (j = 0; j < blks; j++) idat[j] ^= ivp[j]; if (ivp == iv) bcopy(piv, iv, blks); else ivp = iv; } idat += blks; k += blks; i -= blks; } } /* Keep the last block */ if (crd->crd_flags & CRD_F_ENCRYPT) bcopy(ivp, sw->sw_iv, blks); return 0; /* Done with mbuf encryption/decryption */ } /* Unreachable */ return EINVAL; } /* * Compute keyed-hash authenticator. */ int swcr_authcompute(struct cryptodesc *crd, struct swcr_data *sw, caddr_t buf, int outtype) { unsigned char aalg[AALG_MAX_RESULT_LEN]; struct auth_hash *axf; union authctx ctx; int err; if (sw->sw_ictx == 0) return EINVAL; axf = sw->sw_axf; bcopy(sw->sw_ictx, &ctx, axf->ctxsize); if (outtype == CRYPTO_BUF_CONTIG) { axf->Update(&ctx, buf + crd->crd_skip, crd->crd_len); axf->Final(aalg, &ctx); } else { err = m_apply((struct mbuf *) buf, crd->crd_skip, crd->crd_len, (int (*)(caddr_t, caddr_t, unsigned int)) axf->Update, (caddr_t) &ctx); if (err) return err; axf->Final(aalg, &ctx); } /* HMAC processing */ switch (sw->sw_alg) { case CRYPTO_MD5_HMAC96: case CRYPTO_SHA1_HMAC96: case CRYPTO_RIPEMD160_HMAC96: if (sw->sw_octx == NULL) return EINVAL; bcopy(sw->sw_octx, &ctx, axf->ctxsize); axf->Update(&ctx, aalg, axf->hashsize); axf->Final(aalg, &ctx); break; } /* Inject the authentication data */ if (outtype == CRYPTO_BUF_CONTIG) bcopy(aalg, buf + crd->crd_inject, axf->authsize); else m_copyback((struct mbuf *) buf, crd->crd_inject, axf->authsize, aalg); return 0; } /* * Generate a new software session. */ int swcr_newsession(u_int32_t *sid, struct cryptoini *cri) { struct swcr_data **swd; struct auth_hash *axf; struct enc_xform *txf; u_int32_t i; int k; if ((sid == NULL) || (cri == NULL)) return EINVAL; if (swcr_sessions) for (i = 1; i < swcr_sesnum; i++) if (swcr_sessions[i] == NULL) break; if ((swcr_sessions == NULL) || (i == swcr_sesnum)) { if (swcr_sessions == NULL) { i = 1; /* We leave swcr_sessions[0] empty */ swcr_sesnum = CRYPTO_SW_SESSIONS; } else swcr_sesnum *= 2; MALLOC(swd, struct swcr_data **, swcr_sesnum * sizeof(struct swcr_data *), M_XDATA, M_DONTWAIT); if (swd == NULL) { /* Reset session number */ if (swcr_sesnum == CRYPTO_SW_SESSIONS) swcr_sesnum = 0; else swcr_sesnum /= 2; return ENOBUFS; } bzero(swd, swcr_sesnum * sizeof(struct swcr_data *)); /* Copy existing sessions */ if (swcr_sessions) { bcopy(swcr_sessions, swd, (swcr_sesnum / 2) * sizeof(struct swcr_data *)); FREE(swcr_sessions, M_XDATA); } swcr_sessions = swd; } swd = &swcr_sessions[i]; *sid = i; while (cri) { MALLOC(*swd, struct swcr_data *, sizeof(struct swcr_data), M_XDATA, M_DONTWAIT); if (*swd == NULL) { swcr_freesession(i); return ENOBUFS; } bzero(*swd, sizeof(struct swcr_data)); switch (cri->cri_alg) { case CRYPTO_DES_CBC: txf = &enc_xform_des; goto enccommon; case CRYPTO_3DES_CBC: txf = &enc_xform_3des; goto enccommon; case CRYPTO_BLF_CBC: txf = &enc_xform_blf; goto enccommon; case CRYPTO_CAST_CBC: txf = &enc_xform_cast5; goto enccommon; case CRYPTO_SKIPJACK_CBC: txf = &enc_xform_skipjack; enccommon: