diff options
Diffstat (limited to 'net/sunrpc/auth_gss/gss_krb5_wrap.c')
| -rw-r--r-- | net/sunrpc/auth_gss/gss_krb5_wrap.c | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c b/net/sunrpc/auth_gss/gss_krb5_wrap.c index 1c8ebd3..4aa46b2 100644 --- a/net/sunrpc/auth_gss/gss_krb5_wrap.c +++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c @@ -340,6 +340,174 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf) return GSS_S_COMPLETE; } +/* + * We cannot currently handle tokens with rotated data. We need a + * generalized routine to rotate the data in place. It is anticipated + * that we won't encounter rotated data in the general case. + */ +static u32 +rotate_left(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf, u16 rrc) +{ + unsigned int realrrc = rrc % (buf->len - offset - GSS_KRB5_TOK_HDR_LEN); + + if (realrrc == 0) + return 0; + + dprintk("%s: cannot process token with rotated data: " + "rrc %u, realrrc %u\n", __func__, rrc, realrrc); + return 1; +} + +static u32 +gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset, + struct xdr_buf *buf, struct page **pages) +{ + int blocksize; + u8 *ptr, *plainhdr; + s32 now; + u8 flags = 0x00; + __be16 *be16ptr, ec = 0; + __be64 *be64ptr; + u32 err; + + dprintk("RPC: %s\n", __func__); + + if (kctx->gk5e->encrypt_v2 == NULL) + return GSS_S_FAILURE; + + /* make room for gss token header */ + if (xdr_extend_head(buf, offset, GSS_KRB5_TOK_HDR_LEN)) + return GSS_S_FAILURE; + + /* construct gss token header */ + ptr = plainhdr = buf->head[0].iov_base + offset; + *ptr++ = (unsigned char) ((KG2_TOK_WRAP>>8) & 0xff); + *ptr++ = (unsigned char) (KG2_TOK_WRAP & 0xff); + + if ((kctx->flags & KRB5_CTX_FLAG_INITIATOR) == 0) + flags |= KG2_TOKEN_FLAG_SENTBYACCEPTOR; + if ((kctx->flags & KRB5_CTX_FLAG_ACCEPTOR_SUBKEY) != 0) + flags |= KG2_TOKEN_FLAG_ACCEPTORSUBKEY; + /* We always do confidentiality in wrap tokens */ + flags |= KG2_TOKEN_FLAG_SEALED; + + *ptr++ = flags; + *ptr++ = 0xff; + be16ptr = (__be16 *)ptr; + + blocksize = crypto_blkcipher_blocksize(kctx->acceptor_enc); + *be16ptr++ = cpu_to_be16(ec); + /* "inner" token header always uses 0 for RRC */ + *be16ptr++ = cpu_to_be16(0); + + be64ptr = (__be64 *)be16ptr; + spin_lock(&krb5_seq_lock); + *be64ptr = cpu_to_be64(kctx->seq_send64++); + spin_unlock(&krb5_seq_lock); + + err = (*kctx->gk5e->encrypt_v2)(kctx, offset, buf, ec, pages); + if (err) + return err; + + now = get_seconds(); + return (kctx->endtime < now) ? GSS_S_CONTEXT_EXPIRED : GSS_S_COMPLETE; +} + +static u32 +gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf) +{ + s32 now; + u64 seqnum; + u8 *ptr; + u8 flags = 0x00; + u16 ec, rrc; + int err; + u32 headskip, tailskip; + u8 decrypted_hdr[GSS_KRB5_TOK_HDR_LEN]; + unsigned int movelen; + + + dprintk("RPC: %s\n", __func__); + + if (kctx->gk5e->decrypt_v2 == NULL) + return GSS_S_FAILURE; + + ptr = buf->head[0].iov_base + offset; + + if (be16_to_cpu(*((__be16 *)ptr)) != KG2_TOK_WRAP) + return GSS_S_DEFECTIVE_TOKEN; + + flags = ptr[2]; + if ((!kctx->initiate && (flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR)) || + (kctx->initiate && !