cose: add HKDF (HMAC256)

[fjmolinas]

This PR is re-working the work done in #94 and adding Tinycrypt support for hkdf, if intel/tinycrypt#43 is included.

Regarding the todo list on #94:

• Implementation completeness is checked, but allowing it to error out on the invalid salt size
• Checked code style by uncrustifying

What is not addressed is the potential requirement for a streaming API.

@chrysn

[chrysn]

Looks good to me; didn't test it, but then that's what the tests are for (and they are run for sodium; tinycrypt probably doesn't have the patch applied yet, but I trust you've run these locally, and whenever it gets updated the tests will spot anything that's wrong again).

[fjmolinas]

Testing:

CRYPTO=tinycrypt make clean test
rm -rf bin
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/cose_common.o src/cose_common.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/cose_crypto.o src/cose_crypto.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/cose_encrypt.o src/cose_encrypt.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/cose_hdr.o src/cose_hdr.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/cose_hkdf.o src/cose_hkdf.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/cose_key.o src/cose_key.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/cose_recipient.o src/cose_recipient.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/cose_signature.o src/cose_signature.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/cose_sign.o src/cose_sign.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/crypt/keygen_symm.o src/crypt/keygen_symm.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/crypt/tinycrypt.o src/crypt/tinycrypt.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/tests/crypto.o tests/crypto.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/tests/encrypt.o tests/encrypt.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/tests/hdr.o tests/hdr.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/tests/hkdf.o tests/hkdf.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/tests/sign.o tests/sign.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/tests/suit.o tests/suit.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage -c -o bin/objs/tests/test.o tests/test.c
cc -fPIC -Wall -Wextra -pedantic -Werror -Wshadow -Iinclude -I/usr/include -I/home/francisco/workspace/libcose/../nanocbor//include -Os -g3 -DCRYPTO_TINYCRYPT -I/home/francisco/workspace/libcose/../tinycrypt/lib/include  -coverage bin/objs/cose_common.o bin/objs/cose_crypto.o bin/objs/cose_encrypt.o bin/objs/cose_hdr.o bin/objs/cose_hkdf.o bin/objs/cose_key.o bin/objs/cose_recipient.o bin/objs/cose_signature.o bin/objs/cose_sign.o bin/objs/crypt/keygen_symm.o bin/objs/crypt/tinycrypt.o  bin/objs/tests/crypto.o bin/objs/tests/encrypt.o bin/objs/tests/hdr.o bin/objs/tests/hkdf.o bin/objs/tests/sign.o bin/objs/tests/suit.o bin/objs/tests/test.o -o bin/test  -Wl,/home/francisco/workspace/libcose/../nanocbor//bin/libnanocbor.so /home/francisco/workspace/libcose/../tinycrypt/lib/libtinycrypt.a -Wl,-lcunit
LD_LIBRARY_PATH="/home/francisco/workspace/libcose/../nanocbor//bin" bin/test


     CUnit - A unit testing framework for C - Version 2.1-3
     http://cunit.sourceforge.net/


Suite: Suite_hdr
  Test: Simple cbor to hdr conversion ...passed
  Test: Text cbor to hdr conversion ...passed
  Test: Bytes cbor to hdr conversion ...passed
  Test: header to CBOR conversion ...passed
  Test: header with string to CBOR conversion ...passed
  Test: header with bytes to CBOR conversion ...passed
Suite: Suite_signatures
  Test: Sign with 1 sig ...Encode size: 104
D28443A10126A104506B6F656E406578616D706C652E6F72674C496E70757420737472696E675840FBA65330FB66CF7E415B10629A2AB986CDE2648479A3F0DD0A01597B0E7B209E3112BBCB43CB5EC0D66A561A4F03682FC0B151A38B394700292D7D7AF8268AFBpassed
  Test: Sign with 1 sig untagged ...passed
  Test: Sign with two sigs ...D8628441A0A04C496E70757420737472696E67828343A10126A104506B6F656E406578616D706C652E6E657458403A84515092A418A72061E559792DE52A9AA8D3DD14BCCCDC54C15836772820477B107DF0A4976F59F1DF922B7CBD9CD711D1CD7E7161D4B3332FACD74A0E2CB88343A10126A104506B6F656E406578616D706C652E6F7267584008C978FF393EB479E60BA59766B04EE1D4D69A9162316A25D9CDE00DE1062A1CA2CA819D1171781D8AD5C94235DA52DA39C58140DAE31A8261D330B889A0E150
passed
  Test: Content type header test ...passed
  Test: External payload header test ...passed
  Test: Sign1 Sig headers test ...passed
  Test: Sign Sig headers test ...
D8628441A0A04C496E70757420737472696E67828346A20126182D21A204506B6F656E406578616D706C652E6E6574182F225840E7854E038503E3327CAD8590CF625D192EFA5C7ED29D72788A376F378B69F7EFACB8FD42C5CC1E5E70CBE7D1768733BD54ED3370D9DA29B6634E2DC829FC9DCB8346A20126182A03A204506B6F656E406578616D706C652E6F7267182907584050F880412736FB47E31884882D93072D5C54ED60C13F19817775430C6AE04F1405E45093061928984BAADB04E228CDC18815E13D02B778162AB69ACBD00A2DD7
passed
  Test: Sign with aad test ...passed
Suite: Suite_encrypt
  Test: Encryption with encrypt0 over algos ...Testing AAD with 3 algos
Testing encryption with algo 10
D08343A1010AA1054D00000000000000000000000000581C3FD8F4AE3BD080C1E7E943003CADDA4FC9D18D42CFD70E94CEFB29B8
Testing encryption with algo 30
D08344A101181EA1054D0000000000000000000000000058243FD8F4AE3BD080C1E7E943003CADDA4FC9D18D429EACEE6EAABB17D18D0F5A42866DDCC9
passed
Suite: Suite_hkdf
  Test: RFC5869 HKDF-SHA256 test vector 1 ...passed
  Test: RFC5869 HKDF-SHA256 test vector 2 ...passed
  Test: RFC5869 HKDF-SHA256 test vector 3 ...passed
  Test: RFC8613 Key Derivation with ID Contex test vector 3 ...passed
  Test: cose_crypto_is_hkdf ...passed

Run Summary:    Type  Total    Ran Passed Failed Inactive
              suites      6      6    n/a      0        0
               tests     20     20     20      0        0
             asserts    111    111    111      0      n/a

Elapsed time =    0.082 seconds

[bergzand]

Thanks!