txf->setkey(&((*swd)->sw_kschedule), cri->cri_key, cri->cri_klen / 8); MALLOC((*swd)->sw_iv, u_int8_t *, txf->blocksize, M_XDATA, M_DONTWAIT); if ((*swd)->sw_iv == NULL) { swcr_freesession(i); return ENOBUFS; } (*swd)->sw_exf = txf; get_random_bytes((*swd)->sw_iv, txf->blocksize); break; case CRYPTO_MD5_HMAC96: axf = &auth_hash_hmac_md5_96; goto authcommon; case CRYPTO_SHA1_HMAC96: axf = &auth_hash_hmac_sha1_96; goto authcommon; case CRYPTO_RIPEMD160_HMAC96: axf = &auth_hash_hmac_ripemd_160_96; authcommon: MALLOC((*swd)->sw_ictx, u_int8_t *, axf->ctxsize, M_XDATA, M_DONTWAIT); if ((*swd)->sw_ictx == NULL) { swcr_freesession(i); return ENOBUFS; } MALLOC((*swd)->sw_octx, u_int8_t *, axf->ctxsize, M_XDATA, M_DONTWAIT); if ((*swd)->sw_octx == NULL) { swcr_freesession(i); return ENOBUFS; } for (k = 0; k < cri->cri_klen / 8; k++) cri->cri_key[k] ^= HMAC_IPAD_VAL; axf->Init((*swd)->sw_ictx); axf->Update((*swd)->sw_ictx, cri->cri_key, cri->cri_klen / 8); axf->Update((*swd)->sw_ictx, hmac_ipad_buffer, HMAC_BLOCK_LEN - (cri->cri_klen / 8)); for (k = 0; k < cri->cri_klen / 8; k++) cri->cri_key[k] ^= (HMAC_IPAD_VAL ^ HMAC_OPAD_VAL); axf->Init((*swd)->sw_octx); axf->Update((*swd)->sw_octx, cri->cri_key, cri->cri_klen / 8); axf->Update((*swd)->sw_octx, hmac_opad_buffer, HMAC_BLOCK_LEN - (cri->cri_klen / 8)); for (k = 0; k < cri->cri_klen / 8; k++) cri->cri_key[k] ^= HMAC_OPAD_VAL; (*swd)->sw_axf = axf; break; case CRYPTO_MD5_KPDK: axf = &auth_hash_key_md5; goto auth2common; case CRYPTO_SHA1_KPDK: axf = &auth_hash_key_sha1; auth2common: MALLOC((*swd)->sw_ictx, u_int8_t *, axf->ctxsize, M_XDATA, M_DONTWAIT); if ((*swd)->sw_ictx == NULL) { swcr_freesession(i); return ENOBUFS; } axf->Init((*swd)->sw_ictx); axf->Update((*swd)->sw_ictx, cri->cri_key, cri->cri_klen / 8); axf->Final(NULL, (*swd)->sw_ictx); (*swd)->sw_axf = axf; break; default: swcr_freesession(i); return EINVAL; } (*swd)->sw_alg = cri->cri_alg; cri = cri->cri_next; swd = &((*swd)->sw_next); } return 0; } /* * Free a session. */ int swcr_freesession(u_int64_t tid) { struct swcr_data *swd; struct enc_xform *txf; struct auth_hash *axf; u_int32_t sid = ((u_int32_t) tid) & 0xffffffff; if ((sid > swcr_sesnum) || (swcr_sessions == NULL) || (swcr_sessions[sid] == NULL)) return EINVAL; /* Silently accept and return */ if (sid == 0) return 0; while ((swd = swcr_sessions[sid]) != NULL) { swcr_sessions[sid] = swd->sw_next; switch (swd->sw_alg) { case CRYPTO_DES_CBC: case CRYPTO_3DES_CBC: case CRYPTO_BLF_CBC: case CRYPTO_CAST_CBC: case CRYPTO_SKIPJACK_CBC: txf = swd->sw_exf; if (swd->sw_kschedule) txf->zerokey(&(swd->sw_kschedule)); if (swd->sw_iv) FREE(swd->sw_iv, M_XDATA); break; case CRYPTO_MD5_HMAC96: case CRYPTO_SHA1_HMAC96: case CRYPTO_RIPEMD160_HMAC96: case CRYPTO_MD5_KPDK: case CRYPTO_SHA1_KPDK: axf = swd->sw_axf; if (swd->sw_ictx) { bzero(swd->sw_ictx, axf->ctxsize); FREE(swd->sw_ictx, M_XDATA); } if (swd->sw_octx) { bzero(swd->sw_octx, axf->ctxsize); FREE(swd->sw_octx, M_XDATA); } break; } FREE(swd, M_XDATA); } return 