diff options
author | Todd Short <tshort@akamai.com> | 2021-03-22 12:56:36 -0400 |
---|---|---|
committer | Tomas Mraz <tomas@openssl.org> | 2021-04-13 12:29:37 +0200 |
commit | feba11cf2ea1dee9cc6e30bf5953404c9c2c88c6 (patch) | |
tree | 48bee7ecfe5b83d7ea2cd24747f6c817ccd877bf /ssl | |
parent | 3ab736acb89c277bd174f958591c65c66d611c72 (diff) |
Handle set_alpn_protos inputs better.
It's possible to set an invalid protocol list that will be sent in a
ClientHello. This validates the inputs to make sure this does not
happen.
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/14815)
Diffstat (limited to 'ssl')
-rw-r--r-- | ssl/ssl_lib.c | 49 |
1 files changed, 43 insertions, 6 deletions
diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c index c4394cf9e2..3d0f309fd2 100644 --- a/ssl/ssl_lib.c +++ b/ssl/ssl_lib.c @@ -2985,6 +2985,19 @@ void SSL_CTX_set_npn_select_cb(SSL_CTX *ctx, } #endif +static int alpn_value_ok(const unsigned char *protos, unsigned int protos_len) +{ + unsigned int idx; + + if (protos_len < 2 || protos == NULL) + return 0; + + for (idx = 0; idx < protos_len; idx += protos[idx] + 1) { + if (protos[idx] == 0) + return 0; + } + return idx == protos_len; +} /* * SSL_CTX_set_alpn_protos sets the ALPN protocol list on |ctx| to |protos|. * |protos| must be in wire-format (i.e. a series of non-empty, 8-bit @@ -2993,13 +3006,25 @@ void SSL_CTX_set_npn_select_cb(SSL_CTX *ctx, int SSL_CTX_set_alpn_protos(SSL_CTX *ctx, const unsigned char *protos, unsigned int protos_len) { - OPENSSL_free(ctx->ext.alpn); - ctx->ext.alpn = OPENSSL_memdup(protos, protos_len); - if (ctx->ext.alpn == NULL) { + unsigned char *alpn; + + if (protos_len == 0 || protos == NULL) { + OPENSSL_free(ctx->ext.alpn); + ctx->ext.alpn = NULL; ctx->ext.alpn_len = 0; + return 0; + } + /* Not valid per RFC */ + if (!alpn_value_ok(protos, protos_len)) + return 1; + + alpn = OPENSSL_memdup(protos, protos_len); + if (alpn == NULL) { ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE); return 1; } + OPENSSL_free(ctx->ext.alpn); + ctx->ext.alpn = alpn; ctx->ext.alpn_len = protos_len; return 0; @@ -3013,13 +3038,25 @@ int SSL_CTX_set_alpn_protos(SSL_CTX *ctx, const unsigned char *protos, int SSL_set_alpn_protos(SSL *ssl, const unsigned char *protos, unsigned int protos_len) { - OPENSSL_free(ssl->ext.alpn); - ssl->ext.alpn = OPENSSL_memdup(protos, protos_len); - if (ssl->ext.alpn == NULL) { + unsigned char *alpn; + + if (protos_len == 0 || protos == NULL) { + OPENSSL_free(ssl->ext.alpn); + ssl->ext.alpn = NULL; ssl->ext.alpn_len = 0; + return 0; + } + /* Not valid per RFC */ + if (!alpn_value_ok(protos, protos_len)) + return 1; + + alpn = OPENSSL_memdup(protos, protos_len); + if (alpn == NULL) { ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE); return 1; } + OPENSSL_free(ssl->ext.alpn); + ssl->ext.alpn = alpn; ssl->ext.alpn_len = protos_len; return 0; |