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author | Michael Brown | 2012-02-20 22:24:30 +0100 |
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committer | Michael Brown | 2012-02-21 13:42:37 +0100 |
commit | c2668b61ea5ac01279929be6be86cc04fd342ab5 (patch) | |
tree | 1a7e3434ceda88380366731ecd661423f093444d /src/crypto | |
parent | [rng] Add missing #include <string.h> (diff) | |
download | ipxe-c2668b61ea5ac01279929be6be86cc04fd342ab5.tar.gz ipxe-c2668b61ea5ac01279929be6be86cc04fd342ab5.tar.xz ipxe-c2668b61ea5ac01279929be6be86cc04fd342ab5.zip |
[rng] Record validity within DRBG state
Treat an empty (zeroed) DRBG as invalid. This ensures that a DRBG
that has not yet been instantiated (or that has been uninstantiated)
will refuse to attempt to generate random bits.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Diffstat (limited to 'src/crypto')
-rw-r--r-- | src/crypto/drbg.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/src/crypto/drbg.c b/src/crypto/drbg.c index 58e8fa7b..88cf3acd 100644 --- a/src/crypto/drbg.c +++ b/src/crypto/drbg.c @@ -151,6 +151,7 @@ int drbg_instantiate ( struct drbg_state *state, const void *personal, * in-situ.) */ state->reseed_required = 0; + state->valid = 1; /* 12. Return SUCCESS and state_handle. */ return 0; @@ -187,9 +188,13 @@ int drbg_reseed ( struct drbg_state *state, const void *additional, * If state_handle indicates an invalid or empty internal * state, return an ERROR_FLAG. * - * (Nothing to do since the memory holding the internal state - * was passed in by the caller.) + * (Almost nothing to do since the memory holding the internal + * state was passed in by the caller.) */ + if ( ! state->valid ) { + DBGC ( state, "DRBG %p not valid\n", state ); + return -EINVAL; + } /* 2. If prediction_resistance_request is set, and * prediction_resistance_flag is not set, then return an @@ -273,9 +278,13 @@ int drbg_generate ( struct drbg_state *state, const void *additional, * for the instantiation. If state_handle indicates an * invalid or empty internal state, then return an ERROR_FLAG. * - * (Nothing to do since the memory holding the internal state - * was passed in by the caller.) + * (Almost nothing to do since the memory holding the internal + * state was passed in by the caller.) */ + if ( ! state->valid ) { + DBGC ( state, "DRBG %p not valid\n", state ); + return -EINVAL; + } /* 2. If requested_number_of_bits > * max_number_of_bits_per_request, then return an |