diff options
author | Dr. Stephen Henson <steve@openssl.org> | 2014-08-01 14:56:56 +0100 |
---|---|---|
committer | Matt Caswell <matt@openssl.org> | 2014-08-06 20:27:51 +0100 |
commit | d15d17bb6487a3e7b59a22882b6a22300fe5111d (patch) | |
tree | 05ab19c27c6c9f1f6b020f18d78175ef1bed8e67 /ssl/tls_srp.c | |
parent | 966fe81f9befbff62522a158006fb03050a868df (diff) |
Check SRP parameters early.
Check SRP parameters when they are received so we can send back an
appropriate alert.
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
Diffstat (limited to 'ssl/tls_srp.c')
-rw-r--r-- | ssl/tls_srp.c | 48 |
1 files changed, 37 insertions, 11 deletions
diff --git a/ssl/tls_srp.c b/ssl/tls_srp.c index 2315a7c0a2..e7368a8f6b 100644 --- a/ssl/tls_srp.c +++ b/ssl/tls_srp.c @@ -408,16 +408,46 @@ err: return ret; } -int SRP_Calc_A_param(SSL *s) +int srp_verify_server_param(SSL *s, int *al) { - unsigned char rnd[SSL_MAX_MASTER_KEY_LENGTH]; + SRP_CTX *srp = &s->srp_ctx; + /* Sanity check parameters: we can quickly check B % N == 0 + * by checking B != 0 since B < N + */ + if (BN_ucmp(srp->g, srp->N) >=0 || BN_ucmp(srp->B, srp->N) >= 0 + || BN_is_zero(srp->B)) + { + *al = SSL3_AD_ILLEGAL_PARAMETER; + return 0; + } - if (BN_num_bits(s->srp_ctx.N) < s->srp_ctx.strength) - return -1; + if (BN_num_bits(srp->N) < srp->strength) + { + *al = TLS1_AD_INSUFFICIENT_SECURITY; + return 0; + } - if (s->srp_ctx.SRP_verify_param_callback ==NULL && - !SRP_check_known_gN_param(s->srp_ctx.g,s->srp_ctx.N)) - return -1 ; + if (srp->SRP_verify_param_callback) + { + if (srp->SRP_verify_param_callback(s, srp->SRP_cb_arg) <= 0) + { + *al = TLS1_AD_INSUFFICIENT_SECURITY; + return 0; + } + } + else if(!SRP_check_known_gN_param(srp->g, srp->N)) + { + *al = TLS1_AD_INSUFFICIENT_SECURITY; + return 0; + } + + return 1; + } + + +int SRP_Calc_A_param(SSL *s) + { + unsigned char rnd[SSL_MAX_MASTER_KEY_LENGTH]; RAND_bytes(rnd, sizeof(rnd)); s->srp_ctx.a = BN_bin2bn(rnd, sizeof(rnd), s->srp_ctx.a); @@ -426,10 +456,6 @@ int SRP_Calc_A_param(SSL *s) if (!(s->srp_ctx.A = SRP_Calc_A(s->srp_ctx.a,s->srp_ctx.N,s->srp_ctx.g))) return -1; - /* We can have a callback to verify SRP param!! */ - if (s->srp_ctx.SRP_verify_param_callback !=NULL) - return s->srp_ctx.SRP_verify_param_callback(s,s->srp_ctx.SRP_cb_arg); - return 1; } |