since the notes at http://sqlcipher.net/documentation/ios mention 0.9.8k being a "working" openssl version, I grabbed 0.9.8o (on the assumption that 1.0.0 may not be supported). it turns out that the addition of -UOPENSSL_BN_ASM_PART_WORDS in commit c14f8 breaks 0.9.8 series builds for i386 (though arm works fine).
the docs (and build notes for SQLCipher) should probably note that 1.0.0 is the supported OpenSSL version these days.