(flags & KG2_TOKEN_FLAG_SENTBYACCEPTOR))) + return GSS_S_BAD_SIG; + + if ((flags & KG2_TOKEN_FLAG_SEALED) == 0) { + dprintk("%s: token missing expected sealed flag\n", __func__); + return GSS_S_DEFECTIVE_TOKEN; + } + + if (ptr[3] != 0xff) + return GSS_S_DEFECTIVE_TOKEN; + + ec = be16_to_cpup((__be16 *)(ptr + 4)); + rrc = be16_to_cpup((__be16 *)(ptr + 6)); + + seqnum = be64_to_cpup((__be64 *)(ptr + 8)); + + if (rrc != 0) { + err = rotate_left(kctx, offset, buf, rrc); + if (err) + return GSS_S_FAILURE; + } + + err = (*kctx->gk5e->decrypt_v2)(kctx, offset, buf, + &headskip, &tailskip); + if (err) + return GSS_S_FAILURE; + + /* + * Retrieve the decrypted gss token header and verify + * it against the original + */ + err = read_bytes_from_xdr_buf(buf, + buf->len - GSS_KRB5_TOK_HDR_LEN - tailskip, + decrypted_hdr, GSS_KRB5_TOK_HDR_LEN); + if (err) { + dprintk("%s: error %u getting decrypted_hdr\n", __func__, err); + return GSS_S_FAILURE; + } + if (memcmp(ptr, decrypted_hdr, 6) + || memcmp(ptr + 8, decrypted_hdr + 8, 8)) { + dprintk("%s: token hdr, plaintext hdr mismatch!\n", __func__); + return GSS_S_FAILURE; + } + + /* do sequencing checks */ + + /* it got through unscathed. Make sure the context is unexpired */ + now = get_seconds(); + if (now > kctx->endtime) + return GSS_S_CONTEXT_EXPIRED; + + /* + * Move the head data back to the right position in xdr_buf. + * We ignore any "ec" data since it might be in the head or + * the tail, and we really don't need to deal with it. + * Note that buf->head[0].iov_len may indicate the available + * head buffer space rather than that actually occupied. + */ + movelen = min_t(unsigned int, buf->head[0].iov_len, buf->len); + movelen -= offset + GSS_KRB5_TOK_HDR_LEN + headskip; + BUG_ON(offset + GSS_KRB5_TOK_HDR_LEN + headskip + movelen > + buf->head[0].iov_len); + memmove(ptr, ptr + GSS_KRB5_TOK_HDR_LEN + headskip, movelen); + buf->head[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip; + buf->len -= GSS_KRB5_TOK_HDR_LEN + headskip; + + return GSS_S_COMPLETE; +} + u32 gss_wrap_kerberos(struct gss_ctx *gctx, int offset, struct xdr_buf *buf, struct page **pages) @@ -352,6 +520,9 @@ gss_wrap_kerberos(struct gss_ctx *gctx, int offset, case ENCTYPE_DES_CBC_RAW: case ENCTYPE_DES3_CBC_RAW: return gss_wrap_kerberos_v1(kctx, offset, buf, pages); + case ENCTYPE_AES128_CTS_HMAC_SHA1_96: + case ENCTYPE_AES256_CTS_HMAC_SHA1_96: + return gss_wrap_kerberos_v2(kctx, offset, buf, pages); } } @@ -366,6 +537,9 @@ gss_unwrap_kerberos(struct gss_ctx *gctx, int offset, struct xdr_buf *buf) case ENCTYPE_DES_CBC_RAW: case ENCTYPE_DES3_CBC_RAW: return gss_unwrap_kerberos_v1(kctx, offset, buf); + case ENCTYPE_AES128_CTS_HMAC_SHA1_96: + case ENCTYPE_AES256_CTS_HMAC_SHA1_96: + return gss_unwrap_kerberos_v2(kctx, offset, buf); } } |