1SSL_CTX_SET_STATELESS_COOKIE_GENERATSEOS_pLCe_BnC(ST3SX)L_SET_STATELESS_COOKIE_GENERATE_CB(3)
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NAME

6       SSL_CTX_set_stateless_cookie_generate_cb,
7       SSL_CTX_set_stateless_cookie_verify_cb, SSL_CTX_set_cookie_generate_cb,
8       SSL_CTX_set_cookie_verify_cb - Callback functions for stateless TLS1.3
9       cookies
10

SYNOPSIS

12        #include <openssl/ssl.h>
13
14        void SSL_CTX_set_stateless_cookie_generate_cb(
15            SSL_CTX *ctx,
16            int (*gen_stateless_cookie_cb) (SSL *ssl,
17                                            unsigned char *cookie,
18                                            size_t *cookie_len));
19        void SSL_CTX_set_stateless_cookie_verify_cb(
20            SSL_CTX *ctx,
21            int (*verify_stateless_cookie_cb) (SSL *ssl,
22                                               const unsigned char *cookie,
23                                               size_t cookie_len));
24
25        void SSL_CTX_set_cookie_generate_cb(SSL_CTX *ctx,
26                                            int (*app_gen_cookie_cb) (SSL *ssl,
27                                                                      unsigned char
28                                                                      *cookie,
29                                                                      unsigned int
30                                                                      *cookie_len));
31        void SSL_CTX_set_cookie_verify_cb(SSL_CTX *ctx,
32                                          int (*app_verify_cookie_cb) (SSL *ssl,
33                                                                       const unsigned
34                                                                       char *cookie,
35                                                                       unsigned int
36                                                                       cookie_len));
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DESCRIPTION

39       SSL_CTX_set_stateless_cookie_generate_cb() sets the callback used by
40       SSL_stateless(3) to generate the application-controlled portion of the
41       cookie provided to clients in the HelloRetryRequest transmitted as a
42       response to a ClientHello with a missing or invalid cookie.
43       gen_stateless_cookie_cb() must write at most SSL_COOKIE_LENGTH bytes
44       into cookie, and must write the number of bytes written to cookie_len.
45       If a cookie cannot be generated, a zero return value can be used to
46       abort the handshake.
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48       SSL_CTX_set_stateless_cookie_verify_cb() sets the callback used by
49       SSL_stateless(3) to determine whether the application-controlled
50       portion of a ClientHello cookie is valid. The cookie data is pointed to
51       by cookie and is of length cookie_len. A nonzero return value from
52       verify_stateless_cookie_cb() communicates that the cookie is valid. The
53       integrity of the entire cookie, including the application-controlled
54       portion, is automatically verified by HMAC before
55       verify_stateless_cookie_cb() is called.
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57       SSL_CTX_set_cookie_generate_cb() sets the callback used by
58       DTLSv1_listen(3) to generate the cookie provided to clients in the
59       HelloVerifyRequest transmitted as a response to a ClientHello with a
60       missing or invalid cookie.  app_gen_cookie_cb()  must write at most
61       DTLS1_COOKIE_LENGTH bytes into cookie, and must write the number of
62       bytes written to cookie_len. If a cookie cannot be generated, a zero
63       return value can be used to abort the handshake.
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65       SSL_CTX_set_cookie_verify_cb() sets the callback used by
66       DTLSv1_listen(3) to determine whether the cookie in a ClientHello is
67       valid. The cookie data is pointed to by cookie and is of length
68       cookie_len. A nonzero return value from app_verify_cookie_cb()
69       communicates that the cookie is valid. The integrity of the cookie is
70       not verified by OpenSSL. This is an application responsibility.
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RETURN VALUES

73       Neither function returns a value.
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SEE ALSO

76       SSL_stateless(3), DTLSv1_listen(3)
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HISTORY

79       SSL_CTX_set_stateless_cookie_generate_cb() and
80       SSL_CTX_set_stateless_cookie_verify_cb() were added in OpenSSL 1.1.1.
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83       Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
84
85       Licensed under the OpenSSL license (the "License").  You may not use
86       this file except in compliance with the License.  You can obtain a copy
87       in the file LICENSE in the source distribution or at
88       <https://www.openssl.org/source/license.html>.
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921.1.1l                            20S2S1L-_0C9T-X1_5SET_STATELESS_COOKIE_GENERATE_CB(3)
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