0; } /* * Process a software request. */ int swcr_process(struct cryptop *crp) { struct cryptodesc *crd; struct swcr_data *sw; u_int32_t lid; u_int64_t nid; int type; /* Some simple sanity checks */ if ((crp == NULL) || (crp->crp_callback == NULL)) return EINVAL; if ((crp->crp_desc == NULL) || (crp->crp_buf == NULL)) { crp->crp_etype = EINVAL; goto done; } lid = crp->crp_sid & 0xffffffff; if ((lid >= swcr_sesnum) || (lid == 0) || (swcr_sessions[lid] == NULL)) { crp->crp_etype = ENOENT; goto done; } if (crp->crp_flags & CRYPTO_F_IMBUF) type = CRYPTO_BUF_MBUF; else type = CRYPTO_BUF_CONTIG; /* Go through crypto descriptors, processing as we go */ for (crd = crp->crp_desc; crd; crd = crd->crd_next) { /* * Find the crypto context. * * XXX Note that the logic here prevents us from having * XXX the same algorithm multiple times in a session * XXX (or rather, we can but it won't give us the right * XXX results). To do that, we'd need some way of differentiating * XXX between the various instances of an algorithm (so we can * XXX locate the correct crypto context). */ for (sw = swcr_sessions[lid]; sw && sw->sw_alg != crd->crd_alg; sw = sw->sw_next) ; /* No such context ? */ if (sw == NULL) { crp->crp_etype = EINVAL; goto done; } switch (sw->sw_alg) { case CRYPTO_DES_CBC: case CRYPTO_3DES_CBC: case CRYPTO_BLF_CBC: case CRYPTO_CAST_CBC: case CRYPTO_SKIPJACK_CBC: if ((crp->crp_etype = swcr_encdec(crd, sw, crp->crp_buf, type)) != 0) goto done; break; case CRYPTO_MD5_HMAC96: case CRYPTO_SHA1_HMAC96: case CRYPTO_RIPEMD160_HMAC96: case CRYPTO_MD5_KPDK: case CRYPTO_SHA1_KPDK: if ((crp->crp_etype = swcr_authcompute(crd, sw, crp->crp_buf, type)) != 0) goto done; break; default: /* Unknown/unsupported algorithm */ crp->crp_etype = EINVAL; goto done; } } done: if (crp->crp_etype == ENOENT) { crypto_freesession(crp->crp_sid); /* Just in case */ /* Migrate session */ for (crd = crp->crp_desc; crd->crd_next; crd = crd->crd_next) crd->CRD_INI.cri_next = &(crd->crd_next->CRD_INI); if (crypto_newsession(&nid, &(crp->crp_desc->CRD_INI)) == 0) crp->crp_sid = nid; } return crp->crp_callback(crp); } /* * Initialize the driver, called from the kernel main(). */ void swcr_init(void) { swcr_id = crypto_get_driverid(); if (swcr_id >= 0) { crypto_register(swcr_id, CRYPTO_DES_CBC, swcr_newsession, swcr_freesession, swcr_process); crypto_register(swcr_id, CRYPTO_3DES_CBC, NULL, NULL, NULL); crypto_register(swcr_id, CRYPTO_BLF_CBC, NULL, NULL, NULL); crypto_register(swcr_id, CRYPTO_CAST_CBC, NULL, NULL, NULL); crypto_register(swcr_id, CRYPTO_SKIPJACK_CBC, NULL, NULL, NULL); crypto_register(swcr_id, CRYPTO_MD5_HMAC96, NULL, NULL, NULL); crypto_register(swcr_id, CRYPTO_SHA1_HMAC96, NULL, NULL, NULL); crypto_register(swcr_id, CRYPTO_RIPEMD160_HMAC96, NULL, NULL, NULL); crypto_register(swcr_id, CRYPTO_MD5_KPDK, NULL, NULL, NULL); crypto_register(swcr_id, CRYPTO_SHA1_KPDK, NULL, NULL, NULL); return; } /* This should never happen */ panic("Software crypto device cannot initialize!"); }