fix build with Botan 3.11

[thillux]

Fixes:

[ 40%] Building CXX object src/lib/CMakeFiles/librnp-obj.dir/sig_material.cpp.o
[ 40%] Building CXX object src/lib/CMakeFiles/librnp-obj.dir/pass-provider.cpp.o
[ 40%] Building CXX object src/lib/CMakeFiles/librnp-obj.dir/keygen.cpp.o
[ 41%] Building CXX object src/lib/CMakeFiles/librnp-obj.dir/key.cpp.o
[ 41%] Built target man_librnp
[ 41%] Built target man_rnpkeys
/build/source/src/lib/crypto/mem.cpp: In function 'size_t rnp::hex_decode(const char*, uint8_t*, size_t)':
/build/source/src/lib/crypto/mem.cpp:55:21: error: 'strlen' was not declared in this scope
   55 |     size_t hexlen = strlen(hex);
      |                     ^~~~~~
/build/source/src/lib/crypto/mem.cpp:30:1: note: 'strlen' is defined in header '<cstring>'; this is probably fixable by adding '#include <cstring>'
   29 | #include "logging.h"
  +++ |+#include <cstring>
   30 | #include <botan/ffi.h>

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.46%. Comparing base (83a987a) to head (fb7e040).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2381   +/-   ##
=======================================
  Coverage   85.46%   85.46%           
=======================================
  Files         126      126           
  Lines       22711    22711           
=======================================
  Hits        19409    19409           
  Misses       3302     3302           

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[ronaldtse]

Thank you @thillux !

@ni4 could you help review this? Thanks!

[juippis]

This wasn't enough to make it compile for me. The build errored out to:

/var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/ec.cpp: In function 'rnp_result_t ec_generate_generic_native(rnp::RNG*, std::vector<unsigned char>&, std::vector<unsigned char>&, pgp_curve_t, pgp_pubkey_alg_t)':
/var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/ec.cpp:202:92: error: invalid use of incomplete type 'class Botan::EC_Group'
  202 |     Botan::ECDH_PrivateKey privkey_botan(*(rng->obj()), Botan::EC_Group(ec_desc->botan_name));
      |                                                                                            ^
In file included from /usr/include/botan-3/botan/ecdsa.h:13,
                 from /var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/exdsa_ecdhkem.h:38:
/usr/include/botan-3/botan/ecc_key.h:21:7: note: forward declaration of 'class Botan::EC_Group'
   21 | class EC_Group;
      |       ^~~~~~~~
/var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/ec.cpp:203:62: warning: 'const Botan::EC_Point& Botan::EC_PublicKey::public_point() const' is deprecated: Avoid accessing the point directly [-Wdeprecated-declarations]
  203 |     Botan::BigInt          pub_x = privkey_botan.public_point().get_affine_x();
      |                                    ~~~~~~~~~~~~~~~~~~~~~~~~~~^~
/usr/include/botan-3/botan/ecc_key.h:51:78: note: declared here
   51 |       BOTAN_DEPRECATED("Avoid accessing the point directly") const EC_Point& public_point() const;
      |                                                                              ^~~~~~~~~~~~
/var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/ec.cpp:203:62: error: invalid use of incomplete type 'const class Botan::EC_Point'
  203 |     Botan::BigInt          pub_x = privkey_botan.public_point().get_affine_x();
      |                                    ~~~~~~~~~~~~~~~~~~~~~~~~~~^~
/usr/include/botan-3/botan/ecc_key.h:20:7: note: forward declaration of 'class Botan::EC_Point'
   20 | class EC_Point;
      |       ^~~~~~~~
/var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/ec.cpp:204:62: warning: 'const Botan::EC_Point& Botan::EC_PublicKey::public_point() const' is deprecated: Avoid accessing the point directly [-Wdeprecated-declarations]
  204 |     Botan::BigInt          pub_y = privkey_botan.public_point().get_affine_y();
      |                                    ~~~~~~~~~~~~~~~~~~~~~~~~~~^~
/usr/include/botan-3/botan/ecc_key.h:51:78: note: declared here
   51 |       BOTAN_DEPRECATED("Avoid accessing the point directly") const EC_Point& public_point() const;
      |                                                                              ^~~~~~~~~~~~
/var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/ec.cpp:204:62: error: invalid use of incomplete type 'const class Botan::EC_Point'
  204 |     Botan::BigInt          pub_y = privkey_botan.public_point().get_affine_y();
      |                                    ~~~~~~~~~~~~~~~~~~~~~~~~~~^~
/usr/include/botan-3/botan/ecc_key.h:20:7: note: forward declaration of 'class Botan::EC_Point'
   20 | class EC_Point;
      |       ^~~~~~~~

and afterwards to:

/var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/exdsa_ecdhkem.cpp: In member function 'Botan::ECDH_PrivateKey ecdh_kem_private_key_t::botan_key_ecdh(rnp::RNG*) const':
/var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/exdsa_ecdhkem.cpp:74:57: error: invalid use of incomplete type 'class Botan::EC_Group'
   74 |       *(rng->obj()), Botan::EC_Group(ec_desc->botan_name), Botan::BigInt(key_));
      |                                                         ^
In file included from /usr/include/botan-3/botan/ecdsa.h:13,
                 from /var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/exdsa_ecdhkem.h:38:
/usr/include/botan-3/botan/ecc_key.h:21:7: note: forward declaration of 'class Botan::EC_Group'
   21 | class EC_Group;
      |       ^~~~~~~~
/var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/exdsa_ecdhkem.cpp:74:78: error: invalid use of incomplete type 'class Botan::BigInt'
   74 |       *(rng->obj()), Botan::EC_Group(ec_desc->botan_name), Botan::BigInt(key_));
      |                                                                              ^
In file included from /usr/include/botan-3/botan/pubkey.h:11,
                 from /var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/exdsa_ecdhkem.h:37:
/usr/include/botan-3/botan/pk_keys.h:23:7: note: forward declaration of 'class Botan::BigInt'
   23 | class BigInt;
      |       ^~~~~~
/var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/exdsa_ecdhkem.cpp: In member function 'Botan::ECDH_PublicKey ecdh_kem_public_key_t::botan_key_ecdh(rnp::RNG*) const':
/var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/exdsa_ecdhkem.cpp:83:27: error: variable 'Botan::EC_Group group' has initializer but incomplete type
   83 |     Botan::EC_Group group(ec_desc->botan_name);
      |                           ^~~~~~~
/var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/exdsa_ecdhkem.cpp:85:23: error: variable 'Botan::BigInt x' has initializer but incomplete type
   85 |     Botan::BigInt   x(key_.data() + 1, curve_order);
      |                       ^~~~
/var/tmp/portage/dev-util/librnp-0.18.1/work/rnp-0.18.1/src/lib/crypto/exdsa_ecdhkem.cpp:86:23: error: variable 'Botan::BigInt y' has initializer but incomplete type
   86 |     Botan::BigInt   y(key_.data() + 1 + curve_order, curve_order);

However I found a similar problem from keepassxreboot/keepassxc#13161 and applying that fix made it compile successfully:

diff '--color=auto' -Naur a/src/lib/crypto/ec.cpp b/src/lib/crypto/ec.cpp
--- a/src/lib/crypto/ec.cpp     2025-11-21 15:12:02.000000000 +0200
+++ b/src/lib/crypto/ec.cpp     2026-04-04 08:22:12.502593507 +0300
@@ -40,6 +40,10 @@
 #include "botan/ecdh.h"
 #include <cassert>
 #endif
+#include <botan/version.h>
+#if BOTAN_VERSION_CODE >= BOTAN_VERSION_CODE_FOR(3, 11, 0)
+#include <botan/ec_group.h>
+#endif
 
 namespace pgp {
 namespace ec {
diff '--color=auto' -Naur a/src/lib/crypto/exdsa_ecdhkem.cpp b/src/lib/crypto/exdsa_ecdhkem.cpp
--- a/src/lib/crypto/exdsa_ecdhkem.cpp  2025-11-21 15:12:02.000000000 +0200
+++ b/src/lib/crypto/exdsa_ecdhkem.cpp  2026-04-04 08:34:49.684582995 +0300
@@ -34,6 +34,10 @@
 #include "string.h"
 #include "utils.h"
 #include <cassert>
+#include <botan/version.h>
+#if BOTAN_VERSION_CODE >= BOTAN_VERSION_CODE_FOR(3, 11, 0)
+#include <botan/ec_group.h>
+#endif
 
 ec_key_t::~ec_key_t()
 {